Merge branch 'master' into fix-time

247 files changed, 9621 insertions, 3844 deletions

diff --git a/src/compiler/node_generator.cc b/src/compiler/node_generator.cc
index 661587cbd6..a430628dbc 100644
--- a/src/compiler/node_generator.cc
+++ b/src/compiler/node_generator.cc
@@ -20,6 +20,7 @@
 
 #include "src/compiler/config.h"
 #include "src/compiler/generator_helpers.h"
+#include "src/compiler/node_generator.h"
 #include "src/compiler/node_generator_helpers.h"
 
 using grpc::protobuf::Descriptor;
@@ -119,7 +120,8 @@ grpc::string NodeObjectPath(const Descriptor* descriptor) {
 }
 
 // Prints out the message serializer and deserializer functions
-void PrintMessageTransformer(const Descriptor* descriptor, Printer* out) {
+void PrintMessageTransformer(const Descriptor* descriptor, Printer* out,
+                             const Parameters& params) {
   map<grpc::string, grpc::string> template_vars;
   grpc::string full_name = descriptor->full_name();
   template_vars["identifier_name"] = MessageIdentifierName(full_name);
@@ -134,7 +136,12 @@ void PrintMessageTransformer(const Descriptor* descriptor, Printer* out) {
              "throw new Error('Expected argument of type $name$');\n");
   out->Outdent();
   out->Print("}\n");
-  out->Print("return new Buffer(arg.serializeBinary());\n");
+  if (params.minimum_node_version > 5) {
+    // Node version is > 5, we should use Buffer.from
+    out->Print("return Buffer.from(arg.serializeBinary());\n");
+  } else {
+    out->Print("return new Buffer(arg.serializeBinary());\n");
+  }
   out->Outdent();
   out->Print("}\n\n");
 
@@ -219,12 +226,13 @@ void PrintImports(const FileDescriptor* file, Printer* out) {
   out->Print("\n");
 }
 
-void PrintTransformers(const FileDescriptor* file, Printer* out) {
+void PrintTransformers(const FileDescriptor* file, Printer* out,
+                       const Parameters& params) {
   map<grpc::string, const Descriptor*> messages = GetAllMessages(file);
   for (std::map<grpc::string, const Descriptor*>::iterator it =
            messages.begin();
        it != messages.end(); it++) {
-    PrintMessageTransformer(it->second, out);
+    PrintMessageTransformer(it->second, out, params);
   }
   out->Print("\n");
 }
@@ -236,7 +244,8 @@ void PrintServices(const FileDescriptor* file, Printer* out) {
 }
 }  // namespace
 
-grpc::string GenerateFile(const FileDescriptor* file) {
+grpc::string GenerateFile(const FileDescriptor* file,
+                          const Parameters& params) {
   grpc::string output;
   {
     StringOutputStream output_stream(&output);
@@ -257,7 +266,7 @@ grpc::string GenerateFile(const FileDescriptor* file) {
 
     PrintImports(file, &out);
 
-    PrintTransformers(file, &out);
+    PrintTransformers(file, &out, params);
 
     PrintServices(file, &out);
 
diff --git a/src/compiler/node_generator.h b/src/compiler/node_generator.h
index a9ffe75fc8..f3a531597a 100644
--- a/src/compiler/node_generator.h
+++ b/src/compiler/node_generator.h
@@ -23,7 +23,14 @@
 
 namespace grpc_node_generator {
 
-grpc::string GenerateFile(const grpc::protobuf::FileDescriptor* file);
+// Contains all the parameters that are parsed from the command line.
+struct Parameters {
+  // Sets the earliest version of nodejs that needs to be supported.
+  int minimum_node_version;
+};
+
+grpc::string GenerateFile(const grpc::protobuf::FileDescriptor* file,
+                          const Parameters& params);
 
 }  // namespace grpc_node_generator
 
diff --git a/src/compiler/node_plugin.cc b/src/compiler/node_plugin.cc
index bc38e9018a..0d19d8e982 100644
--- a/src/compiler/node_plugin.cc
+++ b/src/compiler/node_plugin.cc
@@ -36,7 +36,27 @@ class NodeGrpcGenerator : public grpc::protobuf::compiler::CodeGenerator {
                 const grpc::string& parameter,
                 grpc::protobuf::compiler::GeneratorContext* context,
                 grpc::string* error) const {
-    grpc::string code = GenerateFile(file);
+    grpc_node_generator::Parameters generator_parameters;
+    generator_parameters.minimum_node_version = 4;
+
+    if (!parameter.empty()) {
+      std::vector<grpc::string> parameters_list =
+          grpc_generator::tokenize(parameter, ",");
+      for (auto parameter_string = parameters_list.begin();
+           parameter_string != parameters_list.end(); parameter_string++) {
+        std::vector<grpc::string> param =
+            grpc_generator::tokenize(*parameter_string, "=");
+        if (param[0] == "minimum_node_version") {
+          sscanf(param[1].c_str(), "%d",
+                 &generator_parameters.minimum_node_version);
+        } else {
+          *error = grpc::string("Unknown parameter: ") + *parameter_string;
+          return false;
+        }
+      }
+    }
+
+    grpc::string code = GenerateFile(file, generator_parameters);
     if (code.size() == 0) {
       return true;
     }
diff --git a/src/compiler/objective_c_generator.cc b/src/compiler/objective_c_generator.cc
index 39f68cb956..e97494f64c 100644
--- a/src/compiler/objective_c_generator.cc
+++ b/src/compiler/objective_c_generator.cc
@@ -222,7 +222,8 @@ void PrintMethodImplementations(Printer* printer,
   map< ::grpc::string, ::grpc::string> vars = {
       {"service_class", ServiceClassName(service)}};
 
-  printer.Print(vars, "@protocol $service_class$ <NSObject>\n\n");
+  printer.Print(
+      vars, "@protocol $service_class$ <NSObject, GRPCProtoServiceInit>\n\n");
   for (int i = 0; i < service->method_count(); i++) {
     PrintMethodDeclarations(&printer, service->method(i));
   }
diff --git a/src/core/ext/filters/client_channel/client_channel.cc b/src/core/ext/filters/client_channel/client_channel.cc
index c51fb97497..d9f3984608 100644
--- a/src/core/ext/filters/client_channel/client_channel.cc
+++ b/src/core/ext/filters/client_channel/client_channel.cc
@@ -174,7 +174,7 @@ static void set_channel_connectivity_state_locked(channel_data* chand,
     }
   }
   if (grpc_client_channel_trace.enabled()) {
-    gpr_log(GPR_DEBUG, "chand=%p: setting connectivity state to %s", chand,
+    gpr_log(GPR_INFO, "chand=%p: setting connectivity state to %s", chand,
             grpc_connectivity_state_name(state));
   }
   grpc_connectivity_state_set(&chand->state_tracker, state, error, reason);
@@ -186,7 +186,7 @@ static void on_lb_policy_state_changed_locked(void* arg, grpc_error* error) {
   /* check if the notification is for the latest policy */
   if (w->lb_policy == w->chand->lb_policy.get()) {
     if (grpc_client_channel_trace.enabled()) {
-      gpr_log(GPR_DEBUG, "chand=%p: lb_policy=%p state changed to %s", w->chand,
+      gpr_log(GPR_INFO, "chand=%p: lb_policy=%p state changed to %s", w->chand,
               w->lb_policy, grpc_connectivity_state_name(w->state));
     }
     set_channel_connectivity_state_locked(w->chand, w->state,
@@ -215,7 +215,7 @@ static void watch_lb_policy_locked(channel_data* chand,
 
 static void start_resolving_locked(channel_data* chand) {
   if (grpc_client_channel_trace.enabled()) {
-    gpr_log(GPR_DEBUG, "chand=%p: starting name resolution", chand);
+    gpr_log(GPR_INFO, "chand=%p: starting name resolution", chand);
   }
   GPR_ASSERT(!chand->started_resolving);
   chand->started_resolving = true;
@@ -297,7 +297,7 @@ static void request_reresolution_locked(void* arg, grpc_error* error) {
     return;
   }
   if (grpc_client_channel_trace.enabled()) {
-    gpr_log(GPR_DEBUG, "chand=%p: started name re-resolving", chand);
+    gpr_log(GPR_INFO, "chand=%p: started name re-resolving", chand);
   }
   chand->resolver->RequestReresolutionLocked();
   // Give back the closure to the LB policy.
@@ -311,7 +311,7 @@ static void request_reresolution_locked(void* arg, grpc_error* error) {
 static void on_resolver_result_changed_locked(void* arg, grpc_error* error) {
   channel_data* chand = static_cast<channel_data*>(arg);
   if (grpc_client_channel_trace.enabled()) {
-    gpr_log(GPR_DEBUG,
+    gpr_log(GPR_INFO,
             "chand=%p: got resolver result: resolver_result=%p error=%s", chand,
             chand->resolver_result, grpc_error_string(error));
   }
@@ -431,7 +431,7 @@ static void on_resolver_result_changed_locked(void* arg, grpc_error* error) {
     }
   }
   if (grpc_client_channel_trace.enabled()) {
-    gpr_log(GPR_DEBUG,
+    gpr_log(GPR_INFO,
             "chand=%p: resolver result: lb_policy_name=\"%s\"%s, "
             "service_config=\"%s\"",
             chand, lb_policy_name_dup,
@@ -466,7 +466,7 @@ static void on_resolver_result_changed_locked(void* arg, grpc_error* error) {
       chand->resolver == nullptr) {
     if (chand->lb_policy != nullptr) {
       if (grpc_client_channel_trace.enabled()) {
-        gpr_log(GPR_DEBUG, "chand=%p: unreffing lb_policy=%p", chand,
+        gpr_log(GPR_INFO, "chand=%p: unreffing lb_policy=%p", chand,
                 chand->lb_policy.get());
       }
       grpc_pollset_set_del_pollset_set(chand->lb_policy->interested_parties(),
@@ -480,11 +480,11 @@ static void on_resolver_result_changed_locked(void* arg, grpc_error* error) {
   // error or shutdown.
   if (error != GRPC_ERROR_NONE || chand->resolver == nullptr) {
     if (grpc_client_channel_trace.enabled()) {
-      gpr_log(GPR_DEBUG, "chand=%p: shutting down", chand);
+      gpr_log(GPR_INFO, "chand=%p: shutting down", chand);
     }
     if (chand->resolver != nullptr) {
       if (grpc_client_channel_trace.enabled()) {
-        gpr_log(GPR_DEBUG, "chand=%p: shutting down resolver", chand);
+        gpr_log(GPR_INFO, "chand=%p: shutting down resolver", chand);
       }
       chand->resolver.reset();
     }
@@ -506,7 +506,7 @@ static void on_resolver_result_changed_locked(void* arg, grpc_error* error) {
         GRPC_ERROR_CREATE_FROM_STATIC_STRING("No load balancing policy");
     if (lb_policy_created) {
       if (grpc_client_channel_trace.enabled()) {
-        gpr_log(GPR_DEBUG, "chand=%p: initializing new LB policy", chand);
+        gpr_log(GPR_INFO, "chand=%p: initializing new LB policy", chand);
       }
       GRPC_ERROR_UNREF(state_error);
       state = chand->lb_policy->CheckConnectivityLocked(&state_error);
@@ -842,10 +842,11 @@ typedef struct {
   bool completed_recv_trailing_metadata : 1;
   // State for callback processing.
   bool retry_dispatched : 1;
-  bool recv_initial_metadata_ready_deferred : 1;
-  bool recv_message_ready_deferred : 1;
+  subchannel_batch_data* recv_initial_metadata_ready_deferred_batch;
   grpc_error* recv_initial_metadata_error;
+  subchannel_batch_data* recv_message_ready_deferred_batch;
   grpc_error* recv_message_error;
+  subchannel_batch_data* recv_trailing_metadata_internal_batch;
 } subchannel_call_retry_state;
 
 // Pending batches stored in call data.
@@ -994,6 +995,39 @@ static void maybe_cache_send_ops_for_batch(call_data* calld,
   }
 }
 
+// Frees cached send_initial_metadata.
+static void free_cached_send_initial_metadata(channel_data* chand,
+                                              call_data* calld) {
+  if (grpc_client_channel_trace.enabled()) {
+    gpr_log(GPR_INFO,
+            "chand=%p calld=%p: destroying calld->send_initial_metadata", chand,
+            calld);
+  }
+  grpc_metadata_batch_destroy(&calld->send_initial_metadata);
+}
+
+// Frees cached send_message at index idx.
+static void free_cached_send_message(channel_data* chand, call_data* calld,
+                                     size_t idx) {
+  if (grpc_client_channel_trace.enabled()) {
+    gpr_log(GPR_INFO,
+            "chand=%p calld=%p: destroying calld->send_messages[%" PRIuPTR "]",
+            chand, calld, idx);
+  }
+  (*calld->send_messages)[idx]->Destroy();
+}
+
+// Frees cached send_trailing_metadata.
+static void free_cached_send_trailing_metadata(channel_data* chand,
+                                               call_data* calld) {
+  if (grpc_client_channel_trace.enabled()) {
+    gpr_log(GPR_INFO,
+            "chand=%p calld=%p: destroying calld->send_trailing_metadata",
+            chand, calld);
+  }
+  grpc_metadata_batch_destroy(&calld->send_trailing_metadata);
+}
+
 // Frees cached send ops that have already been completed after
 // committing the call.
 static void free_cached_send_op_data_after_commit(
@@ -1001,19 +1035,13 @@ static void free_cached_send_op_data_after_commit(
   channel_data* chand = static_cast<channel_data*>(elem->channel_data);
   call_data* calld = static_cast<call_data*>(elem->call_data);
   if (retry_state->completed_send_initial_metadata) {
-    grpc_metadata_batch_destroy(&calld->send_initial_metadata);
+    free_cached_send_initial_metadata(chand, calld);
   }
   for (size_t i = 0; i < retry_state->completed_send_message_count; ++i) {
-    if (grpc_client_channel_trace.enabled()) {
-      gpr_log(GPR_DEBUG,
-              "chand=%p calld=%p: destroying calld->send_messages[%" PRIuPTR
-              "]",
-              chand, calld, i);
-    }
-    (*calld->send_messages)[i]->Destroy();
+    free_cached_send_message(chand, calld, i);
   }
   if (retry_state->completed_send_trailing_metadata) {
-    grpc_metadata_batch_destroy(&calld->send_trailing_metadata);
+    free_cached_send_trailing_metadata(chand, calld);
   }
 }
 
@@ -1025,20 +1053,14 @@ static void free_cached_send_op_data_for_completed_batch(
   channel_data* chand = static_cast<channel_data*>(elem->channel_data);
   call_data* calld = static_cast<call_data*>(elem->call_data);
   if (batch_data->batch.send_initial_metadata) {
-    grpc_metadata_batch_destroy(&calld->send_initial_metadata);
+    free_cached_send_initial_metadata(chand, calld);
   }
   if (batch_data->batch.send_message) {
-    if (grpc_client_channel_trace.enabled()) {
-      gpr_log(GPR_DEBUG,
-              "chand=%p calld=%p: destroying calld->send_messages[%" PRIuPTR
-              "]",
-              chand, calld, retry_state->completed_send_message_count - 1);
-    }
-    (*calld->send_messages)[retry_state->completed_send_message_count - 1]
-        ->Destroy();
+    free_cached_send_message(chand, calld,
+                             retry_state->completed_send_message_count - 1);
   }
   if (batch_data->batch.send_trailing_metadata) {
-    grpc_metadata_batch_destroy(&calld->send_trailing_metadata);
+    free_cached_send_trailing_metadata(chand, calld);
   }
 }
 
@@ -1066,7 +1088,7 @@ static void pending_batches_add(grpc_call_element* elem,
   call_data* calld = static_cast<call_data*>(elem->call_data);
   const size_t idx = get_batch_index(batch);
   if (grpc_client_channel_trace.enabled()) {
-    gpr_log(GPR_DEBUG,
+    gpr_log(GPR_INFO,
             "chand=%p calld=%p: adding pending batch at index %" PRIuPTR, chand,
             calld, idx);
   }
@@ -1094,7 +1116,7 @@ static void pending_batches_add(grpc_call_element* elem,
     }
     if (calld->bytes_buffered_for_retry > chand->per_rpc_retry_buffer_size) {
       if (grpc_client_channel_trace.enabled()) {
-        gpr_log(GPR_DEBUG,
+        gpr_log(GPR_INFO,
                 "chand=%p calld=%p: exceeded retry buffer size, committing",
                 chand, calld);
       }
@@ -1109,7 +1131,7 @@ static void pending_batches_add(grpc_call_element* elem,
       // retries are disabled so that we don't bother with retry overhead.
       if (calld->num_attempts_completed == 0) {
         if (grpc_client_channel_trace.enabled()) {
-          gpr_log(GPR_DEBUG,
+          gpr_log(GPR_INFO,
                   "chand=%p calld=%p: disabling retries before first attempt",
                   chand, calld);
         }
@@ -1156,7 +1178,7 @@ static void pending_batches_fail(grpc_call_element* elem, grpc_error* error,
     for (size_t i = 0; i < GPR_ARRAY_SIZE(calld->pending_batches); ++i) {
       if (calld->pending_batches[i].batch != nullptr) ++num_batches;
     }
-    gpr_log(GPR_DEBUG,
+    gpr_log(GPR_INFO,
             "chand=%p calld=%p: failing %" PRIuPTR " pending batches: %s",
             elem->channel_data, calld, num_batches, grpc_error_string(error));
   }
@@ -1218,7 +1240,7 @@ static void pending_batches_resume(grpc_call_element* elem) {
     for (size_t i = 0; i < GPR_ARRAY_SIZE(calld->pending_batches); ++i) {
       if (calld->pending_batches[i].batch != nullptr) ++num_batches;
     }
-    gpr_log(GPR_DEBUG,
+    gpr_log(GPR_INFO,
             "chand=%p calld=%p: starting %" PRIuPTR
             " pending batches on subchannel_call=%p",
             chand, calld, num_batches, calld->subchannel_call);
@@ -1263,7 +1285,7 @@ static void maybe_clear_pending_batch(grpc_call_element* elem,
       (!batch->recv_message ||
        batch->payload->recv_message.recv_message_ready == nullptr)) {
     if (grpc_client_channel_trace.enabled()) {
-      gpr_log(GPR_DEBUG, "chand=%p calld=%p: clearing pending batch", chand,
+      gpr_log(GPR_INFO, "chand=%p calld=%p: clearing pending batch", chand,
               calld);
     }
     pending_batch_clear(calld, pending);
@@ -1353,7 +1375,7 @@ static void retry_commit(grpc_call_element* elem,
   if (calld->retry_committed) return;
   calld->retry_committed = true;
   if (grpc_client_channel_trace.enabled()) {
-    gpr_log(GPR_DEBUG, "chand=%p calld=%p: committing retries", chand, calld);
+    gpr_log(GPR_INFO, "chand=%p calld=%p: committing retries", chand, calld);
   }
   if (retry_state != nullptr) {
     free_cached_send_op_data_after_commit(elem, retry_state);
@@ -1398,7 +1420,7 @@ static void do_retry(grpc_call_element* elem,
     next_attempt_time = calld->retry_backoff->NextAttemptTime();
   }
   if (grpc_client_channel_trace.enabled()) {
-    gpr_log(GPR_DEBUG,
+    gpr_log(GPR_INFO,
             "chand=%p calld=%p: retrying failed call in %" PRId64 " ms", chand,
             calld, next_attempt_time - grpc_core::ExecCtx::Get()->Now());
   }
@@ -1432,7 +1454,7 @@ static bool maybe_retry(grpc_call_element* elem,
             batch_data->subchannel_call));
     if (retry_state->retry_dispatched) {
       if (grpc_client_channel_trace.enabled()) {
-        gpr_log(GPR_DEBUG, "chand=%p calld=%p: retry already dispatched", chand,
+        gpr_log(GPR_INFO, "chand=%p calld=%p: retry already dispatched", chand,
                 calld);
       }
       return true;
@@ -1444,14 +1466,14 @@ static bool maybe_retry(grpc_call_element* elem,
       calld->retry_throttle_data->RecordSuccess();
     }
     if (grpc_client_channel_trace.enabled()) {
-      gpr_log(GPR_DEBUG, "chand=%p calld=%p: call succeeded", chand, calld);
+      gpr_log(GPR_INFO, "chand=%p calld=%p: call succeeded", chand, calld);
     }
     return false;
   }
   // Status is not OK.  Check whether the status is retryable.
   if (!retry_policy->retryable_status_codes.Contains(status)) {
     if (grpc_client_channel_trace.enabled()) {
-      gpr_log(GPR_DEBUG,
+      gpr_log(GPR_INFO,
               "chand=%p calld=%p: status %s not configured as retryable", chand,
               calld, grpc_status_code_to_string(status));
     }
@@ -1467,14 +1489,14 @@ static bool maybe_retry(grpc_call_element* elem,
   if (calld->retry_throttle_data != nullptr &&
       !calld->retry_throttle_data->RecordFailure()) {
     if (grpc_client_channel_trace.enabled()) {
-      gpr_log(GPR_DEBUG, "chand=%p calld=%p: retries throttled", chand, calld);
+      gpr_log(GPR_INFO, "chand=%p calld=%p: retries throttled", chand, calld);
     }
     return false;
   }
   // Check whether the call is committed.
   if (calld->retry_committed) {
     if (grpc_client_channel_trace.enabled()) {
-      gpr_log(GPR_DEBUG, "chand=%p calld=%p: retries already committed", chand,
+      gpr_log(GPR_INFO, "chand=%p calld=%p: retries already committed", chand,
               calld);
     }
     return false;
@@ -1483,7 +1505,7 @@ static bool maybe_retry(grpc_call_element* elem,
   ++calld->num_attempts_completed;
   if (calld->num_attempts_completed >= retry_policy->max_attempts) {
     if (grpc_client_channel_trace.enabled()) {
-      gpr_log(GPR_DEBUG, "chand=%p calld=%p: exceeded %d retry attempts", chand,
+      gpr_log(GPR_INFO, "chand=%p calld=%p: exceeded %d retry attempts", chand,
               calld, retry_policy->max_attempts);
     }
     return false;
@@ -1491,7 +1513,7 @@ static bool maybe_retry(grpc_call_element* elem,
   // If the call was cancelled from the surface, don't retry.
   if (calld->cancel_error != GRPC_ERROR_NONE) {
     if (grpc_client_channel_trace.enabled()) {
-      gpr_log(GPR_DEBUG,
+      gpr_log(GPR_INFO,
               "chand=%p calld=%p: call cancelled from surface, not retrying",
               chand, calld);
     }
@@ -1504,16 +1526,15 @@ static bool maybe_retry(grpc_call_element* elem,
     uint32_t ms;
     if (!grpc_parse_slice_to_uint32(GRPC_MDVALUE(*server_pushback_md), &ms)) {
       if (grpc_client_channel_trace.enabled()) {
-        gpr_log(GPR_DEBUG,
+        gpr_log(GPR_INFO,
                 "chand=%p calld=%p: not retrying due to server push-back",
                 chand, calld);
       }
       return false;
     } else {
       if (grpc_client_channel_trace.enabled()) {
-        gpr_log(GPR_DEBUG,
-                "chand=%p calld=%p: server push-back: retry in %u ms", chand,
-                calld, ms);
+        gpr_log(GPR_INFO, "chand=%p calld=%p: server push-back: retry in %u ms",
+                chand, calld, ms);
       }
       server_pushback_ms = (grpc_millis)ms;
     }
@@ -1586,7 +1607,7 @@ static void invoke_recv_initial_metadata_callback(void* arg,
         batch->payload->recv_initial_metadata.recv_initial_metadata_ready !=
             nullptr) {
       if (grpc_client_channel_trace.enabled()) {
-        gpr_log(GPR_DEBUG,
+        gpr_log(GPR_INFO,
                 "chand=%p calld=%p: invoking recv_initial_metadata_ready for "
                 "pending batch at index %" PRIuPTR,
                 chand, calld, i);
@@ -1622,7 +1643,7 @@ static void recv_initial_metadata_ready(void* arg, grpc_error* error) {
   channel_data* chand = static_cast<channel_data*>(elem->channel_data);
   call_data* calld = static_cast<call_data*>(elem->call_data);
   if (grpc_client_channel_trace.enabled()) {
-    gpr_log(GPR_DEBUG,
+    gpr_log(GPR_INFO,
             "chand=%p calld=%p: got recv_initial_metadata_ready, error=%s",
             chand, calld, grpc_error_string(error));
   }
@@ -1637,12 +1658,12 @@ static void recv_initial_metadata_ready(void* arg, grpc_error* error) {
   if ((batch_data->trailing_metadata_available || error != GRPC_ERROR_NONE) &&
       !retry_state->completed_recv_trailing_metadata) {
     if (grpc_client_channel_trace.enabled()) {
-      gpr_log(GPR_DEBUG,
+      gpr_log(GPR_INFO,
               "chand=%p calld=%p: deferring recv_initial_metadata_ready "
               "(Trailers-Only)",
               chand, calld);
     }
-    retry_state->recv_initial_metadata_ready_deferred = true;
+    retry_state->recv_initial_metadata_ready_deferred_batch = batch_data;
     retry_state->recv_initial_metadata_error = GRPC_ERROR_REF(error);
     if (!retry_state->started_recv_trailing_metadata) {
       // recv_trailing_metadata not yet started by application; start it
@@ -1679,7 +1700,7 @@ static void invoke_recv_message_callback(void* arg, grpc_error* error) {
     if (batch != nullptr && batch->recv_message &&
         batch->payload->recv_message.recv_message_ready != nullptr) {
       if (grpc_client_channel_trace.enabled()) {
-        gpr_log(GPR_DEBUG,
+        gpr_log(GPR_INFO,
                 "chand=%p calld=%p: invoking recv_message_ready for "
                 "pending batch at index %" PRIuPTR,
                 chand, calld, i);
@@ -1712,7 +1733,7 @@ static void recv_message_ready(void* arg, grpc_error* error) {
   channel_data* chand = static_cast<channel_data*>(elem->channel_data);
   call_data* calld = static_cast<call_data*>(elem->call_data);
   if (grpc_client_channel_trace.enabled()) {
-    gpr_log(GPR_DEBUG, "chand=%p calld=%p: got recv_message_ready, error=%s",
+    gpr_log(GPR_INFO, "chand=%p calld=%p: got recv_message_ready, error=%s",
             chand, calld, grpc_error_string(error));
   }
   subchannel_call_retry_state* retry_state =
@@ -1726,12 +1747,12 @@ static void recv_message_ready(void* arg, grpc_error* error) {
   if ((batch_data->recv_message == nullptr || error != GRPC_ERROR_NONE) &&
       !retry_state->completed_recv_trailing_metadata) {
     if (grpc_client_channel_trace.enabled()) {
-      gpr_log(GPR_DEBUG,
+      gpr_log(GPR_INFO,
               "chand=%p calld=%p: deferring recv_message_ready (nullptr "
               "message and recv_trailing_metadata pending)",
               chand, calld);
     }
-    retry_state->recv_message_ready_deferred = true;
+    retry_state->recv_message_ready_deferred_batch = batch_data;
     retry_state->recv_message_error = GRPC_ERROR_REF(error);
     if (!retry_state->started_recv_trailing_metadata) {
       // recv_trailing_metadata not yet started by application; start it
@@ -1750,6 +1771,59 @@ static void recv_message_ready(void* arg, grpc_error* error) {
 }
 
 //
+// list of closures to execute in call combiner
+//
+
+// Represents a closure that needs to run in the call combiner as part of
+// starting or completing a batch.
+typedef struct {
+  grpc_closure* closure;
+  grpc_error* error;
+  const char* reason;
+  bool free_reason = false;
+} closure_to_execute;
+
+static void execute_closures_in_call_combiner(grpc_call_element* elem,
+                                              const char* caller,
+                                              closure_to_execute* closures,
+                                              size_t num_closures) {
+  channel_data* chand = static_cast<channel_data*>(elem->channel_data);
+  call_data* calld = static_cast<call_data*>(elem->call_data);
+  // Note that the call combiner will be yielded for each closure that
+  // we schedule.  We're already running in the call combiner, so one of
+  // the closures can be scheduled directly, but the others will
+  // have to re-enter the call combiner.
+  if (num_closures > 0) {
+    if (grpc_client_channel_trace.enabled()) {
+      gpr_log(GPR_INFO, "chand=%p calld=%p: %s starting closure: %s", chand,
+              calld, caller, closures[0].reason);
+    }
+    GRPC_CLOSURE_SCHED(closures[0].closure, closures[0].error);
+    if (closures[0].free_reason) {
+      gpr_free(const_cast<char*>(closures[0].reason));
+    }
+    for (size_t i = 1; i < num_closures; ++i) {
+      if (grpc_client_channel_trace.enabled()) {
+        gpr_log(GPR_INFO,
+                "chand=%p calld=%p: %s starting closure in call combiner: %s",
+                chand, calld, caller, closures[i].reason);
+      }
+      GRPC_CALL_COMBINER_START(calld->call_combiner, closures[i].closure,
+                               closures[i].error, closures[i].reason);
+      if (closures[i].free_reason) {
+        gpr_free(const_cast<char*>(closures[i].reason));
+      }
+    }
+  } else {
+    if (grpc_client_channel_trace.enabled()) {
+      gpr_log(GPR_INFO, "chand=%p calld=%p: no closures to run for %s", chand,
+              calld, caller);
+    }
+    GRPC_CALL_COMBINER_STOP(calld->call_combiner, "no closures to run");
+  }
+}
+
+//
 // on_complete callback handling
 //
 
@@ -1777,36 +1851,35 @@ static void update_retry_state_for_completed_batch(
   }
 }
 
-// Represents a closure that needs to run as a result of a completed batch.
-typedef struct {
-  grpc_closure* closure;
-  grpc_error* error;
-  const char* reason;
-} closure_to_execute;
-
 // Adds any necessary closures for deferred recv_initial_metadata and
 // recv_message callbacks to closures, updating *num_closures as needed.
 static void add_closures_for_deferred_recv_callbacks(
     subchannel_batch_data* batch_data, subchannel_call_retry_state* retry_state,
     closure_to_execute* closures, size_t* num_closures) {
-  if (batch_data->batch.recv_trailing_metadata &&
-      retry_state->recv_initial_metadata_ready_deferred) {
-    closure_to_execute* closure = &closures[(*num_closures)++];
-    closure->closure =
-        GRPC_CLOSURE_INIT(&batch_data->recv_initial_metadata_ready,
-                          invoke_recv_initial_metadata_callback, batch_data,
-                          grpc_schedule_on_exec_ctx);
-    closure->error = retry_state->recv_initial_metadata_error;
-    closure->reason = "resuming recv_initial_metadata_ready";
-  }
-  if (batch_data->batch.recv_trailing_metadata &&
-      retry_state->recv_message_ready_deferred) {
-    closure_to_execute* closure = &closures[(*num_closures)++];
-    closure->closure = GRPC_CLOSURE_INIT(&batch_data->recv_message_ready,
-                                         invoke_recv_message_callback,
-                                         batch_data, grpc_schedule_on_exec_ctx);
-    closure->error = retry_state->recv_message_error;
-    closure->reason = "resuming recv_message_ready";
+  if (batch_data->batch.recv_trailing_metadata) {
+    // Add closure for deferred recv_initial_metadata_ready.
+    if (retry_state->recv_initial_metadata_ready_deferred_batch != nullptr) {
+      closure_to_execute* closure = &closures[(*num_closures)++];
+      closure->closure = GRPC_CLOSURE_INIT(
+          &batch_data->recv_initial_metadata_ready,
+          invoke_recv_initial_metadata_callback,
+          retry_state->recv_initial_metadata_ready_deferred_batch,
+          grpc_schedule_on_exec_ctx);
+      closure->error = retry_state->recv_initial_metadata_error;
+      closure->reason = "resuming recv_initial_metadata_ready";
+      retry_state->recv_initial_metadata_ready_deferred_batch = nullptr;
+    }
+    // Add closure for deferred recv_message_ready.
+    if (retry_state->recv_message_ready_deferred_batch != nullptr) {
+      closure_to_execute* closure = &closures[(*num_closures)++];
+      closure->closure = GRPC_CLOSURE_INIT(
+          &batch_data->recv_message_ready, invoke_recv_message_callback,
+          retry_state->recv_message_ready_deferred_batch,
+          grpc_schedule_on_exec_ctx);
+      closure->error = retry_state->recv_message_error;
+      closure->reason = "resuming recv_message_ready";
+      retry_state->recv_message_ready_deferred_batch = nullptr;
+    }
   }
 }
 
@@ -1838,7 +1911,7 @@ static void add_closures_for_replay_or_pending_send_ops(
   }
   if (have_pending_send_message_ops || have_pending_send_trailing_metadata_op) {
     if (grpc_client_channel_trace.enabled()) {
-      gpr_log(GPR_DEBUG,
+      gpr_log(GPR_INFO,
               "chand=%p calld=%p: starting next batch for pending send op(s)",
               chand, calld);
     }
@@ -1863,7 +1936,7 @@ static void add_closures_for_completed_pending_batches(
     pending_batch* pending = &calld->pending_batches[i];
     if (pending_batch_is_completed(pending, calld, retry_state)) {
       if (grpc_client_channel_trace.enabled()) {
-        gpr_log(GPR_DEBUG,
+        gpr_log(GPR_INFO,
                 "chand=%p calld=%p: pending batch completed at index %" PRIuPTR,
                 chand, calld, i);
       }
@@ -1896,7 +1969,7 @@ static void add_closures_to_fail_unstarted_pending_batches(
     pending_batch* pending = &calld->pending_batches[i];
     if (pending_batch_is_unstarted(pending, calld, retry_state)) {
       if (grpc_client_channel_trace.enabled()) {
-        gpr_log(GPR_DEBUG,
+        gpr_log(GPR_INFO,
                 "chand=%p calld=%p: failing unstarted pending batch at index "
                 "%" PRIuPTR,
                 chand, calld, i);
@@ -1940,7 +2013,7 @@ static void on_complete(void* arg, grpc_error* error) {
   call_data* calld = static_cast<call_data*>(elem->call_data);
   if (grpc_client_channel_trace.enabled()) {
     char* batch_str = grpc_transport_stream_op_batch_string(&batch_data->batch);
-    gpr_log(GPR_DEBUG, "chand=%p calld=%p: got on_complete, error=%s, batch=%s",
+    gpr_log(GPR_INFO, "chand=%p calld=%p: got on_complete, error=%s, batch=%s",
             chand, calld, grpc_error_string(error), batch_str);
     gpr_free(batch_str);
   }
@@ -1951,11 +2024,13 @@ static void on_complete(void* arg, grpc_error* error) {
   // If we have previously completed recv_trailing_metadata, then the
   // call is finished.
   bool call_finished = retry_state->completed_recv_trailing_metadata;
+  // Record whether we were already committed before receiving this callback.
+  const bool previously_committed = calld->retry_committed;
   // Update bookkeeping in retry_state.
   update_retry_state_for_completed_batch(batch_data, retry_state);
   if (call_finished) {
     if (grpc_client_channel_trace.enabled()) {
-      gpr_log(GPR_DEBUG, "chand=%p calld=%p: call already finished", chand,
+      gpr_log(GPR_INFO, "chand=%p calld=%p: call already finished", chand,
               calld);
     }
   } else {
@@ -1979,35 +2054,39 @@ static void on_complete(void* arg, grpc_error* error) {
       if (md_batch->idx.named.grpc_retry_pushback_ms != nullptr) {
         server_pushback_md = &md_batch->idx.named.grpc_retry_pushback_ms->md;
       }
-    } else if (retry_state->completed_recv_trailing_metadata) {
-      call_finished = true;
     }
-    if (call_finished && grpc_client_channel_trace.enabled()) {
-      gpr_log(GPR_DEBUG, "chand=%p calld=%p: call finished, status=%s", chand,
-              calld, grpc_status_code_to_string(status));
-    }
-    // If the call is finished, check if we should retry.
-    if (call_finished &&
-        maybe_retry(elem, batch_data, status, server_pushback_md)) {
-      // Unref batch_data for deferred recv_initial_metadata_ready or
-      // recv_message_ready callbacks, if any.
-      if (batch_data->batch.recv_trailing_metadata &&
-          retry_state->recv_initial_metadata_ready_deferred) {
-        batch_data_unref(batch_data);
-        GRPC_ERROR_UNREF(retry_state->recv_initial_metadata_error);
+    // If the call just finished, check if we should retry.
+    if (call_finished) {
+      if (grpc_client_channel_trace.enabled()) {
+        gpr_log(GPR_INFO, "chand=%p calld=%p: call finished, status=%s", chand,
+                calld, grpc_status_code_to_string(status));
       }
-      if (batch_data->batch.recv_trailing_metadata &&
-          retry_state->recv_message_ready_deferred) {
+      if (maybe_retry(elem, batch_data, status, server_pushback_md)) {
+        // Unref batch_data for deferred recv_initial_metadata_ready or
+        // recv_message_ready callbacks, if any.
+        if (batch_data->batch.recv_trailing_metadata &&
+            retry_state->recv_initial_metadata_ready_deferred_batch !=
+                nullptr) {
+          batch_data_unref(batch_data);
+          GRPC_ERROR_UNREF(retry_state->recv_initial_metadata_error);
+        }
+        if (batch_data->batch.recv_trailing_metadata &&
+            retry_state->recv_message_ready_deferred_batch != nullptr) {
+          batch_data_unref(batch_data);
+          GRPC_ERROR_UNREF(retry_state->recv_message_error);
+        }
         batch_data_unref(batch_data);
-        GRPC_ERROR_UNREF(retry_state->recv_message_error);
+        return;
       }
-      batch_data_unref(batch_data);
-      return;
+      // Not retrying, so commit the call.
+      retry_commit(elem, retry_state);
     }
   }
-  // If the call is finished or retries are committed, free cached data for
-  // send ops that we've just completed.
-  if (call_finished || calld->retry_committed) {
+  // If we were already committed before receiving this callback, free
+  // cached data for send ops that we've just completed.  (If the call has
+  // just now finished, the call to retry_commit() above will have freed all
+  // cached send ops, so we don't need to do it here.)
+  if (previously_committed) {
     free_cached_send_op_data_for_completed_batch(elem, batch_data, retry_state);
   }
   // Call not being retried.
@@ -2042,20 +2121,8 @@ static void on_complete(void* arg, grpc_error* error) {
   // Don't need batch_data anymore.
   batch_data_unref(batch_data);
   // Schedule all of the closures identified above.
-  // Note that the call combiner will be yielded for each closure that
-  // we schedule.  We're already running in the call combiner, so one of
-  // the closures can be scheduled directly, but the others will
-  // have to re-enter the call combiner.
-  if (num_closures > 0) {
-    GRPC_CLOSURE_SCHED(closures[0].closure, closures[0].error);
-    for (size_t i = 1; i < num_closures; ++i) {
-      GRPC_CALL_COMBINER_START(calld->call_combiner, closures[i].closure,
-                               closures[i].error, closures[i].reason);
-    }
-  } else {
-    GRPC_CALL_COMBINER_STOP(calld->call_combiner,
-                            "no closures to run for on_complete");
-  }
+  execute_closures_in_call_combiner(elem, "on_complete", closures,
+                                    num_closures);
 }
 
 //
@@ -2072,6 +2139,31 @@ static void start_batch_in_call_combiner(void* arg, grpc_error* ignored) {
   grpc_subchannel_call_process_op(subchannel_call, batch);
 }
 
+// Adds a closure to closures that will execute batch in the call combiner.
+static void add_closure_for_subchannel_batch(
+    call_data* calld, grpc_transport_stream_op_batch* batch,
+    closure_to_execute* closures, size_t* num_closures) {
+  batch->handler_private.extra_arg = calld->subchannel_call;
+  GRPC_CLOSURE_INIT(&batch->handler_private.closure,
+                    start_batch_in_call_combiner, batch,
+                    grpc_schedule_on_exec_ctx);
+  closure_to_execute* closure = &closures[(*num_closures)++];
+  closure->closure = &batch->handler_private.closure;
+  closure->error = GRPC_ERROR_NONE;
+  // If the tracer is enabled, we log a more detailed message, which
+  // requires dynamic allocation.  This will be freed in
+  // start_retriable_subchannel_batches().
+  if (grpc_client_channel_trace.enabled()) {
+    char* batch_str = grpc_transport_stream_op_batch_string(batch);
+    gpr_asprintf(const_cast<char**>(&closure->reason),
+                 "starting batch in call combiner: %s", batch_str);
+    gpr_free(batch_str);
+    closure->free_reason = true;
+  } else {
+    closure->reason = "start_subchannel_batch";
+  }
+}
+
 // Adds retriable send_initial_metadata op to batch_data.
 static void add_retriable_send_initial_metadata_op(
     call_data* calld, subchannel_call_retry_state* retry_state,
@@ -2131,7 +2223,7 @@ static void add_retriable_send_message_op(
   channel_data* chand = static_cast<channel_data*>(elem->channel_data);
   call_data* calld = static_cast<call_data*>(elem->call_data);
   if (grpc_client_channel_trace.enabled()) {
-    gpr_log(GPR_DEBUG,
+    gpr_log(GPR_INFO,
             "chand=%p calld=%p: starting calld->send_messages[%" PRIuPTR "]",
             chand, calld, retry_state->started_send_message_count);
   }
@@ -2218,7 +2310,7 @@ static void start_internal_recv_trailing_metadata(grpc_call_element* elem) {
   channel_data* chand = static_cast<channel_data*>(elem->channel_data);
   call_data* calld = static_cast<call_data*>(elem->call_data);
   if (grpc_client_channel_trace.enabled()) {
-    gpr_log(GPR_DEBUG,
+    gpr_log(GPR_INFO,
             "chand=%p calld=%p: call failed but recv_trailing_metadata not "
             "started; starting it internally",
             chand, calld);
@@ -2227,8 +2319,12 @@ static void start_internal_recv_trailing_metadata(grpc_call_element* elem) {
       static_cast<subchannel_call_retry_state*>(
           grpc_connected_subchannel_call_get_parent_data(
               calld->subchannel_call));
-  subchannel_batch_data* batch_data = batch_data_create(elem, 1);
+  // Create batch_data with 2 refs, since this batch will be unreffed twice:
+  // once when the subchannel batch returns, and again when we actually get
+  // a recv_trailing_metadata op from the surface.
+  subchannel_batch_data* batch_data = batch_data_create(elem, 2);
   add_retriable_recv_trailing_metadata_op(calld, retry_state, batch_data);
+  retry_state->recv_trailing_metadata_internal_batch = batch_data;
   // Note: This will release the call combiner.
   grpc_subchannel_call_process_op(calld->subchannel_call, &batch_data->batch);
 }
@@ -2246,7 +2342,7 @@ static subchannel_batch_data* maybe_create_subchannel_batch_for_replay(
       !retry_state->started_send_initial_metadata &&
       !calld->pending_send_initial_metadata) {
     if (grpc_client_channel_trace.enabled()) {
-      gpr_log(GPR_DEBUG,
+      gpr_log(GPR_INFO,
               "chand=%p calld=%p: replaying previously completed "
               "send_initial_metadata op",
               chand, calld);
@@ -2262,7 +2358,7 @@ static subchannel_batch_data* maybe_create_subchannel_batch_for_replay(
           retry_state->completed_send_message_count &&
       !calld->pending_send_message) {
     if (grpc_client_channel_trace.enabled()) {
-      gpr_log(GPR_DEBUG,
+      gpr_log(GPR_INFO,
               "chand=%p calld=%p: replaying previously completed "
               "send_message op",
               chand, calld);
@@ -2281,7 +2377,7 @@ static subchannel_batch_data* maybe_create_subchannel_batch_for_replay(
       !retry_state->started_send_trailing_metadata &&
       !calld->pending_send_trailing_metadata) {
     if (grpc_client_channel_trace.enabled()) {
-      gpr_log(GPR_DEBUG,
+      gpr_log(GPR_INFO,
               "chand=%p calld=%p: replaying previously completed "
               "send_trailing_metadata op",
               chand, calld);
@@ -2299,7 +2395,7 @@ static subchannel_batch_data* maybe_create_subchannel_batch_for_replay(
 // *num_batches as needed.
 static void add_subchannel_batches_for_pending_batches(
     grpc_call_element* elem, subchannel_call_retry_state* retry_state,
-    grpc_transport_stream_op_batch** batches, size_t* num_batches) {
+    closure_to_execute* closures, size_t* num_closures) {
   call_data* calld = static_cast<call_data*>(elem->call_data);
   for (size_t i = 0; i < GPR_ARRAY_SIZE(calld->pending_batches); ++i) {
     pending_batch* pending = &calld->pending_batches[i];
@@ -2342,13 +2438,37 @@ static void add_subchannel_batches_for_pending_batches(
     }
     if (batch->recv_trailing_metadata &&
         retry_state->started_recv_trailing_metadata) {
+      // If we previously completed a recv_trailing_metadata op
+      // initiated by start_internal_recv_trailing_metadata(), use the
+      // result of that instead of trying to re-start this op.
+      if (retry_state->recv_trailing_metadata_internal_batch != nullptr) {
+        // If the batch completed, then trigger the completion callback
+        // directly, so that we return the previously returned results to
+        // the application.  Otherwise, just unref the internally
+        // started subchannel batch, since we'll propagate the
+        // completion when it completes.
+        if (retry_state->completed_recv_trailing_metadata) {
+          subchannel_batch_data* batch_data =
+              retry_state->recv_trailing_metadata_internal_batch;
+          closure_to_execute* closure = &closures[(*num_closures)++];
+          closure->closure = &batch_data->on_complete;
+          // Batches containing recv_trailing_metadata always succeed.
+          closure->error = GRPC_ERROR_NONE;
+          closure->reason =
+              "re-executing on_complete for recv_trailing_metadata "
+              "to propagate internally triggered result";
+        } else {
+          batch_data_unref(retry_state->recv_trailing_metadata_internal_batch);
+        }
+        retry_state->recv_trailing_metadata_internal_batch = nullptr;
+      }
       continue;
     }
     // If we're not retrying, just send the batch as-is.
     if (calld->method_params == nullptr ||
         calld->method_params->retry_policy() == nullptr ||
         calld->retry_committed) {
-      batches[(*num_batches)++] = batch;
+      add_closure_for_subchannel_batch(calld, batch, closures, num_closures);
       pending_batch_clear(calld, pending);
       continue;
     }
@@ -2385,7 +2505,8 @@ static void add_subchannel_batches_for_pending_batches(
       GPR_ASSERT(batch->collect_stats);
       add_retriable_recv_trailing_metadata_op(calld, retry_state, batch_data);
     }
-    batches[(*num_batches)++] = &batch_data->batch;
+    add_closure_for_subchannel_batch(calld, &batch_data->batch, closures,
+                                     num_closures);
   }
 }
 
@@ -2396,69 +2517,36 @@ static void start_retriable_subchannel_batches(void* arg, grpc_error* ignored) {
   channel_data* chand = static_cast<channel_data*>(elem->channel_data);
   call_data* calld = static_cast<call_data*>(elem->call_data);
   if (grpc_client_channel_trace.enabled()) {
-    gpr_log(GPR_DEBUG, "chand=%p calld=%p: constructing retriable batches",
+    gpr_log(GPR_INFO, "chand=%p calld=%p: constructing retriable batches",
             chand, calld);
   }
   subchannel_call_retry_state* retry_state =
       static_cast<subchannel_call_retry_state*>(
           grpc_connected_subchannel_call_get_parent_data(
               calld->subchannel_call));
+  // Construct list of closures to execute, one for each pending batch.
   // We can start up to 6 batches.
-  grpc_transport_stream_op_batch*
-      batches[GPR_ARRAY_SIZE(calld->pending_batches)];
-  size_t num_batches = 0;
+  closure_to_execute closures[GPR_ARRAY_SIZE(calld->pending_batches)];
+  size_t num_closures = 0;
   // Replay previously-returned send_* ops if needed.
   subchannel_batch_data* replay_batch_data =
       maybe_create_subchannel_batch_for_replay(elem, retry_state);
   if (replay_batch_data != nullptr) {
-    batches[num_batches++] = &replay_batch_data->batch;
+    add_closure_for_subchannel_batch(calld, &replay_batch_data->batch, closures,
+                                     &num_closures);
   }
   // Now add pending batches.
-  add_subchannel_batches_for_pending_batches(elem, retry_state, batches,
-                                             &num_batches);
+  add_subchannel_batches_for_pending_batches(elem, retry_state, closures,
+                                             &num_closures);
   // Start batches on subchannel call.
-  // Note that the call combiner will be yielded for each batch that we
-  // send down.  We're already running in the call combiner, so one of
-  // the batches can be started directly, but the others will have to
-  // re-enter the call combiner.
   if (grpc_client_channel_trace.enabled()) {
-    gpr_log(GPR_DEBUG,
+    gpr_log(GPR_INFO,
             "chand=%p calld=%p: starting %" PRIuPTR
             " retriable batches on subchannel_call=%p",
-            chand, calld, num_batches, calld->subchannel_call);
-  }
-  if (num_batches == 0) {
-    // This should be fairly rare, but it can happen when (e.g.) an
-    // attempt completes before it has finished replaying all
-    // previously sent messages.
-    GRPC_CALL_COMBINER_STOP(calld->call_combiner,
-                            "no retriable subchannel batches to start");
-  } else {
-    for (size_t i = 1; i < num_batches; ++i) {
-      if (grpc_client_channel_trace.enabled()) {
-        char* batch_str = grpc_transport_stream_op_batch_string(batches[i]);
-        gpr_log(GPR_DEBUG,
-                "chand=%p calld=%p: starting batch in call combiner: %s", chand,
-                calld, batch_str);
-        gpr_free(batch_str);
-      }
-      batches[i]->handler_private.extra_arg = calld->subchannel_call;
-      GRPC_CLOSURE_INIT(&batches[i]->handler_private.closure,
-                        start_batch_in_call_combiner, batches[i],
-                        grpc_schedule_on_exec_ctx);
-      GRPC_CALL_COMBINER_START(calld->call_combiner,
-                               &batches[i]->handler_private.closure,
-                               GRPC_ERROR_NONE, "start_subchannel_batch");
-    }
-    if (grpc_client_channel_trace.enabled()) {
-      char* batch_str = grpc_transport_stream_op_batch_string(batches[0]);
-      gpr_log(GPR_DEBUG, "chand=%p calld=%p: starting batch: %s", chand, calld,
-              batch_str);
-      gpr_free(batch_str);
-    }
-    // Note: This will release the call combiner.
-    grpc_subchannel_call_process_op(calld->subchannel_call, batches[0]);
+            chand, calld, num_closures, calld->subchannel_call);
   }
+  execute_closures_in_call_combiner(elem, "start_retriable_subchannel_batches",
+                                    closures, num_closures);
 }
 
 //
@@ -2483,7 +2571,7 @@ static void create_subchannel_call(grpc_call_element* elem, grpc_error* error) {
   grpc_error* new_error = calld->pick.connected_subchannel->CreateCall(
       call_args, &calld->subchannel_call);
   if (grpc_client_channel_trace.enabled()) {
-    gpr_log(GPR_DEBUG, "chand=%p calld=%p: create subchannel_call=%p: error=%s",
+    gpr_log(GPR_INFO, "chand=%p calld=%p: create subchannel_call=%p: error=%s",
             chand, calld, calld->subchannel_call, grpc_error_string(new_error));
   }
   if (new_error != GRPC_ERROR_NONE) {
@@ -2524,7 +2612,7 @@ static void pick_done(void* arg, grpc_error* error) {
               : GRPC_ERROR_CREATE_REFERENCING_FROM_STATIC_STRING(
                     "Failed to create subchannel", &error, 1);
       if (grpc_client_channel_trace.enabled()) {
-        gpr_log(GPR_DEBUG,
+        gpr_log(GPR_INFO,
                 "chand=%p calld=%p: failed to create subchannel: error=%s",
                 chand, calld, grpc_error_string(new_error));
       }
@@ -2568,7 +2656,7 @@ static void pick_callback_cancel_locked(void* arg, grpc_error* error) {
   // the one we started it on.  However, this will just be a no-op.
   if (error != GRPC_ERROR_NONE && chand->lb_policy != nullptr) {
     if (grpc_client_channel_trace.enabled()) {
-      gpr_log(GPR_DEBUG, "chand=%p calld=%p: cancelling pick from LB policy %p",
+      gpr_log(GPR_INFO, "chand=%p calld=%p: cancelling pick from LB policy %p",
               chand, calld, chand->lb_policy.get());
     }
     chand->lb_policy->CancelPickLocked(&calld->pick, GRPC_ERROR_REF(error));
@@ -2583,8 +2671,8 @@ static void pick_callback_done_locked(void* arg, grpc_error* error) {
   channel_data* chand = static_cast<channel_data*>(elem->channel_data);
   call_data* calld = static_cast<call_data*>(elem->call_data);
   if (grpc_client_channel_trace.enabled()) {
-    gpr_log(GPR_DEBUG, "chand=%p calld=%p: pick completed asynchronously",
-            chand, calld);
+    gpr_log(GPR_INFO, "chand=%p calld=%p: pick completed asynchronously", chand,
+            calld);
   }
   async_pick_done_locked(elem, GRPC_ERROR_REF(error));
   GRPC_CALL_STACK_UNREF(calld->owning_call, "pick_callback");
@@ -2596,7 +2684,7 @@ static void apply_service_config_to_call_locked(grpc_call_element* elem) {
   channel_data* chand = static_cast<channel_data*>(elem->channel_data);
   call_data* calld = static_cast<call_data*>(elem->call_data);
   if (grpc_client_channel_trace.enabled()) {
-    gpr_log(GPR_DEBUG, "chand=%p calld=%p: applying service config to call",
+    gpr_log(GPR_INFO, "chand=%p calld=%p: applying service config to call",
             chand, calld);
   }
   if (chand->retry_throttle_data != nullptr) {
@@ -2634,8 +2722,8 @@ static bool pick_callback_start_locked(grpc_call_element* elem) {
   channel_data* chand = static_cast<channel_data*>(elem->channel_data);
   call_data* calld = static_cast<call_data*>(elem->call_data);
   if (grpc_client_channel_trace.enabled()) {
-    gpr_log(GPR_DEBUG, "chand=%p calld=%p: starting pick on lb_policy=%p",
-            chand, calld, chand->lb_policy.get());
+    gpr_log(GPR_INFO, "chand=%p calld=%p: starting pick on lb_policy=%p", chand,
+            calld, chand->lb_policy.get());
   }
   // Only get service config data on the first attempt.
   if (calld->num_attempts_completed == 0) {
@@ -2682,7 +2770,7 @@ static bool pick_callback_start_locked(grpc_call_element* elem) {
   if (pick_done) {
     // Pick completed synchronously.
     if (grpc_client_channel_trace.enabled()) {
-      gpr_log(GPR_DEBUG, "chand=%p calld=%p: pick completed synchronously",
+      gpr_log(GPR_INFO, "chand=%p calld=%p: pick completed synchronously",
               chand, calld);
     }
     GRPC_CALL_STACK_UNREF(calld->owning_call, "pick_callback");
@@ -2726,7 +2814,7 @@ static void pick_after_resolver_result_cancel_locked(void* arg,
   channel_data* chand = static_cast<channel_data*>(elem->channel_data);
   call_data* calld = static_cast<call_data*>(elem->call_data);
   if (grpc_client_channel_trace.enabled()) {
-    gpr_log(GPR_DEBUG,
+    gpr_log(GPR_INFO,
             "chand=%p calld=%p: cancelling pick waiting for resolver result",
             chand, calld);
   }
@@ -2746,7 +2834,7 @@ static void pick_after_resolver_result_done_locked(void* arg,
   if (args->finished) {
     /* cancelled, do nothing */
     if (grpc_client_channel_trace.enabled()) {
-      gpr_log(GPR_DEBUG, "call cancelled before resolver result");
+      gpr_log(GPR_INFO, "call cancelled before resolver result");
     }
     gpr_free(args);
     return;
@@ -2757,14 +2845,14 @@ static void pick_after_resolver_result_done_locked(void* arg,
   call_data* calld = static_cast<call_data*>(elem->call_data);
   if (error != GRPC_ERROR_NONE) {
     if (grpc_client_channel_trace.enabled()) {
-      gpr_log(GPR_DEBUG, "chand=%p calld=%p: resolver failed to return data",
+      gpr_log(GPR_INFO, "chand=%p calld=%p: resolver failed to return data",
               chand, calld);
     }
     async_pick_done_locked(elem, GRPC_ERROR_REF(error));
   } else if (chand->resolver == nullptr) {
     // Shutting down.
     if (grpc_client_channel_trace.enabled()) {
-      gpr_log(GPR_DEBUG, "chand=%p calld=%p: resolver disconnected", chand,
+      gpr_log(GPR_INFO, "chand=%p calld=%p: resolver disconnected", chand,
               calld);
     }
     async_pick_done_locked(
@@ -2780,7 +2868,7 @@ static void pick_after_resolver_result_done_locked(void* arg,
                   .send_initial_metadata_flags;
     if (send_initial_metadata_flags & GRPC_INITIAL_METADATA_WAIT_FOR_READY) {
       if (grpc_client_channel_trace.enabled()) {
-        gpr_log(GPR_DEBUG,
+        gpr_log(GPR_INFO,
                 "chand=%p calld=%p: resolver returned but no LB policy; "
                 "wait_for_ready=true; trying again",
                 chand, calld);
@@ -2788,7 +2876,7 @@ static void pick_after_resolver_result_done_locked(void* arg,
       pick_after_resolver_result_start_locked(elem);
     } else {
       if (grpc_client_channel_trace.enabled()) {
-        gpr_log(GPR_DEBUG,
+        gpr_log(GPR_INFO,
                 "chand=%p calld=%p: resolver returned but no LB policy; "
                 "wait_for_ready=false; failing",
                 chand, calld);
@@ -2801,7 +2889,7 @@ static void pick_after_resolver_result_done_locked(void* arg,
     }
   } else {
     if (grpc_client_channel_trace.enabled()) {
-      gpr_log(GPR_DEBUG, "chand=%p calld=%p: resolver returned, doing pick",
+      gpr_log(GPR_INFO, "chand=%p calld=%p: resolver returned, doing pick",
               chand, calld);
     }
     if (pick_callback_start_locked(elem)) {
@@ -2819,7 +2907,7 @@ static void pick_after_resolver_result_start_locked(grpc_call_element* elem) {
   channel_data* chand = static_cast<channel_data*>(elem->channel_data);
   call_data* calld = static_cast<call_data*>(elem->call_data);
   if (grpc_client_channel_trace.enabled()) {
-    gpr_log(GPR_DEBUG,
+    gpr_log(GPR_INFO,
             "chand=%p calld=%p: deferring pick pending resolver result", chand,
             calld);
   }
@@ -2886,7 +2974,7 @@ static void cc_start_transport_stream_op_batch(
   // If we've previously been cancelled, immediately fail any new batches.
   if (calld->cancel_error != GRPC_ERROR_NONE) {
     if (grpc_client_channel_trace.enabled()) {
-      gpr_log(GPR_DEBUG, "chand=%p calld=%p: failing batch with error: %s",
+      gpr_log(GPR_INFO, "chand=%p calld=%p: failing batch with error: %s",
               chand, calld, grpc_error_string(calld->cancel_error));
     }
     // Note: This will release the call combiner.
@@ -2905,7 +2993,7 @@ static void cc_start_transport_stream_op_batch(
     calld->cancel_error =
         GRPC_ERROR_REF(batch->payload->cancel_stream.cancel_error);
     if (grpc_client_channel_trace.enabled()) {
-      gpr_log(GPR_DEBUG, "chand=%p calld=%p: recording cancel_error=%s", chand,
+      gpr_log(GPR_INFO, "chand=%p calld=%p: recording cancel_error=%s", chand,
               calld, grpc_error_string(calld->cancel_error));
     }
     // If we do not have a subchannel call (i.e., a pick has not yet
@@ -2931,7 +3019,7 @@ static void cc_start_transport_stream_op_batch(
   // streaming calls).
   if (calld->subchannel_call != nullptr) {
     if (grpc_client_channel_trace.enabled()) {
-      gpr_log(GPR_DEBUG,
+      gpr_log(GPR_INFO,
               "chand=%p calld=%p: starting batch on subchannel_call=%p", chand,
               calld, calld->subchannel_call);
     }
@@ -2943,7 +3031,7 @@ static void cc_start_transport_stream_op_batch(
   // combiner to start a pick.
   if (batch->send_initial_metadata) {
     if (grpc_client_channel_trace.enabled()) {
-      gpr_log(GPR_DEBUG, "chand=%p calld=%p: entering client_channel combiner",
+      gpr_log(GPR_INFO, "chand=%p calld=%p: entering client_channel combiner",
               chand, calld);
     }
     GRPC_CLOSURE_SCHED(
@@ -2953,7 +3041,7 @@ static void cc_start_transport_stream_op_batch(
   } else {
     // For all other batches, release the call combiner.
     if (grpc_client_channel_trace.enabled()) {
-      gpr_log(GPR_DEBUG,
+      gpr_log(GPR_INFO,
               "chand=%p calld=%p: saved batch, yeilding call combiner", chand,
               calld);
     }
@@ -3164,6 +3252,8 @@ static void watch_connectivity_state_locked(void* arg,
   external_connectivity_watcher* found = nullptr;
   if (w->state != nullptr) {
     external_connectivity_watcher_list_append(w->chand, w);
+    // An assumption is being made that the closure is scheduled on the exec ctx
+    // scheduler and that GRPC_CLOSURE_RUN would run the closure immediately.
     GRPC_CLOSURE_RUN(w->watcher_timer_init, GRPC_ERROR_NONE);
     GRPC_CLOSURE_INIT(&w->my_closure, on_external_watch_complete_locked, w,
                       grpc_combiner_scheduler(w->chand->combiner));
diff --git a/src/core/ext/filters/client_channel/http_connect_handshaker.cc b/src/core/ext/filters/client_channel/http_connect_handshaker.cc
index fb29fa788d..4e8b8b71db 100644
--- a/src/core/ext/filters/client_channel/http_connect_handshaker.cc
+++ b/src/core/ext/filters/client_channel/http_connect_handshaker.cc
@@ -326,7 +326,7 @@ static void http_connect_handshaker_do_handshake(
 
 static const grpc_handshaker_vtable http_connect_handshaker_vtable = {
     http_connect_handshaker_destroy, http_connect_handshaker_shutdown,
-    http_connect_handshaker_do_handshake};
+    http_connect_handshaker_do_handshake, "http_connect"};
 
 static grpc_handshaker* grpc_http_connect_handshaker_create() {
   http_connect_handshaker* handshaker =
diff --git a/src/core/ext/filters/client_channel/lb_policy.cc b/src/core/ext/filters/client_channel/lb_policy.cc
index fa63dd75b5..e065f45639 100644
--- a/src/core/ext/filters/client_channel/lb_policy.cc
+++ b/src/core/ext/filters/client_channel/lb_policy.cc
@@ -44,13 +44,13 @@ void LoadBalancingPolicy::TryReresolutionLocked(
     GRPC_CLOSURE_SCHED(request_reresolution_, error);
     request_reresolution_ = nullptr;
     if (grpc_lb_trace->enabled()) {
-      gpr_log(GPR_DEBUG,
+      gpr_log(GPR_INFO,
               "%s %p: scheduling re-resolution closure with error=%s.",
               grpc_lb_trace->name(), this, grpc_error_string(error));
     }
   } else {
     if (grpc_lb_trace->enabled()) {
-      gpr_log(GPR_DEBUG, "%s %p: no available re-resolution closure.",
+      gpr_log(GPR_INFO, "%s %p: no available re-resolution closure.",
               grpc_lb_trace->name(), this);
     }
   }
diff --git a/src/core/ext/filters/client_channel/lb_policy.h b/src/core/ext/filters/client_channel/lb_policy.h
index c3e43e5ef6..454e00a690 100644
--- a/src/core/ext/filters/client_channel/lb_policy.h
+++ b/src/core/ext/filters/client_channel/lb_policy.h
@@ -162,6 +162,10 @@ class LoadBalancingPolicy
   GRPC_ABSTRACT_BASE_CLASS
 
  protected:
+  // So Delete() can access our protected dtor.
+  template <typename T>
+  friend void Delete(T*);
+
   explicit LoadBalancingPolicy(const Args& args);
   virtual ~LoadBalancingPolicy();
 
diff --git a/src/core/ext/filters/client_channel/lb_policy/grpclb/grpclb.cc b/src/core/ext/filters/client_channel/lb_policy/grpclb/grpclb.cc
index 79deb0ab83..a31474391e 100644
--- a/src/core/ext/filters/client_channel/lb_policy/grpclb/grpclb.cc
+++ b/src/core/ext/filters/client_channel/lb_policy/grpclb/grpclb.cc
@@ -76,6 +76,7 @@
 #include "src/core/ext/filters/client_channel/client_channel.h"
 #include "src/core/ext/filters/client_channel/client_channel_factory.h"
 #include "src/core/ext/filters/client_channel/lb_policy/grpclb/client_load_reporting_filter.h"
+#include "src/core/ext/filters/client_channel/lb_policy/grpclb/grpclb.h"
 #include "src/core/ext/filters/client_channel/lb_policy/grpclb/grpclb_channel.h"
 #include "src/core/ext/filters/client_channel/lb_policy/grpclb/grpclb_client_stats.h"
 #include "src/core/ext/filters/client_channel/lb_policy/grpclb/load_balancer_api.h"
@@ -189,6 +190,10 @@ class GrpcLb : public LoadBalancingPolicy {
     bool seen_initial_response() const { return seen_initial_response_; }
 
    private:
+    // So Delete() can access our private dtor.
+    template <typename T>
+    friend void grpc_core::Delete(T*);
+
     ~BalancerCallState();
 
     GrpcLb* grpclb_policy() const {
@@ -999,6 +1004,9 @@ grpc_channel_args* BuildBalancerChannelArgs(
       // address updates into the LB channel.
       grpc_core::FakeResolverResponseGenerator::MakeChannelArg(
           response_generator),
+      // A channel arg indicating the target is a grpclb load balancer.
+      grpc_channel_arg_integer_create(
+          const_cast<char*>(GRPC_ARG_ADDRESS_IS_GRPCLB_LOAD_BALANCER), 1),
   };
   // Construct channel args.
   grpc_channel_args* new_args = grpc_channel_args_copy_and_add_and_remove(
@@ -1243,7 +1251,7 @@ bool GrpcLb::PickLocked(PickState* pick) {
     }
   } else {  // rr_policy_ == NULL
     if (grpc_lb_glb_trace.enabled()) {
-      gpr_log(GPR_DEBUG,
+      gpr_log(GPR_INFO,
               "[grpclb %p] No RR policy. Adding to grpclb's pending picks",
               this);
     }
@@ -1409,13 +1417,13 @@ void GrpcLb::OnFallbackTimerLocked(void* arg, grpc_error* error) {
 void GrpcLb::StartBalancerCallRetryTimerLocked() {
   grpc_millis next_try = lb_call_backoff_.NextAttemptTime();
   if (grpc_lb_glb_trace.enabled()) {
-    gpr_log(GPR_DEBUG, "[grpclb %p] Connection to LB server lost...", this);
+    gpr_log(GPR_INFO, "[grpclb %p] Connection to LB server lost...", this);
     grpc_millis timeout = next_try - ExecCtx::Get()->Now();
     if (timeout > 0) {
-      gpr_log(GPR_DEBUG, "[grpclb %p] ... retry_timer_active in %" PRId64 "ms.",
+      gpr_log(GPR_INFO, "[grpclb %p] ... retry_timer_active in %" PRId64 "ms.",
               this, timeout);
     } else {
-      gpr_log(GPR_DEBUG, "[grpclb %p] ... retry_timer_active immediately.",
+      gpr_log(GPR_INFO, "[grpclb %p] ... retry_timer_active immediately.",
               this);
     }
   }
@@ -1694,9 +1702,11 @@ void GrpcLb::CreateRoundRobinPolicyLocked(const Args& args) {
 
 grpc_channel_args* GrpcLb::CreateRoundRobinPolicyArgsLocked() {
   grpc_lb_addresses* addresses;
+  bool is_backend_from_grpclb_load_balancer = false;
   if (serverlist_ != nullptr) {
     GPR_ASSERT(serverlist_->num_servers > 0);
     addresses = ProcessServerlist(serverlist_);
+    is_backend_from_grpclb_load_balancer = true;
   } else {
     // If CreateOrUpdateRoundRobinPolicyLocked() is invoked when we haven't
     // received any serverlist from the balancer, we use the fallback backends
@@ -1710,9 +1720,18 @@ grpc_channel_args* GrpcLb::CreateRoundRobinPolicyArgsLocked() {
   // Replace the LB addresses in the channel args that we pass down to
   // the subchannel.
   static const char* keys_to_remove[] = {GRPC_ARG_LB_ADDRESSES};
-  const grpc_arg arg = grpc_lb_addresses_create_channel_arg(addresses);
+  const grpc_arg args_to_add[] = {
+      grpc_lb_addresses_create_channel_arg(addresses),
+      // A channel arg indicating if the target is a backend inferred from a
+      // grpclb load balancer.
+      grpc_channel_arg_integer_create(
+          const_cast<char*>(
+              GRPC_ARG_ADDRESS_IS_BACKEND_FROM_GRPCLB_LOAD_BALANCER),
+          is_backend_from_grpclb_load_balancer),
+  };
   grpc_channel_args* args = grpc_channel_args_copy_and_add_and_remove(
-      args_, keys_to_remove, GPR_ARRAY_SIZE(keys_to_remove), &arg, 1);
+      args_, keys_to_remove, GPR_ARRAY_SIZE(keys_to_remove), args_to_add,
+      GPR_ARRAY_SIZE(args_to_add));
   grpc_lb_addresses_destroy(addresses);
   return args;
 }
@@ -1723,7 +1742,7 @@ void GrpcLb::CreateOrUpdateRoundRobinPolicyLocked() {
   GPR_ASSERT(args != nullptr);
   if (rr_policy_ != nullptr) {
     if (grpc_lb_glb_trace.enabled()) {
-      gpr_log(GPR_DEBUG, "[grpclb %p] Updating RR policy %p", this,
+      gpr_log(GPR_INFO, "[grpclb %p] Updating RR policy %p", this,
               rr_policy_.get());
     }
     rr_policy_->UpdateLocked(*args);
@@ -1734,7 +1753,7 @@ void GrpcLb::CreateOrUpdateRoundRobinPolicyLocked() {
     lb_policy_args.args = args;
     CreateRoundRobinPolicyLocked(lb_policy_args);
     if (grpc_lb_glb_trace.enabled()) {
-      gpr_log(GPR_DEBUG, "[grpclb %p] Created new RR policy %p", this,
+      gpr_log(GPR_INFO, "[grpclb %p] Created new RR policy %p", this,
               rr_policy_.get());
     }
   }
@@ -1750,7 +1769,7 @@ void GrpcLb::OnRoundRobinRequestReresolutionLocked(void* arg,
   }
   if (grpc_lb_glb_trace.enabled()) {
     gpr_log(
-        GPR_DEBUG,
+        GPR_INFO,
         "[grpclb %p] Re-resolution requested from the internal RR policy (%p).",
         grpclb_policy, grpclb_policy->rr_policy_.get());
   }
diff --git a/src/core/ext/filters/client_channel/lb_policy/grpclb/grpclb.h b/src/core/ext/filters/client_channel/lb_policy/grpclb/grpclb.h
new file mode 100644
index 0000000000..4d39c4d504
--- /dev/null
+++ b/src/core/ext/filters/client_channel/lb_policy/grpclb/grpclb.h
@@ -0,0 +1,36 @@
+/*
+ *
+ * Copyright 2018 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+#ifndef GRPC_CORE_EXT_FILTERS_CLIENT_CHANNEL_LB_POLICY_GRPCLB_GRPCLB_H
+#define GRPC_CORE_EXT_FILTERS_CLIENT_CHANNEL_LB_POLICY_GRPCLB_GRPCLB_H
+
+#include <grpc/support/port_platform.h>
+
+/** Channel arg indicating if a target corresponding to the address is grpclb
+ * loadbalancer. The type of this arg is an integer and the value is treated as
+ * a bool. */
+#define GRPC_ARG_ADDRESS_IS_GRPCLB_LOAD_BALANCER \
+  "grpc.address_is_grpclb_load_balancer"
+/** Channel arg indicating if a target corresponding to the address is a backend
+ * received from a balancer. The type of this arg is an integer and the value is
+ * treated as a bool. */
+#define GRPC_ARG_ADDRESS_IS_BACKEND_FROM_GRPCLB_LOAD_BALANCER \
+  "grpc.address_is_backend_from_grpclb_load_balancer"
+
+#endif /* GRPC_CORE_EXT_FILTERS_CLIENT_CHANNEL_LB_POLICY_GRPCLB_GRPCLB_H \
+        */
diff --git a/src/core/ext/filters/client_channel/lb_policy/pick_first/pick_first.cc b/src/core/ext/filters/client_channel/lb_policy/pick_first/pick_first.cc
index 9090c34412..76df976698 100644
--- a/src/core/ext/filters/client_channel/lb_policy/pick_first/pick_first.cc
+++ b/src/core/ext/filters/client_channel/lb_policy/pick_first/pick_first.cc
@@ -62,31 +62,65 @@ class PickFirst : public LoadBalancingPolicy {
  private:
   ~PickFirst();
 
+  class PickFirstSubchannelList;
+
+  class PickFirstSubchannelData
+      : public SubchannelData<PickFirstSubchannelList,
+                              PickFirstSubchannelData> {
+   public:
+    PickFirstSubchannelData(PickFirstSubchannelList* subchannel_list,
+                            const grpc_lb_user_data_vtable* user_data_vtable,
+                            const grpc_lb_address& address,
+                            grpc_subchannel* subchannel,
+                            grpc_combiner* combiner)
+        : SubchannelData(subchannel_list, user_data_vtable, address, subchannel,
+                         combiner) {}
+
+    void ProcessConnectivityChangeLocked(
+        grpc_connectivity_state connectivity_state, grpc_error* error) override;
+  };
+
+  class PickFirstSubchannelList
+      : public SubchannelList<PickFirstSubchannelList,
+                              PickFirstSubchannelData> {
+   public:
+    PickFirstSubchannelList(PickFirst* policy, TraceFlag* tracer,
+                            const grpc_lb_addresses* addresses,
+                            grpc_combiner* combiner,
+                            grpc_client_channel_factory* client_channel_factory,
+                            const grpc_channel_args& args)
+        : SubchannelList(policy, tracer, addresses, combiner,
+                         client_channel_factory, args) {
+      // Need to maintain a ref to the LB policy as long as we maintain
+      // any references to subchannels, since the subchannels'
+      // pollset_sets will include the LB policy's pollset_set.
+      policy->Ref(DEBUG_LOCATION, "subchannel_list").release();
+    }
+
+    ~PickFirstSubchannelList() {
+      PickFirst* p = static_cast<PickFirst*>(policy());
+      p->Unref(DEBUG_LOCATION, "subchannel_list");
+    }
+  };
+
   void ShutdownLocked() override;
 
   void StartPickingLocked();
   void DestroyUnselectedSubchannelsLocked();
 
-  static void OnConnectivityChangedLocked(void* arg, grpc_error* error);
-
-  void SubchannelListRefForConnectivityWatch(
-      grpc_lb_subchannel_list* subchannel_list, const char* reason);
-  void SubchannelListUnrefForConnectivityWatch(
-      grpc_lb_subchannel_list* subchannel_list, const char* reason);
-
-  /** all our subchannels */
-  grpc_lb_subchannel_list* subchannel_list_ = nullptr;
-  /** latest pending subchannel list */
-  grpc_lb_subchannel_list* latest_pending_subchannel_list_ = nullptr;
-  /** selected subchannel in \a subchannel_list */
-  grpc_lb_subchannel_data* selected_ = nullptr;
-  /** have we started picking? */
+  // All our subchannels.
+  OrphanablePtr<PickFirstSubchannelList> subchannel_list_;
+  // Latest pending subchannel list.
+  OrphanablePtr<PickFirstSubchannelList> latest_pending_subchannel_list_;
+  // Selected subchannel in \a subchannel_list_.
+  PickFirstSubchannelData* selected_ = nullptr;
+  // Have we started picking?
   bool started_picking_ = false;
-  /** are we shut down? */
+  // Are we shut down?
   bool shutdown_ = false;
-  /** list of picks that are waiting on connectivity */
+  // List of picks that are waiting on connectivity.
   PickState* pending_picks_ = nullptr;
-  /** our connectivity state tracker */
+  // Our connectivity state tracker.
   grpc_connectivity_state_tracker state_tracker_;
 };
 
@@ -95,7 +129,7 @@ PickFirst::PickFirst(const Args& args) : LoadBalancingPolicy(args) {
   grpc_connectivity_state_init(&state_tracker_, GRPC_CHANNEL_IDLE,
                                "pick_first");
   if (grpc_lb_pick_first_trace.enabled()) {
-    gpr_log(GPR_DEBUG, "Pick First %p created.", this);
+    gpr_log(GPR_INFO, "Pick First %p created.", this);
   }
   UpdateLocked(*args.args);
   grpc_subchannel_index_ref();
@@ -103,7 +137,7 @@ PickFirst::PickFirst(const Args& args) : LoadBalancingPolicy(args) {
 
 PickFirst::~PickFirst() {
   if (grpc_lb_pick_first_trace.enabled()) {
-    gpr_log(GPR_DEBUG, "Destroying Pick First %p", this);
+    gpr_log(GPR_INFO, "Destroying Pick First %p", this);
   }
   GPR_ASSERT(subchannel_list_ == nullptr);
   GPR_ASSERT(latest_pending_subchannel_list_ == nullptr);
@@ -126,7 +160,7 @@ void PickFirst::HandOffPendingPicksLocked(LoadBalancingPolicy* new_policy) {
 void PickFirst::ShutdownLocked() {
   grpc_error* error = GRPC_ERROR_CREATE_FROM_STATIC_STRING("Channel shutdown");
   if (grpc_lb_pick_first_trace.enabled()) {
-    gpr_log(GPR_DEBUG, "Pick First %p Shutting down", this);
+    gpr_log(GPR_INFO, "Pick First %p Shutting down", this);
   }
   shutdown_ = true;
   PickState* pick;
@@ -137,15 +171,8 @@ void PickFirst::ShutdownLocked() {
   }
   grpc_connectivity_state_set(&state_tracker_, GRPC_CHANNEL_SHUTDOWN,
                               GRPC_ERROR_REF(error), "shutdown");
-  if (subchannel_list_ != nullptr) {
-    grpc_lb_subchannel_list_shutdown_and_unref(subchannel_list_, "pf_shutdown");
-    subchannel_list_ = nullptr;
-  }
-  if (latest_pending_subchannel_list_ != nullptr) {
-    grpc_lb_subchannel_list_shutdown_and_unref(latest_pending_subchannel_list_,
-                                               "pf_shutdown");
-    latest_pending_subchannel_list_ = nullptr;
-  }
+  subchannel_list_.reset();
+  latest_pending_subchannel_list_.reset();
   TryReresolutionLocked(&grpc_lb_pick_first_trace, GRPC_ERROR_CANCELLED);
   GRPC_ERROR_UNREF(error);
 }
@@ -192,14 +219,10 @@ void PickFirst::CancelMatchingPicksLocked(uint32_t initial_metadata_flags_mask,
 
 void PickFirst::StartPickingLocked() {
   started_picking_ = true;
-  if (subchannel_list_ != nullptr && subchannel_list_->num_subchannels > 0) {
-    subchannel_list_->checking_subchannel = 0;
-    for (size_t i = 0; i < subchannel_list_->num_subchannels; ++i) {
-      if (subchannel_list_->subchannels[i].subchannel != nullptr) {
-        SubchannelListRefForConnectivityWatch(
-            subchannel_list_, "connectivity_watch+start_picking");
-        grpc_lb_subchannel_data_start_connectivity_watch(
-            &subchannel_list_->subchannels[i]);
+  if (subchannel_list_ != nullptr) {
+    for (size_t i = 0; i < subchannel_list_->num_subchannels(); ++i) {
+      if (subchannel_list_->subchannel(i)->subchannel() != nullptr) {
+        subchannel_list_->subchannel(i)->StartConnectivityWatchLocked();
         break;
       }
     }
@@ -215,7 +238,7 @@ void PickFirst::ExitIdleLocked() {
 bool PickFirst::PickLocked(PickState* pick) {
   // If we have a selected subchannel already, return synchronously.
   if (selected_ != nullptr) {
-    pick->connected_subchannel = selected_->connected_subchannel;
+    pick->connected_subchannel = selected_->connected_subchannel()->Ref();
     return true;
   }
   // No subchannel selected yet, so handle asynchronously.
@@ -228,11 +251,10 @@ bool PickFirst::PickLocked(PickState* pick) {
 }
 
 void PickFirst::DestroyUnselectedSubchannelsLocked() {
-  for (size_t i = 0; i < subchannel_list_->num_subchannels; ++i) {
-    grpc_lb_subchannel_data* sd = &subchannel_list_->subchannels[i];
+  for (size_t i = 0; i < subchannel_list_->num_subchannels(); ++i) {
+    PickFirstSubchannelData* sd = subchannel_list_->subchannel(i);
     if (selected_ != sd) {
-      grpc_lb_subchannel_data_unref_subchannel(sd,
-                                               "selected_different_subchannel");
+      sd->UnrefSubchannelLocked("selected_different_subchannel");
     }
   }
 }
@@ -249,7 +271,7 @@ void PickFirst::NotifyOnStateChangeLocked(grpc_connectivity_state* current,
 
 void PickFirst::PingOneLocked(grpc_closure* on_initiate, grpc_closure* on_ack) {
   if (selected_ != nullptr) {
-    selected_->connected_subchannel->Ping(on_initiate, on_ack);
+    selected_->connected_subchannel()->Ping(on_initiate, on_ack);
   } else {
     GRPC_CLOSURE_SCHED(on_initiate,
                        GRPC_ERROR_CREATE_FROM_STATIC_STRING("Not connected"));
@@ -258,24 +280,6 @@ void PickFirst::PingOneLocked(grpc_closure* on_initiate, grpc_closure* on_ack) {
   }
 }
 
-void PickFirst::SubchannelListRefForConnectivityWatch(
-    grpc_lb_subchannel_list* subchannel_list, const char* reason) {
-  // TODO(roth): We currently track this ref manually.  Once the new
-  // ClosureRef API is ready and the subchannel_list code has been
-  // converted to a C++ API, find a way to hold the RefCountedPtr<>
-  // somewhere (maybe in the subchannel_data object) instead of doing
-  // this manually.
-  auto self = Ref(DEBUG_LOCATION, reason);
-  self.release();
-  grpc_lb_subchannel_list_ref(subchannel_list, reason);
-}
-
-void PickFirst::SubchannelListUnrefForConnectivityWatch(
-    grpc_lb_subchannel_list* subchannel_list, const char* reason) {
-  Unref(DEBUG_LOCATION, reason);
-  grpc_lb_subchannel_list_unref(subchannel_list, reason);
-}
-
 void PickFirst::UpdateLocked(const grpc_channel_args& args) {
   const grpc_arg* arg = grpc_channel_args_find(&args, GRPC_ARG_LB_ADDRESSES);
   if (arg == nullptr || arg->type != GRPC_ARG_POINTER) {
@@ -295,75 +299,67 @@ void PickFirst::UpdateLocked(const grpc_channel_args& args) {
     return;
   }
   const grpc_lb_addresses* addresses =
-      (const grpc_lb_addresses*)arg->value.pointer.p;
+      static_cast<const grpc_lb_addresses*>(arg->value.pointer.p);
   if (grpc_lb_pick_first_trace.enabled()) {
     gpr_log(GPR_INFO,
             "Pick First %p received update with %" PRIuPTR " addresses", this,
             addresses->num_addresses);
   }
-  grpc_lb_subchannel_list* subchannel_list = grpc_lb_subchannel_list_create(
+  auto subchannel_list = MakeOrphanable<PickFirstSubchannelList>(
       this, &grpc_lb_pick_first_trace, addresses, combiner(),
-      client_channel_factory(), args, &PickFirst::OnConnectivityChangedLocked);
-  if (subchannel_list->num_subchannels == 0) {
+      client_channel_factory(), args);
+  if (subchannel_list->num_subchannels() == 0) {
     // Empty update or no valid subchannels. Unsubscribe from all current
     // subchannels and put the channel in TRANSIENT_FAILURE.
     grpc_connectivity_state_set(
         &state_tracker_, GRPC_CHANNEL_TRANSIENT_FAILURE,
         GRPC_ERROR_CREATE_FROM_STATIC_STRING("Empty update"),
         "pf_update_empty");
-    if (subchannel_list_ != nullptr) {
-      grpc_lb_subchannel_list_shutdown_and_unref(subchannel_list_,
-                                                 "sl_shutdown_empty_update");
-    }
-    subchannel_list_ = subchannel_list;  // Empty list.
+    subchannel_list_ = std::move(subchannel_list);  // Empty list.
     selected_ = nullptr;
     return;
   }
   if (selected_ == nullptr) {
     // We don't yet have a selected subchannel, so replace the current
     // subchannel list immediately.
-    if (subchannel_list_ != nullptr) {
-      grpc_lb_subchannel_list_shutdown_and_unref(subchannel_list_,
-                                                 "pf_update_before_selected");
+    subchannel_list_ = std::move(subchannel_list);
+    // If we've started picking, start trying to connect to the first
+    // subchannel in the new list.
+    if (started_picking_) {
+      subchannel_list_->subchannel(0)->StartConnectivityWatchLocked();
     }
-    subchannel_list_ = subchannel_list;
   } else {
     // We do have a selected subchannel.
     // Check if it's present in the new list.  If so, we're done.
-    for (size_t i = 0; i < subchannel_list->num_subchannels; ++i) {
-      grpc_lb_subchannel_data* sd = &subchannel_list->subchannels[i];
-      if (sd->subchannel == selected_->subchannel) {
+    for (size_t i = 0; i < subchannel_list->num_subchannels(); ++i) {
+      PickFirstSubchannelData* sd = subchannel_list->subchannel(i);
+      if (sd->subchannel() == selected_->subchannel()) {
         // The currently selected subchannel is in the update: we are done.
         if (grpc_lb_pick_first_trace.enabled()) {
           gpr_log(GPR_INFO,
                   "Pick First %p found already selected subchannel %p "
                   "at update index %" PRIuPTR " of %" PRIuPTR "; update done",
-                  this, selected_->subchannel, i,
-                  subchannel_list->num_subchannels);
-        }
-        if (selected_->connected_subchannel != nullptr) {
-          sd->connected_subchannel = selected_->connected_subchannel;
+                  this, selected_->subchannel(), i,
+                  subchannel_list->num_subchannels());
         }
-        selected_ = sd;
-        if (subchannel_list_ != nullptr) {
-          grpc_lb_subchannel_list_shutdown_and_unref(
-              subchannel_list_, "pf_update_includes_selected");
+        // Make sure it's in state READY.  It might not be if we grabbed
+        // the combiner while a connectivity state notification
+        // informing us otherwise is pending.
+        // Note that CheckConnectivityStateLocked() also takes a ref to
+        // the connected subchannel.
+        grpc_error* error = GRPC_ERROR_NONE;
+        if (sd->CheckConnectivityStateLocked(&error) == GRPC_CHANNEL_READY) {
+          selected_ = sd;
+          subchannel_list_ = std::move(subchannel_list);
+          DestroyUnselectedSubchannelsLocked();
+          sd->StartConnectivityWatchLocked();
+          // If there was a previously pending update (which may or may
+          // not have contained the currently selected subchannel), drop
+          // it, so that it doesn't override what we've done here.
+          latest_pending_subchannel_list_.reset();
+          return;
         }
-        subchannel_list_ = subchannel_list;
-        DestroyUnselectedSubchannelsLocked();
-        SubchannelListRefForConnectivityWatch(
-            subchannel_list, "connectivity_watch+replace_selected");
-        grpc_lb_subchannel_data_start_connectivity_watch(sd);
-        // If there was a previously pending update (which may or may
-        // not have contained the currently selected subchannel), drop
-        // it, so that it doesn't override what we've done here.
-        if (latest_pending_subchannel_list_ != nullptr) {
-          grpc_lb_subchannel_list_shutdown_and_unref(
-              latest_pending_subchannel_list_,
-              "pf_update_includes_selected+outdated");
-          latest_pending_subchannel_list_ = nullptr;
-        }
-        return;
+        GRPC_ERROR_UNREF(error);
       }
     }
     // Not keeping the previous selected subchannel, so set the latest
@@ -372,88 +368,66 @@ void PickFirst::UpdateLocked(const grpc_channel_args& args) {
     // subchannel list.
     if (latest_pending_subchannel_list_ != nullptr) {
       if (grpc_lb_pick_first_trace.enabled()) {
-        gpr_log(GPR_DEBUG,
+        gpr_log(GPR_INFO,
                 "Pick First %p Shutting down latest pending subchannel list "
                 "%p, about to be replaced by newer latest %p",
-                this, latest_pending_subchannel_list_, subchannel_list);
+                this, latest_pending_subchannel_list_.get(),
+                subchannel_list.get());
       }
-      grpc_lb_subchannel_list_shutdown_and_unref(
-          latest_pending_subchannel_list_, "sl_outdated_dont_smash");
     }
-    latest_pending_subchannel_list_ = subchannel_list;
-  }
-  // If we've started picking, start trying to connect to the first
-  // subchannel in the new list.
-  if (started_picking_) {
-    SubchannelListRefForConnectivityWatch(subchannel_list,
-                                          "connectivity_watch+update");
-    grpc_lb_subchannel_data_start_connectivity_watch(
-        &subchannel_list->subchannels[0]);
+    latest_pending_subchannel_list_ = std::move(subchannel_list);
+    // If we've started picking, start trying to connect to the first
+    // subchannel in the new list.
+    if (started_picking_) {
+      latest_pending_subchannel_list_->subchannel(0)
+          ->StartConnectivityWatchLocked();
+    }
   }
 }
 
-void PickFirst::OnConnectivityChangedLocked(void* arg, grpc_error* error) {
-  grpc_lb_subchannel_data* sd = static_cast<grpc_lb_subchannel_data*>(arg);
-  PickFirst* p = static_cast<PickFirst*>(sd->subchannel_list->policy);
-  if (grpc_lb_pick_first_trace.enabled()) {
-    gpr_log(GPR_DEBUG,
-            "Pick First %p connectivity changed for subchannel %p (%" PRIuPTR
-            " of %" PRIuPTR
-            "), subchannel_list %p: state=%s p->shutdown_=%d "
-            "sd->subchannel_list->shutting_down=%d error=%s",
-            p, sd->subchannel, sd->subchannel_list->checking_subchannel,
-            sd->subchannel_list->num_subchannels, sd->subchannel_list,
-            grpc_connectivity_state_name(sd->pending_connectivity_state_unsafe),
-            p->shutdown_, sd->subchannel_list->shutting_down,
-            grpc_error_string(error));
-  }
-  // If the policy is shutting down, unref and return.
-  if (p->shutdown_) {
-    grpc_lb_subchannel_data_stop_connectivity_watch(sd);
-    grpc_lb_subchannel_data_unref_subchannel(sd, "pf_shutdown");
-    p->SubchannelListUnrefForConnectivityWatch(sd->subchannel_list,
-                                               "pf_shutdown");
-    return;
-  }
-  // If the subchannel list is shutting down, stop watching.
-  if (sd->subchannel_list->shutting_down || error == GRPC_ERROR_CANCELLED) {
-    grpc_lb_subchannel_data_stop_connectivity_watch(sd);
-    grpc_lb_subchannel_data_unref_subchannel(sd, "pf_sl_shutdown");
-    p->SubchannelListUnrefForConnectivityWatch(sd->subchannel_list,
-                                               "pf_sl_shutdown");
-    return;
-  }
-  // If we're still here, the notification must be for a subchannel in
-  // either the current or latest pending subchannel lists.
-  GPR_ASSERT(sd->subchannel_list == p->subchannel_list_ ||
-             sd->subchannel_list == p->latest_pending_subchannel_list_);
-  // Update state.
-  sd->curr_connectivity_state = sd->pending_connectivity_state_unsafe;
+void PickFirst::PickFirstSubchannelData::ProcessConnectivityChangeLocked(
+    grpc_connectivity_state connectivity_state, grpc_error* error) {
+  PickFirst* p = static_cast<PickFirst*>(subchannel_list()->policy());
+  // The notification must be for a subchannel in either the current or
+  // latest pending subchannel lists.
+  GPR_ASSERT(subchannel_list() == p->subchannel_list_.get() ||
+             subchannel_list() == p->latest_pending_subchannel_list_.get());
   // Handle updates for the currently selected subchannel.
-  if (p->selected_ == sd) {
+  if (p->selected_ == this) {
+    if (grpc_lb_pick_first_trace.enabled()) {
+      gpr_log(GPR_INFO,
+              "Pick First %p connectivity changed for selected subchannel", p);
+    }
     // If the new state is anything other than READY and there is a
     // pending update, switch to the pending update.
-    if (sd->curr_connectivity_state != GRPC_CHANNEL_READY &&
+    if (connectivity_state != GRPC_CHANNEL_READY &&
         p->latest_pending_subchannel_list_ != nullptr) {
+      if (grpc_lb_pick_first_trace.enabled()) {
+        gpr_log(GPR_INFO,
+                "Pick First %p promoting pending subchannel list %p to "
+                "replace %p",
+                p, p->latest_pending_subchannel_list_.get(),
+                p->subchannel_list_.get());
+      }
       p->selected_ = nullptr;
-      grpc_lb_subchannel_data_stop_connectivity_watch(sd);
-      p->SubchannelListUnrefForConnectivityWatch(
-          sd->subchannel_list, "selected_not_ready+switch_to_update");
-      grpc_lb_subchannel_list_shutdown_and_unref(
-          p->subchannel_list_, "selected_not_ready+switch_to_update");
-      p->subchannel_list_ = p->latest_pending_subchannel_list_;
-      p->latest_pending_subchannel_list_ = nullptr;
+      StopConnectivityWatchLocked();
+      p->subchannel_list_ = std::move(p->latest_pending_subchannel_list_);
       grpc_connectivity_state_set(
           &p->state_tracker_, GRPC_CHANNEL_TRANSIENT_FAILURE,
-          GRPC_ERROR_REF(error), "selected_not_ready+switch_to_update");
+          error != GRPC_ERROR_NONE
+              ? GRPC_ERROR_REF(error)
+              : GRPC_ERROR_CREATE_FROM_STATIC_STRING(
+                    "selected subchannel not ready; switching to pending "
+                    "update"),
+          "selected_not_ready+switch_to_update");
     } else {
       // TODO(juanlishen): we re-resolve when the selected subchannel goes to
       // TRANSIENT_FAILURE because we used to shut down in this case before
       // re-resolution is introduced. But we need to investigate whether we
       // really want to take any action instead of waiting for the selected
       // subchannel reconnecting.
-      GPR_ASSERT(sd->curr_connectivity_state != GRPC_CHANNEL_SHUTDOWN);
-      if (sd->curr_connectivity_state == GRPC_CHANNEL_TRANSIENT_FAILURE) {
+      GPR_ASSERT(connectivity_state != GRPC_CHANNEL_SHUTDOWN);
+      if (connectivity_state == GRPC_CHANNEL_TRANSIENT_FAILURE) {
         // If the selected channel goes bad, request a re-resolution.
         grpc_connectivity_state_set(&p->state_tracker_, GRPC_CHANNEL_IDLE,
                                     GRPC_ERROR_NONE,
@@ -462,19 +436,16 @@ void PickFirst::OnConnectivityChangedLocked(void* arg, grpc_error* error) {
         p->TryReresolutionLocked(&grpc_lb_pick_first_trace, GRPC_ERROR_NONE);
         // In transient failure. Rely on re-resolution to recover.
         p->selected_ = nullptr;
-        grpc_lb_subchannel_data_stop_connectivity_watch(sd);
-        p->SubchannelListUnrefForConnectivityWatch(sd->subchannel_list,
-                                                   "pf_selected_shutdown");
-        grpc_lb_subchannel_data_unref_subchannel(
-            sd, "pf_selected_shutdown");  // Unrefs connected subchannel
+        UnrefSubchannelLocked("pf_selected_shutdown");
+        StopConnectivityWatchLocked();
       } else {
-        grpc_connectivity_state_set(&p->state_tracker_,
-                                    sd->curr_connectivity_state,
+        grpc_connectivity_state_set(&p->state_tracker_, connectivity_state,
                                     GRPC_ERROR_REF(error), "selected_changed");
         // Renew notification.
-        grpc_lb_subchannel_data_start_connectivity_watch(sd);
+        RenewConnectivityWatchLocked();
       }
     }
+    GRPC_ERROR_UNREF(error);
     return;
   }
   // If we get here, there are two possible cases:
@@ -486,26 +457,27 @@ void PickFirst::OnConnectivityChangedLocked(void* arg, grpc_error* error) {
   //    for a subchannel in p->latest_pending_subchannel_list_.  The
   //    goal here is to find a subchannel from the update that we can
   //    select in place of the current one.
-  switch (sd->curr_connectivity_state) {
+  switch (connectivity_state) {
     case GRPC_CHANNEL_READY: {
       // Case 2.  Promote p->latest_pending_subchannel_list_ to
       // p->subchannel_list_.
-      sd->connected_subchannel =
-          grpc_subchannel_get_connected_subchannel(sd->subchannel);
-      if (sd->subchannel_list == p->latest_pending_subchannel_list_) {
-        GPR_ASSERT(p->subchannel_list_ != nullptr);
-        grpc_lb_subchannel_list_shutdown_and_unref(p->subchannel_list_,
-                                                   "finish_update");
-        p->subchannel_list_ = p->latest_pending_subchannel_list_;
-        p->latest_pending_subchannel_list_ = nullptr;
+      if (subchannel_list() == p->latest_pending_subchannel_list_.get()) {
+        if (grpc_lb_pick_first_trace.enabled()) {
+          gpr_log(GPR_INFO,
+                  "Pick First %p promoting pending subchannel list %p to "
+                  "replace %p",
+                  p, p->latest_pending_subchannel_list_.get(),
+                  p->subchannel_list_.get());
+        }
+        p->subchannel_list_ = std::move(p->latest_pending_subchannel_list_);
       }
       // Cases 1 and 2.
       grpc_connectivity_state_set(&p->state_tracker_, GRPC_CHANNEL_READY,
                                   GRPC_ERROR_NONE, "connecting_ready");
-      p->selected_ = sd;
+      p->selected_ = this;
       if (grpc_lb_pick_first_trace.enabled()) {
         gpr_log(GPR_INFO, "Pick First %p selected subchannel %p", p,
-                sd->subchannel);
+                subchannel());
       }
       // Drop all other subchannels, since we are now connected.
       p->DestroyUnselectedSubchannelsLocked();
@@ -513,7 +485,8 @@ void PickFirst::OnConnectivityChangedLocked(void* arg, grpc_error* error) {
       PickState* pick;
       while ((pick = p->pending_picks_)) {
         p->pending_picks_ = pick->next;
-        pick->connected_subchannel = p->selected_->connected_subchannel;
+        pick->connected_subchannel =
+            p->selected_->connected_subchannel()->Ref();
         if (grpc_lb_pick_first_trace.enabled()) {
           gpr_log(GPR_INFO,
                   "Servicing pending pick with selected subchannel %p",
@@ -522,45 +495,43 @@ void PickFirst::OnConnectivityChangedLocked(void* arg, grpc_error* error) {
         GRPC_CLOSURE_SCHED(pick->on_complete, GRPC_ERROR_NONE);
       }
       // Renew notification.
-      grpc_lb_subchannel_data_start_connectivity_watch(sd);
+      RenewConnectivityWatchLocked();
       break;
     }
     case GRPC_CHANNEL_TRANSIENT_FAILURE: {
-      grpc_lb_subchannel_data_stop_connectivity_watch(sd);
+      StopConnectivityWatchLocked();
+      PickFirstSubchannelData* sd = this;
       do {
-        sd->subchannel_list->checking_subchannel =
-            (sd->subchannel_list->checking_subchannel + 1) %
-            sd->subchannel_list->num_subchannels;
-        sd = &sd->subchannel_list
-                  ->subchannels[sd->subchannel_list->checking_subchannel];
-      } while (sd->subchannel == nullptr);
+        size_t next_index =
+            (sd->Index() + 1) % subchannel_list()->num_subchannels();
+        sd = subchannel_list()->subchannel(next_index);
+      } while (sd->subchannel() == nullptr);
       // Case 1: Only set state to TRANSIENT_FAILURE if we've tried
       // all subchannels.
-      if (sd->subchannel_list->checking_subchannel == 0 &&
-          sd->subchannel_list == p->subchannel_list_) {
+      if (sd->Index() == 0 && subchannel_list() == p->subchannel_list_.get()) {
         grpc_connectivity_state_set(
             &p->state_tracker_, GRPC_CHANNEL_TRANSIENT_FAILURE,
             GRPC_ERROR_REF(error), "connecting_transient_failure");
       }
-      // Reuses the connectivity refs from the previous watch.
-      grpc_lb_subchannel_data_start_connectivity_watch(sd);
+      sd->StartConnectivityWatchLocked();
       break;
     }
     case GRPC_CHANNEL_CONNECTING:
     case GRPC_CHANNEL_IDLE: {
       // Only update connectivity state in case 1.
-      if (sd->subchannel_list == p->subchannel_list_) {
+      if (subchannel_list() == p->subchannel_list_.get()) {
         grpc_connectivity_state_set(&p->state_tracker_, GRPC_CHANNEL_CONNECTING,
                                     GRPC_ERROR_REF(error),
                                     "connecting_changed");
       }
       // Renew notification.
-      grpc_lb_subchannel_data_start_connectivity_watch(sd);
+      RenewConnectivityWatchLocked();
       break;
     }
     case GRPC_CHANNEL_SHUTDOWN:
       GPR_UNREACHABLE_CODE(break);
   }
+  GRPC_ERROR_UNREF(error);
 }
 
 //
diff --git a/src/core/ext/filters/client_channel/lb_policy/round_robin/round_robin.cc b/src/core/ext/filters/client_channel/lb_policy/round_robin/round_robin.cc
index e534131c02..79e8ad5663 100644
--- a/src/core/ext/filters/client_channel/lb_policy/round_robin/round_robin.cc
+++ b/src/core/ext/filters/client_channel/lb_policy/round_robin/round_robin.cc
@@ -73,23 +73,127 @@ class RoundRobin : public LoadBalancingPolicy {
  private:
   ~RoundRobin();
 
-  void ShutdownLocked() override;
+  // Forward declaration.
+  class RoundRobinSubchannelList;
+
+  // Data for a particular subchannel in a subchannel list.
+  // This subclass adds the following functionality:
+  // - Tracks user_data associated with each address, which will be
+  //   returned along with picks that select the subchannel.
+  // - Tracks the previous connectivity state of the subchannel, so that
+  //   we know how many subchannels are in each state.
+  class RoundRobinSubchannelData
+      : public SubchannelData<RoundRobinSubchannelList,
+                              RoundRobinSubchannelData> {
+   public:
+    RoundRobinSubchannelData(RoundRobinSubchannelList* subchannel_list,
+                             const grpc_lb_user_data_vtable* user_data_vtable,
+                             const grpc_lb_address& address,
+                             grpc_subchannel* subchannel,
+                             grpc_combiner* combiner)
+        : SubchannelData(subchannel_list, user_data_vtable, address, subchannel,
+                         combiner),
+          user_data_vtable_(user_data_vtable),
+          user_data_(user_data_vtable_ != nullptr
+                         ? user_data_vtable_->copy(address.user_data)
+                         : nullptr) {}
+
+    void UnrefSubchannelLocked(const char* reason) override {
+      SubchannelData::UnrefSubchannelLocked(reason);
+      if (user_data_ != nullptr) {
+        GPR_ASSERT(user_data_vtable_ != nullptr);
+        user_data_vtable_->destroy(user_data_);
+        user_data_ = nullptr;
+      }
+    }
 
-  void StartPickingLocked();
-  size_t GetNextReadySubchannelIndexLocked();
-  void UpdateLastReadySubchannelIndexLocked(size_t last_ready_index);
-  void UpdateConnectivityStatusLocked(grpc_lb_subchannel_data* sd,
-                                      grpc_error* error);
+    void* user_data() const { return user_data_; }
+
+    grpc_connectivity_state connectivity_state() const {
+      return last_connectivity_state_;
+    }
 
-  static void OnConnectivityChangedLocked(void* arg, grpc_error* error);
+    void UpdateConnectivityStateLocked(
+        grpc_connectivity_state connectivity_state, grpc_error* error);
+
+   private:
+    void ProcessConnectivityChangeLocked(
+        grpc_connectivity_state connectivity_state, grpc_error* error) override;
+
+    const grpc_lb_user_data_vtable* user_data_vtable_;
+    void* user_data_ = nullptr;
+    grpc_connectivity_state last_connectivity_state_ = GRPC_CHANNEL_IDLE;
+  };
+
+  // A list of subchannels.
+  class RoundRobinSubchannelList
+      : public SubchannelList<RoundRobinSubchannelList,
+                              RoundRobinSubchannelData> {
+   public:
+    RoundRobinSubchannelList(
+        RoundRobin* policy, TraceFlag* tracer,
+        const grpc_lb_addresses* addresses, grpc_combiner* combiner,
+        grpc_client_channel_factory* client_channel_factory,
+        const grpc_channel_args& args)
+        : SubchannelList(policy, tracer, addresses, combiner,
+                         client_channel_factory, args) {
+      // Need to maintain a ref to the LB policy as long as we maintain
+      // any references to subchannels, since the subchannels'
+      // pollset_sets will include the LB policy's pollset_set.
+      policy->Ref(DEBUG_LOCATION, "subchannel_list").release();
+    }
 
-  void SubchannelListRefForConnectivityWatch(
-      grpc_lb_subchannel_list* subchannel_list, const char* reason);
-  void SubchannelListUnrefForConnectivityWatch(
-      grpc_lb_subchannel_list* subchannel_list, const char* reason);
+    ~RoundRobinSubchannelList() {
+      GRPC_ERROR_UNREF(last_transient_failure_error_);
+      RoundRobin* p = static_cast<RoundRobin*>(policy());
+      p->Unref(DEBUG_LOCATION, "subchannel_list");
+    }
+
+    // Starts watching the subchannels in this list.
+    void StartWatchingLocked();
+
+    // Updates the counters of subchannels in each state when a
+    // subchannel transitions from old_state to new_state.
+    // transient_failure_error is the error that is reported when
+    // new_state is TRANSIENT_FAILURE.
+    void UpdateStateCountersLocked(grpc_connectivity_state old_state,
+                                   grpc_connectivity_state new_state,
+                                   grpc_error* transient_failure_error);
+
+    // If this subchannel list is the RR policy's current subchannel
+    // list, updates the RR policy's connectivity state based on the
+    // subchannel list's state counters.
+    void MaybeUpdateRoundRobinConnectivityStateLocked();
+
+    // Updates the RR policy's overall state based on the counters of
+    // subchannels in each state.
+    void UpdateRoundRobinStateFromSubchannelStateCountsLocked();
+
+    size_t GetNextReadySubchannelIndexLocked();
+    void UpdateLastReadySubchannelIndexLocked(size_t last_ready_index);
+
+   private:
+    size_t num_ready_ = 0;
+    size_t num_connecting_ = 0;
+    size_t num_transient_failure_ = 0;
+    grpc_error* last_transient_failure_error_ = GRPC_ERROR_NONE;
+    size_t last_ready_index_ = -1;  // Index into list of last pick.
+  };
+
+  void ShutdownLocked() override;
+
+  void StartPickingLocked();
+  bool DoPickLocked(PickState* pick);
+  void DrainPendingPicksLocked();
 
   /** list of subchannels */
-  grpc_lb_subchannel_list* subchannel_list_ = nullptr;
+  OrphanablePtr<RoundRobinSubchannelList> subchannel_list_;
+  /** Latest version of the subchannel list.
+   * Subchannel connectivity callbacks will only promote updated subchannel
+   * lists if they equal \a latest_pending_subchannel_list. In other words,
+   * racing callbacks that reference outdated subchannel lists won't perform any
+   * update. */
+  OrphanablePtr<RoundRobinSubchannelList> latest_pending_subchannel_list_;
   /** have we started picking? */
   bool started_picking_ = false;
   /** are we shutting down? */
@@ -98,14 +202,6 @@ class RoundRobin : public LoadBalancingPolicy {
   PickState* pending_picks_ = nullptr;
   /** our connectivity state tracker */
   grpc_connectivity_state_tracker state_tracker_;
-  /** Index into subchannels for last pick. */
-  size_t last_ready_subchannel_index_ = 0;
-  /** Latest version of the subchannel list.
-   * Subchannel connectivity callbacks will only promote updated subchannel
-   * lists if they equal \a latest_pending_subchannel_list. In other words,
-   * racing callbacks that reference outdated subchannel lists won't perform any
-   * update. */
-  grpc_lb_subchannel_list* latest_pending_subchannel_list_ = nullptr;
 };
 
 RoundRobin::RoundRobin(const Args& args) : LoadBalancingPolicy(args) {
@@ -114,15 +210,15 @@ RoundRobin::RoundRobin(const Args& args) : LoadBalancingPolicy(args) {
                                "round_robin");
   UpdateLocked(*args.args);
   if (grpc_lb_round_robin_trace.enabled()) {
-    gpr_log(GPR_DEBUG, "[RR %p] Created with %" PRIuPTR " subchannels", this,
-            subchannel_list_->num_subchannels);
+    gpr_log(GPR_INFO, "[RR %p] Created with %" PRIuPTR " subchannels", this,
+            subchannel_list_->num_subchannels());
   }
   grpc_subchannel_index_ref();
 }
 
 RoundRobin::~RoundRobin() {
   if (grpc_lb_round_robin_trace.enabled()) {
-    gpr_log(GPR_DEBUG, "[RR %p] Destroying Round Robin policy", this);
+    gpr_log(GPR_INFO, "[RR %p] Destroying Round Robin policy", this);
   }
   GPR_ASSERT(subchannel_list_ == nullptr);
   GPR_ASSERT(latest_pending_subchannel_list_ == nullptr);
@@ -131,68 +227,6 @@ RoundRobin::~RoundRobin() {
   grpc_subchannel_index_unref();
 }
 
-/** Returns the index into p->subchannel_list->subchannels of the next
- * subchannel in READY state, or p->subchannel_list->num_subchannels if no
- * subchannel is READY.
- *
- * Note that this function does *not* update p->last_ready_subchannel_index.
- * The caller must do that if it returns a pick. */
-size_t RoundRobin::GetNextReadySubchannelIndexLocked() {
-  GPR_ASSERT(subchannel_list_ != nullptr);
-  if (grpc_lb_round_robin_trace.enabled()) {
-    gpr_log(GPR_INFO,
-            "[RR %p] getting next ready subchannel (out of %" PRIuPTR
-            "), "
-            "last_ready_subchannel_index=%" PRIuPTR,
-            this, subchannel_list_->num_subchannels,
-            last_ready_subchannel_index_);
-  }
-  for (size_t i = 0; i < subchannel_list_->num_subchannels; ++i) {
-    const size_t index = (i + last_ready_subchannel_index_ + 1) %
-                         subchannel_list_->num_subchannels;
-    if (grpc_lb_round_robin_trace.enabled()) {
-      gpr_log(
-          GPR_DEBUG,
-          "[RR %p] checking subchannel %p, subchannel_list %p, index %" PRIuPTR
-          ": state=%s",
-          this, subchannel_list_->subchannels[index].subchannel,
-          subchannel_list_, index,
-          grpc_connectivity_state_name(
-              subchannel_list_->subchannels[index].curr_connectivity_state));
-    }
-    if (subchannel_list_->subchannels[index].curr_connectivity_state ==
-        GRPC_CHANNEL_READY) {
-      if (grpc_lb_round_robin_trace.enabled()) {
-        gpr_log(GPR_DEBUG,
-                "[RR %p] found next ready subchannel (%p) at index %" PRIuPTR
-                " of subchannel_list %p",
-                this, subchannel_list_->subchannels[index].subchannel, index,
-                subchannel_list_);
-      }
-      return index;
-    }
-  }
-  if (grpc_lb_round_robin_trace.enabled()) {
-    gpr_log(GPR_DEBUG, "[RR %p] no subchannels in ready state", this);
-  }
-  return subchannel_list_->num_subchannels;
-}
-
-// Sets last_ready_subchannel_index_ to last_ready_index.
-void RoundRobin::UpdateLastReadySubchannelIndexLocked(size_t last_ready_index) {
-  GPR_ASSERT(last_ready_index < subchannel_list_->num_subchannels);
-  last_ready_subchannel_index_ = last_ready_index;
-  if (grpc_lb_round_robin_trace.enabled()) {
-    gpr_log(GPR_DEBUG,
-            "[RR %p] setting last_ready_subchannel_index=%" PRIuPTR
-            " (SC %p, CSC %p)",
-            this, last_ready_index,
-            subchannel_list_->subchannels[last_ready_index].subchannel,
-            subchannel_list_->subchannels[last_ready_index]
-                .connected_subchannel.get());
-  }
-}
-
 void RoundRobin::HandOffPendingPicksLocked(LoadBalancingPolicy* new_policy) {
   PickState* pick;
   while ((pick = pending_picks_) != nullptr) {
@@ -207,7 +241,7 @@ void RoundRobin::HandOffPendingPicksLocked(LoadBalancingPolicy* new_policy) {
 void RoundRobin::ShutdownLocked() {
   grpc_error* error = GRPC_ERROR_CREATE_FROM_STATIC_STRING("Channel shutdown");
   if (grpc_lb_round_robin_trace.enabled()) {
-    gpr_log(GPR_DEBUG, "[RR %p] Shutting down", this);
+    gpr_log(GPR_INFO, "[RR %p] Shutting down", this);
   }
   shutdown_ = true;
   PickState* pick;
@@ -218,16 +252,8 @@ void RoundRobin::ShutdownLocked() {
   }
   grpc_connectivity_state_set(&state_tracker_, GRPC_CHANNEL_SHUTDOWN,
                               GRPC_ERROR_REF(error), "rr_shutdown");
-  if (subchannel_list_ != nullptr) {
-    grpc_lb_subchannel_list_shutdown_and_unref(subchannel_list_,
-                                               "sl_shutdown_rr_shutdown");
-    subchannel_list_ = nullptr;
-  }
-  if (latest_pending_subchannel_list_ != nullptr) {
-    grpc_lb_subchannel_list_shutdown_and_unref(
-        latest_pending_subchannel_list_, "sl_shutdown_pending_rr_shutdown");
-    latest_pending_subchannel_list_ = nullptr;
-  }
+  subchannel_list_.reset();
+  latest_pending_subchannel_list_.reset();
   TryReresolutionLocked(&grpc_lb_round_robin_trace, GRPC_ERROR_CANCELLED);
   GRPC_ERROR_UNREF(error);
 }
@@ -273,70 +299,59 @@ void RoundRobin::CancelMatchingPicksLocked(uint32_t initial_metadata_flags_mask,
   GRPC_ERROR_UNREF(error);
 }
 
-void RoundRobin::SubchannelListRefForConnectivityWatch(
-    grpc_lb_subchannel_list* subchannel_list, const char* reason) {
-  // TODO(roth): We currently track this ref manually.  Once the new
-  // ClosureRef API is ready and the subchannel_list code has been
-  // converted to a C++ API, find a way to hold the RefCountedPtr<>
-  // somewhere (maybe in the subchannel_data object) instead of doing
-  // this manually.
-  auto self = Ref(DEBUG_LOCATION, reason);
-  self.release();
-  grpc_lb_subchannel_list_ref(subchannel_list, reason);
+void RoundRobin::StartPickingLocked() {
+  started_picking_ = true;
+  subchannel_list_->StartWatchingLocked();
 }
 
-void RoundRobin::SubchannelListUnrefForConnectivityWatch(
-    grpc_lb_subchannel_list* subchannel_list, const char* reason) {
-  Unref(DEBUG_LOCATION, reason);
-  grpc_lb_subchannel_list_unref(subchannel_list, reason);
+void RoundRobin::ExitIdleLocked() {
+  if (!started_picking_) {
+    StartPickingLocked();
+  }
 }
 
-void RoundRobin::StartPickingLocked() {
-  started_picking_ = true;
-  for (size_t i = 0; i < subchannel_list_->num_subchannels; i++) {
-    if (subchannel_list_->subchannels[i].subchannel != nullptr) {
-      SubchannelListRefForConnectivityWatch(subchannel_list_,
-                                            "connectivity_watch");
-      grpc_lb_subchannel_data_start_connectivity_watch(
-          &subchannel_list_->subchannels[i]);
+bool RoundRobin::DoPickLocked(PickState* pick) {
+  const size_t next_ready_index =
+      subchannel_list_->GetNextReadySubchannelIndexLocked();
+  if (next_ready_index < subchannel_list_->num_subchannels()) {
+    /* readily available, report right away */
+    RoundRobinSubchannelData* sd =
+        subchannel_list_->subchannel(next_ready_index);
+    GPR_ASSERT(sd->connected_subchannel() != nullptr);
+    pick->connected_subchannel = sd->connected_subchannel()->Ref();
+    if (pick->user_data != nullptr) {
+      *pick->user_data = sd->user_data();
     }
+    if (grpc_lb_round_robin_trace.enabled()) {
+      gpr_log(GPR_INFO,
+              "[RR %p] Picked target <-- Subchannel %p (connected %p) (sl %p, "
+              "index %" PRIuPTR ")",
+              this, sd->subchannel(), pick->connected_subchannel.get(),
+              sd->subchannel_list(), next_ready_index);
+    }
+    /* only advance the last picked pointer if the selection was used */
+    subchannel_list_->UpdateLastReadySubchannelIndexLocked(next_ready_index);
+    return true;
   }
+  return false;
 }
 
-void RoundRobin::ExitIdleLocked() {
-  if (!started_picking_) {
-    StartPickingLocked();
+void RoundRobin::DrainPendingPicksLocked() {
+  PickState* pick;
+  while ((pick = pending_picks_)) {
+    pending_picks_ = pick->next;
+    GPR_ASSERT(DoPickLocked(pick));
+    GRPC_CLOSURE_SCHED(pick->on_complete, GRPC_ERROR_NONE);
   }
 }
 
 bool RoundRobin::PickLocked(PickState* pick) {
   if (grpc_lb_round_robin_trace.enabled()) {
-    gpr_log(GPR_DEBUG, "[RR %p] Trying to pick (shutdown: %d)", this,
-            shutdown_);
+    gpr_log(GPR_INFO, "[RR %p] Trying to pick (shutdown: %d)", this, shutdown_);
   }
   GPR_ASSERT(!shutdown_);
   if (subchannel_list_ != nullptr) {
-    const size_t next_ready_index = GetNextReadySubchannelIndexLocked();
-    if (next_ready_index < subchannel_list_->num_subchannels) {
-      /* readily available, report right away */
-      grpc_lb_subchannel_data* sd =
-          &subchannel_list_->subchannels[next_ready_index];
-      pick->connected_subchannel = sd->connected_subchannel;
-      if (pick->user_data != nullptr) {
-        *pick->user_data = sd->user_data;
-      }
-      if (grpc_lb_round_robin_trace.enabled()) {
-        gpr_log(
-            GPR_DEBUG,
-            "[RR %p] Picked target <-- Subchannel %p (connected %p) (sl %p, "
-            "index %" PRIuPTR ")",
-            this, sd->subchannel, pick->connected_subchannel.get(),
-            sd->subchannel_list, next_ready_index);
-      }
-      /* only advance the last picked pointer if the selection was used */
-      UpdateLastReadySubchannelIndexLocked(next_ready_index);
-      return true;
-    }
+    if (DoPickLocked(pick)) return true;
   }
   /* no pick currently available. Save for later in list of pending picks */
   if (!started_picking_) {
@@ -347,36 +362,62 @@ bool RoundRobin::PickLocked(PickState* pick) {
   return false;
 }
 
-void UpdateStateCountersLocked(grpc_lb_subchannel_data* sd) {
-  grpc_lb_subchannel_list* subchannel_list = sd->subchannel_list;
-  GPR_ASSERT(sd->prev_connectivity_state != GRPC_CHANNEL_SHUTDOWN);
-  GPR_ASSERT(sd->curr_connectivity_state != GRPC_CHANNEL_SHUTDOWN);
-  if (sd->prev_connectivity_state == GRPC_CHANNEL_READY) {
-    GPR_ASSERT(subchannel_list->num_ready > 0);
-    --subchannel_list->num_ready;
-  } else if (sd->prev_connectivity_state == GRPC_CHANNEL_TRANSIENT_FAILURE) {
-    GPR_ASSERT(subchannel_list->num_transient_failures > 0);
-    --subchannel_list->num_transient_failures;
-  } else if (sd->prev_connectivity_state == GRPC_CHANNEL_IDLE) {
-    GPR_ASSERT(subchannel_list->num_idle > 0);
-    --subchannel_list->num_idle;
+void RoundRobin::RoundRobinSubchannelList::StartWatchingLocked() {
+  if (num_subchannels() == 0) return;
+  // Check current state of each subchannel synchronously, since any
+  // subchannel already used by some other channel may have a non-IDLE
+  // state.
+  for (size_t i = 0; i < num_subchannels(); ++i) {
+    grpc_error* error = GRPC_ERROR_NONE;
+    grpc_connectivity_state state =
+        subchannel(i)->CheckConnectivityStateLocked(&error);
+    if (state != GRPC_CHANNEL_IDLE) {
+      subchannel(i)->UpdateConnectivityStateLocked(state, error);
+    }
   }
-  sd->prev_connectivity_state = sd->curr_connectivity_state;
-  if (sd->curr_connectivity_state == GRPC_CHANNEL_READY) {
-    ++subchannel_list->num_ready;
-  } else if (sd->curr_connectivity_state == GRPC_CHANNEL_TRANSIENT_FAILURE) {
-    ++subchannel_list->num_transient_failures;
-  } else if (sd->curr_connectivity_state == GRPC_CHANNEL_IDLE) {
-    ++subchannel_list->num_idle;
+  // Now set the LB policy's state based on the subchannels' states.
+  UpdateRoundRobinStateFromSubchannelStateCountsLocked();
+  // Start connectivity watch for each subchannel.
+  for (size_t i = 0; i < num_subchannels(); i++) {
+    if (subchannel(i)->subchannel() != nullptr) {
+      subchannel(i)->StartConnectivityWatchLocked();
+    }
   }
 }
 
-/** Sets the policy's connectivity status based on that of the passed-in \a sd
- * (the grpc_lb_subchannel_data associated with the updated subchannel) and the
- * subchannel list \a sd belongs to (sd->subchannel_list). \a error will be used
- * only if the policy transitions to state TRANSIENT_FAILURE. */
-void RoundRobin::UpdateConnectivityStatusLocked(grpc_lb_subchannel_data* sd,
-                                                grpc_error* error) {
+void RoundRobin::RoundRobinSubchannelList::UpdateStateCountersLocked(
+    grpc_connectivity_state old_state, grpc_connectivity_state new_state,
+    grpc_error* transient_failure_error) {
+  GPR_ASSERT(old_state != GRPC_CHANNEL_SHUTDOWN);
+  GPR_ASSERT(new_state != GRPC_CHANNEL_SHUTDOWN);
+  if (old_state == GRPC_CHANNEL_READY) {
+    GPR_ASSERT(num_ready_ > 0);
+    --num_ready_;
+  } else if (old_state == GRPC_CHANNEL_CONNECTING) {
+    GPR_ASSERT(num_connecting_ > 0);
+    --num_connecting_;
+  } else if (old_state == GRPC_CHANNEL_TRANSIENT_FAILURE) {
+    GPR_ASSERT(num_transient_failure_ > 0);
+    --num_transient_failure_;
+  }
+  if (new_state == GRPC_CHANNEL_READY) {
+    ++num_ready_;
+  } else if (new_state == GRPC_CHANNEL_CONNECTING) {
+    ++num_connecting_;
+  } else if (new_state == GRPC_CHANNEL_TRANSIENT_FAILURE) {
+    ++num_transient_failure_;
+  }
+  GRPC_ERROR_UNREF(last_transient_failure_error_);
+  last_transient_failure_error_ = transient_failure_error;
+}
+
+// Sets the RR policy's connectivity state based on the current
+// subchannel list.
+void RoundRobin::RoundRobinSubchannelList::
+    MaybeUpdateRoundRobinConnectivityStateLocked() {
+  RoundRobin* p = static_cast<RoundRobin*>(policy());
+  // Only set connectivity state if this is the current subchannel list.
+  if (p->subchannel_list_.get() != this) return;
   /* In priority order. The first rule to match terminates the search (ie, if we
    * are on rule n, all previous rules were unfulfilled).
    *
@@ -391,155 +432,151 @@ void RoundRobin::UpdateConnectivityStatusLocked(grpc_lb_subchannel_data* sd,
    *    CHECK: subchannel_list->num_transient_failures ==
    *           subchannel_list->num_subchannels.
    */
-  grpc_lb_subchannel_list* subchannel_list = sd->subchannel_list;
-  GPR_ASSERT(sd->curr_connectivity_state != GRPC_CHANNEL_IDLE);
-  if (subchannel_list->num_ready > 0) {
+  if (num_ready_ > 0) {
     /* 1) READY */
-    grpc_connectivity_state_set(&state_tracker_, GRPC_CHANNEL_READY,
+    grpc_connectivity_state_set(&p->state_tracker_, GRPC_CHANNEL_READY,
                                 GRPC_ERROR_NONE, "rr_ready");
-  } else if (sd->curr_connectivity_state == GRPC_CHANNEL_CONNECTING) {
+  } else if (num_connecting_ > 0) {
     /* 2) CONNECTING */
-    grpc_connectivity_state_set(&state_tracker_, GRPC_CHANNEL_CONNECTING,
+    grpc_connectivity_state_set(&p->state_tracker_, GRPC_CHANNEL_CONNECTING,
                                 GRPC_ERROR_NONE, "rr_connecting");
-  } else if (subchannel_list->num_transient_failures ==
-             subchannel_list->num_subchannels) {
+  } else if (num_transient_failure_ == num_subchannels()) {
     /* 3) TRANSIENT_FAILURE */
-    grpc_connectivity_state_set(&state_tracker_, GRPC_CHANNEL_TRANSIENT_FAILURE,
-                                GRPC_ERROR_REF(error),
+    grpc_connectivity_state_set(&p->state_tracker_,
+                                GRPC_CHANNEL_TRANSIENT_FAILURE,
+                                GRPC_ERROR_REF(last_transient_failure_error_),
                                 "rr_exhausted_subchannels");
   }
-  GRPC_ERROR_UNREF(error);
 }
 
-void RoundRobin::OnConnectivityChangedLocked(void* arg, grpc_error* error) {
-  grpc_lb_subchannel_data* sd = static_cast<grpc_lb_subchannel_data*>(arg);
-  RoundRobin* p = static_cast<RoundRobin*>(sd->subchannel_list->policy);
+void RoundRobin::RoundRobinSubchannelList::
+    UpdateRoundRobinStateFromSubchannelStateCountsLocked() {
+  RoundRobin* p = static_cast<RoundRobin*>(policy());
+  if (num_ready_ > 0) {
+    if (p->subchannel_list_.get() != this) {
+      // Promote this list to p->subchannel_list_.
+      // This list must be p->latest_pending_subchannel_list_, because
+      // any previous update would have been shut down already and
+      // therefore we would not be receiving a notification for them.
+      GPR_ASSERT(p->latest_pending_subchannel_list_.get() == this);
+      GPR_ASSERT(!shutting_down());
+      if (grpc_lb_round_robin_trace.enabled()) {
+        const size_t old_num_subchannels =
+            p->subchannel_list_ != nullptr
+                ? p->subchannel_list_->num_subchannels()
+                : 0;
+        gpr_log(GPR_INFO,
+                "[RR %p] phasing out subchannel list %p (size %" PRIuPTR
+                ") in favor of %p (size %" PRIuPTR ")",
+                p, p->subchannel_list_.get(), old_num_subchannels, this,
+                num_subchannels());
+      }
+      p->subchannel_list_ = std::move(p->latest_pending_subchannel_list_);
+    }
+    // Drain pending picks.
+    p->DrainPendingPicksLocked();
+  }
+  // Update the RR policy's connectivity state if needed.
+  MaybeUpdateRoundRobinConnectivityStateLocked();
+}
+
+void RoundRobin::RoundRobinSubchannelData::UpdateConnectivityStateLocked(
+    grpc_connectivity_state connectivity_state, grpc_error* error) {
+  RoundRobin* p = static_cast<RoundRobin*>(subchannel_list()->policy());
   if (grpc_lb_round_robin_trace.enabled()) {
     gpr_log(
-        GPR_DEBUG,
-        "[RR %p] connectivity changed for subchannel %p, subchannel_list %p: "
-        "prev_state=%s new_state=%s p->shutdown=%d "
-        "sd->subchannel_list->shutting_down=%d error=%s",
-        p, sd->subchannel, sd->subchannel_list,
-        grpc_connectivity_state_name(sd->prev_connectivity_state),
-        grpc_connectivity_state_name(sd->pending_connectivity_state_unsafe),
-        p->shutdown_, sd->subchannel_list->shutting_down,
-        grpc_error_string(error));
-  }
-  GPR_ASSERT(sd->subchannel != nullptr);
-  // If the policy is shutting down, unref and return.
-  if (p->shutdown_) {
-    grpc_lb_subchannel_data_stop_connectivity_watch(sd);
-    grpc_lb_subchannel_data_unref_subchannel(sd, "rr_shutdown");
-    p->SubchannelListUnrefForConnectivityWatch(sd->subchannel_list,
-                                               "rr_shutdown");
-    return;
+        GPR_INFO,
+        "[RR %p] connectivity changed for subchannel %p, subchannel_list %p "
+        "(index %" PRIuPTR " of %" PRIuPTR "): prev_state=%s new_state=%s",
+        p, subchannel(), subchannel_list(), Index(),
+        subchannel_list()->num_subchannels(),
+        grpc_connectivity_state_name(last_connectivity_state_),
+        grpc_connectivity_state_name(connectivity_state));
+  }
+  subchannel_list()->UpdateStateCountersLocked(last_connectivity_state_,
+                                               connectivity_state, error);
+  last_connectivity_state_ = connectivity_state;
+}
+
+void RoundRobin::RoundRobinSubchannelData::ProcessConnectivityChangeLocked(
+    grpc_connectivity_state connectivity_state, grpc_error* error) {
+  RoundRobin* p = static_cast<RoundRobin*>(subchannel_list()->policy());
+  GPR_ASSERT(subchannel() != nullptr);
+  // If the new state is TRANSIENT_FAILURE, re-resolve.
+  // Only do this if we've started watching, not at startup time.
+  // Otherwise, if the subchannel was already in state TRANSIENT_FAILURE
+  // when the subchannel list was created, we'd wind up in a constant
+  // loop of re-resolution.
+  if (connectivity_state == GRPC_CHANNEL_TRANSIENT_FAILURE) {
+    if (grpc_lb_round_robin_trace.enabled()) {
+      gpr_log(GPR_INFO,
+              "[RR %p] Subchannel %p has gone into TRANSIENT_FAILURE. "
+              "Requesting re-resolution",
+              p, subchannel());
+    }
+    p->TryReresolutionLocked(&grpc_lb_round_robin_trace, GRPC_ERROR_NONE);
   }
-  // If the subchannel list is shutting down, stop watching.
-  if (sd->subchannel_list->shutting_down || error == GRPC_ERROR_CANCELLED) {
-    grpc_lb_subchannel_data_stop_connectivity_watch(sd);
-    grpc_lb_subchannel_data_unref_subchannel(sd, "rr_sl_shutdown");
-    p->SubchannelListUnrefForConnectivityWatch(sd->subchannel_list,
-                                               "rr_sl_shutdown");
-    return;
+  // Update state counters.
+  UpdateConnectivityStateLocked(connectivity_state, error);
+  // Update overall state and renew notification.
+  subchannel_list()->UpdateRoundRobinStateFromSubchannelStateCountsLocked();
+  RenewConnectivityWatchLocked();
+}
+
+/** Returns the index into p->subchannel_list->subchannels of the next
+ * subchannel in READY state, or p->subchannel_list->num_subchannels if no
+ * subchannel is READY.
+ *
+ * Note that this function does *not* update p->last_ready_subchannel_index.
+ * The caller must do that if it returns a pick. */
+size_t
+RoundRobin::RoundRobinSubchannelList::GetNextReadySubchannelIndexLocked() {
+  if (grpc_lb_round_robin_trace.enabled()) {
+    gpr_log(GPR_INFO,
+            "[RR %p] getting next ready subchannel (out of %" PRIuPTR
+            "), last_ready_index=%" PRIuPTR,
+            policy(), num_subchannels(), last_ready_index_);
   }
-  // If we're still here, the notification must be for a subchannel in
-  // either the current or latest pending subchannel lists.
-  GPR_ASSERT(sd->subchannel_list == p->subchannel_list_ ||
-             sd->subchannel_list == p->latest_pending_subchannel_list_);
-  GPR_ASSERT(sd->pending_connectivity_state_unsafe != GRPC_CHANNEL_SHUTDOWN);
-  // Now that we're inside the combiner, copy the pending connectivity
-  // state (which was set by the connectivity state watcher) to
-  // curr_connectivity_state, which is what we use inside of the combiner.
-  sd->curr_connectivity_state = sd->pending_connectivity_state_unsafe;
-  // If the sd's new state is TRANSIENT_FAILURE, unref the *connected*
-  // subchannel, if any.
-  switch (sd->curr_connectivity_state) {
-    case GRPC_CHANNEL_TRANSIENT_FAILURE: {
-      sd->connected_subchannel.reset();
-      if (grpc_lb_round_robin_trace.enabled()) {
-        gpr_log(GPR_DEBUG,
-                "[RR %p] Subchannel %p has gone into TRANSIENT_FAILURE. "
-                "Requesting re-resolution",
-                p, sd->subchannel);
-      }
-      p->TryReresolutionLocked(&grpc_lb_round_robin_trace, GRPC_ERROR_NONE);
-      break;
+  for (size_t i = 0; i < num_subchannels(); ++i) {
+    const size_t index = (i + last_ready_index_ + 1) % num_subchannels();
+    if (grpc_lb_round_robin_trace.enabled()) {
+      gpr_log(
+          GPR_INFO,
+          "[RR %p] checking subchannel %p, subchannel_list %p, index %" PRIuPTR
+          ": state=%s",
+          policy(), subchannel(index)->subchannel(), this, index,
+          grpc_connectivity_state_name(
+              subchannel(index)->connectivity_state()));
     }
-    case GRPC_CHANNEL_READY: {
-      if (sd->connected_subchannel == nullptr) {
-        sd->connected_subchannel =
-            grpc_subchannel_get_connected_subchannel(sd->subchannel);
-      }
-      if (sd->subchannel_list != p->subchannel_list_) {
-        // promote sd->subchannel_list to p->subchannel_list_.
-        // sd->subchannel_list must be equal to
-        // p->latest_pending_subchannel_list_ because we have already filtered
-        // for sds belonging to outdated subchannel lists.
-        GPR_ASSERT(sd->subchannel_list == p->latest_pending_subchannel_list_);
-        GPR_ASSERT(!sd->subchannel_list->shutting_down);
-        if (grpc_lb_round_robin_trace.enabled()) {
-          const size_t num_subchannels =
-              p->subchannel_list_ != nullptr
-                  ? p->subchannel_list_->num_subchannels
-                  : 0;
-          gpr_log(GPR_DEBUG,
-                  "[RR %p] phasing out subchannel list %p (size %" PRIuPTR
-                  ") in favor of %p (size %" PRIuPTR ")",
-                  p, p->subchannel_list_, num_subchannels, sd->subchannel_list,
-                  num_subchannels);
-        }
-        if (p->subchannel_list_ != nullptr) {
-          // dispose of the current subchannel_list
-          grpc_lb_subchannel_list_shutdown_and_unref(p->subchannel_list_,
-                                                     "sl_phase_out_shutdown");
-        }
-        p->subchannel_list_ = p->latest_pending_subchannel_list_;
-        p->latest_pending_subchannel_list_ = nullptr;
-      }
-      /* at this point we know there's at least one suitable subchannel. Go
-       * ahead and pick one and notify the pending suitors in
-       * p->pending_picks. This preemptively replicates rr_pick()'s actions. */
-      const size_t next_ready_index = p->GetNextReadySubchannelIndexLocked();
-      GPR_ASSERT(next_ready_index < p->subchannel_list_->num_subchannels);
-      grpc_lb_subchannel_data* selected =
-          &p->subchannel_list_->subchannels[next_ready_index];
-      if (p->pending_picks_ != nullptr) {
-        // if the selected subchannel is going to be used for the pending
-        // picks, update the last picked pointer
-        p->UpdateLastReadySubchannelIndexLocked(next_ready_index);
-      }
-      PickState* pick;
-      while ((pick = p->pending_picks_)) {
-        p->pending_picks_ = pick->next;
-        pick->connected_subchannel = selected->connected_subchannel;
-        if (pick->user_data != nullptr) {
-          *pick->user_data = selected->user_data;
-        }
-        if (grpc_lb_round_robin_trace.enabled()) {
-          gpr_log(GPR_DEBUG,
-                  "[RR %p] Fulfilling pending pick. Target <-- subchannel %p "
-                  "(subchannel_list %p, index %" PRIuPTR ")",
-                  p, selected->subchannel, p->subchannel_list_,
-                  next_ready_index);
-        }
-        GRPC_CLOSURE_SCHED(pick->on_complete, GRPC_ERROR_NONE);
+    if (subchannel(index)->connectivity_state() == GRPC_CHANNEL_READY) {
+      if (grpc_lb_round_robin_trace.enabled()) {
+        gpr_log(GPR_INFO,
+                "[RR %p] found next ready subchannel (%p) at index %" PRIuPTR
+                " of subchannel_list %p",
+                policy(), subchannel(index)->subchannel(), index, this);
       }
-      break;
+      return index;
     }
-    case GRPC_CHANNEL_SHUTDOWN:
-      GPR_UNREACHABLE_CODE(return );
-    case GRPC_CHANNEL_CONNECTING:
-    case GRPC_CHANNEL_IDLE:;  // fallthrough
   }
-  // Update state counters.
-  UpdateStateCountersLocked(sd);
-  // Only update connectivity based on the selected subchannel list.
-  if (sd->subchannel_list == p->subchannel_list_) {
-    p->UpdateConnectivityStatusLocked(sd, GRPC_ERROR_REF(error));
+  if (grpc_lb_round_robin_trace.enabled()) {
+    gpr_log(GPR_INFO, "[RR %p] no subchannels in ready state", this);
+  }
+  return num_subchannels();
+}
+
+// Sets last_ready_index_ to last_ready_index.
+void RoundRobin::RoundRobinSubchannelList::UpdateLastReadySubchannelIndexLocked(
+    size_t last_ready_index) {
+  GPR_ASSERT(last_ready_index < num_subchannels());
+  last_ready_index_ = last_ready_index;
+  if (grpc_lb_round_robin_trace.enabled()) {
+    gpr_log(GPR_INFO,
+            "[RR %p] setting last_ready_subchannel_index=%" PRIuPTR
+            " (SC %p, CSC %p)",
+            policy(), last_ready_index,
+            subchannel(last_ready_index)->subchannel(),
+            subchannel(last_ready_index)->connected_subchannel());
   }
-  // Renew notification.
-  grpc_lb_subchannel_data_start_connectivity_watch(sd);
 }
 
 grpc_connectivity_state RoundRobin::CheckConnectivityLocked(
@@ -555,11 +592,12 @@ void RoundRobin::NotifyOnStateChangeLocked(grpc_connectivity_state* current,
 
 void RoundRobin::PingOneLocked(grpc_closure* on_initiate,
                                grpc_closure* on_ack) {
-  const size_t next_ready_index = GetNextReadySubchannelIndexLocked();
-  if (next_ready_index < subchannel_list_->num_subchannels) {
-    grpc_lb_subchannel_data* selected =
-        &subchannel_list_->subchannels[next_ready_index];
-    selected->connected_subchannel->Ping(on_initiate, on_ack);
+  const size_t next_ready_index =
+      subchannel_list_->GetNextReadySubchannelIndexLocked();
+  if (next_ready_index < subchannel_list_->num_subchannels()) {
+    RoundRobinSubchannelData* selected =
+        subchannel_list_->subchannel(next_ready_index);
+    selected->connected_subchannel()->Ping(on_initiate, on_ack);
   } else {
     GRPC_CLOSURE_SCHED(on_initiate, GRPC_ERROR_CREATE_FROM_STATIC_STRING(
                                         "Round Robin not connected"));
@@ -582,80 +620,37 @@ void RoundRobin::UpdateLocked(const grpc_channel_args& args) {
     }
     return;
   }
-  grpc_lb_addresses* addresses = (grpc_lb_addresses*)arg->value.pointer.p;
+  grpc_lb_addresses* addresses =
+      static_cast<grpc_lb_addresses*>(arg->value.pointer.p);
   if (grpc_lb_round_robin_trace.enabled()) {
-    gpr_log(GPR_DEBUG, "[RR %p] received update with %" PRIuPTR " addresses",
+    gpr_log(GPR_INFO, "[RR %p] received update with %" PRIuPTR " addresses",
             this, addresses->num_addresses);
   }
-  grpc_lb_subchannel_list* subchannel_list = grpc_lb_subchannel_list_create(
-      this, &grpc_lb_round_robin_trace, addresses, combiner(),
-      client_channel_factory(), args, &RoundRobin::OnConnectivityChangedLocked);
-  if (subchannel_list->num_subchannels == 0) {
-    grpc_connectivity_state_set(
-        &state_tracker_, GRPC_CHANNEL_TRANSIENT_FAILURE,
-        GRPC_ERROR_CREATE_FROM_STATIC_STRING("Empty update"),
-        "rr_update_empty");
-    if (subchannel_list_ != nullptr) {
-      grpc_lb_subchannel_list_shutdown_and_unref(subchannel_list_,
-                                                 "sl_shutdown_empty_update");
+  // Replace latest_pending_subchannel_list_.
+  if (latest_pending_subchannel_list_ != nullptr) {
+    if (grpc_lb_round_robin_trace.enabled()) {
+      gpr_log(GPR_INFO,
+              "[RR %p] Shutting down previous pending subchannel list %p", this,
+              latest_pending_subchannel_list_.get());
     }
-    subchannel_list_ = subchannel_list;  // empty list
-    return;
   }
-  if (started_picking_) {
-    for (size_t i = 0; i < subchannel_list->num_subchannels; ++i) {
-      const grpc_connectivity_state subchannel_state =
-          grpc_subchannel_check_connectivity(
-              subchannel_list->subchannels[i].subchannel, nullptr);
-      // Override the default setting of IDLE for connectivity notification
-      // purposes if the subchannel is already in transient failure. Otherwise
-      // we'd be immediately notified of the IDLE-TRANSIENT_FAILURE
-      // discrepancy, attempt to re-resolve and end up here again.
-      // TODO(roth): As part of C++-ifying the subchannel_list API, design a
-      // better API for notifying the LB policy of subchannel states, which can
-      // be used both for the subchannel's initial state and for subsequent
-      // state changes. This will allow us to handle this more generally instead
-      // of special-casing TRANSIENT_FAILURE (e.g., we can also distribute any
-      // pending picks across all READY subchannels rather than sending them all
-      // to the first one).
-      if (subchannel_state == GRPC_CHANNEL_TRANSIENT_FAILURE) {
-        subchannel_list->subchannels[i].pending_connectivity_state_unsafe =
-            subchannel_list->subchannels[i].curr_connectivity_state =
-                subchannel_list->subchannels[i].prev_connectivity_state =
-                    subchannel_state;
-        --subchannel_list->num_idle;
-        ++subchannel_list->num_transient_failures;
-      }
-    }
-    if (latest_pending_subchannel_list_ != nullptr) {
-      if (grpc_lb_round_robin_trace.enabled()) {
-        gpr_log(GPR_DEBUG,
-                "[RR %p] Shutting down latest pending subchannel list %p, "
-                "about to be replaced by newer latest %p",
-                this, latest_pending_subchannel_list_, subchannel_list);
-      }
-      grpc_lb_subchannel_list_shutdown_and_unref(
-          latest_pending_subchannel_list_, "sl_outdated");
-    }
-    latest_pending_subchannel_list_ = subchannel_list;
-    for (size_t i = 0; i < subchannel_list->num_subchannels; ++i) {
-      /* Watch every new subchannel. A subchannel list becomes active the
-       * moment one of its subchannels is READY. At that moment, we swap
-       * p->subchannel_list for sd->subchannel_list, provided the subchannel
-       * list is still valid (ie, isn't shutting down) */
-      SubchannelListRefForConnectivityWatch(subchannel_list,
-                                            "connectivity_watch");
-      grpc_lb_subchannel_data_start_connectivity_watch(
-          &subchannel_list->subchannels[i]);
+  latest_pending_subchannel_list_ = MakeOrphanable<RoundRobinSubchannelList>(
+      this, &grpc_lb_round_robin_trace, addresses, combiner(),
+      client_channel_factory(), args);
+  // If we haven't started picking yet or the new list is empty,
+  // immediately promote the new list to the current list.
+  if (!started_picking_ ||
+      latest_pending_subchannel_list_->num_subchannels() == 0) {
+    if (latest_pending_subchannel_list_->num_subchannels() == 0) {
+      grpc_connectivity_state_set(
+          &state_tracker_, GRPC_CHANNEL_TRANSIENT_FAILURE,
+          GRPC_ERROR_CREATE_FROM_STATIC_STRING("Empty update"),
+          "rr_update_empty");
     }
+    subchannel_list_ = std::move(latest_pending_subchannel_list_);
   } else {
-    // The policy isn't picking yet. Save the update for later, disposing of
-    // previous version if any.
-    if (subchannel_list_ != nullptr) {
-      grpc_lb_subchannel_list_shutdown_and_unref(
-          subchannel_list_, "rr_update_before_started_picking");
-    }
-    subchannel_list_ = subchannel_list;
+    // If we've started picking, start watching the new list.
+    latest_pending_subchannel_list_->StartWatchingLocked();
   }
 }
 
diff --git a/src/core/ext/filters/client_channel/lb_policy/subchannel_list.cc b/src/core/ext/filters/client_channel/lb_policy/subchannel_list.cc
deleted file mode 100644
index 79cb64c6c6..0000000000
--- a/src/core/ext/filters/client_channel/lb_policy/subchannel_list.cc
+++ /dev/null
@@ -1,253 +0,0 @@
-/*
- *
- * Copyright 2015 gRPC authors.
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- *
- */
-
-#include <grpc/support/port_platform.h>
-
-#include <string.h>
-
-#include <grpc/support/alloc.h>
-
-#include "src/core/ext/filters/client_channel/lb_policy/subchannel_list.h"
-#include "src/core/lib/channel/channel_args.h"
-#include "src/core/lib/debug/trace.h"
-#include "src/core/lib/iomgr/closure.h"
-#include "src/core/lib/iomgr/combiner.h"
-#include "src/core/lib/iomgr/sockaddr_utils.h"
-#include "src/core/lib/transport/connectivity_state.h"
-
-void grpc_lb_subchannel_data_unref_subchannel(grpc_lb_subchannel_data* sd,
-                                              const char* reason) {
-  if (sd->subchannel != nullptr) {
-    if (sd->subchannel_list->tracer->enabled()) {
-      gpr_log(GPR_DEBUG,
-              "[%s %p] subchannel list %p index %" PRIuPTR " of %" PRIuPTR
-              " (subchannel %p): unreffing subchannel",
-              sd->subchannel_list->tracer->name(), sd->subchannel_list->policy,
-              sd->subchannel_list,
-              static_cast<size_t>(sd - sd->subchannel_list->subchannels),
-              sd->subchannel_list->num_subchannels, sd->subchannel);
-    }
-    GRPC_SUBCHANNEL_UNREF(sd->subchannel, reason);
-    sd->subchannel = nullptr;
-    sd->connected_subchannel.reset();
-    if (sd->user_data != nullptr) {
-      GPR_ASSERT(sd->user_data_vtable != nullptr);
-      sd->user_data_vtable->destroy(sd->user_data);
-      sd->user_data = nullptr;
-    }
-  }
-}
-
-void grpc_lb_subchannel_data_start_connectivity_watch(
-    grpc_lb_subchannel_data* sd) {
-  if (sd->subchannel_list->tracer->enabled()) {
-    gpr_log(
-        GPR_DEBUG,
-        "[%s %p] subchannel list %p index %" PRIuPTR " of %" PRIuPTR
-        " (subchannel %p): requesting connectivity change "
-        "notification (from %s)",
-        sd->subchannel_list->tracer->name(), sd->subchannel_list->policy,
-        sd->subchannel_list,
-        static_cast<size_t>(sd - sd->subchannel_list->subchannels),
-        sd->subchannel_list->num_subchannels, sd->subchannel,
-        grpc_connectivity_state_name(sd->pending_connectivity_state_unsafe));
-  }
-  sd->connectivity_notification_pending = true;
-  grpc_subchannel_notify_on_state_change(
-      sd->subchannel, sd->subchannel_list->policy->interested_parties(),
-      &sd->pending_connectivity_state_unsafe,
-      &sd->connectivity_changed_closure);
-}
-
-void grpc_lb_subchannel_data_stop_connectivity_watch(
-    grpc_lb_subchannel_data* sd) {
-  if (sd->subchannel_list->tracer->enabled()) {
-    gpr_log(GPR_DEBUG,
-            "[%s %p] subchannel list %p index %" PRIuPTR " of %" PRIuPTR
-            " (subchannel %p): stopping connectivity watch",
-            sd->subchannel_list->tracer->name(), sd->subchannel_list->policy,
-            sd->subchannel_list,
-            static_cast<size_t>(sd - sd->subchannel_list->subchannels),
-            sd->subchannel_list->num_subchannels, sd->subchannel);
-  }
-  GPR_ASSERT(sd->connectivity_notification_pending);
-  sd->connectivity_notification_pending = false;
-}
-
-grpc_lb_subchannel_list* grpc_lb_subchannel_list_create(
-    grpc_core::LoadBalancingPolicy* p, grpc_core::TraceFlag* tracer,
-    const grpc_lb_addresses* addresses, grpc_combiner* combiner,
-    grpc_client_channel_factory* client_channel_factory,
-    const grpc_channel_args& args, grpc_iomgr_cb_func connectivity_changed_cb) {
-  grpc_lb_subchannel_list* subchannel_list =
-      static_cast<grpc_lb_subchannel_list*>(
-          gpr_zalloc(sizeof(*subchannel_list)));
-  if (tracer->enabled()) {
-    gpr_log(GPR_DEBUG,
-            "[%s %p] Creating subchannel list %p for %" PRIuPTR " subchannels",
-            tracer->name(), p, subchannel_list, addresses->num_addresses);
-  }
-  subchannel_list->policy = p;
-  subchannel_list->tracer = tracer;
-  gpr_ref_init(&subchannel_list->refcount, 1);
-  subchannel_list->subchannels = static_cast<grpc_lb_subchannel_data*>(
-      gpr_zalloc(sizeof(grpc_lb_subchannel_data) * addresses->num_addresses));
-  // We need to remove the LB addresses in order to be able to compare the
-  // subchannel keys of subchannels from a different batch of addresses.
-  static const char* keys_to_remove[] = {GRPC_ARG_SUBCHANNEL_ADDRESS,
-                                         GRPC_ARG_LB_ADDRESSES};
-  // Create a subchannel for each address.
-  grpc_subchannel_args sc_args;
-  size_t subchannel_index = 0;
-  for (size_t i = 0; i < addresses->num_addresses; i++) {
-    // If there were any balancer, we would have chosen grpclb policy instead.
-    GPR_ASSERT(!addresses->addresses[i].is_balancer);
-    memset(&sc_args, 0, sizeof(grpc_subchannel_args));
-    grpc_arg addr_arg =
-        grpc_create_subchannel_address_arg(&addresses->addresses[i].address);
-    grpc_channel_args* new_args = grpc_channel_args_copy_and_add_and_remove(
-        &args, keys_to_remove, GPR_ARRAY_SIZE(keys_to_remove), &addr_arg, 1);
-    gpr_free(addr_arg.value.string);
-    sc_args.args = new_args;
-    grpc_subchannel* subchannel = grpc_client_channel_factory_create_subchannel(
-        client_channel_factory, &sc_args);
-    grpc_channel_args_destroy(new_args);
-    if (subchannel == nullptr) {
-      // Subchannel could not be created.
-      if (tracer->enabled()) {
-        char* address_uri =
-            grpc_sockaddr_to_uri(&addresses->addresses[i].address);
-        gpr_log(GPR_DEBUG,
-                "[%s %p] could not create subchannel for address uri %s, "
-                "ignoring",
-                tracer->name(), subchannel_list->policy, address_uri);
-        gpr_free(address_uri);
-      }
-      continue;
-    }
-    if (tracer->enabled()) {
-      char* address_uri =
-          grpc_sockaddr_to_uri(&addresses->addresses[i].address);
-      gpr_log(GPR_DEBUG,
-              "[%s %p] subchannel list %p index %" PRIuPTR
-              ": Created subchannel %p for address uri %s",
-              tracer->name(), p, subchannel_list, subchannel_index, subchannel,
-              address_uri);
-      gpr_free(address_uri);
-    }
-    grpc_lb_subchannel_data* sd =
-        &subchannel_list->subchannels[subchannel_index++];
-    sd->subchannel_list = subchannel_list;
-    sd->subchannel = subchannel;
-    GRPC_CLOSURE_INIT(&sd->connectivity_changed_closure,
-                      connectivity_changed_cb, sd,
-                      grpc_combiner_scheduler(combiner));
-    // We assume that the current state is IDLE.  If not, we'll get a
-    // callback telling us that.
-    sd->prev_connectivity_state = GRPC_CHANNEL_IDLE;
-    sd->curr_connectivity_state = GRPC_CHANNEL_IDLE;
-    sd->pending_connectivity_state_unsafe = GRPC_CHANNEL_IDLE;
-    sd->user_data_vtable = addresses->user_data_vtable;
-    if (sd->user_data_vtable != nullptr) {
-      sd->user_data =
-          sd->user_data_vtable->copy(addresses->addresses[i].user_data);
-    }
-  }
-  subchannel_list->num_subchannels = subchannel_index;
-  subchannel_list->num_idle = subchannel_index;
-  return subchannel_list;
-}
-
-static void subchannel_list_destroy(grpc_lb_subchannel_list* subchannel_list) {
-  if (subchannel_list->tracer->enabled()) {
-    gpr_log(GPR_DEBUG, "[%s %p] Destroying subchannel_list %p",
-            subchannel_list->tracer->name(), subchannel_list->policy,
-            subchannel_list);
-  }
-  for (size_t i = 0; i < subchannel_list->num_subchannels; i++) {
-    grpc_lb_subchannel_data* sd = &subchannel_list->subchannels[i];
-    grpc_lb_subchannel_data_unref_subchannel(sd, "subchannel_list_destroy");
-  }
-  gpr_free(subchannel_list->subchannels);
-  gpr_free(subchannel_list);
-}
-
-void grpc_lb_subchannel_list_ref(grpc_lb_subchannel_list* subchannel_list,
-                                 const char* reason) {
-  gpr_ref_non_zero(&subchannel_list->refcount);
-  if (subchannel_list->tracer->enabled()) {
-    const gpr_atm count = gpr_atm_acq_load(&subchannel_list->refcount.count);
-    gpr_log(GPR_DEBUG, "[%s %p] subchannel_list %p REF %lu->%lu (%s)",
-            subchannel_list->tracer->name(), subchannel_list->policy,
-            subchannel_list, static_cast<unsigned long>(count - 1),
-            static_cast<unsigned long>(count), reason);
-  }
-}
-
-void grpc_lb_subchannel_list_unref(grpc_lb_subchannel_list* subchannel_list,
-                                   const char* reason) {
-  const bool done = gpr_unref(&subchannel_list->refcount);
-  if (subchannel_list->tracer->enabled()) {
-    const gpr_atm count = gpr_atm_acq_load(&subchannel_list->refcount.count);
-    gpr_log(GPR_DEBUG, "[%s %p] subchannel_list %p UNREF %lu->%lu (%s)",
-            subchannel_list->tracer->name(), subchannel_list->policy,
-            subchannel_list, static_cast<unsigned long>(count + 1),
-            static_cast<unsigned long>(count), reason);
-  }
-  if (done) {
-    subchannel_list_destroy(subchannel_list);
-  }
-}
-
-static void subchannel_data_cancel_connectivity_watch(
-    grpc_lb_subchannel_data* sd, const char* reason) {
-  if (sd->subchannel_list->tracer->enabled()) {
-    gpr_log(GPR_DEBUG,
-            "[%s %p] subchannel list %p index %" PRIuPTR " of %" PRIuPTR
-            " (subchannel %p): canceling connectivity watch (%s)",
-            sd->subchannel_list->tracer->name(), sd->subchannel_list->policy,
-            sd->subchannel_list,
-            static_cast<size_t>(sd - sd->subchannel_list->subchannels),
-            sd->subchannel_list->num_subchannels, sd->subchannel, reason);
-  }
-  grpc_subchannel_notify_on_state_change(sd->subchannel, nullptr, nullptr,
-                                         &sd->connectivity_changed_closure);
-}
-
-void grpc_lb_subchannel_list_shutdown_and_unref(
-    grpc_lb_subchannel_list* subchannel_list, const char* reason) {
-  if (subchannel_list->tracer->enabled()) {
-    gpr_log(GPR_DEBUG, "[%s %p] Shutting down subchannel_list %p (%s)",
-            subchannel_list->tracer->name(), subchannel_list->policy,
-            subchannel_list, reason);
-  }
-  GPR_ASSERT(!subchannel_list->shutting_down);
-  subchannel_list->shutting_down = true;
-  for (size_t i = 0; i < subchannel_list->num_subchannels; i++) {
-    grpc_lb_subchannel_data* sd = &subchannel_list->subchannels[i];
-    // If there's a pending notification for this subchannel, cancel it;
-    // the callback is responsible for unreffing the subchannel.
-    // Otherwise, unref the subchannel directly.
-    if (sd->connectivity_notification_pending) {
-      subchannel_data_cancel_connectivity_watch(sd, reason);
-    } else if (sd->subchannel != nullptr) {
-      grpc_lb_subchannel_data_unref_subchannel(sd, reason);
-    }
-  }
-  grpc_lb_subchannel_list_unref(subchannel_list, reason);
-}
diff --git a/src/core/ext/filters/client_channel/lb_policy/subchannel_list.h b/src/core/ext/filters/client_channel/lb_policy/subchannel_list.h
index 6889d596ac..7e2046bcdc 100644
--- a/src/core/ext/filters/client_channel/lb_policy/subchannel_list.h
+++ b/src/core/ext/filters/client_channel/lb_policy/subchannel_list.h
@@ -21,116 +21,516 @@
 
 #include <grpc/support/port_platform.h>
 
+#include <string.h>
+
+#include <grpc/support/alloc.h>
+
 #include "src/core/ext/filters/client_channel/lb_policy_registry.h"
 #include "src/core/ext/filters/client_channel/subchannel.h"
+#include "src/core/lib/channel/channel_args.h"
 #include "src/core/lib/debug/trace.h"
+#include "src/core/lib/gprpp/abstract.h"
+#include "src/core/lib/gprpp/inlined_vector.h"
+#include "src/core/lib/gprpp/orphanable.h"
+#include "src/core/lib/gprpp/ref_counted.h"
 #include "src/core/lib/gprpp/ref_counted_ptr.h"
+#include "src/core/lib/iomgr/closure.h"
+#include "src/core/lib/iomgr/combiner.h"
+#include "src/core/lib/iomgr/sockaddr_utils.h"
 #include "src/core/lib/transport/connectivity_state.h"
 
-// TODO(roth): This code is intended to be shared between pick_first and
-// round_robin.  However, the interface needs more work to provide clean
-// encapsulation.  For example, the structs here have some fields that are
-// only used in one of the two (e.g., the state counters in
-// grpc_lb_subchannel_list and the prev_connectivity_state field in
-// grpc_lb_subchannel_data are only used in round_robin, and the
-// checking_subchannel field in grpc_lb_subchannel_list is only used by
-// pick_first).  Also, there is probably some code duplication between the
-// connectivity state notification callback code in both pick_first and
-// round_robin that could be refactored and moved here.  In a future PR,
-// need to clean this up.
-
-typedef struct grpc_lb_subchannel_list grpc_lb_subchannel_list;
-
-typedef struct {
-  /** backpointer to owning subchannel list */
-  grpc_lb_subchannel_list* subchannel_list;
-  /** subchannel itself */
-  grpc_subchannel* subchannel;
-  grpc_core::RefCountedPtr<grpc_core::ConnectedSubchannel> connected_subchannel;
-  /** Is a connectivity notification pending? */
-  bool connectivity_notification_pending;
-  /** notification that connectivity has changed on subchannel */
-  grpc_closure connectivity_changed_closure;
-  /** previous and current connectivity states.  Updated by \a
-   * \a connectivity_changed_closure based on
-   * \a pending_connectivity_state_unsafe. */
-  grpc_connectivity_state prev_connectivity_state;
-  grpc_connectivity_state curr_connectivity_state;
-  /** connectivity state to be updated by
-   * grpc_subchannel_notify_on_state_change(), not guarded by
-   * the combiner.  To be copied to \a curr_connectivity_state by
-   * \a connectivity_changed_closure. */
-  grpc_connectivity_state pending_connectivity_state_unsafe;
-  /** the subchannel's target user data */
-  void* user_data;
-  /** vtable to operate over \a user_data */
-  const grpc_lb_user_data_vtable* user_data_vtable;
-} grpc_lb_subchannel_data;
-
-/// Unrefs the subchannel contained in sd.
-void grpc_lb_subchannel_data_unref_subchannel(grpc_lb_subchannel_data* sd,
-                                              const char* reason);
-
-/// Starts watching the connectivity state of the subchannel.
-/// The connectivity_changed_cb callback must invoke either
-/// grpc_lb_subchannel_data_stop_connectivity_watch() or again call
-/// grpc_lb_subchannel_data_start_connectivity_watch().
-void grpc_lb_subchannel_data_start_connectivity_watch(
-    grpc_lb_subchannel_data* sd);
-
-/// Stops watching the connectivity state of the subchannel.
-void grpc_lb_subchannel_data_stop_connectivity_watch(
-    grpc_lb_subchannel_data* sd);
-
-struct grpc_lb_subchannel_list {
-  /** backpointer to owning policy */
-  grpc_core::LoadBalancingPolicy* policy;
-
-  grpc_core::TraceFlag* tracer;
-
-  /** all our subchannels */
-  size_t num_subchannels;
-  grpc_lb_subchannel_data* subchannels;
-
-  /** Index into subchannels of the one we're currently checking.
-   * Used when connecting to subchannels serially instead of in parallel. */
-  // TODO(roth): When we have time, we can probably make this go away
-  // and compute the index dynamically by subtracting
-  // subchannel_list->subchannels from the subchannel_data pointer.
-  size_t checking_subchannel;
-
-  /** how many subchannels are in state READY */
-  size_t num_ready;
-  /** how many subchannels are in state TRANSIENT_FAILURE */
-  size_t num_transient_failures;
-  /** how many subchannels are in state IDLE */
-  size_t num_idle;
-
-  /** There will be one ref for each entry in subchannels for which there is a
-   * pending connectivity state watcher callback. */
-  gpr_refcount refcount;
-
-  /** Is this list shutting down? This may be true due to the shutdown of the
-   * policy itself or because a newer update has arrived while this one hadn't
-   * finished processing. */
-  bool shutting_down;
+// Code for maintaining a list of subchannels within an LB policy.
+//
+// To use this, callers must create their own subclasses, like so:
+/*
+
+class MySubchannelList;  // Forward declaration.
+
+class MySubchannelData
+    : public SubchannelData<MySubchannelList, MySubchannelData> {
+ public:
+  void ProcessConnectivityChangeLocked(
+      grpc_connectivity_state connectivity_state, grpc_error* error) override {
+    // ...code to handle connectivity changes...
+  }
+};
+
+class MySubchannelList
+    : public SubchannelList<MySubchannelList, MySubchannelData> {
 };
 
-grpc_lb_subchannel_list* grpc_lb_subchannel_list_create(
-    grpc_core::LoadBalancingPolicy* p, grpc_core::TraceFlag* tracer,
+*/
+// All methods with a Locked() suffix must be called from within the
+// client_channel combiner.
+
+namespace grpc_core {
+
+// Stores data for a particular subchannel in a subchannel list.
+// Callers must create a subclass that implements the
+// ProcessConnectivityChangeLocked() method.
+template <typename SubchannelListType, typename SubchannelDataType>
+class SubchannelData {
+ public:
+  // Returns a pointer to the subchannel list containing this object.
+  SubchannelListType* subchannel_list() const { return subchannel_list_; }
+
+  // Returns the index into the subchannel list of this object.
+  size_t Index() const {
+    return static_cast<size_t>(static_cast<const SubchannelDataType*>(this) -
+                               subchannel_list_->subchannel(0));
+  }
+
+  // Returns a pointer to the subchannel.
+  grpc_subchannel* subchannel() const { return subchannel_; }
+
+  // Returns the connected subchannel.  Will be null if the subchannel
+  // is not connected.
+  ConnectedSubchannel* connected_subchannel() const {
+    return connected_subchannel_.get();
+  }
+
+  // Synchronously checks the subchannel's connectivity state.
+  // Must not be called while there is a connectivity notification
+  // pending (i.e., between calling StartConnectivityWatchLocked() or
+  // RenewConnectivityWatchLocked() and the resulting invocation of
+  // ProcessConnectivityChangeLocked()).
+  grpc_connectivity_state CheckConnectivityStateLocked(grpc_error** error) {
+    GPR_ASSERT(!connectivity_notification_pending_);
+    pending_connectivity_state_unsafe_ =
+        grpc_subchannel_check_connectivity(subchannel(), error);
+    UpdateConnectedSubchannelLocked();
+    return pending_connectivity_state_unsafe_;
+  }
+
+  // Unrefs the subchannel.  May be used if an individual subchannel is
+  // no longer needed even though the subchannel list as a whole is not
+  // being unreffed.
+  virtual void UnrefSubchannelLocked(const char* reason);
+
+  // Starts watching the connectivity state of the subchannel.
+  // ProcessConnectivityChangeLocked() will be called when the
+  // connectivity state changes.
+  void StartConnectivityWatchLocked();
+
+  // Renews watching the connectivity state of the subchannel.
+  void RenewConnectivityWatchLocked();
+
+  // Stops watching the connectivity state of the subchannel.
+  void StopConnectivityWatchLocked();
+
+  // Cancels watching the connectivity state of the subchannel.
+  // Must be called only while there is a connectivity notification
+  // pending (i.e., between calling StartConnectivityWatchLocked() or
+  // RenewConnectivityWatchLocked() and the resulting invocation of
+  // ProcessConnectivityChangeLocked()).
+  // From within ProcessConnectivityChangeLocked(), use
+  // StopConnectivityWatchLocked() instead.
+  void CancelConnectivityWatchLocked(const char* reason);
+
+  // Cancels any pending connectivity watch and unrefs the subchannel.
+  void ShutdownLocked();
+
+  GRPC_ABSTRACT_BASE_CLASS
+
+ protected:
+  SubchannelData(SubchannelListType* subchannel_list,
+                 const grpc_lb_user_data_vtable* user_data_vtable,
+                 const grpc_lb_address& address, grpc_subchannel* subchannel,
+                 grpc_combiner* combiner);
+
+  virtual ~SubchannelData();
+
+  // After StartConnectivityWatchLocked() or RenewConnectivityWatchLocked()
+  // is called, this method will be invoked when the subchannel's connectivity
+  // state changes.
+  // Implementations must invoke either RenewConnectivityWatchLocked() or
+  // StopConnectivityWatchLocked() before returning.
+  virtual void ProcessConnectivityChangeLocked(
+      grpc_connectivity_state connectivity_state,
+      grpc_error* error) GRPC_ABSTRACT;
+
+ private:
+  // Updates connected_subchannel_ based on pending_connectivity_state_unsafe_.
+  // Returns true if the connectivity state should be reported.
+  bool UpdateConnectedSubchannelLocked();
+
+  static void OnConnectivityChangedLocked(void* arg, grpc_error* error);
+
+  // Backpointer to owning subchannel list.  Not owned.
+  SubchannelListType* subchannel_list_;
+
+  // The subchannel and connected subchannel.
+  grpc_subchannel* subchannel_;
+  RefCountedPtr<ConnectedSubchannel> connected_subchannel_;
+
+  // Notification that connectivity has changed on subchannel.
+  grpc_closure connectivity_changed_closure_;
+  // Is a connectivity notification pending?
+  bool connectivity_notification_pending_ = false;
+  // Connectivity state to be updated by
+  // grpc_subchannel_notify_on_state_change(), not guarded by
+  // the combiner.
+  grpc_connectivity_state pending_connectivity_state_unsafe_;
+};
+
+// A list of subchannels.
+template <typename SubchannelListType, typename SubchannelDataType>
+class SubchannelList
+    : public InternallyRefCountedWithTracing<SubchannelListType> {
+ public:
+  typedef InlinedVector<SubchannelDataType, 10> SubchannelVector;
+
+  // The number of subchannels in the list.
+  size_t num_subchannels() const { return subchannels_.size(); }
+
+  // The data for the subchannel at a particular index.
+  SubchannelDataType* subchannel(size_t index) { return &subchannels_[index]; }
+
+  // Returns true if the subchannel list is shutting down.
+  bool shutting_down() const { return shutting_down_; }
+
+  // Accessors.
+  LoadBalancingPolicy* policy() const { return policy_; }
+  TraceFlag* tracer() const { return tracer_; }
+
+  // Note: Caller must ensure that this is invoked inside of the combiner.
+  void Orphan() override {
+    ShutdownLocked();
+    InternallyRefCountedWithTracing<SubchannelListType>::Unref(DEBUG_LOCATION,
+                                                               "shutdown");
+  }
+
+  GRPC_ABSTRACT_BASE_CLASS
+
+ protected:
+  SubchannelList(LoadBalancingPolicy* policy, TraceFlag* tracer,
+                 const grpc_lb_addresses* addresses, grpc_combiner* combiner,
+                 grpc_client_channel_factory* client_channel_factory,
+                 const grpc_channel_args& args);
+
+  virtual ~SubchannelList();
+
+ private:
+  // So New() can call our private ctor.
+  template <typename T, typename... Args>
+  friend T* New(Args&&... args);
+
+  // For accessing Ref() and Unref().
+  friend class SubchannelData<SubchannelListType, SubchannelDataType>;
+
+  void ShutdownLocked();
+
+  // Backpointer to owning policy.
+  LoadBalancingPolicy* policy_;
+
+  TraceFlag* tracer_;
+
+  grpc_combiner* combiner_;
+
+  // The list of subchannels.
+  SubchannelVector subchannels_;
+
+  // Is this list shutting down? This may be true due to the shutdown of the
+  // policy itself or because a newer update has arrived while this one hadn't
+  // finished processing.
+  bool shutting_down_ = false;
+};
+
+//
+// implementation -- no user-servicable parts below
+//
+
+//
+// SubchannelData
+//
+
+template <typename SubchannelListType, typename SubchannelDataType>
+SubchannelData<SubchannelListType, SubchannelDataType>::SubchannelData(
+    SubchannelListType* subchannel_list,
+    const grpc_lb_user_data_vtable* user_data_vtable,
+    const grpc_lb_address& address, grpc_subchannel* subchannel,
+    grpc_combiner* combiner)
+    : subchannel_list_(subchannel_list),
+      subchannel_(subchannel),
+      // We assume that the current state is IDLE.  If not, we'll get a
+      // callback telling us that.
+      pending_connectivity_state_unsafe_(GRPC_CHANNEL_IDLE) {
+  GRPC_CLOSURE_INIT(
+      &connectivity_changed_closure_,
+      (&SubchannelData<SubchannelListType,
+                       SubchannelDataType>::OnConnectivityChangedLocked),
+      this, grpc_combiner_scheduler(combiner));
+}
+
+template <typename SubchannelListType, typename SubchannelDataType>
+SubchannelData<SubchannelListType, SubchannelDataType>::~SubchannelData() {
+  UnrefSubchannelLocked("subchannel_data_destroy");
+}
+
+template <typename SubchannelListType, typename SubchannelDataType>
+void SubchannelData<SubchannelListType, SubchannelDataType>::
+    UnrefSubchannelLocked(const char* reason) {
+  if (subchannel_ != nullptr) {
+    if (subchannel_list_->tracer()->enabled()) {
+      gpr_log(GPR_INFO,
+              "[%s %p] subchannel list %p index %" PRIuPTR " of %" PRIuPTR
+              " (subchannel %p): unreffing subchannel",
+              subchannel_list_->tracer()->name(), subchannel_list_->policy(),
+              subchannel_list_, Index(), subchannel_list_->num_subchannels(),
+              subchannel_);
+    }
+    GRPC_SUBCHANNEL_UNREF(subchannel_, reason);
+    subchannel_ = nullptr;
+    connected_subchannel_.reset();
+  }
+}
+
+template <typename SubchannelListType, typename SubchannelDataType>
+void SubchannelData<SubchannelListType,
+                    SubchannelDataType>::StartConnectivityWatchLocked() {
+  if (subchannel_list_->tracer()->enabled()) {
+    gpr_log(GPR_INFO,
+            "[%s %p] subchannel list %p index %" PRIuPTR " of %" PRIuPTR
+            " (subchannel %p): starting watch: requesting connectivity change "
+            "notification (from %s)",
+            subchannel_list_->tracer()->name(), subchannel_list_->policy(),
+            subchannel_list_, Index(), subchannel_list_->num_subchannels(),
+            subchannel_,
+            grpc_connectivity_state_name(pending_connectivity_state_unsafe_));
+  }
+  GPR_ASSERT(!connectivity_notification_pending_);
+  connectivity_notification_pending_ = true;
+  subchannel_list()->Ref(DEBUG_LOCATION, "connectivity_watch").release();
+  grpc_subchannel_notify_on_state_change(
+      subchannel_, subchannel_list_->policy()->interested_parties(),
+      &pending_connectivity_state_unsafe_, &connectivity_changed_closure_);
+}
+
+template <typename SubchannelListType, typename SubchannelDataType>
+void SubchannelData<SubchannelListType,
+                    SubchannelDataType>::RenewConnectivityWatchLocked() {
+  if (subchannel_list_->tracer()->enabled()) {
+    gpr_log(GPR_INFO,
+            "[%s %p] subchannel list %p index %" PRIuPTR " of %" PRIuPTR
+            " (subchannel %p): renewing watch: requesting connectivity change "
+            "notification (from %s)",
+            subchannel_list_->tracer()->name(), subchannel_list_->policy(),
+            subchannel_list_, Index(), subchannel_list_->num_subchannels(),
+            subchannel_,
+            grpc_connectivity_state_name(pending_connectivity_state_unsafe_));
+  }
+  GPR_ASSERT(connectivity_notification_pending_);
+  grpc_subchannel_notify_on_state_change(
+      subchannel_, subchannel_list_->policy()->interested_parties(),
+      &pending_connectivity_state_unsafe_, &connectivity_changed_closure_);
+}
+
+template <typename SubchannelListType, typename SubchannelDataType>
+void SubchannelData<SubchannelListType,
+                    SubchannelDataType>::StopConnectivityWatchLocked() {
+  if (subchannel_list_->tracer()->enabled()) {
+    gpr_log(GPR_INFO,
+            "[%s %p] subchannel list %p index %" PRIuPTR " of %" PRIuPTR
+            " (subchannel %p): stopping connectivity watch",
+            subchannel_list_->tracer()->name(), subchannel_list_->policy(),
+            subchannel_list_, Index(), subchannel_list_->num_subchannels(),
+            subchannel_);
+  }
+  GPR_ASSERT(connectivity_notification_pending_);
+  connectivity_notification_pending_ = false;
+  subchannel_list()->Unref(DEBUG_LOCATION, "connectivity_watch");
+}
+
+template <typename SubchannelListType, typename SubchannelDataType>
+void SubchannelData<SubchannelListType, SubchannelDataType>::
+    CancelConnectivityWatchLocked(const char* reason) {
+  if (subchannel_list_->tracer()->enabled()) {
+    gpr_log(GPR_INFO,
+            "[%s %p] subchannel list %p index %" PRIuPTR " of %" PRIuPTR
+            " (subchannel %p): canceling connectivity watch (%s)",
+            subchannel_list_->tracer()->name(), subchannel_list_->policy(),
+            subchannel_list_, Index(), subchannel_list_->num_subchannels(),
+            subchannel_, reason);
+  }
+  GPR_ASSERT(connectivity_notification_pending_);
+  grpc_subchannel_notify_on_state_change(subchannel_, nullptr, nullptr,
+                                         &connectivity_changed_closure_);
+}
+
+template <typename SubchannelListType, typename SubchannelDataType>
+bool SubchannelData<SubchannelListType,
+                    SubchannelDataType>::UpdateConnectedSubchannelLocked() {
+  // If the subchannel is READY, take a ref to the connected subchannel.
+  if (pending_connectivity_state_unsafe_ == GRPC_CHANNEL_READY) {
+    connected_subchannel_ =
+        grpc_subchannel_get_connected_subchannel(subchannel_);
+    // If the subchannel became disconnected between the time that READY
+    // was reported and the time we got here (e.g., between when a
+    // notification callback is scheduled and when it was actually run in
+    // the combiner), then the connected subchannel may have disappeared out
+    // from under us.  In that case, we don't actually want to consider the
+    // subchannel to be in state READY.  Instead, we use IDLE as the
+    // basis for any future connectivity watch; this is the one state that
+    // the subchannel will never transition back into, so this ensures
+    // that we will get a notification for the next state, even if that state
+    // is READY again (e.g., if the subchannel has transitioned back to
+    // READY before the next watch gets requested).
+    if (connected_subchannel_ == nullptr) {
+      if (subchannel_list_->tracer()->enabled()) {
+        gpr_log(GPR_INFO,
+                "[%s %p] subchannel list %p index %" PRIuPTR " of %" PRIuPTR
+                " (subchannel %p): state is READY but connected subchannel is "
+                "null; moving to state IDLE",
+                subchannel_list_->tracer()->name(), subchannel_list_->policy(),
+                subchannel_list_, Index(), subchannel_list_->num_subchannels(),
+                subchannel_);
+      }
+      pending_connectivity_state_unsafe_ = GRPC_CHANNEL_IDLE;
+      return false;
+    }
+  } else {
+    // For any state other than READY, unref the connected subchannel.
+    connected_subchannel_.reset();
+  }
+  return true;
+}
+
+template <typename SubchannelListType, typename SubchannelDataType>
+void SubchannelData<SubchannelListType, SubchannelDataType>::
+    OnConnectivityChangedLocked(void* arg, grpc_error* error) {
+  SubchannelData* sd = static_cast<SubchannelData*>(arg);
+  if (sd->subchannel_list_->tracer()->enabled()) {
+    gpr_log(
+        GPR_INFO,
+        "[%s %p] subchannel list %p index %" PRIuPTR " of %" PRIuPTR
+        " (subchannel %p): connectivity changed: state=%s, error=%s, "
+        "shutting_down=%d",
+        sd->subchannel_list_->tracer()->name(), sd->subchannel_list_->policy(),
+        sd->subchannel_list_, sd->Index(),
+        sd->subchannel_list_->num_subchannels(), sd->subchannel_,
+        grpc_connectivity_state_name(sd->pending_connectivity_state_unsafe_),
+        grpc_error_string(error), sd->subchannel_list_->shutting_down());
+  }
+  // If shutting down, unref subchannel and stop watching.
+  if (sd->subchannel_list_->shutting_down() || error == GRPC_ERROR_CANCELLED) {
+    sd->UnrefSubchannelLocked("connectivity_shutdown");
+    sd->StopConnectivityWatchLocked();
+    return;
+  }
+  // Get or release ref to connected subchannel.
+  if (!sd->UpdateConnectedSubchannelLocked()) {
+    // We don't want to report this connectivity state, so renew the watch.
+    sd->RenewConnectivityWatchLocked();
+    return;
+  }
+  // Call the subclass's ProcessConnectivityChangeLocked() method.
+  sd->ProcessConnectivityChangeLocked(sd->pending_connectivity_state_unsafe_,
+                                      GRPC_ERROR_REF(error));
+}
+
+template <typename SubchannelListType, typename SubchannelDataType>
+void SubchannelData<SubchannelListType, SubchannelDataType>::ShutdownLocked() {
+  // If there's a pending notification for this subchannel, cancel it;
+  // the callback is responsible for unreffing the subchannel.
+  // Otherwise, unref the subchannel directly.
+  if (connectivity_notification_pending_) {
+    CancelConnectivityWatchLocked("shutdown");
+  } else if (subchannel_ != nullptr) {
+    UnrefSubchannelLocked("shutdown");
+  }
+}
+
+//
+// SubchannelList
+//
+
+template <typename SubchannelListType, typename SubchannelDataType>
+SubchannelList<SubchannelListType, SubchannelDataType>::SubchannelList(
+    LoadBalancingPolicy* policy, TraceFlag* tracer,
     const grpc_lb_addresses* addresses, grpc_combiner* combiner,
     grpc_client_channel_factory* client_channel_factory,
-    const grpc_channel_args& args, grpc_iomgr_cb_func connectivity_changed_cb);
+    const grpc_channel_args& args)
+    : InternallyRefCountedWithTracing<SubchannelListType>(tracer),
+      policy_(policy),
+      tracer_(tracer),
+      combiner_(GRPC_COMBINER_REF(combiner, "subchannel_list")) {
+  if (tracer_->enabled()) {
+    gpr_log(GPR_INFO,
+            "[%s %p] Creating subchannel list %p for %" PRIuPTR " subchannels",
+            tracer_->name(), policy, this, addresses->num_addresses);
+  }
+  subchannels_.reserve(addresses->num_addresses);
+  // We need to remove the LB addresses in order to be able to compare the
+  // subchannel keys of subchannels from a different batch of addresses.
+  static const char* keys_to_remove[] = {GRPC_ARG_SUBCHANNEL_ADDRESS,
+                                         GRPC_ARG_LB_ADDRESSES};
+  // Create a subchannel for each address.
+  grpc_subchannel_args sc_args;
+  for (size_t i = 0; i < addresses->num_addresses; i++) {
+    // If there were any balancer, we would have chosen grpclb policy instead.
+    GPR_ASSERT(!addresses->addresses[i].is_balancer);
+    memset(&sc_args, 0, sizeof(grpc_subchannel_args));
+    grpc_arg addr_arg =
+        grpc_create_subchannel_address_arg(&addresses->addresses[i].address);
+    grpc_channel_args* new_args = grpc_channel_args_copy_and_add_and_remove(
+        &args, keys_to_remove, GPR_ARRAY_SIZE(keys_to_remove), &addr_arg, 1);
+    gpr_free(addr_arg.value.string);
+    sc_args.args = new_args;
+    grpc_subchannel* subchannel = grpc_client_channel_factory_create_subchannel(
+        client_channel_factory, &sc_args);
+    grpc_channel_args_destroy(new_args);
+    if (subchannel == nullptr) {
+      // Subchannel could not be created.
+      if (tracer_->enabled()) {
+        char* address_uri =
+            grpc_sockaddr_to_uri(&addresses->addresses[i].address);
+        gpr_log(GPR_INFO,
+                "[%s %p] could not create subchannel for address uri %s, "
+                "ignoring",
+                tracer_->name(), policy_, address_uri);
+        gpr_free(address_uri);
+      }
+      continue;
+    }
+    if (tracer_->enabled()) {
+      char* address_uri =
+          grpc_sockaddr_to_uri(&addresses->addresses[i].address);
+      gpr_log(GPR_INFO,
+              "[%s %p] subchannel list %p index %" PRIuPTR
+              ": Created subchannel %p for address uri %s",
+              tracer_->name(), policy_, this, subchannels_.size(), subchannel,
+              address_uri);
+      gpr_free(address_uri);
+    }
+    subchannels_.emplace_back(static_cast<SubchannelListType*>(this),
+                              addresses->user_data_vtable,
+                              addresses->addresses[i], subchannel, combiner);
+  }
+}
 
-void grpc_lb_subchannel_list_ref(grpc_lb_subchannel_list* subchannel_list,
-                                 const char* reason);
+template <typename SubchannelListType, typename SubchannelDataType>
+SubchannelList<SubchannelListType, SubchannelDataType>::~SubchannelList() {
+  if (tracer_->enabled()) {
+    gpr_log(GPR_INFO, "[%s %p] Destroying subchannel_list %p", tracer_->name(),
+            policy_, this);
+  }
+  GRPC_COMBINER_UNREF(combiner_, "subchannel_list");
+}
 
-void grpc_lb_subchannel_list_unref(grpc_lb_subchannel_list* subchannel_list,
-                                   const char* reason);
+template <typename SubchannelListType, typename SubchannelDataType>
+void SubchannelList<SubchannelListType, SubchannelDataType>::ShutdownLocked() {
+  if (tracer_->enabled()) {
+    gpr_log(GPR_INFO, "[%s %p] Shutting down subchannel_list %p",
+            tracer_->name(), policy_, this);
+  }
+  GPR_ASSERT(!shutting_down_);
+  shutting_down_ = true;
+  for (size_t i = 0; i < subchannels_.size(); i++) {
+    SubchannelDataType* sd = &subchannels_[i];
+    sd->ShutdownLocked();
+  }
+}
 
-/// Mark subchannel_list as discarded. Unsubscribes all its subchannels. The
-/// connectivity state notification callback will ultimately unref it.
-void grpc_lb_subchannel_list_shutdown_and_unref(
-    grpc_lb_subchannel_list* subchannel_list, const char* reason);
+}  // namespace grpc_core
 
 #endif /* GRPC_CORE_EXT_FILTERS_CLIENT_CHANNEL_LB_POLICY_SUBCHANNEL_LIST_H */
diff --git a/src/core/ext/filters/client_channel/method_params.h b/src/core/ext/filters/client_channel/method_params.h
index 099924edf3..a31d360f17 100644
--- a/src/core/ext/filters/client_channel/method_params.h
+++ b/src/core/ext/filters/client_channel/method_params.h
@@ -60,6 +60,10 @@ class ClientChannelMethodParams : public RefCounted<ClientChannelMethodParams> {
   template <typename T, typename... Args>
   friend T* grpc_core::New(Args&&... args);
 
+  // So Delete() can call our private dtor.
+  template <typename T>
+  friend void grpc_core::Delete(T*);
+
   ClientChannelMethodParams() {}
   virtual ~ClientChannelMethodParams() {}
 
diff --git a/src/core/ext/filters/client_channel/resolver.h b/src/core/ext/filters/client_channel/resolver.h
index cdb5a20ea3..02380314dd 100644
--- a/src/core/ext/filters/client_channel/resolver.h
+++ b/src/core/ext/filters/client_channel/resolver.h
@@ -105,6 +105,10 @@ class Resolver : public InternallyRefCountedWithTracing<Resolver> {
   GRPC_ABSTRACT_BASE_CLASS
 
  protected:
+  // So Delete() can access our protected dtor.
+  template <typename T>
+  friend void Delete(T*);
+
   /// Does NOT take ownership of the reference to \a combiner.
   // TODO(roth): Once we have a C++-like interface for combiners, this
   // API should change to take a RefCountedPtr<>, so that we always take
diff --git a/src/core/ext/filters/client_channel/resolver/dns/c_ares/dns_resolver_ares.cc b/src/core/ext/filters/client_channel/resolver/dns/c_ares/dns_resolver_ares.cc
index 40a5c9a7e9..3c40ae14b8 100644
--- a/src/core/ext/filters/client_channel/resolver/dns/c_ares/dns_resolver_ares.cc
+++ b/src/core/ext/filters/client_channel/resolver/dns/c_ares/dns_resolver_ares.cc
@@ -363,6 +363,15 @@ void AresDnsResolver::OnResolvedLocked(void* arg, grpc_error* error) {
 }
 
 void AresDnsResolver::MaybeStartResolvingLocked() {
+  // If there is an existing timer, the time it fires is the earliest time we
+  // can start the next resolution.
+  if (have_next_resolution_timer_) {
+    // TODO(dgq): remove the following two lines once Pick First stops
+    // discarding subchannels after selecting.
+    ++resolved_version_;
+    MaybeFinishNextLocked();
+    return;
+  }
   if (last_resolution_timestamp_ >= 0) {
     const grpc_millis earliest_next_resolution =
         last_resolution_timestamp_ + min_time_between_resolutions_;
@@ -375,17 +384,15 @@ void AresDnsResolver::MaybeStartResolvingLocked() {
               "In cooldown from last resolution (from %" PRId64
               " ms ago). Will resolve again in %" PRId64 " ms",
               last_resolution_ago, ms_until_next_resolution);
-      if (!have_next_resolution_timer_) {
-        have_next_resolution_timer_ = true;
-        // TODO(roth): We currently deal with this ref manually.  Once the
-        // new closure API is done, find a way to track this ref with the timer
-        // callback as part of the type system.
-        RefCountedPtr<Resolver> self =
-            Ref(DEBUG_LOCATION, "next_resolution_timer_cooldown");
-        self.release();
-        grpc_timer_init(&next_resolution_timer_, ms_until_next_resolution,
-                        &on_next_resolution_);
-      }
+      have_next_resolution_timer_ = true;
+      // TODO(roth): We currently deal with this ref manually.  Once the
+      // new closure API is done, find a way to track this ref with the timer
+      // callback as part of the type system.
+      RefCountedPtr<Resolver> self =
+          Ref(DEBUG_LOCATION, "next_resolution_timer_cooldown");
+      self.release();
+      grpc_timer_init(&next_resolution_timer_, ms_until_next_resolution,
+                      &on_next_resolution_);
       // TODO(dgq): remove the following two lines once Pick First stops
       // discarding subchannels after selecting.
       ++resolved_version_;
@@ -397,6 +404,7 @@ void AresDnsResolver::MaybeStartResolvingLocked() {
 }
 
 void AresDnsResolver::StartResolvingLocked() {
+  gpr_log(GPR_DEBUG, "Start resolving.");
   // TODO(roth): We currently deal with this ref manually.  Once the
   // new closure API is done, find a way to track this ref with the timer
   // callback as part of the type system.
diff --git a/src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper.cc b/src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper.cc
index fb2435749d..e86ab5a37e 100644
--- a/src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper.cc
+++ b/src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper.cc
@@ -153,7 +153,10 @@ static void grpc_ares_request_unref(grpc_ares_request* r) {
   /* If there are no pending queries, invoke on_done callback and destroy the
      request */
   if (gpr_unref(&r->pending_queries)) {
-    grpc_cares_wrapper_address_sorting_sort(*(r->lb_addrs_out));
+    grpc_lb_addresses* lb_addrs = *(r->lb_addrs_out);
+    if (lb_addrs != nullptr) {
+      grpc_cares_wrapper_address_sorting_sort(lb_addrs);
+    }
     GRPC_CLOSURE_SCHED(r->on_done, r->error);
     gpr_mu_destroy(&r->mu);
     grpc_ares_ev_driver_destroy(r->ev_driver);
diff --git a/src/core/ext/filters/client_channel/resolver/dns/native/dns_resolver.cc b/src/core/ext/filters/client_channel/resolver/dns/native/dns_resolver.cc
index 78ccf7907e..99514693eb 100644
--- a/src/core/ext/filters/client_channel/resolver/dns/native/dns_resolver.cc
+++ b/src/core/ext/filters/client_channel/resolver/dns/native/dns_resolver.cc
@@ -236,6 +236,15 @@ void NativeDnsResolver::OnResolvedLocked(void* arg, grpc_error* error) {
 }
 
 void NativeDnsResolver::MaybeStartResolvingLocked() {
+  // If there is an existing timer, the time it fires is the earliest time we
+  // can start the next resolution.
+  if (have_next_resolution_timer_) {
+    // TODO(dgq): remove the following two lines once Pick First stops
+    // discarding subchannels after selecting.
+    ++resolved_version_;
+    MaybeFinishNextLocked();
+    return;
+  }
   if (last_resolution_timestamp_ >= 0) {
     const grpc_millis earliest_next_resolution =
         last_resolution_timestamp_ + min_time_between_resolutions_;
@@ -248,17 +257,15 @@ void NativeDnsResolver::MaybeStartResolvingLocked() {
               "In cooldown from last resolution (from %" PRId64
               " ms ago). Will resolve again in %" PRId64 " ms",
               last_resolution_ago, ms_until_next_resolution);
-      if (!have_next_resolution_timer_) {
-        have_next_resolution_timer_ = true;
-        // TODO(roth): We currently deal with this ref manually.  Once the
-        // new closure API is done, find a way to track this ref with the timer
-        // callback as part of the type system.
-        RefCountedPtr<Resolver> self =
-            Ref(DEBUG_LOCATION, "next_resolution_timer_cooldown");
-        self.release();
-        grpc_timer_init(&next_resolution_timer_, ms_until_next_resolution,
-                        &on_next_resolution_);
-      }
+      have_next_resolution_timer_ = true;
+      // TODO(roth): We currently deal with this ref manually.  Once the
+      // new closure API is done, find a way to track this ref with the timer
+      // callback as part of the type system.
+      RefCountedPtr<Resolver> self =
+          Ref(DEBUG_LOCATION, "next_resolution_timer_cooldown");
+      self.release();
+      grpc_timer_init(&next_resolution_timer_, ms_until_next_resolution,
+                      &on_next_resolution_);
       // TODO(dgq): remove the following two lines once Pick First stops
       // discarding subchannels after selecting.
       ++resolved_version_;
@@ -270,6 +277,7 @@ void NativeDnsResolver::MaybeStartResolvingLocked() {
 }
 
 void NativeDnsResolver::StartResolvingLocked() {
+  gpr_log(GPR_DEBUG, "Start resolving.");
   // TODO(roth): We currently deal with this ref manually.  Once the
   // new closure API is done, find a way to track this ref with the timer
   // callback as part of the type system.
diff --git a/src/core/ext/filters/client_channel/retry_throttle.h b/src/core/ext/filters/client_channel/retry_throttle.h
index 2b6fa0a70b..fddafcd903 100644
--- a/src/core/ext/filters/client_channel/retry_throttle.h
+++ b/src/core/ext/filters/client_channel/retry_throttle.h
@@ -42,6 +42,10 @@ class ServerRetryThrottleData : public RefCounted<ServerRetryThrottleData> {
   intptr_t milli_token_ratio() const { return milli_token_ratio_; }
 
  private:
+  // So Delete() can call our private dtor.
+  template <typename T>
+  friend void grpc_core::Delete(T*);
+
   ~ServerRetryThrottleData();
 
   void GetReplacementThrottleDataIfNeeded(
diff --git a/src/core/ext/filters/http/message_compress/message_compress_filter.cc b/src/core/ext/filters/http/message_compress/message_compress_filter.cc
index e7d9949386..f8f478b6c0 100644
--- a/src/core/ext/filters/http/message_compress/message_compress_filter.cc
+++ b/src/core/ext/filters/http/message_compress/message_compress_filter.cc
@@ -234,7 +234,7 @@ static void finish_send_message(grpc_call_element* elem) {
                                              static_cast<float>(before_size);
       GPR_ASSERT(grpc_message_compression_algorithm_name(
           calld->message_compression_algorithm, &algo_name));
-      gpr_log(GPR_DEBUG,
+      gpr_log(GPR_INFO,
               "Compressed[%s] %" PRIuPTR " bytes vs. %" PRIuPTR
               " bytes (%.2f%% savings)",
               algo_name, before_size, after_size, 100 * savings_ratio);
@@ -246,7 +246,7 @@ static void finish_send_message(grpc_call_element* elem) {
       const char* algo_name;
       GPR_ASSERT(grpc_message_compression_algorithm_name(
           calld->message_compression_algorithm, &algo_name));
-      gpr_log(GPR_DEBUG,
+      gpr_log(GPR_INFO,
               "Algorithm '%s' enabled but decided not to compress. Input size: "
               "%" PRIuPTR,
               algo_name, calld->slices.length);
diff --git a/src/core/ext/transport/chttp2/transport/chttp2_transport.cc b/src/core/ext/transport/chttp2/transport/chttp2_transport.cc
index 6980b8671e..0ef73961a5 100644
--- a/src/core/ext/transport/chttp2/transport/chttp2_transport.cc
+++ b/src/core/ext/transport/chttp2/transport/chttp2_transport.cc
@@ -807,7 +807,7 @@ static const char* write_state_name(grpc_chttp2_write_state st) {
 
 static void set_write_state(grpc_chttp2_transport* t,
                             grpc_chttp2_write_state st, const char* reason) {
-  GRPC_CHTTP2_IF_TRACING(gpr_log(GPR_DEBUG, "W:%p %s state %s -> %s [%s]", t,
+  GRPC_CHTTP2_IF_TRACING(gpr_log(GPR_INFO, "W:%p %s state %s -> %s [%s]", t,
                                  t->is_client ? "CLIENT" : "SERVER",
                                  write_state_name(t->write_state),
                                  write_state_name(st), reason));
@@ -1072,7 +1072,7 @@ void grpc_chttp2_add_incoming_goaway(grpc_chttp2_transport* t,
                                      uint32_t goaway_error,
                                      grpc_slice goaway_text) {
   // GRPC_CHTTP2_IF_TRACING(
-  //     gpr_log(GPR_DEBUG, "got goaway [%d]: %s", goaway_error, msg));
+  //     gpr_log(GPR_INFO, "got goaway [%d]: %s", goaway_error, msg));
 
   // Discard the error from a previous goaway frame (if any)
   if (t->goaway_error != GRPC_ERROR_NONE) {
@@ -1118,7 +1118,7 @@ static void maybe_start_some_streams(grpc_chttp2_transport* t) {
          grpc_chttp2_list_pop_waiting_for_concurrency(t, &s)) {
     /* safe since we can't (legally) be parsing this stream yet */
     GRPC_CHTTP2_IF_TRACING(gpr_log(
-        GPR_DEBUG, "HTTP:%s: Allocating new grpc_chttp2_stream %p to id %d",
+        GPR_INFO, "HTTP:%s: Allocating new grpc_chttp2_stream %p to id %d",
         t->is_client ? "CLI" : "SVR", s, t->next_stream_id));
 
     GPR_ASSERT(s->id == 0);
@@ -1183,7 +1183,7 @@ void grpc_chttp2_complete_closure_step(grpc_chttp2_transport* t,
   if (grpc_http_trace.enabled()) {
     const char* errstr = grpc_error_string(error);
     gpr_log(
-        GPR_DEBUG,
+        GPR_INFO,
         "complete_closure_step: t=%p %p refs=%d flags=0x%04x desc=%s err=%s "
         "write_state=%s",
         t, closure,
@@ -1336,7 +1336,7 @@ static void perform_stream_op_locked(void* stream_op,
 
   if (grpc_http_trace.enabled()) {
     char* str = grpc_transport_stream_op_batch_string(op);
-    gpr_log(GPR_DEBUG, "perform_stream_op_locked: %s; on_complete = %p", str,
+    gpr_log(GPR_INFO, "perform_stream_op_locked: %s; on_complete = %p", str,
             op->on_complete);
     gpr_free(str);
     if (op->send_initial_metadata) {
@@ -1638,7 +1638,7 @@ static void perform_stream_op(grpc_transport* gt, grpc_stream* gs,
 
   if (grpc_http_trace.enabled()) {
     char* str = grpc_transport_stream_op_batch_string(op);
-    gpr_log(GPR_DEBUG, "perform_stream_op[s=%p]: %s", s, str);
+    gpr_log(GPR_INFO, "perform_stream_op[s=%p]: %s", s, str);
     gpr_free(str);
   }
 
@@ -2529,7 +2529,7 @@ static void schedule_bdp_ping_locked(grpc_chttp2_transport* t) {
 static void start_bdp_ping_locked(void* tp, grpc_error* error) {
   grpc_chttp2_transport* t = static_cast<grpc_chttp2_transport*>(tp);
   if (grpc_http_trace.enabled()) {
-    gpr_log(GPR_DEBUG, "%s: Start BDP ping err=%s", t->peer_string,
+    gpr_log(GPR_INFO, "%s: Start BDP ping err=%s", t->peer_string,
             grpc_error_string(error));
   }
   /* Reset the keepalive ping timer */
@@ -2542,7 +2542,7 @@ static void start_bdp_ping_locked(void* tp, grpc_error* error) {
 static void finish_bdp_ping_locked(void* tp, grpc_error* error) {
   grpc_chttp2_transport* t = static_cast<grpc_chttp2_transport*>(tp);
   if (grpc_http_trace.enabled()) {
-    gpr_log(GPR_DEBUG, "%s: Complete BDP ping err=%s", t->peer_string,
+    gpr_log(GPR_INFO, "%s: Complete BDP ping err=%s", t->peer_string,
             grpc_error_string(error));
   }
   if (error != GRPC_ERROR_NONE) {
@@ -2716,8 +2716,7 @@ static void keepalive_watchdog_fired_locked(void* arg, grpc_error* error) {
 static void connectivity_state_set(grpc_chttp2_transport* t,
                                    grpc_connectivity_state state,
                                    grpc_error* error, const char* reason) {
-  GRPC_CHTTP2_IF_TRACING(
-      gpr_log(GPR_DEBUG, "set connectivity_state=%d", state));
+  GRPC_CHTTP2_IF_TRACING(gpr_log(GPR_INFO, "set connectivity_state=%d", state));
   grpc_connectivity_state_set(&t->channel_callback.state_tracker, state, error,
                               reason);
 }
@@ -2984,7 +2983,7 @@ static void benign_reclaimer_locked(void* arg, grpc_error* error) {
     /* Channel with no active streams: send a goaway to try and make it
      * disconnect cleanly */
     if (grpc_resource_quota_trace.enabled()) {
-      gpr_log(GPR_DEBUG, "HTTP2: %s - send goaway to free memory",
+      gpr_log(GPR_INFO, "HTTP2: %s - send goaway to free memory",
               t->peer_string);
     }
     send_goaway(t,
@@ -2992,7 +2991,7 @@ static void benign_reclaimer_locked(void* arg, grpc_error* error) {
                     GRPC_ERROR_CREATE_FROM_STATIC_STRING("Buffers full"),
                     GRPC_ERROR_INT_HTTP2_ERROR, GRPC_HTTP2_ENHANCE_YOUR_CALM));
   } else if (error == GRPC_ERROR_NONE && grpc_resource_quota_trace.enabled()) {
-    gpr_log(GPR_DEBUG,
+    gpr_log(GPR_INFO,
             "HTTP2: %s - skip benign reclamation, there are still %" PRIdPTR
             " streams",
             t->peer_string, grpc_chttp2_stream_map_size(&t->stream_map));
@@ -3013,7 +3012,7 @@ static void destructive_reclaimer_locked(void* arg, grpc_error* error) {
     grpc_chttp2_stream* s = static_cast<grpc_chttp2_stream*>(
         grpc_chttp2_stream_map_rand(&t->stream_map));
     if (grpc_resource_quota_trace.enabled()) {
-      gpr_log(GPR_DEBUG, "HTTP2: %s - abandon stream id %d", t->peer_string,
+      gpr_log(GPR_INFO, "HTTP2: %s - abandon stream id %d", t->peer_string,
               s->id);
     }
     grpc_chttp2_cancel_stream(
diff --git a/src/core/ext/transport/chttp2/transport/frame_settings.cc b/src/core/ext/transport/chttp2/transport/frame_settings.cc
index 9ea27dcd47..987ac0e79d 100644
--- a/src/core/ext/transport/chttp2/transport/frame_settings.cc
+++ b/src/core/ext/transport/chttp2/transport/frame_settings.cc
@@ -217,14 +217,14 @@ grpc_error* grpc_chttp2_settings_parser_parse(void* p, grpc_chttp2_transport* t,
             t->initial_window_update += static_cast<int64_t>(parser->value) -
                                         parser->incoming_settings[id];
             if (grpc_http_trace.enabled() || grpc_flowctl_trace.enabled()) {
-              gpr_log(GPR_DEBUG, "%p[%s] adding %d for initial_window change",
-                      t, t->is_client ? "cli" : "svr",
+              gpr_log(GPR_INFO, "%p[%s] adding %d for initial_window change", t,
+                      t->is_client ? "cli" : "svr",
                       static_cast<int>(t->initial_window_update));
             }
           }
           parser->incoming_settings[id] = parser->value;
           if (grpc_http_trace.enabled()) {
-            gpr_log(GPR_DEBUG, "CHTTP2:%s:%s: got setting %s = %d",
+            gpr_log(GPR_INFO, "CHTTP2:%s:%s: got setting %s = %d",
                     t->is_client ? "CLI" : "SVR", t->peer_string, sp->name,
                     parser->value);
           }
diff --git a/src/core/ext/transport/chttp2/transport/hpack_encoder.cc b/src/core/ext/transport/chttp2/transport/hpack_encoder.cc
index e4f3c1b81e..d5ef063883 100644
--- a/src/core/ext/transport/chttp2/transport/hpack_encoder.cc
+++ b/src/core/ext/transport/chttp2/transport/hpack_encoder.cc
@@ -470,7 +470,7 @@ static void hpack_enc(grpc_chttp2_hpack_compressor* c, grpc_mdelem elem,
       v = grpc_slice_to_c_string(GRPC_MDVALUE(elem));
     }
     gpr_log(
-        GPR_DEBUG,
+        GPR_INFO,
         "Encode: '%s: %s', elem_interned=%d [%d], k_interned=%d, v_interned=%d",
         k, v, GRPC_MDELEM_IS_INTERNED(elem), GRPC_MDELEM_STORAGE(elem),
         grpc_slice_is_interned(GRPC_MDKEY(elem)),
@@ -654,7 +654,7 @@ void grpc_chttp2_hpack_compressor_set_max_table_size(
   }
   c->advertise_table_size_change = 1;
   if (grpc_http_trace.enabled()) {
-    gpr_log(GPR_DEBUG, "set max table size from encoder to %d", max_table_size);
+    gpr_log(GPR_INFO, "set max table size from encoder to %d", max_table_size);
   }
 }
 
diff --git a/src/core/ext/transport/chttp2/transport/hpack_parser.cc b/src/core/ext/transport/chttp2/transport/hpack_parser.cc
index fc96a8b3e4..907ba71178 100644
--- a/src/core/ext/transport/chttp2/transport/hpack_parser.cc
+++ b/src/core/ext/transport/chttp2/transport/hpack_parser.cc
@@ -633,7 +633,7 @@ static grpc_error* on_hdr(grpc_chttp2_hpack_parser* p, grpc_mdelem md,
       v = grpc_slice_to_c_string(GRPC_MDVALUE(md));
     }
     gpr_log(
-        GPR_DEBUG,
+        GPR_INFO,
         "Decode: '%s: %s', elem_interned=%d [%d], k_interned=%d, v_interned=%d",
         k, v, GRPC_MDELEM_IS_INTERNED(md), GRPC_MDELEM_STORAGE(md),
         grpc_slice_is_interned(GRPC_MDKEY(md)),
diff --git a/src/core/ext/transport/chttp2/transport/hpack_table.cc b/src/core/ext/transport/chttp2/transport/hpack_table.cc
index f050f502f5..7929258356 100644
--- a/src/core/ext/transport/chttp2/transport/hpack_table.cc
+++ b/src/core/ext/transport/chttp2/transport/hpack_table.cc
@@ -247,7 +247,7 @@ void grpc_chttp2_hptbl_set_max_bytes(grpc_chttp2_hptbl* tbl,
     return;
   }
   if (grpc_http_trace.enabled()) {
-    gpr_log(GPR_DEBUG, "Update hpack parser max size to %d", max_bytes);
+    gpr_log(GPR_INFO, "Update hpack parser max size to %d", max_bytes);
   }
   while (tbl->mem_used > max_bytes) {
     evict1(tbl);
@@ -270,7 +270,7 @@ grpc_error* grpc_chttp2_hptbl_set_current_table_size(grpc_chttp2_hptbl* tbl,
     return err;
   }
   if (grpc_http_trace.enabled()) {
-    gpr_log(GPR_DEBUG, "Update hpack parser table size to %d", bytes);
+    gpr_log(GPR_INFO, "Update hpack parser table size to %d", bytes);
   }
   while (tbl->mem_used > bytes) {
     evict1(tbl);
diff --git a/src/core/ext/transport/chttp2/transport/stream_lists.cc b/src/core/ext/transport/chttp2/transport/stream_lists.cc
index 5d3ec4b53b..6626170a7e 100644
--- a/src/core/ext/transport/chttp2/transport/stream_lists.cc
+++ b/src/core/ext/transport/chttp2/transport/stream_lists.cc
@@ -68,7 +68,7 @@ static bool stream_list_pop(grpc_chttp2_transport* t,
   }
   *stream = s;
   if (s && grpc_trace_http2_stream_state.enabled()) {
-    gpr_log(GPR_DEBUG, "%p[%d][%s]: pop from %s", t, s->id,
+    gpr_log(GPR_INFO, "%p[%d][%s]: pop from %s", t, s->id,
             t->is_client ? "cli" : "svr", stream_list_id_string(id));
   }
   return s != nullptr;
@@ -90,7 +90,7 @@ static void stream_list_remove(grpc_chttp2_transport* t, grpc_chttp2_stream* s,
     t->lists[id].tail = s->links[id].prev;
   }
   if (grpc_trace_http2_stream_state.enabled()) {
-    gpr_log(GPR_DEBUG, "%p[%d][%s]: remove from %s", t, s->id,
+    gpr_log(GPR_INFO, "%p[%d][%s]: remove from %s", t, s->id,
             t->is_client ? "cli" : "svr", stream_list_id_string(id));
   }
 }
@@ -122,7 +122,7 @@ static void stream_list_add_tail(grpc_chttp2_transport* t,
   t->lists[id].tail = s;
   s->included[id] = 1;
   if (grpc_trace_http2_stream_state.enabled()) {
-    gpr_log(GPR_DEBUG, "%p[%d][%s]: add to %s", t, s->id,
+    gpr_log(GPR_INFO, "%p[%d][%s]: add to %s", t, s->id,
             t->is_client ? "cli" : "svr", stream_list_id_string(id));
   }
 }
diff --git a/src/core/ext/transport/chttp2/transport/writing.cc b/src/core/ext/transport/chttp2/transport/writing.cc
index 6f32397a3a..85efe27080 100644
--- a/src/core/ext/transport/chttp2/transport/writing.cc
+++ b/src/core/ext/transport/chttp2/transport/writing.cc
@@ -52,7 +52,7 @@ static void maybe_initiate_ping(grpc_chttp2_transport* t) {
   if (!grpc_closure_list_empty(pq->lists[GRPC_CHTTP2_PCL_INFLIGHT])) {
     /* ping already in-flight: wait */
     if (grpc_http_trace.enabled() || grpc_bdp_estimator_trace.enabled()) {
-      gpr_log(GPR_DEBUG, "%s: Ping delayed [%p]: already pinging",
+      gpr_log(GPR_INFO, "%s: Ping delayed [%p]: already pinging",
               t->is_client ? "CLIENT" : "SERVER", t->peer_string);
     }
     return;
@@ -61,7 +61,7 @@ static void maybe_initiate_ping(grpc_chttp2_transport* t) {
       t->ping_policy.max_pings_without_data != 0) {
     /* need to receive something of substance before sending a ping again */
     if (grpc_http_trace.enabled() || grpc_bdp_estimator_trace.enabled()) {
-      gpr_log(GPR_DEBUG, "%s: Ping delayed [%p]: too many recent pings: %d/%d",
+      gpr_log(GPR_INFO, "%s: Ping delayed [%p]: too many recent pings: %d/%d",
               t->is_client ? "CLIENT" : "SERVER", t->peer_string,
               t->ping_state.pings_before_data_required,
               t->ping_policy.max_pings_without_data);
@@ -81,7 +81,7 @@ static void maybe_initiate_ping(grpc_chttp2_transport* t) {
   if (next_allowed_ping > now) {
     /* not enough elapsed time between successive pings */
     if (grpc_http_trace.enabled() || grpc_bdp_estimator_trace.enabled()) {
-      gpr_log(GPR_DEBUG,
+      gpr_log(GPR_INFO,
               "%s: Ping delayed [%p]: not enough time elapsed since last ping. "
               " Last ping %f: Next ping %f: Now %f",
               t->is_client ? "CLIENT" : "SERVER", t->peer_string,
@@ -107,7 +107,7 @@ static void maybe_initiate_ping(grpc_chttp2_transport* t) {
   GRPC_STATS_INC_HTTP2_PINGS_SENT();
   t->ping_state.last_ping_sent_time = now;
   if (grpc_http_trace.enabled() || grpc_bdp_estimator_trace.enabled()) {
-    gpr_log(GPR_DEBUG, "%s: Ping sent [%p]: %d/%d",
+    gpr_log(GPR_INFO, "%s: Ping sent [%p]: %d/%d",
             t->is_client ? "CLIENT" : "SERVER", t->peer_string,
             t->ping_state.pings_before_data_required,
             t->ping_policy.max_pings_without_data);
@@ -401,7 +401,7 @@ class StreamWriteContext {
   StreamWriteContext(WriteContext* write_context, grpc_chttp2_stream* s)
       : write_context_(write_context), t_(write_context->transport()), s_(s) {
     GRPC_CHTTP2_IF_TRACING(
-        gpr_log(GPR_DEBUG, "W:%p %s[%d] im-(sent,send)=(%d,%d) announce=%d", t_,
+        gpr_log(GPR_INFO, "W:%p %s[%d] im-(sent,send)=(%d,%d) announce=%d", t_,
                 t_->is_client ? "CLIENT" : "SERVER", s->id,
                 s->sent_initial_metadata, s->send_initial_metadata != nullptr,
                 (int)(s->flow_control->local_window_delta() -
diff --git a/src/core/ext/transport/inproc/inproc_transport.cc b/src/core/ext/transport/inproc/inproc_transport.cc
index 67a380077b..2c3bff5c1e 100644
--- a/src/core/ext/transport/inproc/inproc_transport.cc
+++ b/src/core/ext/transport/inproc/inproc_transport.cc
@@ -125,12 +125,12 @@ static bool cancel_stream_locked(inproc_stream* s, grpc_error* error);
 static void op_state_machine(void* arg, grpc_error* error);
 
 static void ref_transport(inproc_transport* t) {
-  INPROC_LOG(GPR_DEBUG, "ref_transport %p", t);
+  INPROC_LOG(GPR_INFO, "ref_transport %p", t);
   gpr_ref(&t->refs);
 }
 
 static void really_destroy_transport(inproc_transport* t) {
-  INPROC_LOG(GPR_DEBUG, "really_destroy_transport %p", t);
+  INPROC_LOG(GPR_INFO, "really_destroy_transport %p", t);
   grpc_connectivity_state_destroy(&t->connectivity);
   if (gpr_unref(&t->mu->refs)) {
     gpr_free(t->mu);
@@ -139,7 +139,7 @@ static void really_destroy_transport(inproc_transport* t) {
 }
 
 static void unref_transport(inproc_transport* t) {
-  INPROC_LOG(GPR_DEBUG, "unref_transport %p", t);
+  INPROC_LOG(GPR_INFO, "unref_transport %p", t);
   if (gpr_unref(&t->refs)) {
     really_destroy_transport(t);
   }
@@ -154,17 +154,17 @@ static void unref_transport(inproc_transport* t) {
 #endif
 
 static void ref_stream(inproc_stream* s, const char* reason) {
-  INPROC_LOG(GPR_DEBUG, "ref_stream %p %s", s, reason);
+  INPROC_LOG(GPR_INFO, "ref_stream %p %s", s, reason);
   STREAM_REF(s->refs, reason);
 }
 
 static void unref_stream(inproc_stream* s, const char* reason) {
-  INPROC_LOG(GPR_DEBUG, "unref_stream %p %s", s, reason);
+  INPROC_LOG(GPR_INFO, "unref_stream %p %s", s, reason);
   STREAM_UNREF(s->refs, reason);
 }
 
 static void really_destroy_stream(inproc_stream* s) {
-  INPROC_LOG(GPR_DEBUG, "really_destroy_stream %p", s);
+  INPROC_LOG(GPR_INFO, "really_destroy_stream %p", s);
 
   GRPC_ERROR_UNREF(s->write_buffer_cancel_error);
   GRPC_ERROR_UNREF(s->cancel_self_error);
@@ -225,7 +225,7 @@ static grpc_error* fill_in_metadata(inproc_stream* s,
 static int init_stream(grpc_transport* gt, grpc_stream* gs,
                        grpc_stream_refcount* refcount, const void* server_data,
                        gpr_arena* arena) {
-  INPROC_LOG(GPR_DEBUG, "init_stream %p %p %p", gt, gs, server_data);
+  INPROC_LOG(GPR_INFO, "init_stream %p %p %p", gt, gs, server_data);
   inproc_transport* t = reinterpret_cast<inproc_transport*>(gt);
   inproc_stream* s = reinterpret_cast<inproc_stream*>(gs);
   s->arena = arena;
@@ -282,8 +282,8 @@ static int init_stream(grpc_transport* gt, grpc_stream* gs,
     // Pass the client-side stream address to the server-side for a ref
     ref_stream(s, "inproc_init_stream:clt");  // ref it now on behalf of server
                                               // side to avoid destruction
-    INPROC_LOG(GPR_DEBUG, "calling accept stream cb %p %p",
-               st->accept_stream_cb, st->accept_stream_data);
+    INPROC_LOG(GPR_INFO, "calling accept stream cb %p %p", st->accept_stream_cb,
+               st->accept_stream_data);
     (*st->accept_stream_cb)(st->accept_stream_data, &st->base, (void*)s);
   } else {
     // This is the server-side and is being called through accept_stream_cb
@@ -378,7 +378,7 @@ static void complete_if_batch_end_locked(inproc_stream* s, grpc_error* error,
   int is_rtm = static_cast<int>(op == s->recv_trailing_md_op);
 
   if ((is_sm + is_stm + is_rim + is_rm + is_rtm) == 1) {
-    INPROC_LOG(GPR_DEBUG, "%s %p %p %p", msg, s, op, error);
+    INPROC_LOG(GPR_INFO, "%s %p %p %p", msg, s, op, error);
     GRPC_CLOSURE_SCHED(op->on_complete, GRPC_ERROR_REF(error));
   }
 }
@@ -393,7 +393,7 @@ static void maybe_schedule_op_closure_locked(inproc_stream* s,
 }
 
 static void fail_helper_locked(inproc_stream* s, grpc_error* error) {
-  INPROC_LOG(GPR_DEBUG, "op_state_machine %p fail_helper", s);
+  INPROC_LOG(GPR_INFO, "op_state_machine %p fail_helper", s);
   // If we're failing this side, we need to make sure that
   // we also send or have already sent trailing metadata
   if (!s->trailing_md_sent) {
@@ -458,7 +458,7 @@ static void fail_helper_locked(inproc_stream* s, grpc_error* error) {
       *s->recv_initial_md_op->payload->recv_initial_metadata
            .trailing_metadata_available = true;
     }
-    INPROC_LOG(GPR_DEBUG,
+    INPROC_LOG(GPR_INFO,
                "fail_helper %p scheduling initial-metadata-ready %p %p", s,
                error, err);
     GRPC_CLOSURE_SCHED(s->recv_initial_md_op->payload->recv_initial_metadata
@@ -472,7 +472,7 @@ static void fail_helper_locked(inproc_stream* s, grpc_error* error) {
     s->recv_initial_md_op = nullptr;
   }
   if (s->recv_message_op) {
-    INPROC_LOG(GPR_DEBUG, "fail_helper %p scheduling message-ready %p", s,
+    INPROC_LOG(GPR_INFO, "fail_helper %p scheduling message-ready %p", s,
                error);
     GRPC_CLOSURE_SCHED(
         s->recv_message_op->payload->recv_message.recv_message_ready,
@@ -496,9 +496,8 @@ static void fail_helper_locked(inproc_stream* s, grpc_error* error) {
     s->send_trailing_md_op = nullptr;
   }
   if (s->recv_trailing_md_op) {
-    INPROC_LOG(GPR_DEBUG,
-               "fail_helper %p scheduling trailing-md-on-complete %p", s,
-               error);
+    INPROC_LOG(GPR_INFO, "fail_helper %p scheduling trailing-md-on-complete %p",
+               s, error);
     complete_if_batch_end_locked(
         s, error, s->recv_trailing_md_op,
         "fail_helper scheduling recv-trailing-metadata-on-complete");
@@ -549,7 +548,7 @@ static void message_transfer_locked(inproc_stream* sender,
   receiver->recv_stream.Init(&receiver->recv_message, 0);
   receiver->recv_message_op->payload->recv_message.recv_message->reset(
       receiver->recv_stream.get());
-  INPROC_LOG(GPR_DEBUG, "message_transfer_locked %p scheduling message-ready",
+  INPROC_LOG(GPR_INFO, "message_transfer_locked %p scheduling message-ready",
              receiver);
   GRPC_CLOSURE_SCHED(
       receiver->recv_message_op->payload->recv_message.recv_message_ready,
@@ -577,7 +576,7 @@ static void op_state_machine(void* arg, grpc_error* error) {
 
   bool needs_close = false;
 
-  INPROC_LOG(GPR_DEBUG, "op_state_machine %p", arg);
+  INPROC_LOG(GPR_INFO, "op_state_machine %p", arg);
   inproc_stream* s = static_cast<inproc_stream*>(arg);
   gpr_mu* mu = &s->t->mu->mu;  // keep aside in case s gets closed
   gpr_mu_lock(mu);
@@ -626,7 +625,7 @@ static void op_state_machine(void* arg, grpc_error* error) {
                                           : &other->to_read_trailing_md_filled;
     if (*destfilled || s->trailing_md_sent) {
       // The buffer is already in use; that's an error!
-      INPROC_LOG(GPR_DEBUG, "Extra trailing metadata %p", s);
+      INPROC_LOG(GPR_INFO, "Extra trailing metadata %p", s);
       new_err = GRPC_ERROR_CREATE_FROM_STATIC_STRING("Extra trailing metadata");
       fail_helper_locked(s, GRPC_ERROR_REF(new_err));
       goto done;
@@ -639,7 +638,7 @@ static void op_state_machine(void* arg, grpc_error* error) {
       }
       s->trailing_md_sent = true;
       if (!s->t->is_client && s->trailing_md_recvd && s->recv_trailing_md_op) {
-        INPROC_LOG(GPR_DEBUG,
+        INPROC_LOG(GPR_INFO,
                    "op_state_machine %p scheduling trailing-md-on-complete", s);
         GRPC_CLOSURE_SCHED(s->recv_trailing_md_op->on_complete,
                            GRPC_ERROR_NONE);
@@ -658,7 +657,7 @@ static void op_state_machine(void* arg, grpc_error* error) {
       new_err =
           GRPC_ERROR_CREATE_FROM_STATIC_STRING("Already recvd initial md");
       INPROC_LOG(
-          GPR_DEBUG,
+          GPR_INFO,
           "op_state_machine %p scheduling on_complete errors for already "
           "recvd initial md %p",
           s, new_err);
@@ -684,7 +683,7 @@ static void op_state_machine(void* arg, grpc_error* error) {
       }
       grpc_metadata_batch_clear(&s->to_read_initial_md);
       s->to_read_initial_md_filled = false;
-      INPROC_LOG(GPR_DEBUG,
+      INPROC_LOG(GPR_INFO,
                  "op_state_machine %p scheduling initial-metadata-ready %p", s,
                  new_err);
       GRPC_CLOSURE_SCHED(s->recv_initial_md_op->payload->recv_initial_metadata
@@ -696,7 +695,7 @@ static void op_state_machine(void* arg, grpc_error* error) {
       s->recv_initial_md_op = nullptr;
 
       if (new_err != GRPC_ERROR_NONE) {
-        INPROC_LOG(GPR_DEBUG,
+        INPROC_LOG(GPR_INFO,
                    "op_state_machine %p scheduling on_complete errors2 %p", s,
                    new_err);
         fail_helper_locked(s, GRPC_ERROR_REF(new_err));
@@ -719,7 +718,7 @@ static void op_state_machine(void* arg, grpc_error* error) {
       new_err =
           GRPC_ERROR_CREATE_FROM_STATIC_STRING("Already recvd trailing md");
       INPROC_LOG(
-          GPR_DEBUG,
+          GPR_INFO,
           "op_state_machine %p scheduling on_complete errors for already "
           "recvd trailing md %p",
           s, new_err);
@@ -729,7 +728,7 @@ static void op_state_machine(void* arg, grpc_error* error) {
     if (s->recv_message_op != nullptr) {
       // This message needs to be wrapped up because it will never be
       // satisfied
-      INPROC_LOG(GPR_DEBUG, "op_state_machine %p scheduling message-ready", s);
+      INPROC_LOG(GPR_INFO, "op_state_machine %p scheduling message-ready", s);
       GRPC_CLOSURE_SCHED(
           s->recv_message_op->payload->recv_message.recv_message_ready,
           GRPC_ERROR_NONE);
@@ -764,7 +763,7 @@ static void op_state_machine(void* arg, grpc_error* error) {
       //    (If the server hasn't already sent its trailing md, it doesn't have
       //     a final status, so don't mark this op complete)
       if (s->t->is_client || s->trailing_md_sent) {
-        INPROC_LOG(GPR_DEBUG,
+        INPROC_LOG(GPR_INFO,
                    "op_state_machine %p scheduling trailing-md-on-complete %p",
                    s, new_err);
         GRPC_CLOSURE_SCHED(s->recv_trailing_md_op->on_complete,
@@ -772,21 +771,21 @@ static void op_state_machine(void* arg, grpc_error* error) {
         s->recv_trailing_md_op = nullptr;
         needs_close = true;
       } else {
-        INPROC_LOG(GPR_DEBUG,
+        INPROC_LOG(GPR_INFO,
                    "op_state_machine %p server needs to delay handling "
                    "trailing-md-on-complete %p",
                    s, new_err);
       }
     } else {
       INPROC_LOG(
-          GPR_DEBUG,
+          GPR_INFO,
           "op_state_machine %p has trailing md but not yet waiting for it", s);
     }
   }
   if (s->trailing_md_recvd && s->recv_message_op) {
     // No further message will come on this stream, so finish off the
     // recv_message_op
-    INPROC_LOG(GPR_DEBUG, "op_state_machine %p scheduling message-ready", s);
+    INPROC_LOG(GPR_INFO, "op_state_machine %p scheduling message-ready", s);
     GRPC_CLOSURE_SCHED(
         s->recv_message_op->payload->recv_message.recv_message_ready,
         GRPC_ERROR_NONE);
@@ -810,7 +809,7 @@ static void op_state_machine(void* arg, grpc_error* error) {
     // Didn't get the item we wanted so we still need to get
     // rescheduled
     INPROC_LOG(
-        GPR_DEBUG, "op_state_machine %p still needs closure %p %p %p %p %p", s,
+        GPR_INFO, "op_state_machine %p still needs closure %p %p %p %p %p", s,
         s->send_message_op, s->send_trailing_md_op, s->recv_initial_md_op,
         s->recv_message_op, s->recv_trailing_md_op);
     s->ops_needed = true;
@@ -826,8 +825,7 @@ done:
 
 static bool cancel_stream_locked(inproc_stream* s, grpc_error* error) {
   bool ret = false;  // was the cancel accepted
-  INPROC_LOG(GPR_DEBUG, "cancel_stream %p with %s", s,
-             grpc_error_string(error));
+  INPROC_LOG(GPR_INFO, "cancel_stream %p with %s", s, grpc_error_string(error));
   if (s->cancel_self_error == GRPC_ERROR_NONE) {
     ret = true;
     s->cancel_self_error = GRPC_ERROR_REF(error);
@@ -877,7 +875,7 @@ static bool cancel_stream_locked(inproc_stream* s, grpc_error* error) {
 
 static void perform_stream_op(grpc_transport* gt, grpc_stream* gs,
                               grpc_transport_stream_op_batch* op) {
-  INPROC_LOG(GPR_DEBUG, "perform_stream_op %p %p %p", gt, gs, op);
+  INPROC_LOG(GPR_INFO, "perform_stream_op %p %p %p", gt, gs, op);
   inproc_stream* s = reinterpret_cast<inproc_stream*>(gs);
   gpr_mu* mu = &s->t->mu->mu;  // save aside in case s gets closed
   gpr_mu_lock(mu);
@@ -907,7 +905,7 @@ static void perform_stream_op(grpc_transport* gt, grpc_stream* gs,
     // already self-canceled so still give it an error
     error = GRPC_ERROR_REF(s->cancel_self_error);
   } else {
-    INPROC_LOG(GPR_DEBUG, "perform_stream_op %p %s%s%s%s%s%s%s", s,
+    INPROC_LOG(GPR_INFO, "perform_stream_op %p %s%s%s%s%s%s%s", s,
                s->t->is_client ? "client" : "server",
                op->send_initial_metadata ? " send_initial_metadata" : "",
                op->send_message ? " send_message" : "",
@@ -936,7 +934,7 @@ static void perform_stream_op(grpc_transport* gt, grpc_stream* gs,
                                             : &other->to_read_initial_md_filled;
       if (*destfilled || s->initial_md_sent) {
         // The buffer is already in use; that's an error!
-        INPROC_LOG(GPR_DEBUG, "Extra initial metadata %p", s);
+        INPROC_LOG(GPR_INFO, "Extra initial metadata %p", s);
         error = GRPC_ERROR_CREATE_FROM_STATIC_STRING("Extra initial metadata");
       } else {
         if (!other || !other->closed) {
@@ -1013,7 +1011,7 @@ static void perform_stream_op(grpc_transport* gt, grpc_stream* gs,
               true;
         }
         INPROC_LOG(
-            GPR_DEBUG,
+            GPR_INFO,
             "perform_stream_op error %p scheduling initial-metadata-ready %p",
             s, error);
         GRPC_CLOSURE_SCHED(
@@ -1022,14 +1020,14 @@ static void perform_stream_op(grpc_transport* gt, grpc_stream* gs,
       }
       if (op->recv_message) {
         INPROC_LOG(
-            GPR_DEBUG,
+            GPR_INFO,
             "perform_stream_op error %p scheduling recv message-ready %p", s,
             error);
         GRPC_CLOSURE_SCHED(op->payload->recv_message.recv_message_ready,
                            GRPC_ERROR_REF(error));
       }
     }
-    INPROC_LOG(GPR_DEBUG, "perform_stream_op %p scheduling on_complete %p", s,
+    INPROC_LOG(GPR_INFO, "perform_stream_op %p scheduling on_complete %p", s,
                error);
     GRPC_CLOSURE_SCHED(on_complete, GRPC_ERROR_REF(error));
   }
@@ -1042,7 +1040,7 @@ static void perform_stream_op(grpc_transport* gt, grpc_stream* gs,
 }
 
 static void close_transport_locked(inproc_transport* t) {
-  INPROC_LOG(GPR_DEBUG, "close_transport %p %d", t, t->is_closed);
+  INPROC_LOG(GPR_INFO, "close_transport %p %d", t, t->is_closed);
   grpc_connectivity_state_set(
       &t->connectivity, GRPC_CHANNEL_SHUTDOWN,
       GRPC_ERROR_CREATE_FROM_STATIC_STRING("Closing transport."),
@@ -1063,7 +1061,7 @@ static void close_transport_locked(inproc_transport* t) {
 
 static void perform_transport_op(grpc_transport* gt, grpc_transport_op* op) {
   inproc_transport* t = reinterpret_cast<inproc_transport*>(gt);
-  INPROC_LOG(GPR_DEBUG, "perform_transport_op %p %p", t, op);
+  INPROC_LOG(GPR_INFO, "perform_transport_op %p %p", t, op);
   gpr_mu_lock(&t->mu->mu);
   if (op->on_connectivity_state_change) {
     grpc_connectivity_state_notify_on_state_change(
@@ -1096,7 +1094,7 @@ static void perform_transport_op(grpc_transport* gt, grpc_transport_op* op) {
 
 static void destroy_stream(grpc_transport* gt, grpc_stream* gs,
                            grpc_closure* then_schedule_closure) {
-  INPROC_LOG(GPR_DEBUG, "destroy_stream %p %p", gs, then_schedule_closure);
+  INPROC_LOG(GPR_INFO, "destroy_stream %p %p", gs, then_schedule_closure);
   inproc_stream* s = reinterpret_cast<inproc_stream*>(gs);
   s->closure_at_destroy = then_schedule_closure;
   really_destroy_stream(s);
@@ -1104,7 +1102,7 @@ static void destroy_stream(grpc_transport* gt, grpc_stream* gs,
 
 static void destroy_transport(grpc_transport* gt) {
   inproc_transport* t = reinterpret_cast<inproc_transport*>(gt);
-  INPROC_LOG(GPR_DEBUG, "destroy_transport %p", t);
+  INPROC_LOG(GPR_INFO, "destroy_transport %p", t);
   gpr_mu_lock(&t->mu->mu);
   close_transport_locked(t);
   gpr_mu_unlock(&t->mu->mu);
@@ -1165,7 +1163,7 @@ static void inproc_transports_create(grpc_transport** server_transport,
                                      const grpc_channel_args* server_args,
                                      grpc_transport** client_transport,
                                      const grpc_channel_args* client_args) {
-  INPROC_LOG(GPR_DEBUG, "inproc_transports_create");
+  INPROC_LOG(GPR_INFO, "inproc_transports_create");
   inproc_transport* st =
       static_cast<inproc_transport*>(gpr_zalloc(sizeof(*st)));
   inproc_transport* ct =
diff --git a/src/core/lib/channel/channel_args.cc b/src/core/lib/channel/channel_args.cc
index 66a86c2286..e49d532e11 100644
--- a/src/core/lib/channel/channel_args.cc
+++ b/src/core/lib/channel/channel_args.cc
@@ -411,3 +411,31 @@ grpc_arg grpc_channel_arg_pointer_create(
   arg.value.pointer.vtable = vtable;
   return arg;
 }
+
+char* grpc_channel_args_string(const grpc_channel_args* args) {
+  if (args == nullptr) return nullptr;
+  gpr_strvec v;
+  gpr_strvec_init(&v);
+  for (size_t i = 0; i < args->num_args; ++i) {
+    const grpc_arg& arg = args->args[i];
+    char* s;
+    switch (arg.type) {
+      case GRPC_ARG_INTEGER:
+        gpr_asprintf(&s, "%s=%d", arg.key, arg.value.integer);
+        break;
+      case GRPC_ARG_STRING:
+        gpr_asprintf(&s, "%s=%s", arg.key, arg.value.string);
+        break;
+      case GRPC_ARG_POINTER:
+        gpr_asprintf(&s, "%s=%p", arg.key, arg.value.pointer.p);
+        break;
+      default:
+        gpr_asprintf(&s, "arg with unknown type");
+    }
+    gpr_strvec_add(&v, s);
+  }
+  char* result =
+      gpr_strjoin_sep(const_cast<const char**>(v.strs), v.count, ", ", nullptr);
+  gpr_strvec_destroy(&v);
+  return result;
+}
diff --git a/src/core/lib/channel/channel_args.h b/src/core/lib/channel/channel_args.h
index c0d6a17356..5ff303a9dc 100644
--- a/src/core/lib/channel/channel_args.h
+++ b/src/core/lib/channel/channel_args.h
@@ -124,4 +124,8 @@ grpc_arg grpc_channel_arg_integer_create(char* name, int value);
 grpc_arg grpc_channel_arg_pointer_create(char* name, void* value,
                                          const grpc_arg_pointer_vtable* vtable);
 
+// Returns a string representing channel args in human-readable form.
+// Callers takes ownership of result.
+char* grpc_channel_args_string(const grpc_channel_args* args);
+
 #endif /* GRPC_CORE_LIB_CHANNEL_CHANNEL_ARGS_H */
diff --git a/src/core/lib/channel/handshaker.cc b/src/core/lib/channel/handshaker.cc
index 9b1af8d6cb..2faeb64cb6 100644
--- a/src/core/lib/channel/handshaker.cc
+++ b/src/core/lib/channel/handshaker.cc
@@ -22,11 +22,15 @@
 
 #include <grpc/support/alloc.h>
 #include <grpc/support/log.h>
+#include <grpc/support/string_util.h>
 
 #include "src/core/lib/channel/channel_args.h"
 #include "src/core/lib/channel/handshaker.h"
+#include "src/core/lib/debug/trace.h"
 #include "src/core/lib/iomgr/timer.h"
 
+grpc_core::TraceFlag grpc_handshaker_trace(false, "handshaker");
+
 //
 // grpc_handshaker
 //
@@ -52,6 +56,10 @@ void grpc_handshaker_do_handshake(grpc_handshaker* handshaker,
                                    args);
 }
 
+const char* grpc_handshaker_name(grpc_handshaker* handshaker) {
+  return handshaker->vtable->name;
+}
+
 //
 // grpc_handshake_manager
 //
@@ -127,6 +135,12 @@ static bool is_power_of_2(size_t n) { return (n & (n - 1)) == 0; }
 
 void grpc_handshake_manager_add(grpc_handshake_manager* mgr,
                                 grpc_handshaker* handshaker) {
+  if (grpc_handshaker_trace.enabled()) {
+    gpr_log(
+        GPR_INFO,
+        "handshake_manager %p: adding handshaker %s [%p] at index %" PRIuPTR,
+        mgr, grpc_handshaker_name(handshaker), handshaker, mgr->count);
+  }
   gpr_mu_lock(&mgr->mu);
   // To avoid allocating memory for each handshaker we add, we double
   // the number of elements every time we need more.
@@ -172,23 +186,56 @@ void grpc_handshake_manager_shutdown(grpc_handshake_manager* mgr,
   GRPC_ERROR_UNREF(why);
 }
 
+static char* handshaker_args_string(grpc_handshaker_args* args) {
+  char* args_str = grpc_channel_args_string(args->args);
+  size_t num_args = args->args != nullptr ? args->args->num_args : 0;
+  size_t read_buffer_length =
+      args->read_buffer != nullptr ? args->read_buffer->length : 0;
+  char* str;
+  gpr_asprintf(&str,
+               "{endpoint=%p, args=%p {size=%" PRIuPTR
+               ": %s}, read_buffer=%p (length=%" PRIuPTR "), exit_early=%d}",
+               args->endpoint, args->args, num_args, args_str,
+               args->read_buffer, read_buffer_length, args->exit_early);
+  gpr_free(args_str);
+  return str;
+}
+
 // Helper function to call either the next handshaker or the
 // on_handshake_done callback.
 // Returns true if we've scheduled the on_handshake_done callback.
 static bool call_next_handshaker_locked(grpc_handshake_manager* mgr,
                                         grpc_error* error) {
+  if (grpc_handshaker_trace.enabled()) {
+    char* args_str = handshaker_args_string(&mgr->args);
+    gpr_log(GPR_INFO,
+            "handshake_manager %p: error=%s shutdown=%d index=%" PRIuPTR
+            ", args=%s",
+            mgr, grpc_error_string(error), mgr->shutdown, mgr->index, args_str);
+    gpr_free(args_str);
+  }
   GPR_ASSERT(mgr->index <= mgr->count);
   // If we got an error or we've been shut down or we're exiting early or
   // we've finished the last handshaker, invoke the on_handshake_done
   // callback.  Otherwise, call the next handshaker.
   if (error != GRPC_ERROR_NONE || mgr->shutdown || mgr->args.exit_early ||
       mgr->index == mgr->count) {
+    if (grpc_handshaker_trace.enabled()) {
+      gpr_log(GPR_INFO, "handshake_manager %p: handshaking complete", mgr);
+    }
     // Cancel deadline timer, since we're invoking the on_handshake_done
     // callback now.
     grpc_timer_cancel(&mgr->deadline_timer);
     GRPC_CLOSURE_SCHED(&mgr->on_handshake_done, error);
     mgr->shutdown = true;
   } else {
+    if (grpc_handshaker_trace.enabled()) {
+      gpr_log(
+          GPR_INFO,
+          "handshake_manager %p: calling handshaker %s [%p] at index %" PRIuPTR,
+          mgr, grpc_handshaker_name(mgr->handshakers[mgr->index]),
+          mgr->handshakers[mgr->index], mgr->index);
+    }
     grpc_handshaker_do_handshake(mgr->handshakers[mgr->index], mgr->acceptor,
                                  &mgr->call_next_handshaker, &mgr->args);
   }
diff --git a/src/core/lib/channel/handshaker.h b/src/core/lib/channel/handshaker.h
index dfecd81004..be7fd127e4 100644
--- a/src/core/lib/channel/handshaker.h
+++ b/src/core/lib/channel/handshaker.h
@@ -84,6 +84,9 @@ typedef struct {
                        grpc_tcp_server_acceptor* acceptor,
                        grpc_closure* on_handshake_done,
                        grpc_handshaker_args* args);
+
+  /// The name of the handshaker, for debugging purposes.
+  const char* name;
 } grpc_handshaker_vtable;
 
 /// Base struct.  To subclass, make this the first member of the
@@ -102,6 +105,7 @@ void grpc_handshaker_do_handshake(grpc_handshaker* handshaker,
                                   grpc_tcp_server_acceptor* acceptor,
                                   grpc_closure* on_handshake_done,
                                   grpc_handshaker_args* args);
+const char* grpc_handshaker_name(grpc_handshaker* handshaker);
 
 ///
 /// grpc_handshake_manager
diff --git a/src/core/lib/debug/trace.h b/src/core/lib/debug/trace.h
index bfec92c529..28157c6383 100644
--- a/src/core/lib/debug/trace.h
+++ b/src/core/lib/debug/trace.h
@@ -57,13 +57,22 @@ class TraceFlag {
 
   const char* name() const { return name_; }
 
+// This following define may be commented out to ensure that the compiler
+// deletes any "if (tracer.enabled()) {...}" codeblocks. This is useful to
+// test the performance impact tracers have on the system.
+//
+// #define COMPILE_OUT_ALL_TRACERS_IN_OPT_BUILD
+#ifdef COMPILE_OUT_ALL_TRACERS_IN_OPT_BUILD
+  bool enabled() { return false; }
+#else
   bool enabled() {
 #ifdef GRPC_THREADSAFE_TRACER
     return gpr_atm_no_barrier_load(&value_) != 0;
 #else
     return value_;
-#endif
+#endif  // GRPC_THREADSAFE_TRACER
   }
+#endif  // COMPILE_OUT_ALL_TRACERS_IN_OPT_BUILD
 
  private:
   friend void grpc_core::testing::grpc_tracer_enable_flag(TraceFlag* flag);
diff --git a/src/core/lib/gprpp/orphanable.h b/src/core/lib/gprpp/orphanable.h
index a5bc8d8efc..73a73995c7 100644
--- a/src/core/lib/gprpp/orphanable.h
+++ b/src/core/lib/gprpp/orphanable.h
@@ -100,7 +100,7 @@ class InternallyRefCounted : public Orphanable {
 
   void Unref() {
     if (gpr_unref(&refs_)) {
-      Delete(this);
+      Delete(static_cast<Child*>(this));
     }
   }
 
@@ -159,7 +159,7 @@ class InternallyRefCountedWithTracing : public Orphanable {
                            const char* reason) GRPC_MUST_USE_RESULT {
     if (location.Log() && trace_flag_ != nullptr && trace_flag_->enabled()) {
       gpr_atm old_refs = gpr_atm_no_barrier_load(&refs_.count);
-      gpr_log(GPR_DEBUG, "%s:%p %s:%d ref %" PRIdPTR " -> %" PRIdPTR " %s",
+      gpr_log(GPR_INFO, "%s:%p %s:%d ref %" PRIdPTR " -> %" PRIdPTR " %s",
               trace_flag_->name(), this, location.file(), location.line(),
               old_refs, old_refs + 1, reason);
     }
@@ -173,14 +173,14 @@ class InternallyRefCountedWithTracing : public Orphanable {
 
   void Unref() {
     if (gpr_unref(&refs_)) {
-      Delete(this);
+      Delete(static_cast<Child*>(this));
     }
   }
 
   void Unref(const DebugLocation& location, const char* reason) {
     if (location.Log() && trace_flag_ != nullptr && trace_flag_->enabled()) {
       gpr_atm old_refs = gpr_atm_no_barrier_load(&refs_.count);
-      gpr_log(GPR_DEBUG, "%s:%p %s:%d unref %" PRIdPTR " -> %" PRIdPTR " %s",
+      gpr_log(GPR_INFO, "%s:%p %s:%d unref %" PRIdPTR " -> %" PRIdPTR " %s",
               trace_flag_->name(), this, location.file(), location.line(),
               old_refs, old_refs - 1, reason);
     }
diff --git a/src/core/lib/gprpp/ref_counted.h b/src/core/lib/gprpp/ref_counted.h
index 46bfaf7fb8..c67e3f315c 100644
--- a/src/core/lib/gprpp/ref_counted.h
+++ b/src/core/lib/gprpp/ref_counted.h
@@ -54,7 +54,7 @@ class RefCounted {
   // friend of this class.
   void Unref() {
     if (gpr_unref(&refs_)) {
-      Delete(this);
+      Delete(static_cast<Child*>(this));
     }
   }
 
@@ -100,7 +100,7 @@ class RefCountedWithTracing {
                            const char* reason) GRPC_MUST_USE_RESULT {
     if (location.Log() && trace_flag_ != nullptr && trace_flag_->enabled()) {
       gpr_atm old_refs = gpr_atm_no_barrier_load(&refs_.count);
-      gpr_log(GPR_DEBUG, "%s:%p %s:%d ref %" PRIdPTR " -> %" PRIdPTR " %s",
+      gpr_log(GPR_INFO, "%s:%p %s:%d ref %" PRIdPTR " -> %" PRIdPTR " %s",
               trace_flag_->name(), this, location.file(), location.line(),
               old_refs, old_refs + 1, reason);
     }
@@ -114,14 +114,14 @@ class RefCountedWithTracing {
 
   void Unref() {
     if (gpr_unref(&refs_)) {
-      Delete(this);
+      Delete(static_cast<Child*>(this));
     }
   }
 
   void Unref(const DebugLocation& location, const char* reason) {
     if (location.Log() && trace_flag_ != nullptr && trace_flag_->enabled()) {
       gpr_atm old_refs = gpr_atm_no_barrier_load(&refs_.count);
-      gpr_log(GPR_DEBUG, "%s:%p %s:%d unref %" PRIdPTR " -> %" PRIdPTR " %s",
+      gpr_log(GPR_INFO, "%s:%p %s:%d unref %" PRIdPTR " -> %" PRIdPTR " %s",
               trace_flag_->name(), this, location.file(), location.line(),
               old_refs, old_refs - 1, reason);
     }
diff --git a/src/core/lib/iomgr/call_combiner.cc b/src/core/lib/iomgr/call_combiner.cc
index 24e11b687b..00a839b64c 100644
--- a/src/core/lib/iomgr/call_combiner.cc
+++ b/src/core/lib/iomgr/call_combiner.cc
@@ -64,7 +64,7 @@ void grpc_call_combiner_start(grpc_call_combiner* call_combiner,
                               const char* reason) {
   GPR_TIMER_SCOPE("call_combiner_start", 0);
   if (grpc_call_combiner_trace.enabled()) {
-    gpr_log(GPR_DEBUG,
+    gpr_log(GPR_INFO,
             "==> grpc_call_combiner_start() [%p] closure=%p [" DEBUG_FMT_STR
             "%s] error=%s",
             call_combiner, closure DEBUG_FMT_ARGS, reason,
@@ -73,7 +73,7 @@ void grpc_call_combiner_start(grpc_call_combiner* call_combiner,
   size_t prev_size = static_cast<size_t>(
       gpr_atm_full_fetch_add(&call_combiner->size, (gpr_atm)1));
   if (grpc_call_combiner_trace.enabled()) {
-    gpr_log(GPR_DEBUG, "  size: %" PRIdPTR " -> %" PRIdPTR, prev_size,
+    gpr_log(GPR_INFO, "  size: %" PRIdPTR " -> %" PRIdPTR, prev_size,
             prev_size + 1);
   }
   GRPC_STATS_INC_CALL_COMBINER_LOCKS_SCHEDULED_ITEMS();
@@ -82,7 +82,7 @@ void grpc_call_combiner_start(grpc_call_combiner* call_combiner,
 
     GPR_TIMER_MARK("call_combiner_initiate", 0);
     if (grpc_call_combiner_trace.enabled()) {
-      gpr_log(GPR_DEBUG, "  EXECUTING IMMEDIATELY");
+      gpr_log(GPR_INFO, "  EXECUTING IMMEDIATELY");
     }
     // Queue was empty, so execute this closure immediately.
     GRPC_CLOSURE_SCHED(closure, error);
@@ -101,21 +101,21 @@ void grpc_call_combiner_stop(grpc_call_combiner* call_combiner DEBUG_ARGS,
                              const char* reason) {
   GPR_TIMER_SCOPE("call_combiner_stop", 0);
   if (grpc_call_combiner_trace.enabled()) {
-    gpr_log(GPR_DEBUG,
+    gpr_log(GPR_INFO,
             "==> grpc_call_combiner_stop() [%p] [" DEBUG_FMT_STR "%s]",
             call_combiner DEBUG_FMT_ARGS, reason);
   }
   size_t prev_size = static_cast<size_t>(
       gpr_atm_full_fetch_add(&call_combiner->size, (gpr_atm)-1));
   if (grpc_call_combiner_trace.enabled()) {
-    gpr_log(GPR_DEBUG, "  size: %" PRIdPTR " -> %" PRIdPTR, prev_size,
+    gpr_log(GPR_INFO, "  size: %" PRIdPTR " -> %" PRIdPTR, prev_size,
             prev_size - 1);
   }
   GPR_ASSERT(prev_size >= 1);
   if (prev_size > 1) {
     while (true) {
       if (grpc_call_combiner_trace.enabled()) {
-        gpr_log(GPR_DEBUG, "  checking queue");
+        gpr_log(GPR_INFO, "  checking queue");
       }
       bool empty;
       grpc_closure* closure = reinterpret_cast<grpc_closure*>(
@@ -124,19 +124,19 @@ void grpc_call_combiner_stop(grpc_call_combiner* call_combiner DEBUG_ARGS,
         // This can happen either due to a race condition within the mpscq
         // code or because of a race with grpc_call_combiner_start().
         if (grpc_call_combiner_trace.enabled()) {
-          gpr_log(GPR_DEBUG, "  queue returned no result; checking again");
+          gpr_log(GPR_INFO, "  queue returned no result; checking again");
         }
         continue;
       }
       if (grpc_call_combiner_trace.enabled()) {
-        gpr_log(GPR_DEBUG, "  EXECUTING FROM QUEUE: closure=%p error=%s",
+        gpr_log(GPR_INFO, "  EXECUTING FROM QUEUE: closure=%p error=%s",
                 closure, grpc_error_string(closure->error_data.error));
       }
       GRPC_CLOSURE_SCHED(closure, closure->error_data.error);
       break;
     }
   } else if (grpc_call_combiner_trace.enabled()) {
-    gpr_log(GPR_DEBUG, "  queue empty");
+    gpr_log(GPR_INFO, "  queue empty");
   }
 }
 
@@ -151,7 +151,7 @@ void grpc_call_combiner_set_notify_on_cancel(grpc_call_combiner* call_combiner,
     // Otherwise, store the new closure.
     if (original_error != GRPC_ERROR_NONE) {
       if (grpc_call_combiner_trace.enabled()) {
-        gpr_log(GPR_DEBUG,
+        gpr_log(GPR_INFO,
                 "call_combiner=%p: scheduling notify_on_cancel callback=%p "
                 "for pre-existing cancellation",
                 call_combiner, closure);
@@ -162,7 +162,7 @@ void grpc_call_combiner_set_notify_on_cancel(grpc_call_combiner* call_combiner,
       if (gpr_atm_full_cas(&call_combiner->cancel_state, original_state,
                            (gpr_atm)closure)) {
         if (grpc_call_combiner_trace.enabled()) {
-          gpr_log(GPR_DEBUG, "call_combiner=%p: setting notify_on_cancel=%p",
+          gpr_log(GPR_INFO, "call_combiner=%p: setting notify_on_cancel=%p",
                   call_combiner, closure);
         }
         // If we replaced an earlier closure, invoke the original
@@ -171,7 +171,7 @@ void grpc_call_combiner_set_notify_on_cancel(grpc_call_combiner* call_combiner,
         if (original_state != 0) {
           closure = (grpc_closure*)original_state;
           if (grpc_call_combiner_trace.enabled()) {
-            gpr_log(GPR_DEBUG,
+            gpr_log(GPR_INFO,
                     "call_combiner=%p: scheduling old cancel callback=%p",
                     call_combiner, closure);
           }
@@ -199,7 +199,7 @@ void grpc_call_combiner_cancel(grpc_call_combiner* call_combiner,
       if (original_state != 0) {
         grpc_closure* notify_on_cancel = (grpc_closure*)original_state;
         if (grpc_call_combiner_trace.enabled()) {
-          gpr_log(GPR_DEBUG,
+          gpr_log(GPR_INFO,
                   "call_combiner=%p: scheduling notify_on_cancel callback=%p",
                   call_combiner, notify_on_cancel);
         }
diff --git a/src/core/lib/iomgr/closure.h b/src/core/lib/iomgr/closure.h
index 64527d6bb1..34a494485d 100644
--- a/src/core/lib/iomgr/closure.h
+++ b/src/core/lib/iomgr/closure.h
@@ -253,8 +253,8 @@ inline void grpc_closure_run(grpc_closure* c, grpc_error* error) {
     c->file_initiated = file;
     c->line_initiated = line;
     c->run = true;
+    GPR_ASSERT(c->cb != nullptr);
 #endif
-    assert(c->cb);
     c->scheduler->vtable->run(c, error);
   } else {
     GRPC_ERROR_UNREF(error);
@@ -292,8 +292,8 @@ inline void grpc_closure_sched(grpc_closure* c, grpc_error* error) {
     c->file_initiated = file;
     c->line_initiated = line;
     c->run = false;
+    GPR_ASSERT(c->cb != nullptr);
 #endif
-    assert(c->cb);
     c->scheduler->vtable->sched(c, error);
   } else {
     GRPC_ERROR_UNREF(error);
@@ -330,8 +330,8 @@ inline void grpc_closure_list_sched(grpc_closure_list* list) {
     c->file_initiated = file;
     c->line_initiated = line;
     c->run = false;
+    GPR_ASSERT(c->cb != nullptr);
 #endif
-    assert(c->cb);
     c->scheduler->vtable->sched(c, c->error_data.error);
     c = next;
   }
diff --git a/src/core/lib/iomgr/combiner.cc b/src/core/lib/iomgr/combiner.cc
index e66df03182..9429842eb8 100644
--- a/src/core/lib/iomgr/combiner.cc
+++ b/src/core/lib/iomgr/combiner.cc
@@ -83,12 +83,12 @@ grpc_combiner* grpc_combiner_create(void) {
   grpc_closure_list_init(&lock->final_list);
   GRPC_CLOSURE_INIT(&lock->offload, offload, lock,
                     grpc_executor_scheduler(GRPC_EXECUTOR_SHORT));
-  GRPC_COMBINER_TRACE(gpr_log(GPR_DEBUG, "C:%p create", lock));
+  GRPC_COMBINER_TRACE(gpr_log(GPR_INFO, "C:%p create", lock));
   return lock;
 }
 
 static void really_destroy(grpc_combiner* lock) {
-  GRPC_COMBINER_TRACE(gpr_log(GPR_DEBUG, "C:%p really_destroy", lock));
+  GRPC_COMBINER_TRACE(gpr_log(GPR_INFO, "C:%p really_destroy", lock));
   GPR_ASSERT(gpr_atm_no_barrier_load(&lock->state) == 0);
   gpr_mpscq_destroy(&lock->queue);
   gpr_free(lock);
@@ -97,7 +97,7 @@ static void really_destroy(grpc_combiner* lock) {
 static void start_destroy(grpc_combiner* lock) {
   gpr_atm old_state = gpr_atm_full_fetch_add(&lock->state, -STATE_UNORPHANED);
   GRPC_COMBINER_TRACE(gpr_log(
-      GPR_DEBUG, "C:%p really_destroy old_state=%" PRIdPTR, lock, old_state));
+      GPR_INFO, "C:%p really_destroy old_state=%" PRIdPTR, lock, old_state));
   if (old_state == 1) {
     really_destroy(lock);
   }
@@ -159,7 +159,7 @@ static void combiner_exec(grpc_closure* cl, grpc_error* error) {
   GRPC_STATS_INC_COMBINER_LOCKS_SCHEDULED_ITEMS();
   grpc_combiner* lock = COMBINER_FROM_CLOSURE_SCHEDULER(cl, scheduler);
   gpr_atm last = gpr_atm_full_fetch_add(&lock->state, STATE_ELEM_COUNT_LOW_BIT);
-  GRPC_COMBINER_TRACE(gpr_log(GPR_DEBUG,
+  GRPC_COMBINER_TRACE(gpr_log(GPR_INFO,
                               "C:%p grpc_combiner_execute c=%p last=%" PRIdPTR,
                               lock, cl, last));
   if (last == 1) {
@@ -203,7 +203,7 @@ static void offload(void* arg, grpc_error* error) {
 static void queue_offload(grpc_combiner* lock) {
   GRPC_STATS_INC_COMBINER_LOCKS_OFFLOADED();
   move_next();
-  GRPC_COMBINER_TRACE(gpr_log(GPR_DEBUG, "C:%p queue_offload", lock));
+  GRPC_COMBINER_TRACE(gpr_log(GPR_INFO, "C:%p queue_offload", lock));
   GRPC_CLOSURE_SCHED(&lock->offload, GRPC_ERROR_NONE);
 }
 
@@ -218,7 +218,7 @@ bool grpc_combiner_continue_exec_ctx() {
   bool contended =
       gpr_atm_no_barrier_load(&lock->initiating_exec_ctx_or_null) == 0;
 
-  GRPC_COMBINER_TRACE(gpr_log(GPR_DEBUG,
+  GRPC_COMBINER_TRACE(gpr_log(GPR_INFO,
                               "C:%p grpc_combiner_continue_exec_ctx "
                               "contended=%d "
                               "exec_ctx_ready_to_finish=%d "
@@ -242,7 +242,7 @@ bool grpc_combiner_continue_exec_ctx() {
       (gpr_atm_acq_load(&lock->state) >> 1) > 1) {
     gpr_mpscq_node* n = gpr_mpscq_pop(&lock->queue);
     GRPC_COMBINER_TRACE(
-        gpr_log(GPR_DEBUG, "C:%p maybe_finish_one n=%p", lock, n));
+        gpr_log(GPR_INFO, "C:%p maybe_finish_one n=%p", lock, n));
     if (n == nullptr) {
       // queue is in an inconsistent state: use this as a cue that we should
       // go off and do something else for a while (and come back later)
@@ -266,7 +266,7 @@ bool grpc_combiner_continue_exec_ctx() {
     while (c != nullptr) {
       GPR_TIMER_SCOPE("combiner.exec_1final", 0);
       GRPC_COMBINER_TRACE(
-          gpr_log(GPR_DEBUG, "C:%p execute_final[%d] c=%p", lock, loops, c));
+          gpr_log(GPR_INFO, "C:%p execute_final[%d] c=%p", lock, loops, c));
       grpc_closure* next = c->next_data.next;
       grpc_error* error = c->error_data.error;
 #ifndef NDEBUG
@@ -284,7 +284,7 @@ bool grpc_combiner_continue_exec_ctx() {
   gpr_atm old_state =
       gpr_atm_full_fetch_add(&lock->state, -STATE_ELEM_COUNT_LOW_BIT);
   GRPC_COMBINER_TRACE(
-      gpr_log(GPR_DEBUG, "C:%p finish old_state=%" PRIdPTR, lock, old_state));
+      gpr_log(GPR_INFO, "C:%p finish old_state=%" PRIdPTR, lock, old_state));
 // Define a macro to ease readability of the following switch statement.
 #define OLD_STATE_WAS(orphaned, elem_count) \
   (((orphaned) ? 0 : STATE_UNORPHANED) |    \
@@ -327,8 +327,8 @@ static void combiner_finally_exec(grpc_closure* closure, grpc_error* error) {
   grpc_combiner* lock =
       COMBINER_FROM_CLOSURE_SCHEDULER(closure, finally_scheduler);
   GRPC_COMBINER_TRACE(gpr_log(
-      GPR_DEBUG, "C:%p grpc_combiner_execute_finally c=%p; ac=%p", lock,
-      closure, grpc_core::ExecCtx::Get()->combiner_data()->active_combiner));
+      GPR_INFO, "C:%p grpc_combiner_execute_finally c=%p; ac=%p", lock, closure,
+      grpc_core::ExecCtx::Get()->combiner_data()->active_combiner));
   if (grpc_core::ExecCtx::Get()->combiner_data()->active_combiner != lock) {
     GPR_TIMER_MARK("slowpath", 0);
     GRPC_CLOSURE_SCHED(GRPC_CLOSURE_CREATE(enqueue_finally, closure,
diff --git a/src/core/lib/iomgr/ev_epoll1_linux.cc b/src/core/lib/iomgr/ev_epoll1_linux.cc
index 3ebaf181c1..e5db1be0e0 100644
--- a/src/core/lib/iomgr/ev_epoll1_linux.cc
+++ b/src/core/lib/iomgr/ev_epoll1_linux.cc
@@ -658,7 +658,7 @@ static grpc_error* do_epoll_wait(grpc_pollset* ps, grpc_millis deadline) {
   GRPC_STATS_INC_POLL_EVENTS_RETURNED(r);
 
   if (grpc_polling_trace.enabled()) {
-    gpr_log(GPR_DEBUG, "ps: %p poll got %d events", ps, r);
+    gpr_log(GPR_INFO, "ps: %p poll got %d events", ps, r);
   }
 
   gpr_atm_rel_store(&g_epoll_set.num_events, r);
@@ -678,7 +678,7 @@ static bool begin_worker(grpc_pollset* pollset, grpc_pollset_worker* worker,
   pollset->begin_refs++;
 
   if (grpc_polling_trace.enabled()) {
-    gpr_log(GPR_DEBUG, "PS:%p BEGIN_STARTS:%p", pollset, worker);
+    gpr_log(GPR_INFO, "PS:%p BEGIN_STARTS:%p", pollset, worker);
   }
 
   if (pollset->seen_inactive) {
@@ -697,7 +697,7 @@ static bool begin_worker(grpc_pollset* pollset, grpc_pollset_worker* worker,
     gpr_mu_lock(&neighborhood->mu);
     gpr_mu_lock(&pollset->mu);
     if (grpc_polling_trace.enabled()) {
-      gpr_log(GPR_DEBUG, "PS:%p BEGIN_REORG:%p kick_state=%s is_reassigning=%d",
+      gpr_log(GPR_INFO, "PS:%p BEGIN_REORG:%p kick_state=%s is_reassigning=%d",
               pollset, worker, kick_state_string(worker->state),
               is_reassigning);
     }
@@ -749,7 +749,7 @@ static bool begin_worker(grpc_pollset* pollset, grpc_pollset_worker* worker,
     gpr_cv_init(&worker->cv);
     while (worker->state == UNKICKED && !pollset->shutting_down) {
       if (grpc_polling_trace.enabled()) {
-        gpr_log(GPR_DEBUG, "PS:%p BEGIN_WAIT:%p kick_state=%s shutdown=%d",
+        gpr_log(GPR_INFO, "PS:%p BEGIN_WAIT:%p kick_state=%s shutdown=%d",
                 pollset, worker, kick_state_string(worker->state),
                 pollset->shutting_down);
       }
@@ -766,7 +766,7 @@ static bool begin_worker(grpc_pollset* pollset, grpc_pollset_worker* worker,
   }
 
   if (grpc_polling_trace.enabled()) {
-    gpr_log(GPR_DEBUG,
+    gpr_log(GPR_INFO,
             "PS:%p BEGIN_DONE:%p kick_state=%s shutdown=%d "
             "kicked_without_poller: %d",
             pollset, worker, kick_state_string(worker->state),
@@ -809,7 +809,7 @@ static bool check_neighborhood_for_available_poller(
             if (gpr_atm_no_barrier_cas(&g_active_poller, 0,
                                        (gpr_atm)inspect_worker)) {
               if (grpc_polling_trace.enabled()) {
-                gpr_log(GPR_DEBUG, " .. choose next poller to be %p",
+                gpr_log(GPR_INFO, " .. choose next poller to be %p",
                         inspect_worker);
               }
               SET_KICK_STATE(inspect_worker, DESIGNATED_POLLER);
@@ -820,7 +820,7 @@ static bool check_neighborhood_for_available_poller(
               }
             } else {
               if (grpc_polling_trace.enabled()) {
-                gpr_log(GPR_DEBUG, " .. beaten to choose next poller");
+                gpr_log(GPR_INFO, " .. beaten to choose next poller");
               }
             }
             // even if we didn't win the cas, there's a worker, we can stop
@@ -838,7 +838,7 @@ static bool check_neighborhood_for_available_poller(
     }
     if (!found_worker) {
       if (grpc_polling_trace.enabled()) {
-        gpr_log(GPR_DEBUG, " .. mark pollset %p inactive", inspect);
+        gpr_log(GPR_INFO, " .. mark pollset %p inactive", inspect);
       }
       inspect->seen_inactive = true;
       if (inspect == neighborhood->active_root) {
@@ -858,7 +858,7 @@ static void end_worker(grpc_pollset* pollset, grpc_pollset_worker* worker,
                        grpc_pollset_worker** worker_hdl) {
   GPR_TIMER_SCOPE("end_worker", 0);
   if (grpc_polling_trace.enabled()) {
-    gpr_log(GPR_DEBUG, "PS:%p END_WORKER:%p", pollset, worker);
+    gpr_log(GPR_INFO, "PS:%p END_WORKER:%p", pollset, worker);
   }
   if (worker_hdl != nullptr) *worker_hdl = nullptr;
   /* Make sure we appear kicked */
@@ -868,7 +868,7 @@ static void end_worker(grpc_pollset* pollset, grpc_pollset_worker* worker,
   if (gpr_atm_no_barrier_load(&g_active_poller) == (gpr_atm)worker) {
     if (worker->next != worker && worker->next->state == UNKICKED) {
       if (grpc_polling_trace.enabled()) {
-        gpr_log(GPR_DEBUG, " .. choose next poller to be peer %p", worker);
+        gpr_log(GPR_INFO, " .. choose next poller to be peer %p", worker);
       }
       GPR_ASSERT(worker->next->initialized_cv);
       gpr_atm_no_barrier_store(&g_active_poller, (gpr_atm)worker->next);
@@ -920,7 +920,7 @@ static void end_worker(grpc_pollset* pollset, grpc_pollset_worker* worker,
     gpr_cv_destroy(&worker->cv);
   }
   if (grpc_polling_trace.enabled()) {
-    gpr_log(GPR_DEBUG, " .. remove worker");
+    gpr_log(GPR_INFO, " .. remove worker");
   }
   if (EMPTIED == worker_remove(pollset, worker)) {
     pollset_maybe_finish_shutdown(pollset);
@@ -1022,7 +1022,7 @@ static grpc_error* pollset_kick(grpc_pollset* pollset,
         GRPC_STATS_INC_POLLSET_KICKED_WITHOUT_POLLER();
         pollset->kicked_without_poller = true;
         if (grpc_polling_trace.enabled()) {
-          gpr_log(GPR_DEBUG, " .. kicked_without_poller");
+          gpr_log(GPR_INFO, " .. kicked_without_poller");
         }
         goto done;
       }
@@ -1030,14 +1030,14 @@ static grpc_error* pollset_kick(grpc_pollset* pollset,
       if (root_worker->state == KICKED) {
         GRPC_STATS_INC_POLLSET_KICKED_AGAIN();
         if (grpc_polling_trace.enabled()) {
-          gpr_log(GPR_DEBUG, " .. already kicked %p", root_worker);
+          gpr_log(GPR_INFO, " .. already kicked %p", root_worker);
         }
         SET_KICK_STATE(root_worker, KICKED);
         goto done;
       } else if (next_worker->state == KICKED) {
         GRPC_STATS_INC_POLLSET_KICKED_AGAIN();
         if (grpc_polling_trace.enabled()) {
-          gpr_log(GPR_DEBUG, " .. already kicked %p", next_worker);
+          gpr_log(GPR_INFO, " .. already kicked %p", next_worker);
         }
         SET_KICK_STATE(next_worker, KICKED);
         goto done;
@@ -1048,7 +1048,7 @@ static grpc_error* pollset_kick(grpc_pollset* pollset,
                                     &g_active_poller)) {
         GRPC_STATS_INC_POLLSET_KICK_WAKEUP_FD();
         if (grpc_polling_trace.enabled()) {
-          gpr_log(GPR_DEBUG, " .. kicked %p", root_worker);
+          gpr_log(GPR_INFO, " .. kicked %p", root_worker);
         }
         SET_KICK_STATE(root_worker, KICKED);
         ret_err = grpc_wakeup_fd_wakeup(&global_wakeup_fd);
@@ -1056,7 +1056,7 @@ static grpc_error* pollset_kick(grpc_pollset* pollset,
       } else if (next_worker->state == UNKICKED) {
         GRPC_STATS_INC_POLLSET_KICK_WAKEUP_CV();
         if (grpc_polling_trace.enabled()) {
-          gpr_log(GPR_DEBUG, " .. kicked %p", next_worker);
+          gpr_log(GPR_INFO, " .. kicked %p", next_worker);
         }
         GPR_ASSERT(next_worker->initialized_cv);
         SET_KICK_STATE(next_worker, KICKED);
@@ -1066,7 +1066,7 @@ static grpc_error* pollset_kick(grpc_pollset* pollset,
         if (root_worker->state != DESIGNATED_POLLER) {
           if (grpc_polling_trace.enabled()) {
             gpr_log(
-                GPR_DEBUG,
+                GPR_INFO,
                 " .. kicked root non-poller %p (initialized_cv=%d) (poller=%p)",
                 root_worker, root_worker->initialized_cv, next_worker);
           }
@@ -1079,7 +1079,7 @@ static grpc_error* pollset_kick(grpc_pollset* pollset,
         } else {
           GRPC_STATS_INC_POLLSET_KICK_WAKEUP_FD();
           if (grpc_polling_trace.enabled()) {
-            gpr_log(GPR_DEBUG, " .. non-root poller %p (root=%p)", next_worker,
+            gpr_log(GPR_INFO, " .. non-root poller %p (root=%p)", next_worker,
                     root_worker);
           }
           SET_KICK_STATE(next_worker, KICKED);
@@ -1095,7 +1095,7 @@ static grpc_error* pollset_kick(grpc_pollset* pollset,
     } else {
       GRPC_STATS_INC_POLLSET_KICK_OWN_THREAD();
       if (grpc_polling_trace.enabled()) {
-        gpr_log(GPR_DEBUG, " .. kicked while waking up");
+        gpr_log(GPR_INFO, " .. kicked while waking up");
       }
       goto done;
     }
@@ -1105,14 +1105,14 @@ static grpc_error* pollset_kick(grpc_pollset* pollset,
 
   if (specific_worker->state == KICKED) {
     if (grpc_polling_trace.enabled()) {
-      gpr_log(GPR_DEBUG, " .. specific worker already kicked");
+      gpr_log(GPR_INFO, " .. specific worker already kicked");
     }
     goto done;
   } else if (gpr_tls_get(&g_current_thread_worker) ==
              (intptr_t)specific_worker) {
     GRPC_STATS_INC_POLLSET_KICK_OWN_THREAD();
     if (grpc_polling_trace.enabled()) {
-      gpr_log(GPR_DEBUG, " .. mark %p kicked", specific_worker);
+      gpr_log(GPR_INFO, " .. mark %p kicked", specific_worker);
     }
     SET_KICK_STATE(specific_worker, KICKED);
     goto done;
@@ -1120,7 +1120,7 @@ static grpc_error* pollset_kick(grpc_pollset* pollset,
              (grpc_pollset_worker*)gpr_atm_no_barrier_load(&g_active_poller)) {
     GRPC_STATS_INC_POLLSET_KICK_WAKEUP_FD();
     if (grpc_polling_trace.enabled()) {
-      gpr_log(GPR_DEBUG, " .. kick active poller");
+      gpr_log(GPR_INFO, " .. kick active poller");
     }
     SET_KICK_STATE(specific_worker, KICKED);
     ret_err = grpc_wakeup_fd_wakeup(&global_wakeup_fd);
@@ -1128,7 +1128,7 @@ static grpc_error* pollset_kick(grpc_pollset* pollset,
   } else if (specific_worker->initialized_cv) {
     GRPC_STATS_INC_POLLSET_KICK_WAKEUP_CV();
     if (grpc_polling_trace.enabled()) {
-      gpr_log(GPR_DEBUG, " .. kick waiting worker");
+      gpr_log(GPR_INFO, " .. kick waiting worker");
     }
     SET_KICK_STATE(specific_worker, KICKED);
     gpr_cv_signal(&specific_worker->cv);
@@ -1136,7 +1136,7 @@ static grpc_error* pollset_kick(grpc_pollset* pollset,
   } else {
     GRPC_STATS_INC_POLLSET_KICKED_AGAIN();
     if (grpc_polling_trace.enabled()) {
-      gpr_log(GPR_DEBUG, " .. kick non-waiting worker");
+      gpr_log(GPR_INFO, " .. kick non-waiting worker");
     }
     SET_KICK_STATE(specific_worker, KICKED);
     goto done;
diff --git a/src/core/lib/iomgr/ev_epollex_linux.cc b/src/core/lib/iomgr/ev_epollex_linux.cc
index 377e2866bc..5bd7df1858 100644
--- a/src/core/lib/iomgr/ev_epollex_linux.cc
+++ b/src/core/lib/iomgr/ev_epollex_linux.cc
@@ -518,7 +518,7 @@ static grpc_error* pollable_add_fd(pollable* p, grpc_fd* fd) {
   const int epfd = p->epfd;
 
   if (grpc_polling_trace.enabled()) {
-    gpr_log(GPR_DEBUG, "add fd %p (%d) to pollable %p", fd, fd->fd, p);
+    gpr_log(GPR_INFO, "add fd %p (%d) to pollable %p", fd, fd->fd, p);
   }
 
   struct epoll_event ev_fd;
@@ -560,7 +560,7 @@ static void pollset_global_shutdown(void) {
 /* pollset->mu must be held while calling this function */
 static void pollset_maybe_finish_shutdown(grpc_pollset* pollset) {
   if (grpc_polling_trace.enabled()) {
-    gpr_log(GPR_DEBUG,
+    gpr_log(GPR_INFO,
             "PS:%p (pollable:%p) maybe_finish_shutdown sc=%p (target:!NULL) "
             "rw=%p (target:NULL) cpsc=%d (target:0)",
             pollset, pollset->active_pollable, pollset->shutdown_closure,
@@ -585,14 +585,14 @@ static grpc_error* kick_one_worker(grpc_pollset_worker* specific_worker) {
   GPR_ASSERT(specific_worker != nullptr);
   if (specific_worker->kicked) {
     if (grpc_polling_trace.enabled()) {
-      gpr_log(GPR_DEBUG, "PS:%p kicked_specific_but_already_kicked", p);
+      gpr_log(GPR_INFO, "PS:%p kicked_specific_but_already_kicked", p);
     }
     GRPC_STATS_INC_POLLSET_KICKED_AGAIN();
     return GRPC_ERROR_NONE;
   }
   if (gpr_tls_get(&g_current_thread_worker) == (intptr_t)specific_worker) {
     if (grpc_polling_trace.enabled()) {
-      gpr_log(GPR_DEBUG, "PS:%p kicked_specific_but_awake", p);
+      gpr_log(GPR_INFO, "PS:%p kicked_specific_but_awake", p);
     }
     GRPC_STATS_INC_POLLSET_KICK_OWN_THREAD();
     specific_worker->kicked = true;
@@ -601,7 +601,7 @@ static grpc_error* kick_one_worker(grpc_pollset_worker* specific_worker) {
   if (specific_worker == p->root_worker) {
     GRPC_STATS_INC_POLLSET_KICK_WAKEUP_FD();
     if (grpc_polling_trace.enabled()) {
-      gpr_log(GPR_DEBUG, "PS:%p kicked_specific_via_wakeup_fd", p);
+      gpr_log(GPR_INFO, "PS:%p kicked_specific_via_wakeup_fd", p);
     }
     specific_worker->kicked = true;
     grpc_error* error = grpc_wakeup_fd_wakeup(&p->wakeup);
@@ -610,7 +610,7 @@ static grpc_error* kick_one_worker(grpc_pollset_worker* specific_worker) {
   if (specific_worker->initialized_cv) {
     GRPC_STATS_INC_POLLSET_KICK_WAKEUP_CV();
     if (grpc_polling_trace.enabled()) {
-      gpr_log(GPR_DEBUG, "PS:%p kicked_specific_via_cv", p);
+      gpr_log(GPR_INFO, "PS:%p kicked_specific_via_cv", p);
     }
     specific_worker->kicked = true;
     gpr_cv_signal(&specific_worker->cv);
@@ -626,7 +626,7 @@ static grpc_error* pollset_kick(grpc_pollset* pollset,
   GPR_TIMER_SCOPE("pollset_kick", 0);
   GRPC_STATS_INC_POLLSET_KICK();
   if (grpc_polling_trace.enabled()) {
-    gpr_log(GPR_DEBUG,
+    gpr_log(GPR_INFO,
             "PS:%p kick %p tls_pollset=%p tls_worker=%p pollset.root_worker=%p",
             pollset, specific_worker,
             (void*)gpr_tls_get(&g_current_thread_pollset),
@@ -636,7 +636,7 @@ static grpc_error* pollset_kick(grpc_pollset* pollset,
     if (gpr_tls_get(&g_current_thread_pollset) != (intptr_t)pollset) {
       if (pollset->root_worker == nullptr) {
         if (grpc_polling_trace.enabled()) {
-          gpr_log(GPR_DEBUG, "PS:%p kicked_any_without_poller", pollset);
+          gpr_log(GPR_INFO, "PS:%p kicked_any_without_poller", pollset);
         }
         GRPC_STATS_INC_POLLSET_KICKED_WITHOUT_POLLER();
         pollset->kicked_without_poller = true;
@@ -662,7 +662,7 @@ static grpc_error* pollset_kick(grpc_pollset* pollset,
       }
     } else {
       if (grpc_polling_trace.enabled()) {
-        gpr_log(GPR_DEBUG, "PS:%p kicked_any_but_awake", pollset);
+        gpr_log(GPR_INFO, "PS:%p kicked_any_but_awake", pollset);
       }
       GRPC_STATS_INC_POLLSET_KICK_OWN_THREAD();
       return GRPC_ERROR_NONE;
@@ -784,7 +784,7 @@ static grpc_error* pollable_process_events(grpc_pollset* pollset,
     void* data_ptr = ev->data.ptr;
     if (1 & (intptr_t)data_ptr) {
       if (grpc_polling_trace.enabled()) {
-        gpr_log(GPR_DEBUG, "PS:%p got pollset_wakeup %p", pollset, data_ptr);
+        gpr_log(GPR_INFO, "PS:%p got pollset_wakeup %p", pollset, data_ptr);
       }
       append_error(&error,
                    grpc_wakeup_fd_consume_wakeup(
@@ -797,7 +797,7 @@ static grpc_error* pollable_process_events(grpc_pollset* pollset,
       bool read_ev = (ev->events & (EPOLLIN | EPOLLPRI)) != 0;
       bool write_ev = (ev->events & EPOLLOUT) != 0;
       if (grpc_polling_trace.enabled()) {
-        gpr_log(GPR_DEBUG,
+        gpr_log(GPR_INFO,
                 "PS:%p got fd %p: cancel=%d read=%d "
                 "write=%d",
                 pollset, fd, cancel, read_ev, write_ev);
@@ -827,7 +827,7 @@ static grpc_error* pollable_epoll(pollable* p, grpc_millis deadline) {
 
   if (grpc_polling_trace.enabled()) {
     char* desc = pollable_desc(p);
-    gpr_log(GPR_DEBUG, "POLLABLE:%p[%s] poll for %dms", p, desc, timeout);
+    gpr_log(GPR_INFO, "POLLABLE:%p[%s] poll for %dms", p, desc, timeout);
     gpr_free(desc);
   }
 
@@ -846,7 +846,7 @@ static grpc_error* pollable_epoll(pollable* p, grpc_millis deadline) {
   if (r < 0) return GRPC_OS_ERROR(errno, "epoll_wait");
 
   if (grpc_polling_trace.enabled()) {
-    gpr_log(GPR_DEBUG, "POLLABLE:%p got %d events", p, r);
+    gpr_log(GPR_INFO, "POLLABLE:%p got %d events", p, r);
   }
 
   p->event_cursor = 0;
@@ -917,7 +917,7 @@ static bool begin_worker(grpc_pollset* pollset, grpc_pollset_worker* worker,
     gpr_mu_unlock(&pollset->mu);
     if (grpc_polling_trace.enabled() &&
         worker->pollable_obj->root_worker != worker) {
-      gpr_log(GPR_DEBUG, "PS:%p wait %p w=%p for %dms", pollset,
+      gpr_log(GPR_INFO, "PS:%p wait %p w=%p for %dms", pollset,
               worker->pollable_obj, worker,
               poll_deadline_to_millis_timeout(deadline));
     }
@@ -925,19 +925,19 @@ static bool begin_worker(grpc_pollset* pollset, grpc_pollset_worker* worker,
       if (gpr_cv_wait(&worker->cv, &worker->pollable_obj->mu,
                       grpc_millis_to_timespec(deadline, GPR_CLOCK_REALTIME))) {
         if (grpc_polling_trace.enabled()) {
-          gpr_log(GPR_DEBUG, "PS:%p timeout_wait %p w=%p", pollset,
+          gpr_log(GPR_INFO, "PS:%p timeout_wait %p w=%p", pollset,
                   worker->pollable_obj, worker);
         }
         do_poll = false;
       } else if (worker->kicked) {
         if (grpc_polling_trace.enabled()) {
-          gpr_log(GPR_DEBUG, "PS:%p wakeup %p w=%p", pollset,
+          gpr_log(GPR_INFO, "PS:%p wakeup %p w=%p", pollset,
                   worker->pollable_obj, worker);
         }
         do_poll = false;
       } else if (grpc_polling_trace.enabled() &&
                  worker->pollable_obj->root_worker != worker) {
-        gpr_log(GPR_DEBUG, "PS:%p spurious_wakeup %p w=%p", pollset,
+        gpr_log(GPR_INFO, "PS:%p spurious_wakeup %p w=%p", pollset,
                 worker->pollable_obj, worker);
       }
     }
@@ -1009,7 +1009,7 @@ static grpc_error* pollset_work(grpc_pollset* pollset,
   WORKER_PTR->originator = gettid();
 #endif
   if (grpc_polling_trace.enabled()) {
-    gpr_log(GPR_DEBUG,
+    gpr_log(GPR_INFO,
             "PS:%p work hdl=%p worker=%p now=%" PRId64 " deadline=%" PRId64
             " kwp=%d pollable=%p",
             pollset, worker_hdl, WORKER_PTR, grpc_core::ExecCtx::Get()->Now(),
@@ -1050,7 +1050,7 @@ static grpc_error* pollset_transition_pollable_from_empty_to_fd_locked(
   static const char* err_desc = "pollset_transition_pollable_from_empty_to_fd";
   grpc_error* error = GRPC_ERROR_NONE;
   if (grpc_polling_trace.enabled()) {
-    gpr_log(GPR_DEBUG,
+    gpr_log(GPR_INFO,
             "PS:%p add fd %p (%d); transition pollable from empty to fd",
             pollset, fd, fd->fd);
   }
@@ -1067,7 +1067,7 @@ static grpc_error* pollset_transition_pollable_from_fd_to_multi_locked(
   grpc_error* error = GRPC_ERROR_NONE;
   if (grpc_polling_trace.enabled()) {
     gpr_log(
-        GPR_DEBUG,
+        GPR_INFO,
         "PS:%p add fd %p (%d); transition pollable from fd %p to multipoller",
         pollset, and_add_fd, and_add_fd ? and_add_fd->fd : -1,
         pollset->active_pollable->owner_fd);
@@ -1137,7 +1137,7 @@ static grpc_error* pollset_as_multipollable_locked(grpc_pollset* pollset,
       /* Any workers currently polling on this pollset must now be woked up so
        * that they can pick up the new active_pollable */
       if (grpc_polling_trace.enabled()) {
-        gpr_log(GPR_DEBUG,
+        gpr_log(GPR_INFO,
                 "PS:%p active pollable transition from empty to multi",
                 pollset);
       }
@@ -1224,7 +1224,7 @@ static void pollset_set_unref(grpc_pollset_set* pss) {
 static void pollset_set_add_fd(grpc_pollset_set* pss, grpc_fd* fd) {
   GPR_TIMER_SCOPE("pollset_set_add_fd", 0);
   if (grpc_polling_trace.enabled()) {
-    gpr_log(GPR_DEBUG, "PSS:%p: add fd %p (%d)", pss, fd, fd->fd);
+    gpr_log(GPR_INFO, "PSS:%p: add fd %p (%d)", pss, fd, fd->fd);
   }
   grpc_error* error = GRPC_ERROR_NONE;
   static const char* err_desc = "pollset_set_add_fd";
@@ -1248,7 +1248,7 @@ static void pollset_set_add_fd(grpc_pollset_set* pss, grpc_fd* fd) {
 static void pollset_set_del_fd(grpc_pollset_set* pss, grpc_fd* fd) {
   GPR_TIMER_SCOPE("pollset_set_del_fd", 0);
   if (grpc_polling_trace.enabled()) {
-    gpr_log(GPR_DEBUG, "PSS:%p: del fd %p", pss, fd);
+    gpr_log(GPR_INFO, "PSS:%p: del fd %p", pss, fd);
   }
   pss = pss_lock_adam(pss);
   size_t i;
@@ -1269,7 +1269,7 @@ static void pollset_set_del_fd(grpc_pollset_set* pss, grpc_fd* fd) {
 static void pollset_set_del_pollset(grpc_pollset_set* pss, grpc_pollset* ps) {
   GPR_TIMER_SCOPE("pollset_set_del_pollset", 0);
   if (grpc_polling_trace.enabled()) {
-    gpr_log(GPR_DEBUG, "PSS:%p: del pollset %p", pss, ps);
+    gpr_log(GPR_INFO, "PSS:%p: del pollset %p", pss, ps);
   }
   pss = pss_lock_adam(pss);
   size_t i;
@@ -1321,7 +1321,7 @@ static grpc_error* add_fds_to_pollsets(grpc_fd** fds, size_t fd_count,
 static void pollset_set_add_pollset(grpc_pollset_set* pss, grpc_pollset* ps) {
   GPR_TIMER_SCOPE("pollset_set_add_pollset", 0);
   if (grpc_polling_trace.enabled()) {
-    gpr_log(GPR_DEBUG, "PSS:%p: add pollset %p", pss, ps);
+    gpr_log(GPR_INFO, "PSS:%p: add pollset %p", pss, ps);
   }
   grpc_error* error = GRPC_ERROR_NONE;
   static const char* err_desc = "pollset_set_add_pollset";
@@ -1358,7 +1358,7 @@ static void pollset_set_add_pollset_set(grpc_pollset_set* a,
                                         grpc_pollset_set* b) {
   GPR_TIMER_SCOPE("pollset_set_add_pollset_set", 0);
   if (grpc_polling_trace.enabled()) {
-    gpr_log(GPR_DEBUG, "PSS: merge (%p, %p)", a, b);
+    gpr_log(GPR_INFO, "PSS: merge (%p, %p)", a, b);
   }
   grpc_error* error = GRPC_ERROR_NONE;
   static const char* err_desc = "pollset_set_add_fd";
@@ -1392,7 +1392,7 @@ static void pollset_set_add_pollset_set(grpc_pollset_set* a,
     GPR_SWAP(grpc_pollset_set*, a, b);
   }
   if (grpc_polling_trace.enabled()) {
-    gpr_log(GPR_DEBUG, "PSS: parent %p to %p", b, a);
+    gpr_log(GPR_INFO, "PSS: parent %p to %p", b, a);
   }
   gpr_ref(&a->refs);
   b->parent = a;
diff --git a/src/core/lib/iomgr/ev_epollsig_linux.cc b/src/core/lib/iomgr/ev_epollsig_linux.cc
index 1e30f6637b..494bc71c1d 100644
--- a/src/core/lib/iomgr/ev_epollsig_linux.cc
+++ b/src/core/lib/iomgr/ev_epollsig_linux.cc
@@ -292,7 +292,7 @@ static void pi_add_ref_dbg(polling_island* pi, const char* reason,
                            const char* file, int line) {
   if (grpc_polling_trace.enabled()) {
     gpr_atm old_cnt = gpr_atm_acq_load(&pi->ref_count);
-    gpr_log(GPR_DEBUG,
+    gpr_log(GPR_INFO,
             "Add ref pi: %p, old:%" PRIdPTR " -> new:%" PRIdPTR
             " (%s) - (%s, %d)",
             pi, old_cnt, old_cnt + 1, reason, file, line);
@@ -304,7 +304,7 @@ static void pi_unref_dbg(polling_island* pi, const char* reason,
                          const char* file, int line) {
   if (grpc_polling_trace.enabled()) {
     gpr_atm old_cnt = gpr_atm_acq_load(&pi->ref_count);
-    gpr_log(GPR_DEBUG,
+    gpr_log(GPR_INFO,
             "Unref pi: %p, old:%" PRIdPTR " -> new:%" PRIdPTR
             " (%s) - (%s, %d)",
             pi, old_cnt, (old_cnt - 1), reason, file, line);
diff --git a/src/core/lib/iomgr/ev_poll_posix.cc b/src/core/lib/iomgr/ev_poll_posix.cc
index d9aba9b6a3..504787e659 100644
--- a/src/core/lib/iomgr/ev_poll_posix.cc
+++ b/src/core/lib/iomgr/ev_poll_posix.cc
@@ -983,7 +983,7 @@ static grpc_error* pollset_work(grpc_pollset* pollset,
       GRPC_SCHEDULING_END_BLOCKING_REGION;
 
       if (grpc_polling_trace.enabled()) {
-        gpr_log(GPR_DEBUG, "%p poll=%d", pollset, r);
+        gpr_log(GPR_INFO, "%p poll=%d", pollset, r);
       }
 
       if (r < 0) {
@@ -1007,7 +1007,7 @@ static grpc_error* pollset_work(grpc_pollset* pollset,
       } else {
         if (pfds[0].revents & POLLIN_CHECK) {
           if (grpc_polling_trace.enabled()) {
-            gpr_log(GPR_DEBUG, "%p: got_wakeup", pollset);
+            gpr_log(GPR_INFO, "%p: got_wakeup", pollset);
           }
           work_combine_error(
               &error, grpc_wakeup_fd_consume_wakeup(&worker.wakeup_fd->fd));
@@ -1017,7 +1017,7 @@ static grpc_error* pollset_work(grpc_pollset* pollset,
             fd_end_poll(&watchers[i], 0, 0, nullptr);
           } else {
             if (grpc_polling_trace.enabled()) {
-              gpr_log(GPR_DEBUG, "%p got_event: %d r:%d w:%d [%d]", pollset,
+              gpr_log(GPR_INFO, "%p got_event: %d r:%d w:%d [%d]", pollset,
                       pfds[i].fd, (pfds[i].revents & POLLIN_CHECK) != 0,
                       (pfds[i].revents & POLLOUT_CHECK) != 0, pfds[i].revents);
             }
diff --git a/src/core/lib/iomgr/ev_posix.cc b/src/core/lib/iomgr/ev_posix.cc
index 76545c442d..0ae25b0a5c 100644
--- a/src/core/lib/iomgr/ev_posix.cc
+++ b/src/core/lib/iomgr/ev_posix.cc
@@ -46,9 +46,9 @@ grpc_core::DebugOnlyTraceFlag grpc_polling_api_trace(false, "polling_api");
 #ifndef NDEBUG
 
 // Polling API trace only enabled in debug builds
-#define GRPC_POLLING_API_TRACE(format, ...)                   \
-  if (grpc_polling_api_trace.enabled()) {                     \
-    gpr_log(GPR_DEBUG, "(polling-api) " format, __VA_ARGS__); \
+#define GRPC_POLLING_API_TRACE(format, ...)                  \
+  if (grpc_polling_api_trace.enabled()) {                    \
+    gpr_log(GPR_INFO, "(polling-api) " format, __VA_ARGS__); \
   }
 #else
 #define GRPC_POLLING_API_TRACE(...)
diff --git a/src/core/lib/iomgr/executor.cc b/src/core/lib/iomgr/executor.cc
index b017db53f8..f19f8cf20d 100644
--- a/src/core/lib/iomgr/executor.cc
+++ b/src/core/lib/iomgr/executor.cc
@@ -69,7 +69,7 @@ static size_t run_closures(grpc_closure_list list) {
       gpr_log(GPR_DEBUG, "EXECUTOR: run %p [created by %s:%d]", c,
               c->file_created, c->line_created);
 #else
-      gpr_log(GPR_DEBUG, "EXECUTOR: run %p", c);
+      gpr_log(GPR_INFO, "EXECUTOR: run %p", c);
 #endif
     }
 #ifndef NDEBUG
@@ -150,7 +150,7 @@ static void executor_thread(void* arg) {
   size_t subtract_depth = 0;
   for (;;) {
     if (executor_trace.enabled()) {
-      gpr_log(GPR_DEBUG, "EXECUTOR[%d]: step (sub_depth=%" PRIdPTR ")",
+      gpr_log(GPR_INFO, "EXECUTOR[%d]: step (sub_depth=%" PRIdPTR ")",
               static_cast<int>(ts - g_thread_state), subtract_depth);
     }
     gpr_mu_lock(&ts->mu);
@@ -161,7 +161,7 @@ static void executor_thread(void* arg) {
     }
     if (ts->shutdown) {
       if (executor_trace.enabled()) {
-        gpr_log(GPR_DEBUG, "EXECUTOR[%d]: shutdown",
+        gpr_log(GPR_INFO, "EXECUTOR[%d]: shutdown",
                 static_cast<int>(ts - g_thread_state));
       }
       gpr_mu_unlock(&ts->mu);
@@ -172,7 +172,7 @@ static void executor_thread(void* arg) {
     ts->elems = GRPC_CLOSURE_LIST_INIT;
     gpr_mu_unlock(&ts->mu);
     if (executor_trace.enabled()) {
-      gpr_log(GPR_DEBUG, "EXECUTOR[%d]: execute",
+      gpr_log(GPR_INFO, "EXECUTOR[%d]: execute",
               static_cast<int>(ts - g_thread_state));
     }
 
@@ -199,7 +199,7 @@ static void executor_push(grpc_closure* closure, grpc_error* error,
         gpr_log(GPR_DEBUG, "EXECUTOR: schedule %p (created %s:%d) inline",
                 closure, closure->file_created, closure->line_created);
 #else
-        gpr_log(GPR_DEBUG, "EXECUTOR: schedule %p inline", closure);
+        gpr_log(GPR_INFO, "EXECUTOR: schedule %p inline", closure);
 #endif
       }
       grpc_closure_list_append(grpc_core::ExecCtx::Get()->closure_list(),
@@ -225,7 +225,7 @@ static void executor_push(grpc_closure* closure, grpc_error* error,
             closure, is_short ? "short" : "long", closure->file_created,
             closure->line_created, static_cast<int>(ts - g_thread_state));
 #else
-        gpr_log(GPR_DEBUG, "EXECUTOR: try to schedule %p (%s) to thread %d",
+        gpr_log(GPR_INFO, "EXECUTOR: try to schedule %p (%s) to thread %d",
                 closure, is_short ? "short" : "long",
                 (int)(ts - g_thread_state));
 #endif
diff --git a/src/core/lib/iomgr/fork_posix.cc b/src/core/lib/iomgr/fork_posix.cc
index f8645ab157..6c506eb5c9 100644
--- a/src/core/lib/iomgr/fork_posix.cc
+++ b/src/core/lib/iomgr/fork_posix.cc
@@ -74,7 +74,6 @@ void grpc_postfork_child() {
     grpc_timer_manager_set_threading(true);
     grpc_core::ExecCtx exec_ctx;
     grpc_executor_set_threading(true);
-    grpc_core::ExecCtx::Get()->Flush();
   }
 }
 
diff --git a/src/core/lib/iomgr/resource_quota.cc b/src/core/lib/iomgr/resource_quota.cc
index 8c42dd78cf..8cf4fe9928 100644
--- a/src/core/lib/iomgr/resource_quota.cc
+++ b/src/core/lib/iomgr/resource_quota.cc
@@ -289,7 +289,7 @@ static bool rq_alloc(grpc_resource_quota* resource_quota) {
                                           GRPC_RULIST_AWAITING_ALLOCATION))) {
     gpr_mu_lock(&resource_user->mu);
     if (grpc_resource_quota_trace.enabled()) {
-      gpr_log(GPR_DEBUG,
+      gpr_log(GPR_INFO,
               "RQ: check allocation for user %p shutdown=%" PRIdPTR
               " free_pool=%" PRId64,
               resource_user, gpr_atm_no_barrier_load(&resource_user->shutdown),
@@ -315,7 +315,7 @@ static bool rq_alloc(grpc_resource_quota* resource_quota) {
       resource_quota->free_pool -= amt;
       rq_update_estimate(resource_quota);
       if (grpc_resource_quota_trace.enabled()) {
-        gpr_log(GPR_DEBUG,
+        gpr_log(GPR_INFO,
                 "RQ %s %s: grant alloc %" PRId64
                 " bytes; rq_free_pool -> %" PRId64,
                 resource_quota->name, resource_user->name, amt,
@@ -323,7 +323,7 @@ static bool rq_alloc(grpc_resource_quota* resource_quota) {
       }
     } else if (grpc_resource_quota_trace.enabled() &&
                resource_user->free_pool >= 0) {
-      gpr_log(GPR_DEBUG, "RQ %s %s: discard already satisfied alloc request",
+      gpr_log(GPR_INFO, "RQ %s %s: discard already satisfied alloc request",
               resource_quota->name, resource_user->name);
     }
     if (resource_user->free_pool >= 0) {
@@ -353,7 +353,7 @@ static bool rq_reclaim_from_per_user_free_pool(
       resource_quota->free_pool += amt;
       rq_update_estimate(resource_quota);
       if (grpc_resource_quota_trace.enabled()) {
-        gpr_log(GPR_DEBUG,
+        gpr_log(GPR_INFO,
                 "RQ %s %s: reclaim_from_per_user_free_pool %" PRId64
                 " bytes; rq_free_pool -> %" PRId64,
                 resource_quota->name, resource_user->name, amt,
@@ -376,9 +376,8 @@ static bool rq_reclaim(grpc_resource_quota* resource_quota, bool destructive) {
   grpc_resource_user* resource_user = rulist_pop_head(resource_quota, list);
   if (resource_user == nullptr) return false;
   if (grpc_resource_quota_trace.enabled()) {
-    gpr_log(GPR_DEBUG, "RQ %s %s: initiate %s reclamation",
-            resource_quota->name, resource_user->name,
-            destructive ? "destructive" : "benign");
+    gpr_log(GPR_INFO, "RQ %s %s: initiate %s reclamation", resource_quota->name,
+            resource_user->name, destructive ? "destructive" : "benign");
   }
   resource_quota->reclaiming = true;
   grpc_resource_quota_ref_internal(resource_quota);
@@ -506,7 +505,7 @@ static void ru_post_destructive_reclaimer(void* ru, grpc_error* error) {
 
 static void ru_shutdown(void* ru, grpc_error* error) {
   if (grpc_resource_quota_trace.enabled()) {
-    gpr_log(GPR_DEBUG, "RU shutdown %p", ru);
+    gpr_log(GPR_INFO, "RU shutdown %p", ru);
   }
   grpc_resource_user* resource_user = static_cast<grpc_resource_user*>(ru);
   gpr_mu_lock(&resource_user->mu);
@@ -793,7 +792,7 @@ void grpc_resource_user_alloc(grpc_resource_user* resource_user, size_t size,
   resource_user->free_pool -= static_cast<int64_t>(size);
   resource_user->outstanding_allocations += static_cast<int64_t>(size);
   if (grpc_resource_quota_trace.enabled()) {
-    gpr_log(GPR_DEBUG, "RQ %s %s: alloc %" PRIdPTR "; free_pool -> %" PRId64,
+    gpr_log(GPR_INFO, "RQ %s %s: alloc %" PRIdPTR "; free_pool -> %" PRId64,
             resource_user->resource_quota->name, resource_user->name, size,
             resource_user->free_pool);
   }
@@ -816,7 +815,7 @@ void grpc_resource_user_free(grpc_resource_user* resource_user, size_t size) {
   bool was_zero_or_negative = resource_user->free_pool <= 0;
   resource_user->free_pool += static_cast<int64_t>(size);
   if (grpc_resource_quota_trace.enabled()) {
-    gpr_log(GPR_DEBUG, "RQ %s %s: free %" PRIdPTR "; free_pool -> %" PRId64,
+    gpr_log(GPR_INFO, "RQ %s %s: free %" PRIdPTR "; free_pool -> %" PRId64,
             resource_user->resource_quota->name, resource_user->name, size,
             resource_user->free_pool);
   }
@@ -842,7 +841,7 @@ void grpc_resource_user_post_reclaimer(grpc_resource_user* resource_user,
 
 void grpc_resource_user_finish_reclamation(grpc_resource_user* resource_user) {
   if (grpc_resource_quota_trace.enabled()) {
-    gpr_log(GPR_DEBUG, "RQ %s %s: reclamation complete",
+    gpr_log(GPR_INFO, "RQ %s %s: reclamation complete",
             resource_user->resource_quota->name, resource_user->name);
   }
   GRPC_CLOSURE_SCHED(
diff --git a/src/core/lib/iomgr/tcp_client_custom.cc b/src/core/lib/iomgr/tcp_client_custom.cc
index 55632a55a1..932c79ea0b 100644
--- a/src/core/lib/iomgr/tcp_client_custom.cc
+++ b/src/core/lib/iomgr/tcp_client_custom.cc
@@ -66,7 +66,7 @@ static void on_alarm(void* acp, grpc_error* error) {
   grpc_custom_tcp_connect* connect = socket->connector;
   if (grpc_tcp_trace.enabled()) {
     const char* str = grpc_error_string(error);
-    gpr_log(GPR_DEBUG, "CLIENT_CONNECT: %s: on_alarm: error=%s",
+    gpr_log(GPR_INFO, "CLIENT_CONNECT: %s: on_alarm: error=%s",
             connect->addr_name, str);
   }
   if (error == GRPC_ERROR_NONE) {
@@ -136,7 +136,7 @@ static void tcp_connect(grpc_closure* closure, grpc_endpoint** ep,
   connect->refs = 2;
 
   if (grpc_tcp_trace.enabled()) {
-    gpr_log(GPR_DEBUG, "CLIENT_CONNECT: %p %s: asynchronously connecting",
+    gpr_log(GPR_INFO, "CLIENT_CONNECT: %p %s: asynchronously connecting",
             socket, connect->addr_name);
   }
 
diff --git a/src/core/lib/iomgr/tcp_client_posix.cc b/src/core/lib/iomgr/tcp_client_posix.cc
index 9f19b833da..6144d389f7 100644
--- a/src/core/lib/iomgr/tcp_client_posix.cc
+++ b/src/core/lib/iomgr/tcp_client_posix.cc
@@ -104,7 +104,7 @@ static void tc_on_alarm(void* acp, grpc_error* error) {
   async_connect* ac = static_cast<async_connect*>(acp);
   if (grpc_tcp_trace.enabled()) {
     const char* str = grpc_error_string(error);
-    gpr_log(GPR_DEBUG, "CLIENT_CONNECT: %s: on_alarm: error=%s", ac->addr_str,
+    gpr_log(GPR_INFO, "CLIENT_CONNECT: %s: on_alarm: error=%s", ac->addr_str,
             str);
   }
   gpr_mu_lock(&ac->mu);
@@ -141,8 +141,8 @@ static void on_writable(void* acp, grpc_error* error) {
 
   if (grpc_tcp_trace.enabled()) {
     const char* str = grpc_error_string(error);
-    gpr_log(GPR_DEBUG, "CLIENT_CONNECT: %s: on_writable: error=%s",
-            ac->addr_str, str);
+    gpr_log(GPR_INFO, "CLIENT_CONNECT: %s: on_writable: error=%s", ac->addr_str,
+            str);
   }
 
   gpr_mu_lock(&ac->mu);
@@ -325,7 +325,7 @@ void grpc_tcp_client_create_from_prepared_fd(
   ac->channel_args = grpc_channel_args_copy(channel_args);
 
   if (grpc_tcp_trace.enabled()) {
-    gpr_log(GPR_DEBUG, "CLIENT_CONNECT: %s: asynchronously connecting fd %p",
+    gpr_log(GPR_INFO, "CLIENT_CONNECT: %s: asynchronously connecting fd %p",
             ac->addr_str, fdobj);
   }
 
diff --git a/src/core/lib/iomgr/tcp_custom.cc b/src/core/lib/iomgr/tcp_custom.cc
index 2b1fc93028..b3b2934014 100644
--- a/src/core/lib/iomgr/tcp_custom.cc
+++ b/src/core/lib/iomgr/tcp_custom.cc
@@ -125,16 +125,16 @@ static void tcp_ref(custom_tcp_endpoint* tcp) { gpr_ref(&tcp->refcount); }
 static void call_read_cb(custom_tcp_endpoint* tcp, grpc_error* error) {
   grpc_closure* cb = tcp->read_cb;
   if (grpc_tcp_trace.enabled()) {
-    gpr_log(GPR_DEBUG, "TCP:%p call_cb %p %p:%p", tcp->socket, cb, cb->cb,
+    gpr_log(GPR_INFO, "TCP:%p call_cb %p %p:%p", tcp->socket, cb, cb->cb,
             cb->cb_arg);
     size_t i;
     const char* str = grpc_error_string(error);
-    gpr_log(GPR_DEBUG, "read: error=%s", str);
+    gpr_log(GPR_INFO, "read: error=%s", str);
 
     for (i = 0; i < tcp->read_slices->count; i++) {
       char* dump = grpc_dump_slice(tcp->read_slices->slices[i],
                                    GPR_DUMP_HEX | GPR_DUMP_ASCII);
-      gpr_log(GPR_DEBUG, "READ %p (peer=%s): %s", tcp, tcp->peer_string, dump);
+      gpr_log(GPR_INFO, "READ %p (peer=%s): %s", tcp, tcp->peer_string, dump);
       gpr_free(dump);
     }
   }
@@ -171,7 +171,7 @@ static void custom_read_callback(grpc_custom_socket* socket, size_t nread,
 static void tcp_read_allocation_done(void* tcpp, grpc_error* error) {
   custom_tcp_endpoint* tcp = (custom_tcp_endpoint*)tcpp;
   if (grpc_tcp_trace.enabled()) {
-    gpr_log(GPR_DEBUG, "TCP:%p read_allocation_done: %s", tcp->socket,
+    gpr_log(GPR_INFO, "TCP:%p read_allocation_done: %s", tcp->socket,
             grpc_error_string(error));
   }
   if (error == GRPC_ERROR_NONE) {
@@ -188,7 +188,7 @@ static void tcp_read_allocation_done(void* tcpp, grpc_error* error) {
   }
   if (grpc_tcp_trace.enabled()) {
     const char* str = grpc_error_string(error);
-    gpr_log(GPR_DEBUG, "Initiating read on %p: error=%s", tcp->socket, str);
+    gpr_log(GPR_INFO, "Initiating read on %p: error=%s", tcp->socket, str);
   }
 }
 
@@ -214,7 +214,7 @@ static void custom_write_callback(grpc_custom_socket* socket,
   tcp->write_cb = nullptr;
   if (grpc_tcp_trace.enabled()) {
     const char* str = grpc_error_string(error);
-    gpr_log(GPR_DEBUG, "write complete on %p: error=%s", tcp->socket, str);
+    gpr_log(GPR_INFO, "write complete on %p: error=%s", tcp->socket, str);
   }
   TCP_UNREF(tcp, "write");
   GRPC_CLOSURE_SCHED(cb, error);
@@ -231,8 +231,8 @@ static void endpoint_write(grpc_endpoint* ep, grpc_slice_buffer* write_slices,
     for (j = 0; j < write_slices->count; j++) {
       char* data = grpc_dump_slice(write_slices->slices[j],
                                    GPR_DUMP_HEX | GPR_DUMP_ASCII);
-      gpr_log(GPR_DEBUG, "WRITE %p (peer=%s): %s", tcp->socket,
-              tcp->peer_string, data);
+      gpr_log(GPR_INFO, "WRITE %p (peer=%s): %s", tcp->socket, tcp->peer_string,
+              data);
       gpr_free(data);
     }
   }
@@ -283,7 +283,7 @@ static void endpoint_shutdown(grpc_endpoint* ep, grpc_error* why) {
   if (!tcp->shutting_down) {
     if (grpc_tcp_trace.enabled()) {
       const char* str = grpc_error_string(why);
-      gpr_log(GPR_DEBUG, "TCP %p shutdown why=%s", tcp->socket, str);
+      gpr_log(GPR_INFO, "TCP %p shutdown why=%s", tcp->socket, str);
     }
     tcp->shutting_down = true;
     // GRPC_CLOSURE_SCHED(tcp->read_cb, GRPC_ERROR_REF(why));
@@ -345,7 +345,7 @@ grpc_endpoint* custom_tcp_endpoint_create(grpc_custom_socket* socket,
   grpc_core::ExecCtx exec_ctx;
 
   if (grpc_tcp_trace.enabled()) {
-    gpr_log(GPR_DEBUG, "Creating TCP endpoint %p", socket);
+    gpr_log(GPR_INFO, "Creating TCP endpoint %p", socket);
   }
   memset(tcp, 0, sizeof(custom_tcp_endpoint));
   socket->refs++;
diff --git a/src/core/lib/iomgr/tcp_posix.cc b/src/core/lib/iomgr/tcp_posix.cc
index 205af22531..153be05e83 100644
--- a/src/core/lib/iomgr/tcp_posix.cc
+++ b/src/core/lib/iomgr/tcp_posix.cc
@@ -120,7 +120,7 @@ static void tcp_drop_uncovered_then_handle_write(void* arg /* grpc_tcp */,
 static void done_poller(void* bp, grpc_error* error_ignored) {
   backup_poller* p = static_cast<backup_poller*>(bp);
   if (grpc_tcp_trace.enabled()) {
-    gpr_log(GPR_DEBUG, "BACKUP_POLLER:%p destroy", p);
+    gpr_log(GPR_INFO, "BACKUP_POLLER:%p destroy", p);
   }
   grpc_pollset_destroy(BACKUP_POLLER_POLLSET(p));
   gpr_free(p);
@@ -129,7 +129,7 @@ static void done_poller(void* bp, grpc_error* error_ignored) {
 static void run_poller(void* bp, grpc_error* error_ignored) {
   backup_poller* p = static_cast<backup_poller*>(bp);
   if (grpc_tcp_trace.enabled()) {
-    gpr_log(GPR_DEBUG, "BACKUP_POLLER:%p run", p);
+    gpr_log(GPR_INFO, "BACKUP_POLLER:%p run", p);
   }
   gpr_mu_lock(p->pollset_mu);
   grpc_millis deadline = grpc_core::ExecCtx::Get()->Now() + 10 * GPR_MS_PER_SEC;
@@ -145,18 +145,18 @@ static void run_poller(void* bp, grpc_error* error_ignored) {
     gpr_mu_lock(p->pollset_mu);
     bool cas_ok = gpr_atm_full_cas(&g_backup_poller, (gpr_atm)p, 0);
     if (grpc_tcp_trace.enabled()) {
-      gpr_log(GPR_DEBUG, "BACKUP_POLLER:%p done cas_ok=%d", p, cas_ok);
+      gpr_log(GPR_INFO, "BACKUP_POLLER:%p done cas_ok=%d", p, cas_ok);
     }
     gpr_mu_unlock(p->pollset_mu);
     if (grpc_tcp_trace.enabled()) {
-      gpr_log(GPR_DEBUG, "BACKUP_POLLER:%p shutdown", p);
+      gpr_log(GPR_INFO, "BACKUP_POLLER:%p shutdown", p);
     }
     grpc_pollset_shutdown(BACKUP_POLLER_POLLSET(p),
                           GRPC_CLOSURE_INIT(&p->run_poller, done_poller, p,
                                             grpc_schedule_on_exec_ctx));
   } else {
     if (grpc_tcp_trace.enabled()) {
-      gpr_log(GPR_DEBUG, "BACKUP_POLLER:%p reschedule", p);
+      gpr_log(GPR_INFO, "BACKUP_POLLER:%p reschedule", p);
     }
     GRPC_CLOSURE_SCHED(&p->run_poller, GRPC_ERROR_NONE);
   }
@@ -167,7 +167,7 @@ static void drop_uncovered(grpc_tcp* tcp) {
   gpr_atm old_count =
       gpr_atm_no_barrier_fetch_add(&g_uncovered_notifications_pending, -1);
   if (grpc_tcp_trace.enabled()) {
-    gpr_log(GPR_DEBUG, "BACKUP_POLLER:%p uncover cnt %d->%d", p,
+    gpr_log(GPR_INFO, "BACKUP_POLLER:%p uncover cnt %d->%d", p,
             static_cast<int>(old_count), static_cast<int>(old_count) - 1);
   }
   GPR_ASSERT(old_count != 1);
@@ -178,7 +178,7 @@ static void cover_self(grpc_tcp* tcp) {
   gpr_atm old_count =
       gpr_atm_no_barrier_fetch_add(&g_uncovered_notifications_pending, 2);
   if (grpc_tcp_trace.enabled()) {
-    gpr_log(GPR_DEBUG, "BACKUP_POLLER: cover cnt %d->%d",
+    gpr_log(GPR_INFO, "BACKUP_POLLER: cover cnt %d->%d",
             static_cast<int>(old_count), 2 + static_cast<int>(old_count));
   }
   if (old_count == 0) {
@@ -186,7 +186,7 @@ static void cover_self(grpc_tcp* tcp) {
     p = static_cast<backup_poller*>(
         gpr_zalloc(sizeof(*p) + grpc_pollset_size()));
     if (grpc_tcp_trace.enabled()) {
-      gpr_log(GPR_DEBUG, "BACKUP_POLLER:%p create", p);
+      gpr_log(GPR_INFO, "BACKUP_POLLER:%p create", p);
     }
     grpc_pollset_init(BACKUP_POLLER_POLLSET(p), &p->pollset_mu);
     gpr_atm_rel_store(&g_backup_poller, (gpr_atm)p);
@@ -201,7 +201,7 @@ static void cover_self(grpc_tcp* tcp) {
     }
   }
   if (grpc_tcp_trace.enabled()) {
-    gpr_log(GPR_DEBUG, "BACKUP_POLLER:%p add %p", p, tcp);
+    gpr_log(GPR_INFO, "BACKUP_POLLER:%p add %p", p, tcp);
   }
   grpc_pollset_add_fd(BACKUP_POLLER_POLLSET(p), tcp->em_fd);
   if (old_count != 0) {
@@ -211,7 +211,7 @@ static void cover_self(grpc_tcp* tcp) {
 
 static void notify_on_read(grpc_tcp* tcp) {
   if (grpc_tcp_trace.enabled()) {
-    gpr_log(GPR_DEBUG, "TCP:%p notify_on_read", tcp);
+    gpr_log(GPR_INFO, "TCP:%p notify_on_read", tcp);
   }
   GRPC_CLOSURE_INIT(&tcp->read_done_closure, tcp_handle_read, tcp,
                     grpc_schedule_on_exec_ctx);
@@ -220,7 +220,7 @@ static void notify_on_read(grpc_tcp* tcp) {
 
 static void notify_on_write(grpc_tcp* tcp) {
   if (grpc_tcp_trace.enabled()) {
-    gpr_log(GPR_DEBUG, "TCP:%p notify_on_write", tcp);
+    gpr_log(GPR_INFO, "TCP:%p notify_on_write", tcp);
   }
   cover_self(tcp);
   GRPC_CLOSURE_INIT(&tcp->write_done_closure,
@@ -231,7 +231,7 @@ static void notify_on_write(grpc_tcp* tcp) {
 
 static void tcp_drop_uncovered_then_handle_write(void* arg, grpc_error* error) {
   if (grpc_tcp_trace.enabled()) {
-    gpr_log(GPR_DEBUG, "TCP:%p got_write: %s", arg, grpc_error_string(error));
+    gpr_log(GPR_INFO, "TCP:%p got_write: %s", arg, grpc_error_string(error));
   }
   drop_uncovered(static_cast<grpc_tcp*>(arg));
   tcp_handle_write(arg, error);
@@ -351,15 +351,15 @@ static void call_read_cb(grpc_tcp* tcp, grpc_error* error) {
   grpc_closure* cb = tcp->read_cb;
 
   if (grpc_tcp_trace.enabled()) {
-    gpr_log(GPR_DEBUG, "TCP:%p call_cb %p %p:%p", tcp, cb, cb->cb, cb->cb_arg);
+    gpr_log(GPR_INFO, "TCP:%p call_cb %p %p:%p", tcp, cb, cb->cb, cb->cb_arg);
     size_t i;
     const char* str = grpc_error_string(error);
-    gpr_log(GPR_DEBUG, "read: error=%s", str);
+    gpr_log(GPR_INFO, "read: error=%s", str);
 
     for (i = 0; i < tcp->incoming_buffer->count; i++) {
       char* dump = grpc_dump_slice(tcp->incoming_buffer->slices[i],
                                    GPR_DUMP_HEX | GPR_DUMP_ASCII);
-      gpr_log(GPR_DEBUG, "READ %p (peer=%s): %s", tcp, tcp->peer_string, dump);
+      gpr_log(GPR_INFO, "READ %p (peer=%s): %s", tcp, tcp->peer_string, dump);
       gpr_free(dump);
     }
   }
@@ -371,7 +371,7 @@ static void call_read_cb(grpc_tcp* tcp, grpc_error* error) {
 
 #define MAX_READ_IOVEC 4
 static void tcp_do_read(grpc_tcp* tcp) {
-  GPR_TIMER_SCOPE("tcp_continue_read", 0);
+  GPR_TIMER_SCOPE("tcp_do_read", 0);
   struct msghdr msg;
   struct iovec iov[MAX_READ_IOVEC];
   ssize_t read_bytes;
@@ -441,7 +441,7 @@ static void tcp_do_read(grpc_tcp* tcp) {
 static void tcp_read_allocation_done(void* tcpp, grpc_error* error) {
   grpc_tcp* tcp = static_cast<grpc_tcp*>(tcpp);
   if (grpc_tcp_trace.enabled()) {
-    gpr_log(GPR_DEBUG, "TCP:%p read_allocation_done: %s", tcp,
+    gpr_log(GPR_INFO, "TCP:%p read_allocation_done: %s", tcp,
             grpc_error_string(error));
   }
   if (error != GRPC_ERROR_NONE) {
@@ -459,13 +459,13 @@ static void tcp_continue_read(grpc_tcp* tcp) {
   if (tcp->incoming_buffer->length < target_read_size &&
       tcp->incoming_buffer->count < MAX_READ_IOVEC) {
     if (grpc_tcp_trace.enabled()) {
-      gpr_log(GPR_DEBUG, "TCP:%p alloc_slices", tcp);
+      gpr_log(GPR_INFO, "TCP:%p alloc_slices", tcp);
     }
     grpc_resource_user_alloc_slices(&tcp->slice_allocator, target_read_size, 1,
                                     tcp->incoming_buffer);
   } else {
     if (grpc_tcp_trace.enabled()) {
-      gpr_log(GPR_DEBUG, "TCP:%p do_read", tcp);
+      gpr_log(GPR_INFO, "TCP:%p do_read", tcp);
     }
     tcp_do_read(tcp);
   }
@@ -475,7 +475,7 @@ static void tcp_handle_read(void* arg /* grpc_tcp */, grpc_error* error) {
   grpc_tcp* tcp = static_cast<grpc_tcp*>(arg);
   GPR_ASSERT(!tcp->finished_edge);
   if (grpc_tcp_trace.enabled()) {
-    gpr_log(GPR_DEBUG, "TCP:%p got_read: %s", tcp, grpc_error_string(error));
+    gpr_log(GPR_INFO, "TCP:%p got_read: %s", tcp, grpc_error_string(error));
   }
 
   if (error != GRPC_ERROR_NONE) {
@@ -618,7 +618,7 @@ static void tcp_handle_write(void* arg /* grpc_tcp */, grpc_error* error) {
 
   if (!tcp_flush(tcp, &error)) {
     if (grpc_tcp_trace.enabled()) {
-      gpr_log(GPR_DEBUG, "write: delayed");
+      gpr_log(GPR_INFO, "write: delayed");
     }
     notify_on_write(tcp);
   } else {
@@ -626,7 +626,7 @@ static void tcp_handle_write(void* arg /* grpc_tcp */, grpc_error* error) {
     tcp->write_cb = nullptr;
     if (grpc_tcp_trace.enabled()) {
       const char* str = grpc_error_string(error);
-      gpr_log(GPR_DEBUG, "write: %s", str);
+      gpr_log(GPR_INFO, "write: %s", str);
     }
 
     GRPC_CLOSURE_RUN(cb, error);
@@ -646,7 +646,7 @@ static void tcp_write(grpc_endpoint* ep, grpc_slice_buffer* buf,
     for (i = 0; i < buf->count; i++) {
       char* data =
           grpc_dump_slice(buf->slices[i], GPR_DUMP_HEX | GPR_DUMP_ASCII);
-      gpr_log(GPR_DEBUG, "WRITE %p (peer=%s): %s", tcp, tcp->peer_string, data);
+      gpr_log(GPR_INFO, "WRITE %p (peer=%s): %s", tcp, tcp->peer_string, data);
       gpr_free(data);
     }
   }
@@ -668,13 +668,13 @@ static void tcp_write(grpc_endpoint* ep, grpc_slice_buffer* buf,
     TCP_REF(tcp, "write");
     tcp->write_cb = cb;
     if (grpc_tcp_trace.enabled()) {
-      gpr_log(GPR_DEBUG, "write: delayed");
+      gpr_log(GPR_INFO, "write: delayed");
     }
     notify_on_write(tcp);
   } else {
     if (grpc_tcp_trace.enabled()) {
       const char* str = grpc_error_string(error);
-      gpr_log(GPR_DEBUG, "write: %s", str);
+      gpr_log(GPR_INFO, "write: %s", str);
     }
     GRPC_CLOSURE_SCHED(cb, error);
   }
diff --git a/src/core/lib/iomgr/tcp_server_custom.cc b/src/core/lib/iomgr/tcp_server_custom.cc
index 79ba5c39ee..019b354473 100644
--- a/src/core/lib/iomgr/tcp_server_custom.cc
+++ b/src/core/lib/iomgr/tcp_server_custom.cc
@@ -222,10 +222,10 @@ static void finish_accept(grpc_tcp_listener* sp, grpc_custom_socket* socket) {
   }
   if (grpc_tcp_trace.enabled()) {
     if (peer_name_string) {
-      gpr_log(GPR_DEBUG, "SERVER_CONNECT: %p accepted connection: %s",
+      gpr_log(GPR_INFO, "SERVER_CONNECT: %p accepted connection: %s",
               sp->server, peer_name_string);
     } else {
-      gpr_log(GPR_DEBUG, "SERVER_CONNECT: %p accepted connection", sp->server);
+      gpr_log(GPR_INFO, "SERVER_CONNECT: %p accepted connection", sp->server);
     }
   }
   ep = custom_tcp_endpoint_create(socket, sp->server->resource_quota,
@@ -377,10 +377,10 @@ static grpc_error* tcp_server_add_port(grpc_tcp_server* s,
     grpc_sockaddr_to_string(&port_string, addr, 0);
     const char* str = grpc_error_string(error);
     if (port_string) {
-      gpr_log(GPR_DEBUG, "SERVER %p add_port %s error=%s", s, port_string, str);
+      gpr_log(GPR_INFO, "SERVER %p add_port %s error=%s", s, port_string, str);
       gpr_free(port_string);
     } else {
-      gpr_log(GPR_DEBUG, "SERVER %p add_port error=%s", s, str);
+      gpr_log(GPR_INFO, "SERVER %p add_port error=%s", s, str);
     }
   }
 
@@ -419,7 +419,7 @@ static void tcp_server_start(grpc_tcp_server* server, grpc_pollset** pollsets,
   (void)pollset_count;
   GRPC_CUSTOM_IOMGR_ASSERT_SAME_THREAD();
   if (grpc_tcp_trace.enabled()) {
-    gpr_log(GPR_DEBUG, "SERVER_START %p", server);
+    gpr_log(GPR_INFO, "SERVER_START %p", server);
   }
   GPR_ASSERT(on_accept_cb);
   GPR_ASSERT(!server->on_accept_cb);
diff --git a/src/core/lib/iomgr/tcp_server_posix.cc b/src/core/lib/iomgr/tcp_server_posix.cc
index f11b82f7ab..524beba9ab 100644
--- a/src/core/lib/iomgr/tcp_server_posix.cc
+++ b/src/core/lib/iomgr/tcp_server_posix.cc
@@ -228,7 +228,7 @@ static void on_read(void* arg, grpc_error* err) {
     gpr_asprintf(&name, "tcp-server-connection:%s", addr_str);
 
     if (grpc_tcp_trace.enabled()) {
-      gpr_log(GPR_DEBUG, "SERVER_CONNECT: incoming connection: %s", addr_str);
+      gpr_log(GPR_INFO, "SERVER_CONNECT: incoming connection: %s", addr_str);
     }
 
     grpc_fd* fdobj = grpc_fd_create(fd, name);
diff --git a/src/core/lib/iomgr/tcp_uv.cc b/src/core/lib/iomgr/tcp_uv.cc
index f20f8dcb74..8d0e4a5e79 100644
--- a/src/core/lib/iomgr/tcp_uv.cc
+++ b/src/core/lib/iomgr/tcp_uv.cc
@@ -204,6 +204,9 @@ static grpc_error* uv_socket_init_helper(uv_socket_t* uv_socket, int domain) {
   uv_socket->write_buffers = nullptr;
   uv_socket->read_len = 0;
   uv_tcp_nodelay(uv_socket->handle, 1);
+  // Node uses a garbage collector to call destructors, so we don't
+  // want to hold the uv loop open with active gRPC objects.
+  uv_unref((uv_handle_t*)uv_socket->handle);
   uv_socket->pending_connection = false;
   uv_socket->accept_socket = nullptr;
   uv_socket->accept_error = GRPC_ERROR_NONE;
diff --git a/src/core/lib/iomgr/tcp_windows.cc b/src/core/lib/iomgr/tcp_windows.cc
index 04e6f11eee..5d316d477b 100644
--- a/src/core/lib/iomgr/tcp_windows.cc
+++ b/src/core/lib/iomgr/tcp_windows.cc
@@ -74,12 +74,28 @@ static grpc_error* set_dualstack(SOCKET sock) {
              : GRPC_WSA_ERROR(WSAGetLastError(), "setsockopt(IPV6_V6ONLY)");
 }
 
+static grpc_error* enable_loopback_fast_path(SOCKET sock) {
+  int status;
+  uint32_t param = 1;
+  DWORD ret;
+  status = WSAIoctl(sock, /*SIO_LOOPBACK_FAST_PATH==*/_WSAIOW(IOC_VENDOR, 16),
+                    &param, sizeof(param), NULL, 0, &ret, 0, 0);
+  if (status == SOCKET_ERROR) {
+    status = WSAGetLastError();
+  }
+  return status == 0 || status == WSAEOPNOTSUPP
+             ? GRPC_ERROR_NONE
+             : GRPC_WSA_ERROR(status, "WSAIoctl(SIO_LOOPBACK_FAST_PATH)");
+}
+
 grpc_error* grpc_tcp_prepare_socket(SOCKET sock) {
   grpc_error* err;
   err = set_non_block(sock);
   if (err != GRPC_ERROR_NONE) return err;
   err = set_dualstack(sock);
   if (err != GRPC_ERROR_NONE) return err;
+  err = enable_loopback_fast_path(sock);
+  if (err != GRPC_ERROR_NONE) return err;
   return GRPC_ERROR_NONE;
 }
 
diff --git a/src/core/lib/iomgr/timer_generic.cc b/src/core/lib/iomgr/timer_generic.cc
index d3245dee4c..2bbc9d8874 100644
--- a/src/core/lib/iomgr/timer_generic.cc
+++ b/src/core/lib/iomgr/timer_generic.cc
@@ -362,7 +362,7 @@ static void timer_init(grpc_timer* timer, grpc_millis deadline,
 #endif
 
   if (grpc_timer_trace.enabled()) {
-    gpr_log(GPR_DEBUG, "TIMER %p: SET %" PRId64 " now %" PRId64 " call %p[%p]",
+    gpr_log(GPR_INFO, "TIMER %p: SET %" PRId64 " now %" PRId64 " call %p[%p]",
             timer, deadline, grpc_core::ExecCtx::Get()->Now(), closure,
             closure->cb);
   }
@@ -398,7 +398,7 @@ static void timer_init(grpc_timer* timer, grpc_millis deadline,
     list_join(&shard->list, timer);
   }
   if (grpc_timer_trace.enabled()) {
-    gpr_log(GPR_DEBUG,
+    gpr_log(GPR_INFO,
             "  .. add to shard %d with queue_deadline_cap=%" PRId64
             " => is_first_timer=%s",
             static_cast<int>(shard - g_shards), shard->queue_deadline_cap,
@@ -420,7 +420,7 @@ static void timer_init(grpc_timer* timer, grpc_millis deadline,
   if (is_first_timer) {
     gpr_mu_lock(&g_shared_mutables.mu);
     if (grpc_timer_trace.enabled()) {
-      gpr_log(GPR_DEBUG, "  .. old shard min_deadline=%" PRId64,
+      gpr_log(GPR_INFO, "  .. old shard min_deadline=%" PRId64,
               shard->min_deadline);
     }
     if (deadline < shard->min_deadline) {
@@ -460,7 +460,7 @@ static void timer_cancel(grpc_timer* timer) {
   timer_shard* shard = &g_shards[GPR_HASH_POINTER(timer, g_num_shards)];
   gpr_mu_lock(&shard->mu);
   if (grpc_timer_trace.enabled()) {
-    gpr_log(GPR_DEBUG, "TIMER %p: CANCEL pending=%s", timer,
+    gpr_log(GPR_INFO, "TIMER %p: CANCEL pending=%s", timer,
             timer->pending ? "true" : "false");
   }
 
@@ -501,7 +501,7 @@ static int refill_heap(timer_shard* shard, grpc_millis now) {
                      static_cast<grpc_millis>(deadline_delta * 1000.0));
 
   if (grpc_timer_check_trace.enabled()) {
-    gpr_log(GPR_DEBUG, "  .. shard[%d]->queue_deadline_cap --> %" PRId64,
+    gpr_log(GPR_INFO, "  .. shard[%d]->queue_deadline_cap --> %" PRId64,
             static_cast<int>(shard - g_shards), shard->queue_deadline_cap);
   }
   for (timer = shard->list.next; timer != &shard->list; timer = next) {
@@ -509,7 +509,7 @@ static int refill_heap(timer_shard* shard, grpc_millis now) {
 
     if (timer->deadline < shard->queue_deadline_cap) {
       if (grpc_timer_check_trace.enabled()) {
-        gpr_log(GPR_DEBUG, "  .. add timer with deadline %" PRId64 " to heap",
+        gpr_log(GPR_INFO, "  .. add timer with deadline %" PRId64 " to heap",
                 timer->deadline);
       }
       list_remove(timer);
@@ -526,7 +526,7 @@ static grpc_timer* pop_one(timer_shard* shard, grpc_millis now) {
   grpc_timer* timer;
   for (;;) {
     if (grpc_timer_check_trace.enabled()) {
-      gpr_log(GPR_DEBUG, "  .. shard[%d]: heap_empty=%s",
+      gpr_log(GPR_INFO, "  .. shard[%d]: heap_empty=%s",
               static_cast<int>(shard - g_shards),
               grpc_timer_heap_is_empty(&shard->heap) ? "true" : "false");
     }
@@ -536,13 +536,13 @@ static grpc_timer* pop_one(timer_shard* shard, grpc_millis now) {
     }
     timer = grpc_timer_heap_top(&shard->heap);
     if (grpc_timer_check_trace.enabled()) {
-      gpr_log(GPR_DEBUG,
+      gpr_log(GPR_INFO,
               "  .. check top timer deadline=%" PRId64 " now=%" PRId64,
               timer->deadline, now);
     }
     if (timer->deadline > now) return nullptr;
     if (grpc_timer_trace.enabled()) {
-      gpr_log(GPR_DEBUG, "TIMER %p: FIRE %" PRId64 "ms late via %s scheduler",
+      gpr_log(GPR_INFO, "TIMER %p: FIRE %" PRId64 "ms late via %s scheduler",
               timer, now - timer->deadline,
               timer->closure->scheduler->vtable->name);
     }
@@ -566,7 +566,7 @@ static size_t pop_timers(timer_shard* shard, grpc_millis now,
   *new_min_deadline = compute_min_deadline(shard);
   gpr_mu_unlock(&shard->mu);
   if (grpc_timer_check_trace.enabled()) {
-    gpr_log(GPR_DEBUG, "  .. shard[%d] popped %" PRIdPTR,
+    gpr_log(GPR_INFO, "  .. shard[%d] popped %" PRIdPTR,
             static_cast<int>(shard - g_shards), n);
   }
   return n;
@@ -599,7 +599,7 @@ static grpc_timer_check_result run_some_expired_timers(grpc_millis now,
     result = GRPC_TIMERS_CHECKED_AND_EMPTY;
 
     if (grpc_timer_check_trace.enabled()) {
-      gpr_log(GPR_DEBUG, "  .. shard[%d]->min_deadline = %" PRId64,
+      gpr_log(GPR_INFO, "  .. shard[%d]->min_deadline = %" PRId64,
               static_cast<int>(g_shard_queue[0] - g_shards),
               g_shard_queue[0]->min_deadline);
     }
@@ -617,7 +617,7 @@ static grpc_timer_check_result run_some_expired_timers(grpc_millis now,
       }
 
       if (grpc_timer_check_trace.enabled()) {
-        gpr_log(GPR_DEBUG,
+        gpr_log(GPR_INFO,
                 "  .. result --> %d"
                 ", shard[%d]->min_deadline %" PRId64 " --> %" PRId64
                 ", now=%" PRId64,
@@ -681,7 +681,7 @@ static grpc_timer_check_result timer_check(grpc_millis* next) {
       *next = GPR_MIN(*next, min_timer);
     }
     if (grpc_timer_check_trace.enabled()) {
-      gpr_log(GPR_DEBUG, "TIMER CHECK SKIP: now=%" PRId64 " min_timer=%" PRId64,
+      gpr_log(GPR_INFO, "TIMER CHECK SKIP: now=%" PRId64 " min_timer=%" PRId64,
               now, min_timer);
     }
     return GRPC_TIMERS_CHECKED_AND_EMPTY;
@@ -701,16 +701,15 @@ static grpc_timer_check_result timer_check(grpc_millis* next) {
       gpr_asprintf(&next_str, "%" PRId64, *next);
     }
 #if GPR_ARCH_64
-    gpr_log(GPR_DEBUG,
+    gpr_log(GPR_INFO,
             "TIMER CHECK BEGIN: now=%" PRId64 " next=%s tls_min=%" PRId64
             " glob_min=%" PRId64,
             now, next_str, min_timer,
             gpr_atm_no_barrier_load(
                 static_cast<gpr_atm*>(&g_shared_mutables.min_timer)));
 #else
-    gpr_log(GPR_DEBUG,
-            "TIMER CHECK BEGIN: now=%" PRId64 " next=%s min=%" PRId64, now,
-            next_str, min_timer);
+    gpr_log(GPR_INFO, "TIMER CHECK BEGIN: now=%" PRId64 " next=%s min=%" PRId64,
+            now, next_str, min_timer);
 #endif
     gpr_free(next_str);
   }
@@ -725,7 +724,7 @@ static grpc_timer_check_result timer_check(grpc_millis* next) {
     } else {
       gpr_asprintf(&next_str, "%" PRId64, *next);
     }
-    gpr_log(GPR_DEBUG, "TIMER CHECK END: r=%d; next=%s", r, next_str);
+    gpr_log(GPR_INFO, "TIMER CHECK END: r=%d; next=%s", r, next_str);
     gpr_free(next_str);
   }
   return r;
diff --git a/src/core/lib/iomgr/timer_manager.cc b/src/core/lib/iomgr/timer_manager.cc
index a14fa8d901..9fdae17909 100644
--- a/src/core/lib/iomgr/timer_manager.cc
+++ b/src/core/lib/iomgr/timer_manager.cc
@@ -82,7 +82,7 @@ static void start_timer_thread_and_unlock(void) {
   ++g_thread_count;
   gpr_mu_unlock(&g_mu);
   if (grpc_timer_check_trace.enabled()) {
-    gpr_log(GPR_DEBUG, "Spawn timer thread");
+    gpr_log(GPR_INFO, "Spawn timer thread");
   }
   completed_thread* ct =
       static_cast<completed_thread*>(gpr_malloc(sizeof(*ct)));
@@ -108,7 +108,7 @@ static void run_some_timers() {
     // waiter so that the next deadline is not missed
     if (!g_has_timed_waiter) {
       if (grpc_timer_check_trace.enabled()) {
-        gpr_log(GPR_DEBUG, "kick untimed waiter");
+        gpr_log(GPR_INFO, "kick untimed waiter");
       }
       gpr_cv_signal(&g_cv_wait);
     }
@@ -116,7 +116,7 @@ static void run_some_timers() {
   }
   // without our lock, flush the exec_ctx
   if (grpc_timer_check_trace.enabled()) {
-    gpr_log(GPR_DEBUG, "flush exec_ctx");
+    gpr_log(GPR_INFO, "flush exec_ctx");
   }
   grpc_core::ExecCtx::Get()->Flush();
   gpr_mu_lock(&g_mu);
@@ -172,7 +172,7 @@ static bool wait_until(grpc_millis next) {
 
         if (grpc_timer_check_trace.enabled()) {
           grpc_millis wait_time = next - grpc_core::ExecCtx::Get()->Now();
-          gpr_log(GPR_DEBUG, "sleep for a %" PRId64 " milliseconds", wait_time);
+          gpr_log(GPR_INFO, "sleep for a %" PRId64 " milliseconds", wait_time);
         }
       } else {  // g_timed_waiter == true && next >= g_timed_waiter_deadline
         next = GRPC_MILLIS_INF_FUTURE;
@@ -180,14 +180,14 @@ static bool wait_until(grpc_millis next) {
     }
 
     if (grpc_timer_check_trace.enabled() && next == GRPC_MILLIS_INF_FUTURE) {
-      gpr_log(GPR_DEBUG, "sleep until kicked");
+      gpr_log(GPR_INFO, "sleep until kicked");
     }
 
     gpr_cv_wait(&g_cv_wait, &g_mu,
                 grpc_millis_to_timespec(next, GPR_CLOCK_MONOTONIC));
 
     if (grpc_timer_check_trace.enabled()) {
-      gpr_log(GPR_DEBUG, "wait ended: was_timed:%d kicked:%d",
+      gpr_log(GPR_INFO, "wait ended: was_timed:%d kicked:%d",
               my_timed_waiter_generation == g_timed_waiter_generation,
               g_kicked);
     }
@@ -232,7 +232,7 @@ static void timer_main_loop() {
            Consequently, we can just sleep forever here and be happy at some
            saved wakeup cycles. */
         if (grpc_timer_check_trace.enabled()) {
-          gpr_log(GPR_DEBUG, "timers not checked: expect another thread to");
+          gpr_log(GPR_INFO, "timers not checked: expect another thread to");
         }
         next = GRPC_MILLIS_INF_FUTURE;
       /* fall through */
@@ -258,7 +258,7 @@ static void timer_thread_cleanup(completed_thread* ct) {
   g_completed_threads = ct;
   gpr_mu_unlock(&g_mu);
   if (grpc_timer_check_trace.enabled()) {
-    gpr_log(GPR_DEBUG, "End timer thread");
+    gpr_log(GPR_INFO, "End timer thread");
   }
 }
 
@@ -300,18 +300,18 @@ void grpc_timer_manager_init(void) {
 static void stop_threads(void) {
   gpr_mu_lock(&g_mu);
   if (grpc_timer_check_trace.enabled()) {
-    gpr_log(GPR_DEBUG, "stop timer threads: threaded=%d", g_threaded);
+    gpr_log(GPR_INFO, "stop timer threads: threaded=%d", g_threaded);
   }
   if (g_threaded) {
     g_threaded = false;
     gpr_cv_broadcast(&g_cv_wait);
     if (grpc_timer_check_trace.enabled()) {
-      gpr_log(GPR_DEBUG, "num timer threads: %d", g_thread_count);
+      gpr_log(GPR_INFO, "num timer threads: %d", g_thread_count);
     }
     while (g_thread_count > 0) {
       gpr_cv_wait(&g_cv_shutdown, &g_mu, gpr_inf_future(GPR_CLOCK_MONOTONIC));
       if (grpc_timer_check_trace.enabled()) {
-        gpr_log(GPR_DEBUG, "num timer threads: %d", g_thread_count);
+        gpr_log(GPR_INFO, "num timer threads: %d", g_thread_count);
       }
       gc_completed_threads();
     }
diff --git a/src/core/lib/iomgr/timer_uv.cc b/src/core/lib/iomgr/timer_uv.cc
index dadeb960b2..8b7c82eb7d 100644
--- a/src/core/lib/iomgr/timer_uv.cc
+++ b/src/core/lib/iomgr/timer_uv.cc
@@ -52,6 +52,9 @@ static void timer_start(grpc_custom_timer* t) {
   uv_timer->data = t;
   t->timer = (void*)uv_timer;
   uv_timer_start(uv_timer, run_expired_timer, t->timeout_ms, 0);
+  // Node uses a garbage collector to call destructors, so we don't
+  // want to hold the uv loop open with active gRPC objects.
+  uv_unref((uv_handle_t*)uv_timer);
 }
 
 static void timer_stop(grpc_custom_timer* t) {
diff --git a/src/core/lib/profiling/basic_timers.cc b/src/core/lib/profiling/basic_timers.cc
index 652a498b6e..b19ad9fc23 100644
--- a/src/core/lib/profiling/basic_timers.cc
+++ b/src/core/lib/profiling/basic_timers.cc
@@ -27,6 +27,7 @@
 #include <grpc/support/sync.h>
 #include <grpc/support/time.h>
 #include <inttypes.h>
+#include <pthread.h>
 #include <stdio.h>
 #include <string.h>
 
diff --git a/src/core/lib/security/credentials/credentials.h b/src/core/lib/security/credentials/credentials.h
index b1421e83c5..b486d25ab2 100644
--- a/src/core/lib/security/credentials/credentials.h
+++ b/src/core/lib/security/credentials/credentials.h
@@ -45,6 +45,7 @@ typedef enum {
 #define GRPC_CHANNEL_CREDENTIALS_TYPE_SSL "Ssl"
 #define GRPC_CHANNEL_CREDENTIALS_TYPE_FAKE_TRANSPORT_SECURITY \
   "FakeTransportSecurity"
+#define GRPC_CHANNEL_CREDENTIALS_TYPE_GOOGLE_DEFAULT "GoogleDefault"
 
 #define GRPC_CALL_CREDENTIALS_TYPE_OAUTH2 "Oauth2"
 #define GRPC_CALL_CREDENTIALS_TYPE_JWT "Jwt"
diff --git a/src/core/lib/security/credentials/google_default/google_default_credentials.cc b/src/core/lib/security/credentials/google_default/google_default_credentials.cc
index 70d4c3ea51..4b267afe3f 100644
--- a/src/core/lib/security/credentials/google_default/google_default_credentials.cc
+++ b/src/core/lib/security/credentials/google_default/google_default_credentials.cc
@@ -26,12 +26,15 @@
 #include <grpc/support/log.h>
 #include <grpc/support/sync.h>
 
+#include "src/core/ext/filters/client_channel/lb_policy/grpclb/grpclb.h"
+#include "src/core/lib/channel/channel_args.h"
 #include "src/core/lib/gpr/env.h"
 #include "src/core/lib/gpr/string.h"
 #include "src/core/lib/http/httpcli.h"
 #include "src/core/lib/http/parser.h"
 #include "src/core/lib/iomgr/load_file.h"
 #include "src/core/lib/iomgr/polling_entity.h"
+#include "src/core/lib/security/credentials/alts/alts_credentials.h"
 #include "src/core/lib/security/credentials/google_default/google_default_credentials.h"
 #include "src/core/lib/security/credentials/jwt/jwt_credentials.h"
 #include "src/core/lib/security/credentials/oauth2/oauth2_credentials.h"
@@ -45,8 +48,8 @@
 
 /* -- Default credentials. -- */
 
-static grpc_channel_credentials* default_credentials = nullptr;
-static int compute_engine_detection_done = 0;
+static grpc_channel_credentials* g_default_credentials = nullptr;
+static int g_compute_engine_detection_done = 0;
 static gpr_mu g_state_mu;
 static gpr_mu* g_polling_mu;
 static gpr_once g_once = GPR_ONCE_INIT;
@@ -60,6 +63,52 @@ typedef struct {
   grpc_http_response response;
 } compute_engine_detector;
 
+static void google_default_credentials_destruct(
+    grpc_channel_credentials* creds) {
+  grpc_google_default_channel_credentials* c =
+      reinterpret_cast<grpc_google_default_channel_credentials*>(creds);
+  grpc_channel_credentials_unref(c->alts_creds);
+  grpc_channel_credentials_unref(c->ssl_creds);
+}
+
+static grpc_security_status google_default_create_security_connector(
+    grpc_channel_credentials* creds, grpc_call_credentials* call_creds,
+    const char* target, const grpc_channel_args* args,
+    grpc_channel_security_connector** sc, grpc_channel_args** new_args) {
+  grpc_google_default_channel_credentials* c =
+      reinterpret_cast<grpc_google_default_channel_credentials*>(creds);
+  bool is_grpclb_load_balancer = grpc_channel_arg_get_bool(
+      grpc_channel_args_find(args, GRPC_ARG_ADDRESS_IS_GRPCLB_LOAD_BALANCER),
+      false);
+  bool is_backend_from_grpclb_load_balancer = grpc_channel_arg_get_bool(
+      grpc_channel_args_find(
+          args, GRPC_ARG_ADDRESS_IS_BACKEND_FROM_GRPCLB_LOAD_BALANCER),
+      false);
+  bool use_alts =
+      is_grpclb_load_balancer || is_backend_from_grpclb_load_balancer;
+  grpc_security_status status = GRPC_SECURITY_ERROR;
+  status = use_alts ? c->alts_creds->vtable->create_security_connector(
+                          c->alts_creds, call_creds, target, args, sc, new_args)
+                    : c->ssl_creds->vtable->create_security_connector(
+                          c->ssl_creds, call_creds, target, args, sc, new_args);
+  /* grpclb-specific channel args are removed from the channel args set
+   * to ensure backends and fallback adresses will have the same set of channel
+   * args. By doing that, it guarantees the connections to backends will not be
+   * torn down and re-connected when switching in and out of fallback mode.
+   */
+  static const char* args_to_remove[] = {
+      GRPC_ARG_ADDRESS_IS_GRPCLB_LOAD_BALANCER,
+      GRPC_ARG_ADDRESS_IS_BACKEND_FROM_GRPCLB_LOAD_BALANCER,
+  };
+  *new_args = grpc_channel_args_copy_and_add_and_remove(
+      args, args_to_remove, GPR_ARRAY_SIZE(args_to_remove), nullptr, 0);
+  return status;
+}
+
+static grpc_channel_credentials_vtable google_default_credentials_vtable = {
+    google_default_credentials_destruct,
+    google_default_create_security_connector, nullptr};
+
 static void on_compute_engine_detection_http_response(void* user_data,
                                                       grpc_error* error) {
   compute_engine_detector* detector =
@@ -234,8 +283,8 @@ grpc_channel_credentials* grpc_google_default_credentials_create(void) {
 
   gpr_mu_lock(&g_state_mu);
 
-  if (default_credentials != nullptr) {
-    result = grpc_channel_credentials_ref(default_credentials);
+  if (g_default_credentials != nullptr) {
+    result = grpc_channel_credentials_ref(g_default_credentials);
     goto end;
   }
 
@@ -253,9 +302,9 @@ grpc_channel_credentials* grpc_google_default_credentials_create(void) {
 
   /* At last try to see if we're on compute engine (do the detection only once
      since it requires a network test). */
-  if (!compute_engine_detection_done) {
+  if (!g_compute_engine_detection_done) {
     int need_compute_engine_creds = is_stack_running_on_compute_engine();
-    compute_engine_detection_done = 1;
+    g_compute_engine_detection_done = 1;
     if (need_compute_engine_creds) {
       call_creds = grpc_google_compute_engine_credentials_create(nullptr);
       if (call_creds == nullptr) {
@@ -269,18 +318,25 @@ grpc_channel_credentials* grpc_google_default_credentials_create(void) {
 end:
   if (result == nullptr) {
     if (call_creds != nullptr) {
-      /* Blend with default ssl credentials and add a global reference so that
-         it
-         can be cached and re-served. */
-      grpc_channel_credentials* ssl_creds =
-          grpc_ssl_credentials_create(nullptr, nullptr, nullptr);
-      default_credentials = grpc_channel_credentials_ref(
-          grpc_composite_channel_credentials_create(ssl_creds, call_creds,
-                                                    nullptr));
-      GPR_ASSERT(default_credentials != nullptr);
-      grpc_channel_credentials_unref(ssl_creds);
+      /* Create google default credentials. */
+      auto creds = static_cast<grpc_google_default_channel_credentials*>(
+          gpr_zalloc(sizeof(grpc_google_default_channel_credentials)));
+      creds->base.vtable = &google_default_credentials_vtable;
+      creds->base.type = GRPC_CHANNEL_CREDENTIALS_TYPE_GOOGLE_DEFAULT;
+      gpr_ref_init(&creds->base.refcount, 1);
+      creds->ssl_creds = grpc_ssl_credentials_create(nullptr, nullptr, nullptr);
+      GPR_ASSERT(creds->ssl_creds != nullptr);
+      grpc_alts_credentials_options* options =
+          grpc_alts_credentials_client_options_create();
+      creds->alts_creds = grpc_alts_credentials_create(options);
+      grpc_alts_credentials_options_destroy(options);
+      /* Add a global reference so that it can be cached and re-served. */
+      g_default_credentials = grpc_composite_channel_credentials_create(
+          &creds->base, call_creds, nullptr);
+      GPR_ASSERT(g_default_credentials != nullptr);
+      grpc_channel_credentials_unref(&creds->base);
       grpc_call_credentials_unref(call_creds);
-      result = default_credentials;
+      result = grpc_channel_credentials_ref(g_default_credentials);
     } else {
       gpr_log(GPR_ERROR, "Could not create google default credentials.");
     }
@@ -299,11 +355,11 @@ void grpc_flush_cached_google_default_credentials(void) {
   grpc_core::ExecCtx exec_ctx;
   gpr_once_init(&g_once, init_default_credentials);
   gpr_mu_lock(&g_state_mu);
-  if (default_credentials != nullptr) {
-    grpc_channel_credentials_unref(default_credentials);
-    default_credentials = nullptr;
+  if (g_default_credentials != nullptr) {
+    grpc_channel_credentials_unref(g_default_credentials);
+    g_default_credentials = nullptr;
   }
-  compute_engine_detection_done = 0;
+  g_compute_engine_detection_done = 0;
   gpr_mu_unlock(&g_state_mu);
 }
 
diff --git a/src/core/lib/security/credentials/google_default/google_default_credentials.h b/src/core/lib/security/credentials/google_default/google_default_credentials.h
index b163e48631..9b4063c775 100644
--- a/src/core/lib/security/credentials/google_default/google_default_credentials.h
+++ b/src/core/lib/security/credentials/google_default/google_default_credentials.h
@@ -39,6 +39,12 @@
   "/" GRPC_GOOGLE_WELL_KNOWN_CREDENTIALS_FILE
 #endif
 
+typedef struct {
+  grpc_channel_credentials base;
+  grpc_channel_credentials* alts_creds;
+  grpc_channel_credentials* ssl_creds;
+} grpc_google_default_channel_credentials;
+
 void grpc_flush_cached_google_default_credentials(void);
 
 #endif /* GRPC_CORE_LIB_SECURITY_CREDENTIALS_GOOGLE_DEFAULT_GOOGLE_DEFAULT_CREDENTIALS_H \
diff --git a/src/core/lib/security/security_connector/security_connector.cc b/src/core/lib/security/security_connector/security_connector.cc
index 3551061aa4..6eae30a6e5 100644
--- a/src/core/lib/security/security_connector/security_connector.cc
+++ b/src/core/lib/security/security_connector/security_connector.cc
@@ -786,23 +786,26 @@ static void ssl_server_add_handshakers(grpc_server_security_connector* sc,
                          tsi_create_adapter_handshaker(tsi_hs), &sc->base));
 }
 
-static int ssl_host_matches_name(const tsi_peer* peer, const char* peer_name) {
+int grpc_ssl_host_matches_name(const tsi_peer* peer, const char* peer_name) {
   char* allocated_name = nullptr;
   int r;
 
-  if (strchr(peer_name, ':') != nullptr) {
-    char* ignored_port;
-    gpr_split_host_port(peer_name, &allocated_name, &ignored_port);
-    gpr_free(ignored_port);
-    peer_name = allocated_name;
-    if (!peer_name) return 0;
-  }
+  char* ignored_port;
+  gpr_split_host_port(peer_name, &allocated_name, &ignored_port);
+  gpr_free(ignored_port);
+  peer_name = allocated_name;
+  if (!peer_name) return 0;
+
+  // IPv6 zone-id should not be included in comparisons.
+  char* const zone_id = strchr(allocated_name, '%');
+  if (zone_id != nullptr) *zone_id = '\0';
+
   r = tsi_ssl_peer_matches_name(peer, peer_name);
   gpr_free(allocated_name);
   return r;
 }
 
-grpc_auth_context* tsi_ssl_peer_to_auth_context(const tsi_peer* peer) {
+grpc_auth_context* grpc_ssl_peer_to_auth_context(const tsi_peer* peer) {
   size_t i;
   grpc_auth_context* ctx = nullptr;
   const char* peer_identity_property_name = nullptr;
@@ -859,14 +862,14 @@ static grpc_error* ssl_check_peer(grpc_security_connector* sc,
   }
 
   /* Check the peer name if specified. */
-  if (peer_name != nullptr && !ssl_host_matches_name(peer, peer_name)) {
+  if (peer_name != nullptr && !grpc_ssl_host_matches_name(peer, peer_name)) {
     char* msg;
     gpr_asprintf(&msg, "Peer name %s is not in peer certificate", peer_name);
     grpc_error* error = GRPC_ERROR_CREATE_FROM_COPIED_STRING(msg);
     gpr_free(msg);
     return error;
   }
-  *auth_context = tsi_ssl_peer_to_auth_context(peer);
+  *auth_context = grpc_ssl_peer_to_auth_context(peer);
   return GRPC_ERROR_NONE;
 }
 
@@ -924,7 +927,7 @@ static void add_shallow_auth_property_to_peer(tsi_peer* peer,
   tsi_prop->value.length = prop->value_length;
 }
 
-tsi_peer tsi_shallow_peer_from_ssl_auth_context(
+tsi_peer grpc_shallow_peer_from_ssl_auth_context(
     const grpc_auth_context* auth_context) {
   size_t max_num_props = 0;
   grpc_auth_property_iterator it;
@@ -955,7 +958,7 @@ tsi_peer tsi_shallow_peer_from_ssl_auth_context(
   return peer;
 }
 
-void tsi_shallow_peer_destruct(tsi_peer* peer) {
+void grpc_shallow_peer_destruct(tsi_peer* peer) {
   if (peer->properties != nullptr) gpr_free(peer->properties);
 }
 
@@ -967,8 +970,8 @@ static bool ssl_channel_check_call_host(grpc_channel_security_connector* sc,
   grpc_ssl_channel_security_connector* c =
       reinterpret_cast<grpc_ssl_channel_security_connector*>(sc);
   grpc_security_status status = GRPC_SECURITY_ERROR;
-  tsi_peer peer = tsi_shallow_peer_from_ssl_auth_context(auth_context);
-  if (ssl_host_matches_name(&peer, host)) status = GRPC_SECURITY_OK;
+  tsi_peer peer = grpc_shallow_peer_from_ssl_auth_context(auth_context);
+  if (grpc_ssl_host_matches_name(&peer, host)) status = GRPC_SECURITY_OK;
   /* If the target name was overridden, then the original target_name was
      'checked' transitively during the previous peer check at the end of the
      handshake. */
@@ -980,7 +983,7 @@ static bool ssl_channel_check_call_host(grpc_channel_security_connector* sc,
     *error = GRPC_ERROR_CREATE_FROM_STATIC_STRING(
         "call host does not match SSL server name");
   }
-  tsi_shallow_peer_destruct(&peer);
+  grpc_shallow_peer_destruct(&peer);
   return true;
 }
 
diff --git a/src/core/lib/security/security_connector/security_connector.h b/src/core/lib/security/security_connector/security_connector.h
index c4cc19db81..f9723166d0 100644
--- a/src/core/lib/security/security_connector/security_connector.h
+++ b/src/core/lib/security/security_connector/security_connector.h
@@ -239,10 +239,11 @@ const tsi_peer_property* tsi_peer_get_property_by_name(const tsi_peer* peer,
                                                        const char* name);
 
 /* Exposed for testing only. */
-grpc_auth_context* tsi_ssl_peer_to_auth_context(const tsi_peer* peer);
-tsi_peer tsi_shallow_peer_from_ssl_auth_context(
+grpc_auth_context* grpc_ssl_peer_to_auth_context(const tsi_peer* peer);
+tsi_peer grpc_shallow_peer_from_ssl_auth_context(
     const grpc_auth_context* auth_context);
-void tsi_shallow_peer_destruct(tsi_peer* peer);
+void grpc_shallow_peer_destruct(tsi_peer* peer);
+int grpc_ssl_host_matches_name(const tsi_peer* peer, const char* peer_name);
 
 /* --- Default SSL Root Store. --- */
 namespace grpc_core {
diff --git a/src/core/lib/security/transport/secure_endpoint.cc b/src/core/lib/security/transport/secure_endpoint.cc
index 31b779e333..840b2e73bc 100644
--- a/src/core/lib/security/transport/secure_endpoint.cc
+++ b/src/core/lib/security/transport/secure_endpoint.cc
@@ -133,7 +133,7 @@ static void call_read_cb(secure_endpoint* ep, grpc_error* error) {
     for (i = 0; i < ep->read_buffer->count; i++) {
       char* data = grpc_dump_slice(ep->read_buffer->slices[i],
                                    GPR_DUMP_HEX | GPR_DUMP_ASCII);
-      gpr_log(GPR_DEBUG, "READ %p: %s", ep, data);
+      gpr_log(GPR_INFO, "READ %p: %s", ep, data);
       gpr_free(data);
     }
   }
@@ -269,7 +269,7 @@ static void endpoint_write(grpc_endpoint* secure_ep, grpc_slice_buffer* slices,
     for (i = 0; i < slices->count; i++) {
       char* data =
           grpc_dump_slice(slices->slices[i], GPR_DUMP_HEX | GPR_DUMP_ASCII);
-      gpr_log(GPR_DEBUG, "WRITE %p: %s", ep, data);
+      gpr_log(GPR_INFO, "WRITE %p: %s", ep, data);
       gpr_free(data);
     }
   }
diff --git a/src/core/lib/security/transport/security_handshaker.cc b/src/core/lib/security/transport/security_handshaker.cc
index 0c97dfa6b3..d9ba3483e6 100644
--- a/src/core/lib/security/transport/security_handshaker.cc
+++ b/src/core/lib/security/transport/security_handshaker.cc
@@ -232,6 +232,10 @@ static grpc_error* on_handshake_next_done_locked(
     const unsigned char* bytes_to_send, size_t bytes_to_send_size,
     tsi_handshaker_result* handshaker_result) {
   grpc_error* error = GRPC_ERROR_NONE;
+  // Handshaker was shutdown.
+  if (h->shutdown) {
+    return GRPC_ERROR_CREATE_FROM_STATIC_STRING("Handshaker shutdown");
+  }
   // Read more if we need to.
   if (result == TSI_INCOMPLETE_DATA) {
     GPR_ASSERT(bytes_to_send_size == 0);
@@ -406,7 +410,7 @@ static void security_handshaker_do_handshake(grpc_handshaker* handshaker,
 
 static const grpc_handshaker_vtable security_handshaker_vtable = {
     security_handshaker_destroy, security_handshaker_shutdown,
-    security_handshaker_do_handshake};
+    security_handshaker_do_handshake, "security"};
 
 static grpc_handshaker* security_handshaker_create(
     tsi_handshaker* handshaker, grpc_security_connector* connector) {
@@ -456,7 +460,7 @@ static void fail_handshaker_do_handshake(grpc_handshaker* handshaker,
 
 static const grpc_handshaker_vtable fail_handshaker_vtable = {
     fail_handshaker_destroy, fail_handshaker_shutdown,
-    fail_handshaker_do_handshake};
+    fail_handshaker_do_handshake, "security_fail"};
 
 static grpc_handshaker* fail_handshaker_create() {
   grpc_handshaker* h = static_cast<grpc_handshaker*>(gpr_malloc(sizeof(*h)));
diff --git a/src/core/lib/slice/slice_hash_table.h b/src/core/lib/slice/slice_hash_table.h
index fbe9cc58e8..4bbcf88e89 100644
--- a/src/core/lib/slice/slice_hash_table.h
+++ b/src/core/lib/slice/slice_hash_table.h
@@ -81,6 +81,10 @@ class SliceHashTable : public RefCounted<SliceHashTable<T>> {
   template <typename T2, typename... Args>
   friend T2* New(Args&&... args);
 
+  // So Delete() can call our private dtor.
+  template <typename T2>
+  friend void Delete(T2*);
+
   SliceHashTable(size_t num_entries, Entry* entries, ValueCmp value_cmp);
   virtual ~SliceHashTable();
 
diff --git a/src/core/lib/slice/slice_weak_hash_table.h b/src/core/lib/slice/slice_weak_hash_table.h
index 9d0ddfc2d2..dc3ccc5dad 100644
--- a/src/core/lib/slice/slice_weak_hash_table.h
+++ b/src/core/lib/slice/slice_weak_hash_table.h
@@ -65,6 +65,10 @@ class SliceWeakHashTable : public RefCounted<SliceWeakHashTable<T, Size>> {
   template <typename T2, typename... Args>
   friend T2* New(Args&&... args);
 
+  // So Delete() can call our private dtor.
+  template <typename T2>
+  friend void Delete(T2*);
+
   SliceWeakHashTable() = default;
   ~SliceWeakHashTable() = default;
 
diff --git a/src/core/lib/surface/call.cc b/src/core/lib/surface/call.cc
index 9a9113643d..da488034ca 100644
--- a/src/core/lib/surface/call.cc
+++ b/src/core/lib/surface/call.cc
@@ -610,7 +610,7 @@ grpc_call_error grpc_call_cancel(grpc_call* call, void* reserved) {
 // This is called via the call combiner to start sending a batch down
 // the filter stack.
 static void execute_batch_in_call_combiner(void* arg, grpc_error* ignored) {
-  GPR_TIMER_SCOPE("execute_batch", 0);
+  GPR_TIMER_SCOPE("execute_batch_in_call_combiner", 0);
   grpc_transport_stream_op_batch* batch =
       static_cast<grpc_transport_stream_op_batch*>(arg);
   grpc_call* call = static_cast<grpc_call*>(batch->handler_private.extra_arg);
@@ -747,10 +747,10 @@ static void get_final_status(
     status[i] = unpack_received_status(gpr_atm_acq_load(&call->status[i]));
   }
   if (grpc_call_error_trace.enabled()) {
-    gpr_log(GPR_DEBUG, "get_final_status %s", call->is_client ? "CLI" : "SVR");
+    gpr_log(GPR_INFO, "get_final_status %s", call->is_client ? "CLI" : "SVR");
     for (i = 0; i < STATUS_SOURCE_COUNT; i++) {
       if (status[i].is_set) {
-        gpr_log(GPR_DEBUG, "  %d: %s", i, grpc_error_string(status[i].error));
+        gpr_log(GPR_INFO, "  %d: %s", i, grpc_error_string(status[i].error));
       }
     }
   }
@@ -1539,7 +1539,7 @@ static void free_no_op_completion(void* p, grpc_cq_completion* completion) {
 static grpc_call_error call_start_batch(grpc_call* call, const grpc_op* ops,
                                         size_t nops, void* notify_tag,
                                         int is_notify_tag_closure) {
-  GPR_TIMER_SCOPE("grpc_call_start_batch", 0);
+  GPR_TIMER_SCOPE("call_start_batch", 0);
 
   size_t i;
   const grpc_op* op;
diff --git a/src/core/lib/surface/server.cc b/src/core/lib/surface/server.cc
index f7505c888e..cb34def740 100644
--- a/src/core/lib/surface/server.cc
+++ b/src/core/lib/surface/server.cc
@@ -1161,6 +1161,22 @@ static void listener_destroy_done(void* s, grpc_error* error) {
   gpr_mu_unlock(&server->mu_global);
 }
 
+/*
+  - Kills all pending requests-for-incoming-RPC-calls (i.e the requests made via
+    grpc_server_request_call and grpc_server_request_registered call will now be
+    cancelled). See 'kill_pending_work_locked()'
+
+  - Shuts down the listeners (i.e the server will no longer listen on the port
+    for new incoming channels).
+
+  - Iterates through all channels on the server and sends shutdown msg (see
+    'channel_broadcaster_shutdown()' for details) to the clients via the
+    transport layer. The transport layer then guarantees the following:
+     -- Sends shutdown to the client (for eg: HTTP2 transport sends GOAWAY)
+     -- If the server has outstanding calls that are in the process, the
+        connection is NOT closed until the server is done with all those calls
+     -- Once, there are no more calls in progress, the channel is closed
+ */
 void grpc_server_shutdown_and_notify(grpc_server* server,
                                      grpc_completion_queue* cq, void* tag) {
   listener* l;
diff --git a/src/core/lib/surface/version.cc b/src/core/lib/surface/version.cc
index a712e10037..306b7c395e 100644
--- a/src/core/lib/surface/version.cc
+++ b/src/core/lib/surface/version.cc
@@ -25,4 +25,4 @@
 
 const char* grpc_version_string(void) { return "6.0.0-dev"; }
 
-const char* grpc_g_stands_for(void) { return "glorious"; }
+const char* grpc_g_stands_for(void) { return "gloriosa"; }
diff --git a/src/core/lib/transport/bdp_estimator.cc b/src/core/lib/transport/bdp_estimator.cc
index 8130535ddd..8e71f86989 100644
--- a/src/core/lib/transport/bdp_estimator.cc
+++ b/src/core/lib/transport/bdp_estimator.cc
@@ -47,7 +47,7 @@ grpc_millis BdpEstimator::CompletePing() {
   double bw = dt > 0 ? (static_cast<double>(accumulator_) / dt) : 0;
   int start_inter_ping_delay = inter_ping_delay_;
   if (grpc_bdp_estimator_trace.enabled()) {
-    gpr_log(GPR_DEBUG,
+    gpr_log(GPR_INFO,
             "bdp[%s]:complete acc=%" PRId64 " est=%" PRId64
             " dt=%lf bw=%lfMbs bw_est=%lfMbs",
             name_, accumulator_, estimate_, dt, bw / 125000.0,
@@ -58,7 +58,7 @@ grpc_millis BdpEstimator::CompletePing() {
     estimate_ = GPR_MAX(accumulator_, estimate_ * 2);
     bw_est_ = bw;
     if (grpc_bdp_estimator_trace.enabled()) {
-      gpr_log(GPR_DEBUG, "bdp[%s]: estimate increased to %" PRId64, name_,
+      gpr_log(GPR_INFO, "bdp[%s]: estimate increased to %" PRId64, name_,
               estimate_);
     }
     inter_ping_delay_ /= 2;  // if the ping estimate changes,
@@ -75,7 +75,7 @@ grpc_millis BdpEstimator::CompletePing() {
   if (start_inter_ping_delay != inter_ping_delay_) {
     stable_estimate_count_ = 0;
     if (grpc_bdp_estimator_trace.enabled()) {
-      gpr_log(GPR_DEBUG, "bdp[%s]:update_inter_time to %dms", name_,
+      gpr_log(GPR_INFO, "bdp[%s]:update_inter_time to %dms", name_,
               inter_ping_delay_);
     }
   }
diff --git a/src/core/lib/transport/bdp_estimator.h b/src/core/lib/transport/bdp_estimator.h
index e703af121c..ab13ae4be4 100644
--- a/src/core/lib/transport/bdp_estimator.h
+++ b/src/core/lib/transport/bdp_estimator.h
@@ -50,7 +50,7 @@ class BdpEstimator {
   // transport (but not necessarily started)
   void SchedulePing() {
     if (grpc_bdp_estimator_trace.enabled()) {
-      gpr_log(GPR_DEBUG, "bdp[%s]:sched acc=%" PRId64 " est=%" PRId64, name_,
+      gpr_log(GPR_INFO, "bdp[%s]:sched acc=%" PRId64 " est=%" PRId64, name_,
               accumulator_, estimate_);
     }
     GPR_ASSERT(ping_state_ == PingState::UNSCHEDULED);
@@ -63,7 +63,7 @@ class BdpEstimator {
   // the ping is on the wire
   void StartPing() {
     if (grpc_bdp_estimator_trace.enabled()) {
-      gpr_log(GPR_DEBUG, "bdp[%s]:start acc=%" PRId64 " est=%" PRId64, name_,
+      gpr_log(GPR_INFO, "bdp[%s]:start acc=%" PRId64 " est=%" PRId64, name_,
               accumulator_, estimate_);
     }
     GPR_ASSERT(ping_state_ == PingState::SCHEDULED);
diff --git a/src/core/lib/transport/connectivity_state.cc b/src/core/lib/transport/connectivity_state.cc
index 0122e773ca..db6b6c0444 100644
--- a/src/core/lib/transport/connectivity_state.cc
+++ b/src/core/lib/transport/connectivity_state.cc
@@ -78,7 +78,7 @@ grpc_connectivity_state grpc_connectivity_state_check(
   grpc_connectivity_state cur = static_cast<grpc_connectivity_state>(
       gpr_atm_no_barrier_load(&tracker->current_state_atm));
   if (grpc_connectivity_state_trace.enabled()) {
-    gpr_log(GPR_DEBUG, "CONWATCH: %p %s: get %s", tracker, tracker->name,
+    gpr_log(GPR_INFO, "CONWATCH: %p %s: get %s", tracker, tracker->name,
             grpc_connectivity_state_name(cur));
   }
   return cur;
@@ -89,7 +89,7 @@ grpc_connectivity_state grpc_connectivity_state_get(
   grpc_connectivity_state cur = static_cast<grpc_connectivity_state>(
       gpr_atm_no_barrier_load(&tracker->current_state_atm));
   if (grpc_connectivity_state_trace.enabled()) {
-    gpr_log(GPR_DEBUG, "CONWATCH: %p %s: get %s", tracker, tracker->name,
+    gpr_log(GPR_INFO, "CONWATCH: %p %s: get %s", tracker, tracker->name,
             grpc_connectivity_state_name(cur));
   }
   if (error != nullptr) {
@@ -110,10 +110,10 @@ bool grpc_connectivity_state_notify_on_state_change(
       gpr_atm_no_barrier_load(&tracker->current_state_atm));
   if (grpc_connectivity_state_trace.enabled()) {
     if (current == nullptr) {
-      gpr_log(GPR_DEBUG, "CONWATCH: %p %s: unsubscribe notify=%p", tracker,
+      gpr_log(GPR_INFO, "CONWATCH: %p %s: unsubscribe notify=%p", tracker,
               tracker->name, notify);
     } else {
-      gpr_log(GPR_DEBUG, "CONWATCH: %p %s: from %s [cur=%s] notify=%p", tracker,
+      gpr_log(GPR_INFO, "CONWATCH: %p %s: from %s [cur=%s] notify=%p", tracker,
               tracker->name, grpc_connectivity_state_name(*current),
               grpc_connectivity_state_name(cur), notify);
     }
@@ -161,7 +161,7 @@ void grpc_connectivity_state_set(grpc_connectivity_state_tracker* tracker,
   grpc_connectivity_state_watcher* w;
   if (grpc_connectivity_state_trace.enabled()) {
     const char* error_string = grpc_error_string(error);
-    gpr_log(GPR_DEBUG, "SET: %p %s: %s --> %s [%s] error=%p %s", tracker,
+    gpr_log(GPR_INFO, "SET: %p %s: %s --> %s [%s] error=%p %s", tracker,
             tracker->name, grpc_connectivity_state_name(cur),
             grpc_connectivity_state_name(state), reason, error, error_string);
   }
@@ -187,8 +187,7 @@ void grpc_connectivity_state_set(grpc_connectivity_state_tracker* tracker,
     *w->current = state;
     tracker->watchers = w->next;
     if (grpc_connectivity_state_trace.enabled()) {
-      gpr_log(GPR_DEBUG, "NOTIFY: %p %s: %p", tracker, tracker->name,
-              w->notify);
+      gpr_log(GPR_INFO, "NOTIFY: %p %s: %p", tracker, tracker->name, w->notify);
     }
     GRPC_CLOSURE_SCHED(w->notify, GRPC_ERROR_REF(tracker->current_error));
     gpr_free(w);
diff --git a/src/core/tsi/ssl/session_cache/ssl_session_cache.h b/src/core/tsi/ssl/session_cache/ssl_session_cache.h
index 488638c9bb..a90cca1a2e 100644
--- a/src/core/tsi/ssl/session_cache/ssl_session_cache.h
+++ b/src/core/tsi/ssl/session_cache/ssl_session_cache.h
@@ -69,6 +69,10 @@ class SslSessionLRUCache : public grpc_core::RefCounted<SslSessionLRUCache> {
   template <typename T, typename... Args>
   friend T* grpc_core::New(Args&&... args);
 
+  // So Delete() can call our private dtor.
+  template <typename T>
+  friend void grpc_core::Delete(T*);
+
   class Node;
 
   explicit SslSessionLRUCache(size_t capacity);
diff --git a/src/core/tsi/ssl_transport_security.cc b/src/core/tsi/ssl_transport_security.cc
index 0ba6587678..a2301be40a 100644
--- a/src/core/tsi/ssl_transport_security.cc
+++ b/src/core/tsi/ssl_transport_security.cc
@@ -120,12 +120,14 @@ typedef struct {
 /* --- Library Initialization. ---*/
 
 static gpr_once g_init_openssl_once = GPR_ONCE_INIT;
-static gpr_mu* g_openssl_mutexes = nullptr;
 static int g_ssl_ctx_ex_factory_index = -1;
+static const unsigned char kSslSessionIdContext[] = {'g', 'r', 'p', 'c'};
+
+#if OPENSSL_VERSION_NUMBER < 0x10100000
+static gpr_mu* g_openssl_mutexes = nullptr;
 static void openssl_locking_cb(int mode, int type, const char* file,
                                int line) GRPC_UNUSED;
 static unsigned long openssl_thread_id_cb(void) GRPC_UNUSED;
-static const unsigned char kSslSessionIdContext[] = {'g', 'r', 'p', 'c'};
 
 static void openssl_locking_cb(int mode, int type, const char* file, int line) {
   if (mode & CRYPTO_LOCK) {
@@ -138,22 +140,27 @@ static void openssl_locking_cb(int mode, int type, const char* file, int line) {
 static unsigned long openssl_thread_id_cb(void) {
   return static_cast<unsigned long>(gpr_thd_currentid());
 }
+#endif
 
 static void init_openssl(void) {
-  int i;
-  int num_locks;
   SSL_library_init();
   SSL_load_error_strings();
   OpenSSL_add_all_algorithms();
-  num_locks = CRYPTO_num_locks();
-  GPR_ASSERT(num_locks > 0);
-  g_openssl_mutexes = static_cast<gpr_mu*>(
-      gpr_malloc(static_cast<size_t>(num_locks) * sizeof(gpr_mu)));
-  for (i = 0; i < CRYPTO_num_locks(); i++) {
-    gpr_mu_init(&g_openssl_mutexes[i]);
-  }
-  CRYPTO_set_locking_callback(openssl_locking_cb);
-  CRYPTO_set_id_callback(openssl_thread_id_cb);
+#if OPENSSL_VERSION_NUMBER < 0x10100000
+  if (!CRYPTO_get_locking_callback()) {
+    int num_locks = CRYPTO_num_locks();
+    GPR_ASSERT(num_locks > 0);
+    g_openssl_mutexes = static_cast<gpr_mu*>(
+        gpr_malloc(static_cast<size_t>(num_locks) * sizeof(gpr_mu)));
+    for (int i = 0; i < num_locks; i++) {
+      gpr_mu_init(&g_openssl_mutexes[i]);
+    }
+    CRYPTO_set_locking_callback(openssl_locking_cb);
+    CRYPTO_set_id_callback(openssl_thread_id_cb);
+  } else {
+    gpr_log(GPR_INFO, "OpenSSL callback has already been set.");
+  }
+#endif
   g_ssl_ctx_ex_factory_index =
       SSL_CTX_get_ex_new_index(0, nullptr, nullptr, nullptr, nullptr);
   GPR_ASSERT(g_ssl_ctx_ex_factory_index != -1);
diff --git a/src/cpp/common/version_cc.cc b/src/cpp/common/version_cc.cc
index d669ea21a9..54cd2076ec 100644
--- a/src/cpp/common/version_cc.cc
+++ b/src/cpp/common/version_cc.cc
@@ -22,5 +22,5 @@
 #include <grpcpp/grpcpp.h>
 
 namespace grpc {
-grpc::string Version() { return "1.12.0-dev"; }
+grpc::string Version() { return "1.13.0-dev"; }
 }  // namespace grpc
diff --git a/src/cpp/server/load_reporter/load_data_store.cc b/src/cpp/server/load_reporter/load_data_store.cc
new file mode 100644
index 0000000000..70f12c1102
--- /dev/null
+++ b/src/cpp/server/load_reporter/load_data_store.cc
@@ -0,0 +1,273 @@
+/*
+ *
+ * Copyright 2018 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+#include <cstdlib>
+#include <set>
+#include <unordered_map>
+#include <vector>
+
+#include "src/cpp/server/load_reporter/load_data_store.h"
+
+namespace grpc {
+namespace load_reporter {
+
+// Some helper functions.
+namespace {
+
+// Given a map from type K to a set of value type V, finds the set associated
+// with the given key and erases the value from the set. If the set becomes
+// empty, also erases the key-set pair. Returns true if the value is erased
+// successfully.
+template <typename K, typename V>
+bool UnorderedMapOfSetEraseKeyValue(std::unordered_map<K, std::set<V>>& map,
+                                    const K& key, const V& value) {
+  auto it = map.find(key);
+  if (it != map.end()) {
+    size_t erased = it->second.erase(value);
+    if (it->second.size() == 0) {
+      map.erase(it);
+    }
+    return erased;
+  }
+  return false;
+};
+
+// Given a map from type K to a set of value type V, removes the given key and
+// the associated set, and returns the set. Returns an empty set if the key is
+// not found.
+template <typename K, typename V>
+std::set<V> UnorderedMapOfSetExtract(std::unordered_map<K, std::set<V>>& map,
+                                     const K& key) {
+  auto it = map.find(key);
+  if (it != map.end()) {
+    auto set = std::move(it->second);
+    map.erase(it);
+    return set;
+  }
+  return {};
+};
+
+// From a non-empty container, returns a pointer to a random element.
+template <typename C>
+const typename C::value_type* RandomElement(const C& container) {
+  GPR_ASSERT(!container.empty());
+  auto it = container.begin();
+  std::advance(it, std::rand() % container.size());
+  return &(*it);
+}
+
+}  // namespace
+
+void PerBalancerStore::MergeRow(const LoadRecordKey& key,
+                                const LoadRecordValue& value) {
+  // During suspension, the load data received will be dropped.
+  if (!suspended_) {
+    load_record_map_[key].MergeFrom(value);
+    gpr_log(GPR_DEBUG,
+            "[PerBalancerStore %p] Load data merged (Key: %s, Value: %s).",
+            this, key.ToString().c_str(), value.ToString().c_str());
+  } else {
+    gpr_log(GPR_DEBUG,
+            "[PerBalancerStore %p] Load data dropped (Key: %s, Value: %s).",
+            this, key.ToString().c_str(), value.ToString().c_str());
+  }
+  // We always keep track of num_calls_in_progress_, so that when this
+  // store is resumed, we still have a correct value of
+  // num_calls_in_progress_.
+  GPR_ASSERT(static_cast<int64_t>(num_calls_in_progress_) +
+                 value.GetNumCallsInProgressDelta() >=
+             0);
+  num_calls_in_progress_ += value.GetNumCallsInProgressDelta();
+}
+
+void PerBalancerStore::Suspend() {
+  suspended_ = true;
+  load_record_map_.clear();
+  gpr_log(GPR_DEBUG, "[PerBalancerStore %p] Suspended.", this);
+}
+
+void PerBalancerStore::Resume() {
+  suspended_ = false;
+  gpr_log(GPR_DEBUG, "[PerBalancerStore %p] Resumed.", this);
+}
+
+uint64_t PerBalancerStore::GetNumCallsInProgressForReport() {
+  GPR_ASSERT(!suspended_);
+  last_reported_num_calls_in_progress_ = num_calls_in_progress_;
+  return num_calls_in_progress_;
+}
+
+void PerHostStore::ReportStreamCreated(const grpc::string& lb_id,
+                                       const grpc::string& load_key) {
+  GPR_ASSERT(lb_id != kInvalidLbId);
+  SetUpForNewLbId(lb_id, load_key);
+  // Prior to this one, there was no load balancer receiving report, so we may
+  // have unassigned orphaned stores to assign to this new balancer.
+  // TODO(juanlishen): If the load key of this new stream is the same with
+  // some previously adopted orphan store, we may want to take the orphan to
+  // this stream. Need to discuss with LB team.
+  if (assigned_stores_.size() == 1) {
+    for (const auto& p : per_balancer_stores_) {
+      const grpc::string& other_lb_id = p.first;
+      const std::unique_ptr<PerBalancerStore>& orphaned_store = p.second;
+      if (other_lb_id != lb_id) {
+        orphaned_store->Resume();
+        AssignOrphanedStore(orphaned_store.get(), lb_id);
+      }
+    }
+  }
+  // The first connected balancer will adopt the kInvalidLbId.
+  if (per_balancer_stores_.size() == 1) {
+    SetUpForNewLbId(kInvalidLbId, "");
+    ReportStreamClosed(kInvalidLbId);
+  }
+}
+
+void PerHostStore::ReportStreamClosed(const grpc::string& lb_id) {
+  auto it_store_for_gone_lb = per_balancer_stores_.find(lb_id);
+  GPR_ASSERT(it_store_for_gone_lb != per_balancer_stores_.end());
+  // Remove this closed stream from our records.
+  GPR_ASSERT(UnorderedMapOfSetEraseKeyValue(
+      load_key_to_receiving_lb_ids_, it_store_for_gone_lb->second->load_key(),
+      lb_id));
+  std::set<PerBalancerStore*> orphaned_stores =
+      UnorderedMapOfSetExtract(assigned_stores_, lb_id);
+  // The stores that were assigned to this balancer are orphaned now. They
+  // should be re-assigned to other balancers which are still receiving reports.
+  for (PerBalancerStore* orphaned_store : orphaned_stores) {
+    const grpc::string* new_receiver = nullptr;
+    auto it = load_key_to_receiving_lb_ids_.find(orphaned_store->load_key());
+    if (it != load_key_to_receiving_lb_ids_.end()) {
+      // First, try to pick from the active balancers with the same load key.
+      new_receiver = RandomElement(it->second);
+    } else if (!assigned_stores_.empty()) {
+      // If failed, pick from all the remaining active balancers.
+      new_receiver = &(RandomElement(assigned_stores_)->first);
+    }
+    if (new_receiver != nullptr) {
+      AssignOrphanedStore(orphaned_store, *new_receiver);
+    } else {
+      // Load data for an LB ID that can't be assigned to any stream should
+      // be dropped.
+      orphaned_store->Suspend();
+    }
+  }
+}
+
+PerBalancerStore* PerHostStore::FindPerBalancerStore(
+    const grpc::string& lb_id) const {
+  return per_balancer_stores_.find(lb_id) != per_balancer_stores_.end()
+             ? per_balancer_stores_.find(lb_id)->second.get()
+             : nullptr;
+}
+
+const std::set<PerBalancerStore*>* PerHostStore::GetAssignedStores(
+    const grpc::string& lb_id) const {
+  auto it = assigned_stores_.find(lb_id);
+  if (it == assigned_stores_.end()) return nullptr;
+  return &(it->second);
+}
+
+void PerHostStore::AssignOrphanedStore(PerBalancerStore* orphaned_store,
+                                       const grpc::string& new_receiver) {
+  auto it = assigned_stores_.find(new_receiver);
+  GPR_ASSERT(it != assigned_stores_.end());
+  it->second.insert(orphaned_store);
+  gpr_log(GPR_INFO,
+          "[PerHostStore %p] Re-assigned orphaned store (%p) with original LB"
+          " ID of %s to new receiver %s",
+          this, orphaned_store, orphaned_store->lb_id().c_str(),
+          new_receiver.c_str());
+}
+
+void PerHostStore::SetUpForNewLbId(const grpc::string& lb_id,
+                                   const grpc::string& load_key) {
+  // The top-level caller (i.e., LoadReportService) should guarantee the
+  // lb_id is unique for each reporting stream.
+  GPR_ASSERT(per_balancer_stores_.find(lb_id) == per_balancer_stores_.end());
+  GPR_ASSERT(assigned_stores_.find(lb_id) == assigned_stores_.end());
+  load_key_to_receiving_lb_ids_[load_key].insert(lb_id);
+  std::unique_ptr<PerBalancerStore> per_balancer_store(
+      new PerBalancerStore(lb_id, load_key));
+  assigned_stores_[lb_id] = {per_balancer_store.get()};
+  per_balancer_stores_[lb_id] = std::move(per_balancer_store);
+}
+
+PerBalancerStore* LoadDataStore::FindPerBalancerStore(
+    const string& hostname, const string& lb_id) const {
+  auto it = per_host_stores_.find(hostname);
+  if (it != per_host_stores_.end()) {
+    const PerHostStore& per_host_store = it->second;
+    return per_host_store.FindPerBalancerStore(lb_id);
+  } else {
+    return nullptr;
+  }
+}
+
+void LoadDataStore::MergeRow(const grpc::string& hostname,
+                             const LoadRecordKey& key,
+                             const LoadRecordValue& value) {
+  PerBalancerStore* per_balancer_store =
+      FindPerBalancerStore(hostname, key.lb_id());
+  if (per_balancer_store != nullptr) {
+    per_balancer_store->MergeRow(key, value);
+    return;
+  }
+  // Unknown LB ID. Track it until its number of in-progress calls drops to
+  // zero.
+  int64_t in_progress_delta = value.GetNumCallsInProgressDelta();
+  if (in_progress_delta != 0) {
+    auto it_tracker = unknown_balancer_id_trackers_.find(key.lb_id());
+    if (it_tracker == unknown_balancer_id_trackers_.end()) {
+      gpr_log(
+          GPR_DEBUG,
+          "[LoadDataStore %p] Start tracking unknown balancer (lb_id_: %s).",
+          this, key.lb_id().c_str());
+      unknown_balancer_id_trackers_.insert(
+          {key.lb_id(), static_cast<uint64_t>(in_progress_delta)});
+    } else if ((it_tracker->second += in_progress_delta) == 0) {
+      unknown_balancer_id_trackers_.erase(it_tracker);
+      gpr_log(GPR_DEBUG,
+              "[LoadDataStore %p] Stop tracking unknown balancer (lb_id_: %s).",
+              this, key.lb_id().c_str());
+    }
+  }
+}
+
+const std::set<PerBalancerStore*>* LoadDataStore::GetAssignedStores(
+    const grpc::string& hostname, const grpc::string& lb_id) {
+  auto it = per_host_stores_.find(hostname);
+  if (it == per_host_stores_.end()) return nullptr;
+  return it->second.GetAssignedStores(lb_id);
+}
+
+void LoadDataStore::ReportStreamCreated(const grpc::string& hostname,
+                                        const grpc::string& lb_id,
+                                        const grpc::string& load_key) {
+  per_host_stores_[hostname].ReportStreamCreated(lb_id, load_key);
+}
+
+void LoadDataStore::ReportStreamClosed(const grpc::string& hostname,
+                                       const grpc::string& lb_id) {
+  auto it_per_host_store = per_host_stores_.find(hostname);
+  GPR_ASSERT(it_per_host_store != per_host_stores_.end());
+  it_per_host_store->second.ReportStreamClosed(lb_id);
+}
+
+}  // namespace load_reporter
+}  // namespace grpc
diff --git a/src/cpp/server/load_reporter/load_data_store.h b/src/cpp/server/load_reporter/load_data_store.h
new file mode 100644
index 0000000000..feb8b2fd59
--- /dev/null
+++ b/src/cpp/server/load_reporter/load_data_store.h
@@ -0,0 +1,339 @@
+/*
+ *
+ * Copyright 2018 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+#ifndef GRPC_SRC_CPP_SERVER_LOAD_REPORTER_LOAD_DATA_STORE_H
+#define GRPC_SRC_CPP_SERVER_LOAD_REPORTER_LOAD_DATA_STORE_H
+
+#include <grpc/support/port_platform.h>
+
+#include <memory>
+#include <set>
+#include <unordered_map>
+
+#include <grpc/support/log.h>
+#include <grpcpp/impl/codegen/config.h>
+
+namespace grpc {
+namespace load_reporter {
+
+constexpr char kInvalidLbId[] = "<INVALID_LBID_238dsb234890rb>";
+constexpr uint8_t kLbIdLen = 8;
+
+// The load data storage is organized in hierarchy. The LoadDataStore is the
+// top-level data store. In LoadDataStore, for each host we keep a
+// PerHostStore, in which for each balancer we keep a PerBalancerStore. Each
+// PerBalancerStore maintains a map of load records, mapping from LoadRecordKey
+// to LoadRecordValue. The LoadRecordValue contains a map of customized call
+// metrics, mapping from a call metric name to the CallMetricValue.
+
+// The value of a customized call metric.
+class CallMetricValue {
+ public:
+  explicit CallMetricValue(uint64_t num_calls = 0,
+                           double total_metric_value = 0)
+      : num_calls_(num_calls), total_metric_value_(total_metric_value) {}
+
+  void MergeFrom(CallMetricValue other) {
+    num_calls_ += other.num_calls_;
+    total_metric_value_ += other.total_metric_value_;
+  }
+
+  // Getters.
+  uint64_t num_calls() const { return num_calls_; }
+  double total_metric_value() const { return total_metric_value_; }
+
+ private:
+  // The number of calls that finished with this metric.
+  uint64_t num_calls_ = 0;
+  // The sum of metric values across all the calls that finished with this
+  // metric.
+  double total_metric_value_ = 0;
+};
+
+// The key of a load record.
+class LoadRecordKey {
+ public:
+  explicit LoadRecordKey(grpc::string lb_id, grpc::string lb_tag,
+                         grpc::string user_id, grpc::string client_ip_hex)
+      : lb_id_(std::move(lb_id)),
+        lb_tag_(std::move(lb_tag)),
+        user_id_(std::move(user_id)),
+        client_ip_hex_(std::move(client_ip_hex)) {}
+
+  grpc::string ToString() const {
+    return "[lb_id_=" + lb_id_ + ", lb_tag_=" + lb_tag_ +
+           ", user_id_=" + user_id_ + ", client_ip_hex_=" + client_ip_hex_ +
+           "]";
+  }
+
+  bool operator==(const LoadRecordKey& other) const {
+    return lb_id_ == other.lb_id_ && lb_tag_ == other.lb_tag_ &&
+           user_id_ == other.user_id_ && client_ip_hex_ == other.client_ip_hex_;
+  }
+
+  // Getters.
+  const grpc::string& lb_id() const { return lb_id_; }
+  const grpc::string& lb_tag() const { return lb_tag_; }
+  const grpc::string& user_id() const { return user_id_; }
+  const grpc::string& client_ip_hex() const { return client_ip_hex_; }
+
+  struct Hasher {
+    void hash_combine(size_t* seed, const grpc::string& k) const {
+      *seed ^= std::hash<grpc::string>()(k) + 0x9e3779b9 + (*seed << 6) +
+               (*seed >> 2);
+    }
+
+    size_t operator()(const LoadRecordKey& k) const {
+      size_t h = 0;
+      hash_combine(&h, k.lb_id_);
+      hash_combine(&h, k.lb_tag_);
+      hash_combine(&h, k.user_id_);
+      hash_combine(&h, k.client_ip_hex_);
+      return h;
+    }
+  };
+
+ private:
+  grpc::string lb_id_;
+  grpc::string lb_tag_;
+  grpc::string user_id_;
+  grpc::string client_ip_hex_;
+};
+
+// The value of a load record.
+class LoadRecordValue {
+ public:
+  explicit LoadRecordValue(uint64_t start_count = 0, uint64_t ok_count = 0,
+                           uint64_t error_count = 0, double bytes_sent = 0,
+                           double bytes_recv = 0, double latency_ms = 0)
+      : start_count_(start_count),
+        ok_count_(ok_count),
+        error_count_(error_count),
+        bytes_sent_(bytes_sent),
+        bytes_recv_(bytes_recv),
+        latency_ms_(latency_ms) {}
+
+  void MergeFrom(const LoadRecordValue& other) {
+    start_count_ += other.start_count_;
+    ok_count_ += other.ok_count_;
+    error_count_ += other.error_count_;
+    bytes_sent_ += other.bytes_sent_;
+    bytes_recv_ += other.bytes_recv_;
+    latency_ms_ += other.latency_ms_;
+    for (const auto& p : other.call_metrics_) {
+      const grpc::string& key = p.first;
+      const CallMetricValue& value = p.second;
+      call_metrics_[key].MergeFrom(value);
+    }
+  }
+
+  int64_t GetNumCallsInProgressDelta() const {
+    return static_cast<int64_t>(start_count_ - ok_count_ - error_count_);
+  }
+
+  grpc::string ToString() const {
+    return "[start_count_=" + grpc::to_string(start_count_) +
+           ", ok_count_=" + grpc::to_string(ok_count_) +
+           ", error_count_=" + grpc::to_string(error_count_) +
+           ", bytes_sent_=" + grpc::to_string(bytes_sent_) +
+           ", bytes_recv_=" + grpc::to_string(bytes_recv_) +
+           ", latency_ms_=" + grpc::to_string(latency_ms_) + "]";
+  }
+
+  bool InsertCallMetric(const grpc::string& metric_name,
+                        const CallMetricValue& metric_value) {
+    return call_metrics_.insert({metric_name, metric_value}).second;
+  }
+
+  // Getters.
+  uint64_t start_count() const { return start_count_; }
+  uint64_t ok_count() const { return ok_count_; }
+  uint64_t error_count() const { return error_count_; }
+  double bytes_sent() const { return bytes_sent_; }
+  double bytes_recv() const { return bytes_recv_; }
+  double latency_ms() const { return latency_ms_; }
+  const std::unordered_map<grpc::string, CallMetricValue>& call_metrics()
+      const {
+    return call_metrics_;
+  }
+
+ private:
+  uint64_t start_count_ = 0;
+  uint64_t ok_count_ = 0;
+  uint64_t error_count_ = 0;
+  double bytes_sent_ = 0;
+  double bytes_recv_ = 0;
+  double latency_ms_ = 0;
+  std::unordered_map<grpc::string, CallMetricValue> call_metrics_;
+};
+
+// Stores the data associated with a particular LB ID.
+class PerBalancerStore {
+ public:
+  using LoadRecordMap =
+      std::unordered_map<LoadRecordKey, LoadRecordValue, LoadRecordKey::Hasher>;
+
+  PerBalancerStore(grpc::string lb_id, grpc::string load_key)
+      : lb_id_(std::move(lb_id)), load_key_(std::move(load_key)) {}
+
+  // Merge a load record with the given key and value if the store is not
+  // suspended.
+  void MergeRow(const LoadRecordKey& key, const LoadRecordValue& value);
+
+  // Suspend this store, so that no detailed load data will be recorded.
+  void Suspend();
+  // Resume this store from suspension.
+  void Resume();
+  // Is this store suspended or not?
+  bool IsSuspended() const { return suspended_; }
+
+  bool IsNumCallsInProgressChangedSinceLastReport() const {
+    return num_calls_in_progress_ != last_reported_num_calls_in_progress_;
+  }
+
+  uint64_t GetNumCallsInProgressForReport();
+
+  grpc::string ToString() {
+    return "[PerBalancerStore lb_id_=" + lb_id_ + " load_key_=" + load_key_ +
+           "]";
+  }
+
+  void ClearLoadRecordMap() { load_record_map_.clear(); }
+
+  // Getters.
+  const grpc::string& lb_id() const { return lb_id_; }
+  const grpc::string& load_key() const { return load_key_; }
+  const LoadRecordMap& load_record_map() const { return load_record_map_; }
+
+ private:
+  grpc::string lb_id_;
+  // TODO(juanlishen): Use bytestring protobuf type?
+  grpc::string load_key_;
+  LoadRecordMap load_record_map_;
+  uint64_t num_calls_in_progress_ = 0;
+  uint64_t last_reported_num_calls_in_progress_ = 0;
+  bool suspended_ = false;
+};
+
+// Stores the data associated with a particular host.
+class PerHostStore {
+ public:
+  // When a report stream is created, a PerBalancerStore is created for the
+  // LB ID (guaranteed unique) associated with that stream. If it is the only
+  // active store, adopt all the orphaned stores. If it is the first created
+  // store, adopt the store of kInvalidLbId.
+  void ReportStreamCreated(const grpc::string& lb_id,
+                           const grpc::string& load_key);
+
+  // When a report stream is closed, the PerBalancerStores assigned to the
+  // associate LB ID need to be re-assigned to other active balancers,
+  // ideally with the same load key. If there is no active balancer, we have
+  // to suspend those stores and drop the incoming load data until they are
+  // resumed.
+  void ReportStreamClosed(const grpc::string& lb_id);
+
+  // Returns null if not found. Caller doesn't own the returned store.
+  PerBalancerStore* FindPerBalancerStore(const grpc::string& lb_id) const;
+
+  // Returns null if lb_id is not found. The returned pointer points to the
+  // underlying data structure, which is not owned by the caller.
+  const std::set<PerBalancerStore*>* GetAssignedStores(
+      const grpc::string& lb_id) const;
+
+ private:
+  // Creates a PerBalancerStore for the given LB ID, assigns the store to
+  // itself, and records the LB ID to the load key.
+  void SetUpForNewLbId(const grpc::string& lb_id, const grpc::string& load_key);
+
+  void AssignOrphanedStore(PerBalancerStore* orphaned_store,
+                           const grpc::string& new_receiver);
+
+  std::unordered_map<grpc::string, std::set<grpc::string>>
+      load_key_to_receiving_lb_ids_;
+
+  // Key: LB ID. The key set includes all the LB IDs that have been
+  // allocated for reporting streams so far.
+  // Value: the unique pointer to the PerBalancerStore of the LB ID.
+  std::unordered_map<grpc::string, std::unique_ptr<PerBalancerStore>>
+      per_balancer_stores_;
+
+  // Key: LB ID. The key set includes the LB IDs of the balancers that are
+  // currently receiving report.
+  // Value: the set of raw pointers to the PerBalancerStores assigned to the LB
+  // ID. Note that the sets in assigned_stores_ form a division of the value set
+  // of per_balancer_stores_.
+  std::unordered_map<grpc::string, std::set<PerBalancerStore*>>
+      assigned_stores_;
+};
+
+// Thread-unsafe two-level bookkeeper of all the load data.
+// Note: We never remove any store objects from this class, as per the
+// current spec. That's because premature removal of the store objects
+// may lead to loss of critical information, e.g., mapping from lb_id to
+// load_key, and the number of in-progress calls. Such loss will cause
+// information inconsistency when the balancer is re-connected. Keeping
+// all the stores should be fine for PerHostStore, since we assume there
+// should only be a few hostnames. But it's a potential problem for
+// PerBalancerStore.
+class LoadDataStore {
+ public:
+  // Returns null if not found. Caller doesn't own the returned store.
+  PerBalancerStore* FindPerBalancerStore(const grpc::string& hostname,
+                                         const grpc::string& lb_id) const;
+
+  // Returns null if hostname or lb_id is not found. The returned pointer points
+  // to the underlying data structure, which is not owned by the caller.
+  const std::set<PerBalancerStore*>* GetAssignedStores(const string& hostname,
+                                                       const string& lb_id);
+
+  // If a PerBalancerStore can be found by the hostname and LB ID in
+  // LoadRecordKey, the load data will be merged to that store. Otherwise,
+  // only track the number of the in-progress calls for this unknown LB ID.
+  void MergeRow(const grpc::string& hostname, const LoadRecordKey& key,
+                const LoadRecordValue& value);
+
+  // Is the given lb_id a tracked unknown LB ID (i.e., the LB ID was associated
+  // with some received load data but unknown to this load data store)?
+  bool IsTrackedUnknownBalancerId(const grpc::string& lb_id) const {
+    return unknown_balancer_id_trackers_.find(lb_id) !=
+           unknown_balancer_id_trackers_.end();
+  }
+
+  // Wrapper around PerHostStore::ReportStreamCreated.
+  void ReportStreamCreated(const grpc::string& hostname,
+                           const grpc::string& lb_id,
+                           const grpc::string& load_key);
+
+  // Wrapper around PerHostStore::ReportStreamClosed.
+  void ReportStreamClosed(const grpc::string& hostname,
+                          const grpc::string& lb_id);
+
+ private:
+  // Buffered data that was fetched from Census but hasn't been sent to
+  // balancer. We need to keep this data ourselves because Census will
+  // delete the data once it's returned.
+  std::unordered_map<grpc::string, PerHostStore> per_host_stores_;
+
+  // Tracks the number of in-progress calls for each unknown LB ID.
+  std::unordered_map<grpc::string, uint64_t> unknown_balancer_id_trackers_;
+};
+
+}  // namespace load_reporter
+}  // namespace grpc
+
+#endif  // GRPC_SRC_CPP_SERVER_LOAD_REPORTER_LOAD_DATA_STORE_H
diff --git a/src/csharp/Grpc.Core.Testing/TestServerCallContext.cs b/src/csharp/Grpc.Core.Testing/TestServerCallContext.cs
new file mode 100644
index 0000000000..5418417d7e
--- /dev/null
+++ b/src/csharp/Grpc.Core.Testing/TestServerCallContext.cs
@@ -0,0 +1,58 @@
+#region Copyright notice and license
+
+// Copyright 2015 gRPC authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#endregion
+
+using System;
+using System.Threading;
+using System.Threading.Tasks;
+using Grpc.Core;
+
+namespace Grpc.Core.Testing
+{
+    /// <summary>
+    /// Creates test doubles for <c>ServerCallContext</c>.
+    /// </summary>
+    public static class TestServerCallContext
+    {
+        /// <summary>
+        /// Creates a test double for <c>ServerCallContext</c>. Only for testing.
+        /// Note: experimental API that can change or be removed without any prior notice.
+        /// </summary>
+        public static ServerCallContext Create(string method, string host, DateTime deadline, Metadata requestHeaders, CancellationToken cancellationToken,
+            string peer, AuthContext authContext, ContextPropagationToken contextPropagationToken,
+            Func<Metadata, Task> writeHeadersFunc, Func<WriteOptions> writeOptionsGetter, Action<WriteOptions> writeOptionsSetter)
+        {
+            return new ServerCallContext(null, method, host, deadline, requestHeaders, cancellationToken,
+                writeHeadersFunc, new WriteOptionsHolder(writeOptionsGetter, writeOptionsSetter),
+                () => peer, () => authContext, () => contextPropagationToken);
+        }
+
+        private class WriteOptionsHolder : IHasWriteOptions
+        {
+            Func<WriteOptions> writeOptionsGetter;
+            Action<WriteOptions> writeOptionsSetter;
+
+            public WriteOptionsHolder(Func<WriteOptions> writeOptionsGetter, Action<WriteOptions> writeOptionsSetter)
+            {
+                this.writeOptionsGetter = writeOptionsGetter;
+                this.writeOptionsSetter = writeOptionsSetter;
+            }
+
+            public WriteOptions WriteOptions { get => writeOptionsGetter(); set => writeOptionsSetter(value); }
+        }
+    }
+}
diff --git a/src/csharp/Grpc.Core/NativeDeps.Mac.csproj.include b/src/csharp/Grpc.Core/NativeDeps.Mac.csproj.include
index f1b85c3730..309e33d47e 100644
--- a/src/csharp/Grpc.Core/NativeDeps.Mac.csproj.include
+++ b/src/csharp/Grpc.Core/NativeDeps.Mac.csproj.include
@@ -1,13 +1,5 @@
 <Project>
   <ItemGroup>
-    <!-- We are relying on run_tests.py to build grpc_csharp_ext with the right bitness
-    and we copy it as both x86 (needed by net45) and x64 (needed by netcoreapp1.0) as we don't
-    know which one will be needed to run the tests. -->
-    <Content Include="..\..\..\libs\$(NativeDependenciesConfigurationUnix)\libgrpc_csharp_ext.dylib">
-      <Link>libgrpc_csharp_ext.x86.dylib</Link>
-      <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
-      <Pack>false</Pack>
-    </Content>
     <Content Include="..\..\..\libs\$(NativeDependenciesConfigurationUnix)\libgrpc_csharp_ext.dylib">
       <Link>libgrpc_csharp_ext.x64.dylib</Link>
       <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
diff --git a/src/csharp/Grpc.Core/RpcException.cs b/src/csharp/Grpc.Core/RpcException.cs
index d2c912e73a..94429d74ce 100644
--- a/src/csharp/Grpc.Core/RpcException.cs
+++ b/src/csharp/Grpc.Core/RpcException.cs
@@ -73,6 +73,17 @@ namespace Grpc.Core
         }
 
         /// <summary>
+        /// Returns the status code of the call, as a convenient alternative to <see cref="StatusCode">Status.StatusCode</see>.
+        /// </summary>
+        public StatusCode StatusCode
+        {
+            get
+            {
+                return status.StatusCode;
+            }
+        }
+
+        /// <summary>
         /// Gets the call trailing metadata.
         /// Trailers only have meaningful content for client-side calls (in which case they represent the trailing metadata sent by the server when closing the call).
         /// Instances of <c>RpcException</c> thrown by the server-side part of the stack will have trailers always set to empty.
diff --git a/src/csharp/Grpc.Core/ServerCallContext.cs b/src/csharp/Grpc.Core/ServerCallContext.cs
index c63a4c45db..74a7deabea 100644
--- a/src/csharp/Grpc.Core/ServerCallContext.cs
+++ b/src/csharp/Grpc.Core/ServerCallContext.cs
@@ -36,14 +36,25 @@ namespace Grpc.Core
         private readonly Metadata requestHeaders;
         private readonly CancellationToken cancellationToken;
         private readonly Metadata responseTrailers = new Metadata();
+        private readonly Func<Metadata, Task> writeHeadersFunc;
+        private readonly IHasWriteOptions writeOptionsHolder;
+        private readonly Lazy<AuthContext> authContext;
+        private readonly Func<string> testingOnlyPeerGetter;
+        private readonly Func<AuthContext> testingOnlyAuthContextGetter;
+        private readonly Func<ContextPropagationToken> testingOnlyContextPropagationTokenFactory;
 
         private Status status = Status.DefaultSuccess;
-        private Func<Metadata, Task> writeHeadersFunc;
-        private IHasWriteOptions writeOptionsHolder;
-        private Lazy<AuthContext> authContext;
 
         internal ServerCallContext(CallSafeHandle callHandle, string method, string host, DateTime deadline, Metadata requestHeaders, CancellationToken cancellationToken,
             Func<Metadata, Task> writeHeadersFunc, IHasWriteOptions writeOptionsHolder)
+            : this(callHandle, method, host, deadline, requestHeaders, cancellationToken, writeHeadersFunc, writeOptionsHolder, null, null, null)
+        {
+        }
+
+        // Additional constructor params should be used for testing only
+        internal ServerCallContext(CallSafeHandle callHandle, string method, string host, DateTime deadline, Metadata requestHeaders, CancellationToken cancellationToken,
+            Func<Metadata, Task> writeHeadersFunc, IHasWriteOptions writeOptionsHolder,
+            Func<string> testingOnlyPeerGetter, Func<AuthContext> testingOnlyAuthContextGetter, Func<ContextPropagationToken> testingOnlyContextPropagationTokenFactory)
         {
             this.callHandle = callHandle;
             this.method = method;
@@ -54,6 +65,9 @@ namespace Grpc.Core
             this.writeHeadersFunc = writeHeadersFunc;
             this.writeOptionsHolder = writeOptionsHolder;
             this.authContext = new Lazy<AuthContext>(GetAuthContextEager);
+            this.testingOnlyPeerGetter = testingOnlyPeerGetter;
+            this.testingOnlyAuthContextGetter = testingOnlyAuthContextGetter;
+            this.testingOnlyContextPropagationTokenFactory = testingOnlyContextPropagationTokenFactory;
         }
 
         /// <summary>
@@ -73,6 +87,10 @@ namespace Grpc.Core
         /// </summary>
         public ContextPropagationToken CreatePropagationToken(ContextPropagationOptions options = null)
         {
+            if (testingOnlyContextPropagationTokenFactory != null)
+            {
+                return testingOnlyContextPropagationTokenFactory();
+            }
             return new ContextPropagationToken(callHandle, deadline, cancellationToken, options);
         }
             
@@ -99,6 +117,10 @@ namespace Grpc.Core
         {
             get
             {
+                if (testingOnlyPeerGetter != null)
+                {
+                    return testingOnlyPeerGetter();
+                }
                 // Getting the peer lazily is fine as the native call is guaranteed
                 // not to be disposed before user-supplied server side handler returns.
                 // Most users won't need to read this field anyway.
@@ -182,6 +204,10 @@ namespace Grpc.Core
         {
             get
             {
+                if (testingOnlyAuthContextGetter != null)
+                {
+                    return testingOnlyAuthContextGetter();
+                }
                 return authContext.Value;
             }
         }
@@ -198,7 +224,7 @@ namespace Grpc.Core
     /// <summary>
     /// Allows sharing write options between ServerCallContext and other objects.
     /// </summary>
-    public interface IHasWriteOptions
+    internal interface IHasWriteOptions
     {
         /// <summary>
         /// Gets or sets the write options.
diff --git a/src/csharp/Grpc.Core/Version.csproj.include b/src/csharp/Grpc.Core/Version.csproj.include
index f7a7a5cbe9..f5d63b77f0 100755
--- a/src/csharp/Grpc.Core/Version.csproj.include
+++ b/src/csharp/Grpc.Core/Version.csproj.include
@@ -1,7 +1,7 @@
 <!-- This file is generated -->
 <Project>
   <PropertyGroup>
-    <GrpcCsharpVersion>1.12.0-dev</GrpcCsharpVersion>
-    <GoogleProtobufVersion>3.3.0</GoogleProtobufVersion>
+    <GrpcCsharpVersion>1.13.0-dev</GrpcCsharpVersion>
+    <GoogleProtobufVersion>3.5.1</GoogleProtobufVersion>
   </PropertyGroup>
 </Project>
diff --git a/src/csharp/Grpc.Core/VersionInfo.cs b/src/csharp/Grpc.Core/VersionInfo.cs
index 06a0396c34..87edddae3f 100644
--- a/src/csharp/Grpc.Core/VersionInfo.cs
+++ b/src/csharp/Grpc.Core/VersionInfo.cs
@@ -33,11 +33,11 @@ namespace Grpc.Core
         /// <summary>
         /// Current <c>AssemblyFileVersion</c> of gRPC C# assemblies
         /// </summary>
-        public const string CurrentAssemblyFileVersion = "1.12.0.0";
+        public const string CurrentAssemblyFileVersion = "1.13.0.0";
 
         /// <summary>
         /// Current version of gRPC C#
         /// </summary>
-        public const string CurrentVersion = "1.12.0-dev";
+        public const string CurrentVersion = "1.13.0-dev";
     }
 }
diff --git a/src/csharp/Grpc.Examples/Math.cs b/src/csharp/Grpc.Examples/Math.cs
index e5b76f8305..4c3879f577 100644
--- a/src/csharp/Grpc.Examples/Math.cs
+++ b/src/csharp/Grpc.Examples/Math.cs
@@ -1,5 +1,7 @@
-// Generated by the protocol buffer compiler.  DO NOT EDIT!
-// source: math/math.proto
+// <auto-generated>
+//     Generated by the protocol buffer compiler.  DO NOT EDIT!
+//     source: math/math.proto
+// </auto-generated>
 #pragma warning disable 1591, 0612, 3021
 #region Designer generated code
 
@@ -47,6 +49,7 @@ namespace Math {
   #region Messages
   public sealed partial class DivArgs : pb::IMessage<DivArgs> {
     private static readonly pb::MessageParser<DivArgs> _parser = new pb::MessageParser<DivArgs>(() => new DivArgs());
+    private pb::UnknownFieldSet _unknownFields;
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public static pb::MessageParser<DivArgs> Parser { get { return _parser; } }
 
@@ -71,6 +74,7 @@ namespace Math {
     public DivArgs(DivArgs other) : this() {
       dividend_ = other.dividend_;
       divisor_ = other.divisor_;
+      _unknownFields = pb::UnknownFieldSet.Clone(other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -115,7 +119,7 @@ namespace Math {
       }
       if (Dividend != other.Dividend) return false;
       if (Divisor != other.Divisor) return false;
-      return true;
+      return Equals(_unknownFields, other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -123,6 +127,9 @@ namespace Math {
       int hash = 1;
       if (Dividend != 0L) hash ^= Dividend.GetHashCode();
       if (Divisor != 0L) hash ^= Divisor.GetHashCode();
+      if (_unknownFields != null) {
+        hash ^= _unknownFields.GetHashCode();
+      }
       return hash;
     }
 
@@ -141,6 +148,9 @@ namespace Math {
         output.WriteRawTag(16);
         output.WriteInt64(Divisor);
       }
+      if (_unknownFields != null) {
+        _unknownFields.WriteTo(output);
+      }
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -152,6 +162,9 @@ namespace Math {
       if (Divisor != 0L) {
         size += 1 + pb::CodedOutputStream.ComputeInt64Size(Divisor);
       }
+      if (_unknownFields != null) {
+        size += _unknownFields.CalculateSize();
+      }
       return size;
     }
 
@@ -166,6 +179,7 @@ namespace Math {
       if (other.Divisor != 0L) {
         Divisor = other.Divisor;
       }
+      _unknownFields = pb::UnknownFieldSet.MergeFrom(_unknownFields, other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -174,7 +188,7 @@ namespace Math {
       while ((tag = input.ReadTag()) != 0) {
         switch(tag) {
           default:
-            input.SkipLastField();
+            _unknownFields = pb::UnknownFieldSet.MergeFieldFrom(_unknownFields, input);
             break;
           case 8: {
             Dividend = input.ReadInt64();
@@ -192,6 +206,7 @@ namespace Math {
 
   public sealed partial class DivReply : pb::IMessage<DivReply> {
     private static readonly pb::MessageParser<DivReply> _parser = new pb::MessageParser<DivReply>(() => new DivReply());
+    private pb::UnknownFieldSet _unknownFields;
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public static pb::MessageParser<DivReply> Parser { get { return _parser; } }
 
@@ -216,6 +231,7 @@ namespace Math {
     public DivReply(DivReply other) : this() {
       quotient_ = other.quotient_;
       remainder_ = other.remainder_;
+      _unknownFields = pb::UnknownFieldSet.Clone(other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -260,7 +276,7 @@ namespace Math {
       }
       if (Quotient != other.Quotient) return false;
       if (Remainder != other.Remainder) return false;
-      return true;
+      return Equals(_unknownFields, other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -268,6 +284,9 @@ namespace Math {
       int hash = 1;
       if (Quotient != 0L) hash ^= Quotient.GetHashCode();
       if (Remainder != 0L) hash ^= Remainder.GetHashCode();
+      if (_unknownFields != null) {
+        hash ^= _unknownFields.GetHashCode();
+      }
       return hash;
     }
 
@@ -286,6 +305,9 @@ namespace Math {
         output.WriteRawTag(16);
         output.WriteInt64(Remainder);
       }
+      if (_unknownFields != null) {
+        _unknownFields.WriteTo(output);
+      }
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -297,6 +319,9 @@ namespace Math {
       if (Remainder != 0L) {
         size += 1 + pb::CodedOutputStream.ComputeInt64Size(Remainder);
       }
+      if (_unknownFields != null) {
+        size += _unknownFields.CalculateSize();
+      }
       return size;
     }
 
@@ -311,6 +336,7 @@ namespace Math {
       if (other.Remainder != 0L) {
         Remainder = other.Remainder;
       }
+      _unknownFields = pb::UnknownFieldSet.MergeFrom(_unknownFields, other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -319,7 +345,7 @@ namespace Math {
       while ((tag = input.ReadTag()) != 0) {
         switch(tag) {
           default:
-            input.SkipLastField();
+            _unknownFields = pb::UnknownFieldSet.MergeFieldFrom(_unknownFields, input);
             break;
           case 8: {
             Quotient = input.ReadInt64();
@@ -337,6 +363,7 @@ namespace Math {
 
   public sealed partial class FibArgs : pb::IMessage<FibArgs> {
     private static readonly pb::MessageParser<FibArgs> _parser = new pb::MessageParser<FibArgs>(() => new FibArgs());
+    private pb::UnknownFieldSet _unknownFields;
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public static pb::MessageParser<FibArgs> Parser { get { return _parser; } }
 
@@ -360,6 +387,7 @@ namespace Math {
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public FibArgs(FibArgs other) : this() {
       limit_ = other.limit_;
+      _unknownFields = pb::UnknownFieldSet.Clone(other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -392,13 +420,16 @@ namespace Math {
         return true;
       }
       if (Limit != other.Limit) return false;
-      return true;
+      return Equals(_unknownFields, other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public override int GetHashCode() {
       int hash = 1;
       if (Limit != 0L) hash ^= Limit.GetHashCode();
+      if (_unknownFields != null) {
+        hash ^= _unknownFields.GetHashCode();
+      }
       return hash;
     }
 
@@ -413,6 +444,9 @@ namespace Math {
         output.WriteRawTag(8);
         output.WriteInt64(Limit);
       }
+      if (_unknownFields != null) {
+        _unknownFields.WriteTo(output);
+      }
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -421,6 +455,9 @@ namespace Math {
       if (Limit != 0L) {
         size += 1 + pb::CodedOutputStream.ComputeInt64Size(Limit);
       }
+      if (_unknownFields != null) {
+        size += _unknownFields.CalculateSize();
+      }
       return size;
     }
 
@@ -432,6 +469,7 @@ namespace Math {
       if (other.Limit != 0L) {
         Limit = other.Limit;
       }
+      _unknownFields = pb::UnknownFieldSet.MergeFrom(_unknownFields, other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -440,7 +478,7 @@ namespace Math {
       while ((tag = input.ReadTag()) != 0) {
         switch(tag) {
           default:
-            input.SkipLastField();
+            _unknownFields = pb::UnknownFieldSet.MergeFieldFrom(_unknownFields, input);
             break;
           case 8: {
             Limit = input.ReadInt64();
@@ -454,6 +492,7 @@ namespace Math {
 
   public sealed partial class Num : pb::IMessage<Num> {
     private static readonly pb::MessageParser<Num> _parser = new pb::MessageParser<Num>(() => new Num());
+    private pb::UnknownFieldSet _unknownFields;
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public static pb::MessageParser<Num> Parser { get { return _parser; } }
 
@@ -477,6 +516,7 @@ namespace Math {
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public Num(Num other) : this() {
       num_ = other.num_;
+      _unknownFields = pb::UnknownFieldSet.Clone(other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -509,13 +549,16 @@ namespace Math {
         return true;
       }
       if (Num_ != other.Num_) return false;
-      return true;
+      return Equals(_unknownFields, other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public override int GetHashCode() {
       int hash = 1;
       if (Num_ != 0L) hash ^= Num_.GetHashCode();
+      if (_unknownFields != null) {
+        hash ^= _unknownFields.GetHashCode();
+      }
       return hash;
     }
 
@@ -530,6 +573,9 @@ namespace Math {
         output.WriteRawTag(8);
         output.WriteInt64(Num_);
       }
+      if (_unknownFields != null) {
+        _unknownFields.WriteTo(output);
+      }
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -538,6 +584,9 @@ namespace Math {
       if (Num_ != 0L) {
         size += 1 + pb::CodedOutputStream.ComputeInt64Size(Num_);
       }
+      if (_unknownFields != null) {
+        size += _unknownFields.CalculateSize();
+      }
       return size;
     }
 
@@ -549,6 +598,7 @@ namespace Math {
       if (other.Num_ != 0L) {
         Num_ = other.Num_;
       }
+      _unknownFields = pb::UnknownFieldSet.MergeFrom(_unknownFields, other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -557,7 +607,7 @@ namespace Math {
       while ((tag = input.ReadTag()) != 0) {
         switch(tag) {
           default:
-            input.SkipLastField();
+            _unknownFields = pb::UnknownFieldSet.MergeFieldFrom(_unknownFields, input);
             break;
           case 8: {
             Num_ = input.ReadInt64();
@@ -571,6 +621,7 @@ namespace Math {
 
   public sealed partial class FibReply : pb::IMessage<FibReply> {
     private static readonly pb::MessageParser<FibReply> _parser = new pb::MessageParser<FibReply>(() => new FibReply());
+    private pb::UnknownFieldSet _unknownFields;
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public static pb::MessageParser<FibReply> Parser { get { return _parser; } }
 
@@ -594,6 +645,7 @@ namespace Math {
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public FibReply(FibReply other) : this() {
       count_ = other.count_;
+      _unknownFields = pb::UnknownFieldSet.Clone(other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -626,13 +678,16 @@ namespace Math {
         return true;
       }
       if (Count != other.Count) return false;
-      return true;
+      return Equals(_unknownFields, other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public override int GetHashCode() {
       int hash = 1;
       if (Count != 0L) hash ^= Count.GetHashCode();
+      if (_unknownFields != null) {
+        hash ^= _unknownFields.GetHashCode();
+      }
       return hash;
     }
 
@@ -647,6 +702,9 @@ namespace Math {
         output.WriteRawTag(8);
         output.WriteInt64(Count);
       }
+      if (_unknownFields != null) {
+        _unknownFields.WriteTo(output);
+      }
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -655,6 +713,9 @@ namespace Math {
       if (Count != 0L) {
         size += 1 + pb::CodedOutputStream.ComputeInt64Size(Count);
       }
+      if (_unknownFields != null) {
+        size += _unknownFields.CalculateSize();
+      }
       return size;
     }
 
@@ -666,6 +727,7 @@ namespace Math {
       if (other.Count != 0L) {
         Count = other.Count;
       }
+      _unknownFields = pb::UnknownFieldSet.MergeFrom(_unknownFields, other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -674,7 +736,7 @@ namespace Math {
       while ((tag = input.ReadTag()) != 0) {
         switch(tag) {
           default:
-            input.SkipLastField();
+            _unknownFields = pb::UnknownFieldSet.MergeFieldFrom(_unknownFields, input);
             break;
           case 8: {
             Count = input.ReadInt64();
diff --git a/src/csharp/Grpc.HealthCheck/Health.cs b/src/csharp/Grpc.HealthCheck/Health.cs
index b9880d9636..a90f261d28 100644
--- a/src/csharp/Grpc.HealthCheck/Health.cs
+++ b/src/csharp/Grpc.HealthCheck/Health.cs
@@ -1,5 +1,7 @@
-// Generated by the protocol buffer compiler.  DO NOT EDIT!
-// source: grpc/health/v1/health.proto
+// <auto-generated>
+//     Generated by the protocol buffer compiler.  DO NOT EDIT!
+//     source: grpc/health/v1/health.proto
+// </auto-generated>
 #pragma warning disable 1591, 0612, 3021
 #region Designer generated code
 
@@ -29,7 +31,9 @@ namespace Grpc.Health.V1 {
             "ZXJ2aW5nU3RhdHVzEgsKB1VOS05PV04QABILCgdTRVJWSU5HEAESDwoLTk9U",
             "X1NFUlZJTkcQAjJaCgZIZWFsdGgSUAoFQ2hlY2sSIi5ncnBjLmhlYWx0aC52",
             "MS5IZWFsdGhDaGVja1JlcXVlc3QaIy5ncnBjLmhlYWx0aC52MS5IZWFsdGhD",
-            "aGVja1Jlc3BvbnNlQhGqAg5HcnBjLkhlYWx0aC5WMWIGcHJvdG8z"));
+            "aGVja1Jlc3BvbnNlQmEKEWlvLmdycGMuaGVhbHRoLnYxQgtIZWFsdGhQcm90",
+            "b1ABWixnb29nbGUuZ29sYW5nLm9yZy9ncnBjL2hlYWx0aC9ncnBjX2hlYWx0",
+            "aF92MaoCDkdycGMuSGVhbHRoLlYxYgZwcm90bzM="));
       descriptor = pbr::FileDescriptor.FromGeneratedCode(descriptorData,
           new pbr::FileDescriptor[] { },
           new pbr::GeneratedClrTypeInfo(null, new pbr::GeneratedClrTypeInfo[] {
@@ -43,6 +47,7 @@ namespace Grpc.Health.V1 {
   #region Messages
   public sealed partial class HealthCheckRequest : pb::IMessage<HealthCheckRequest> {
     private static readonly pb::MessageParser<HealthCheckRequest> _parser = new pb::MessageParser<HealthCheckRequest>(() => new HealthCheckRequest());
+    private pb::UnknownFieldSet _unknownFields;
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public static pb::MessageParser<HealthCheckRequest> Parser { get { return _parser; } }
 
@@ -66,6 +71,7 @@ namespace Grpc.Health.V1 {
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public HealthCheckRequest(HealthCheckRequest other) : this() {
       service_ = other.service_;
+      _unknownFields = pb::UnknownFieldSet.Clone(other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -98,13 +104,16 @@ namespace Grpc.Health.V1 {
         return true;
       }
       if (Service != other.Service) return false;
-      return true;
+      return Equals(_unknownFields, other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public override int GetHashCode() {
       int hash = 1;
       if (Service.Length != 0) hash ^= Service.GetHashCode();
+      if (_unknownFields != null) {
+        hash ^= _unknownFields.GetHashCode();
+      }
       return hash;
     }
 
@@ -119,6 +128,9 @@ namespace Grpc.Health.V1 {
         output.WriteRawTag(10);
         output.WriteString(Service);
       }
+      if (_unknownFields != null) {
+        _unknownFields.WriteTo(output);
+      }
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -127,6 +139,9 @@ namespace Grpc.Health.V1 {
       if (Service.Length != 0) {
         size += 1 + pb::CodedOutputStream.ComputeStringSize(Service);
       }
+      if (_unknownFields != null) {
+        size += _unknownFields.CalculateSize();
+      }
       return size;
     }
 
@@ -138,6 +153,7 @@ namespace Grpc.Health.V1 {
       if (other.Service.Length != 0) {
         Service = other.Service;
       }
+      _unknownFields = pb::UnknownFieldSet.MergeFrom(_unknownFields, other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -146,7 +162,7 @@ namespace Grpc.Health.V1 {
       while ((tag = input.ReadTag()) != 0) {
         switch(tag) {
           default:
-            input.SkipLastField();
+            _unknownFields = pb::UnknownFieldSet.MergeFieldFrom(_unknownFields, input);
             break;
           case 10: {
             Service = input.ReadString();
@@ -160,6 +176,7 @@ namespace Grpc.Health.V1 {
 
   public sealed partial class HealthCheckResponse : pb::IMessage<HealthCheckResponse> {
     private static readonly pb::MessageParser<HealthCheckResponse> _parser = new pb::MessageParser<HealthCheckResponse>(() => new HealthCheckResponse());
+    private pb::UnknownFieldSet _unknownFields;
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public static pb::MessageParser<HealthCheckResponse> Parser { get { return _parser; } }
 
@@ -183,6 +200,7 @@ namespace Grpc.Health.V1 {
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public HealthCheckResponse(HealthCheckResponse other) : this() {
       status_ = other.status_;
+      _unknownFields = pb::UnknownFieldSet.Clone(other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -215,13 +233,16 @@ namespace Grpc.Health.V1 {
         return true;
       }
       if (Status != other.Status) return false;
-      return true;
+      return Equals(_unknownFields, other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public override int GetHashCode() {
       int hash = 1;
       if (Status != 0) hash ^= Status.GetHashCode();
+      if (_unknownFields != null) {
+        hash ^= _unknownFields.GetHashCode();
+      }
       return hash;
     }
 
@@ -236,6 +257,9 @@ namespace Grpc.Health.V1 {
         output.WriteRawTag(8);
         output.WriteEnum((int) Status);
       }
+      if (_unknownFields != null) {
+        _unknownFields.WriteTo(output);
+      }
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -244,6 +268,9 @@ namespace Grpc.Health.V1 {
       if (Status != 0) {
         size += 1 + pb::CodedOutputStream.ComputeEnumSize((int) Status);
       }
+      if (_unknownFields != null) {
+        size += _unknownFields.CalculateSize();
+      }
       return size;
     }
 
@@ -255,6 +282,7 @@ namespace Grpc.Health.V1 {
       if (other.Status != 0) {
         Status = other.Status;
       }
+      _unknownFields = pb::UnknownFieldSet.MergeFrom(_unknownFields, other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -263,7 +291,7 @@ namespace Grpc.Health.V1 {
       while ((tag = input.ReadTag()) != 0) {
         switch(tag) {
           default:
-            input.SkipLastField();
+            _unknownFields = pb::UnknownFieldSet.MergeFieldFrom(_unknownFields, input);
             break;
           case 8: {
             status_ = (global::Grpc.Health.V1.HealthCheckResponse.Types.ServingStatus) input.ReadEnum();
diff --git a/src/csharp/Grpc.HealthCheck/HealthGrpc.cs b/src/csharp/Grpc.HealthCheck/HealthGrpc.cs
index 1d80bcd59e..a26f483981 100644
--- a/src/csharp/Grpc.HealthCheck/HealthGrpc.cs
+++ b/src/csharp/Grpc.HealthCheck/HealthGrpc.cs
@@ -3,7 +3,7 @@
 //     source: grpc/health/v1/health.proto
 // </auto-generated>
 // Original file comments:
-// Copyright 2015 gRPC authors.
+// Copyright 2015 The gRPC Authors
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
@@ -17,6 +17,9 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 //
+// The canonical version of this proto can be found at
+// https://github.com/grpc/grpc-proto/blob/master/grpc/health/v1/health.proto
+//
 #pragma warning disable 1591
 #region Designer generated code
 
diff --git a/src/csharp/Grpc.IntegrationTesting/BenchmarkService.cs b/src/csharp/Grpc.IntegrationTesting/BenchmarkService.cs
new file mode 100644
index 0000000000..bc8c10352a
--- /dev/null
+++ b/src/csharp/Grpc.IntegrationTesting/BenchmarkService.cs
@@ -0,0 +1,48 @@
+// <auto-generated>
+//     Generated by the protocol buffer compiler.  DO NOT EDIT!
+//     source: src/proto/grpc/testing/benchmark_service.proto
+// </auto-generated>
+#pragma warning disable 1591, 0612, 3021
+#region Designer generated code
+
+using pb = global::Google.Protobuf;
+using pbc = global::Google.Protobuf.Collections;
+using pbr = global::Google.Protobuf.Reflection;
+using scg = global::System.Collections.Generic;
+namespace Grpc.Testing {
+
+  /// <summary>Holder for reflection information generated from src/proto/grpc/testing/benchmark_service.proto</summary>
+  public static partial class BenchmarkServiceReflection {
+
+    #region Descriptor
+    /// <summary>File descriptor for src/proto/grpc/testing/benchmark_service.proto</summary>
+    public static pbr::FileDescriptor Descriptor {
+      get { return descriptor; }
+    }
+    private static pbr::FileDescriptor descriptor;
+
+    static BenchmarkServiceReflection() {
+      byte[] descriptorData = global::System.Convert.FromBase64String(
+          string.Concat(
+            "Ci5zcmMvcHJvdG8vZ3JwYy90ZXN0aW5nL2JlbmNobWFya19zZXJ2aWNlLnBy",
+            "b3RvEgxncnBjLnRlc3RpbmcaJXNyYy9wcm90by9ncnBjL3Rlc3RpbmcvbWVz",
+            "c2FnZXMucHJvdG8ypgMKEEJlbmNobWFya1NlcnZpY2USRgoJVW5hcnlDYWxs",
+            "EhsuZ3JwYy50ZXN0aW5nLlNpbXBsZVJlcXVlc3QaHC5ncnBjLnRlc3Rpbmcu",
+            "U2ltcGxlUmVzcG9uc2USTgoNU3RyZWFtaW5nQ2FsbBIbLmdycGMudGVzdGlu",
+            "Zy5TaW1wbGVSZXF1ZXN0GhwuZ3JwYy50ZXN0aW5nLlNpbXBsZVJlc3BvbnNl",
+            "KAEwARJSChNTdHJlYW1pbmdGcm9tQ2xpZW50EhsuZ3JwYy50ZXN0aW5nLlNp",
+            "bXBsZVJlcXVlc3QaHC5ncnBjLnRlc3RpbmcuU2ltcGxlUmVzcG9uc2UoARJS",
+            "ChNTdHJlYW1pbmdGcm9tU2VydmVyEhsuZ3JwYy50ZXN0aW5nLlNpbXBsZVJl",
+            "cXVlc3QaHC5ncnBjLnRlc3RpbmcuU2ltcGxlUmVzcG9uc2UwARJSChFTdHJl",
+            "YW1pbmdCb3RoV2F5cxIbLmdycGMudGVzdGluZy5TaW1wbGVSZXF1ZXN0Ghwu",
+            "Z3JwYy50ZXN0aW5nLlNpbXBsZVJlc3BvbnNlKAEwAWIGcHJvdG8z"));
+      descriptor = pbr::FileDescriptor.FromGeneratedCode(descriptorData,
+          new pbr::FileDescriptor[] { global::Grpc.Testing.MessagesReflection.Descriptor, },
+          new pbr::GeneratedClrTypeInfo(null, null));
+    }
+    #endregion
+
+  }
+}
+
+#endregion Designer generated code
diff --git a/src/csharp/Grpc.IntegrationTesting/BenchmarkServiceGrpc.cs b/src/csharp/Grpc.IntegrationTesting/BenchmarkServiceGrpc.cs
new file mode 100644
index 0000000000..20b933fdfa
--- /dev/null
+++ b/src/csharp/Grpc.IntegrationTesting/BenchmarkServiceGrpc.cs
@@ -0,0 +1,329 @@
+// <auto-generated>
+//     Generated by the protocol buffer compiler.  DO NOT EDIT!
+//     source: src/proto/grpc/testing/benchmark_service.proto
+// </auto-generated>
+// Original file comments:
+// Copyright 2015 gRPC authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+// An integration test service that covers all the method signature permutations
+// of unary/streaming requests/responses.
+#pragma warning disable 1591
+#region Designer generated code
+
+using grpc = global::Grpc.Core;
+
+namespace Grpc.Testing {
+  public static partial class BenchmarkService
+  {
+    static readonly string __ServiceName = "grpc.testing.BenchmarkService";
+
+    static readonly grpc::Marshaller<global::Grpc.Testing.SimpleRequest> __Marshaller_SimpleRequest = grpc::Marshallers.Create((arg) => global::Google.Protobuf.MessageExtensions.ToByteArray(arg), global::Grpc.Testing.SimpleRequest.Parser.ParseFrom);
+    static readonly grpc::Marshaller<global::Grpc.Testing.SimpleResponse> __Marshaller_SimpleResponse = grpc::Marshallers.Create((arg) => global::Google.Protobuf.MessageExtensions.ToByteArray(arg), global::Grpc.Testing.SimpleResponse.Parser.ParseFrom);
+
+    static readonly grpc::Method<global::Grpc.Testing.SimpleRequest, global::Grpc.Testing.SimpleResponse> __Method_UnaryCall = new grpc::Method<global::Grpc.Testing.SimpleRequest, global::Grpc.Testing.SimpleResponse>(
+        grpc::MethodType.Unary,
+        __ServiceName,
+        "UnaryCall",
+        __Marshaller_SimpleRequest,
+        __Marshaller_SimpleResponse);
+
+    static readonly grpc::Method<global::Grpc.Testing.SimpleRequest, global::Grpc.Testing.SimpleResponse> __Method_StreamingCall = new grpc::Method<global::Grpc.Testing.SimpleRequest, global::Grpc.Testing.SimpleResponse>(
+        grpc::MethodType.DuplexStreaming,
+        __ServiceName,
+        "StreamingCall",
+        __Marshaller_SimpleRequest,
+        __Marshaller_SimpleResponse);
+
+    static readonly grpc::Method<global::Grpc.Testing.SimpleRequest, global::Grpc.Testing.SimpleResponse> __Method_StreamingFromClient = new grpc::Method<global::Grpc.Testing.SimpleRequest, global::Grpc.Testing.SimpleResponse>(
+        grpc::MethodType.ClientStreaming,
+        __ServiceName,
+        "StreamingFromClient",
+        __Marshaller_SimpleRequest,
+        __Marshaller_SimpleResponse);
+
+    static readonly grpc::Method<global::Grpc.Testing.SimpleRequest, global::Grpc.Testing.SimpleResponse> __Method_StreamingFromServer = new grpc::Method<global::Grpc.Testing.SimpleRequest, global::Grpc.Testing.SimpleResponse>(
+        grpc::MethodType.ServerStreaming,
+        __ServiceName,
+        "StreamingFromServer",
+        __Marshaller_SimpleRequest,
+        __Marshaller_SimpleResponse);
+
+    static readonly grpc::Method<global::Grpc.Testing.SimpleRequest, global::Grpc.Testing.SimpleResponse> __Method_StreamingBothWays = new grpc::Method<global::Grpc.Testing.SimpleRequest, global::Grpc.Testing.SimpleResponse>(
+        grpc::MethodType.DuplexStreaming,
+        __ServiceName,
+        "StreamingBothWays",
+        __Marshaller_SimpleRequest,
+        __Marshaller_SimpleResponse);
+
+    /// <summary>Service descriptor</summary>
+    public static global::Google.Protobuf.Reflection.ServiceDescriptor Descriptor
+    {
+      get { return global::Grpc.Testing.BenchmarkServiceReflection.Descriptor.Services[0]; }
+    }
+
+    /// <summary>Base class for server-side implementations of BenchmarkService</summary>
+    public abstract partial class BenchmarkServiceBase
+    {
+      /// <summary>
+      /// One request followed by one response.
+      /// The server returns the client payload as-is.
+      /// </summary>
+      /// <param name="request">The request received from the client.</param>
+      /// <param name="context">The context of the server-side call handler being invoked.</param>
+      /// <returns>The response to send back to the client (wrapped by a task).</returns>
+      public virtual global::System.Threading.Tasks.Task<global::Grpc.Testing.SimpleResponse> UnaryCall(global::Grpc.Testing.SimpleRequest request, grpc::ServerCallContext context)
+      {
+        throw new grpc::RpcException(new grpc::Status(grpc::StatusCode.Unimplemented, ""));
+      }
+
+      /// <summary>
+      /// Repeated sequence of one request followed by one response.
+      /// Should be called streaming ping-pong
+      /// The server returns the client payload as-is on each response
+      /// </summary>
+      /// <param name="requestStream">Used for reading requests from the client.</param>
+      /// <param name="responseStream">Used for sending responses back to the client.</param>
+      /// <param name="context">The context of the server-side call handler being invoked.</param>
+      /// <returns>A task indicating completion of the handler.</returns>
+      public virtual global::System.Threading.Tasks.Task StreamingCall(grpc::IAsyncStreamReader<global::Grpc.Testing.SimpleRequest> requestStream, grpc::IServerStreamWriter<global::Grpc.Testing.SimpleResponse> responseStream, grpc::ServerCallContext context)
+      {
+        throw new grpc::RpcException(new grpc::Status(grpc::StatusCode.Unimplemented, ""));
+      }
+
+      /// <summary>
+      /// Single-sided unbounded streaming from client to server
+      /// The server returns the client payload as-is once the client does WritesDone
+      /// </summary>
+      /// <param name="requestStream">Used for reading requests from the client.</param>
+      /// <param name="context">The context of the server-side call handler being invoked.</param>
+      /// <returns>The response to send back to the client (wrapped by a task).</returns>
+      public virtual global::System.Threading.Tasks.Task<global::Grpc.Testing.SimpleResponse> StreamingFromClient(grpc::IAsyncStreamReader<global::Grpc.Testing.SimpleRequest> requestStream, grpc::ServerCallContext context)
+      {
+        throw new grpc::RpcException(new grpc::Status(grpc::StatusCode.Unimplemented, ""));
+      }
+
+      /// <summary>
+      /// Single-sided unbounded streaming from server to client
+      /// The server repeatedly returns the client payload as-is
+      /// </summary>
+      /// <param name="request">The request received from the client.</param>
+      /// <param name="responseStream">Used for sending responses back to the client.</param>
+      /// <param name="context">The context of the server-side call handler being invoked.</param>
+      /// <returns>A task indicating completion of the handler.</returns>
+      public virtual global::System.Threading.Tasks.Task StreamingFromServer(global::Grpc.Testing.SimpleRequest request, grpc::IServerStreamWriter<global::Grpc.Testing.SimpleResponse> responseStream, grpc::ServerCallContext context)
+      {
+        throw new grpc::RpcException(new grpc::Status(grpc::StatusCode.Unimplemented, ""));
+      }
+
+      /// <summary>
+      /// Two-sided unbounded streaming between server to client
+      /// Both sides send the content of their own choice to the other
+      /// </summary>
+      /// <param name="requestStream">Used for reading requests from the client.</param>
+      /// <param name="responseStream">Used for sending responses back to the client.</param>
+      /// <param name="context">The context of the server-side call handler being invoked.</param>
+      /// <returns>A task indicating completion of the handler.</returns>
+      public virtual global::System.Threading.Tasks.Task StreamingBothWays(grpc::IAsyncStreamReader<global::Grpc.Testing.SimpleRequest> requestStream, grpc::IServerStreamWriter<global::Grpc.Testing.SimpleResponse> responseStream, grpc::ServerCallContext context)
+      {
+        throw new grpc::RpcException(new grpc::Status(grpc::StatusCode.Unimplemented, ""));
+      }
+
+    }
+
+    /// <summary>Client for BenchmarkService</summary>
+    public partial class BenchmarkServiceClient : grpc::ClientBase<BenchmarkServiceClient>
+    {
+      /// <summary>Creates a new client for BenchmarkService</summary>
+      /// <param name="channel">The channel to use to make remote calls.</param>
+      public BenchmarkServiceClient(grpc::Channel channel) : base(channel)
+      {
+      }
+      /// <summary>Creates a new client for BenchmarkService that uses a custom <c>CallInvoker</c>.</summary>
+      /// <param name="callInvoker">The callInvoker to use to make remote calls.</param>
+      public BenchmarkServiceClient(grpc::CallInvoker callInvoker) : base(callInvoker)
+      {
+      }
+      /// <summary>Protected parameterless constructor to allow creation of test doubles.</summary>
+      protected BenchmarkServiceClient() : base()
+      {
+      }
+      /// <summary>Protected constructor to allow creation of configured clients.</summary>
+      /// <param name="configuration">The client configuration.</param>
+      protected BenchmarkServiceClient(ClientBaseConfiguration configuration) : base(configuration)
+      {
+      }
+
+      /// <summary>
+      /// One request followed by one response.
+      /// The server returns the client payload as-is.
+      /// </summary>
+      /// <param name="request">The request to send to the server.</param>
+      /// <param name="headers">The initial metadata to send with the call. This parameter is optional.</param>
+      /// <param name="deadline">An optional deadline for the call. The call will be cancelled if deadline is hit.</param>
+      /// <param name="cancellationToken">An optional token for canceling the call.</param>
+      /// <returns>The response received from the server.</returns>
+      public virtual global::Grpc.Testing.SimpleResponse UnaryCall(global::Grpc.Testing.SimpleRequest request, grpc::Metadata headers = null, global::System.DateTime? deadline = null, global::System.Threading.CancellationToken cancellationToken = default(global::System.Threading.CancellationToken))
+      {
+        return UnaryCall(request, new grpc::CallOptions(headers, deadline, cancellationToken));
+      }
+      /// <summary>
+      /// One request followed by one response.
+      /// The server returns the client payload as-is.
+      /// </summary>
+      /// <param name="request">The request to send to the server.</param>
+      /// <param name="options">The options for the call.</param>
+      /// <returns>The response received from the server.</returns>
+      public virtual global::Grpc.Testing.SimpleResponse UnaryCall(global::Grpc.Testing.SimpleRequest request, grpc::CallOptions options)
+      {
+        return CallInvoker.BlockingUnaryCall(__Method_UnaryCall, null, options, request);
+      }
+      /// <summary>
+      /// One request followed by one response.
+      /// The server returns the client payload as-is.
+      /// </summary>
+      /// <param name="request">The request to send to the server.</param>
+      /// <param name="headers">The initial metadata to send with the call. This parameter is optional.</param>
+      /// <param name="deadline">An optional deadline for the call. The call will be cancelled if deadline is hit.</param>
+      /// <param name="cancellationToken">An optional token for canceling the call.</param>
+      /// <returns>The call object.</returns>
+      public virtual grpc::AsyncUnaryCall<global::Grpc.Testing.SimpleResponse> UnaryCallAsync(global::Grpc.Testing.SimpleRequest request, grpc::Metadata headers = null, global::System.DateTime? deadline = null, global::System.Threading.CancellationToken cancellationToken = default(global::System.Threading.CancellationToken))
+      {
+        return UnaryCallAsync(request, new grpc::CallOptions(headers, deadline, cancellationToken));
+      }
+      /// <summary>
+      /// One request followed by one response.
+      /// The server returns the client payload as-is.
+      /// </summary>
+      /// <param name="request">The request to send to the server.</param>
+      /// <param name="options">The options for the call.</param>
+      /// <returns>The call object.</returns>
+      public virtual grpc::AsyncUnaryCall<global::Grpc.Testing.SimpleResponse> UnaryCallAsync(global::Grpc.Testing.SimpleRequest request, grpc::CallOptions options)
+      {
+        return CallInvoker.AsyncUnaryCall(__Method_UnaryCall, null, options, request);
+      }
+      /// <summary>
+      /// Repeated sequence of one request followed by one response.
+      /// Should be called streaming ping-pong
+      /// The server returns the client payload as-is on each response
+      /// </summary>
+      /// <param name="headers">The initial metadata to send with the call. This parameter is optional.</param>
+      /// <param name="deadline">An optional deadline for the call. The call will be cancelled if deadline is hit.</param>
+      /// <param name="cancellationToken">An optional token for canceling the call.</param>
+      /// <returns>The call object.</returns>
+      public virtual grpc::AsyncDuplexStreamingCall<global::Grpc.Testing.SimpleRequest, global::Grpc.Testing.SimpleResponse> StreamingCall(grpc::Metadata headers = null, global::System.DateTime? deadline = null, global::System.Threading.CancellationToken cancellationToken = default(global::System.Threading.CancellationToken))
+      {
+        return StreamingCall(new grpc::CallOptions(headers, deadline, cancellationToken));
+      }
+      /// <summary>
+      /// Repeated sequence of one request followed by one response.
+      /// Should be called streaming ping-pong
+      /// The server returns the client payload as-is on each response
+      /// </summary>
+      /// <param name="options">The options for the call.</param>
+      /// <returns>The call object.</returns>
+      public virtual grpc::AsyncDuplexStreamingCall<global::Grpc.Testing.SimpleRequest, global::Grpc.Testing.SimpleResponse> StreamingCall(grpc::CallOptions options)
+      {
+        return CallInvoker.AsyncDuplexStreamingCall(__Method_StreamingCall, null, options);
+      }
+      /// <summary>
+      /// Single-sided unbounded streaming from client to server
+      /// The server returns the client payload as-is once the client does WritesDone
+      /// </summary>
+      /// <param name="headers">The initial metadata to send with the call. This parameter is optional.</param>
+      /// <param name="deadline">An optional deadline for the call. The call will be cancelled if deadline is hit.</param>
+      /// <param name="cancellationToken">An optional token for canceling the call.</param>
+      /// <returns>The call object.</returns>
+      public virtual grpc::AsyncClientStreamingCall<global::Grpc.Testing.SimpleRequest, global::Grpc.Testing.SimpleResponse> StreamingFromClient(grpc::Metadata headers = null, global::System.DateTime? deadline = null, global::System.Threading.CancellationToken cancellationToken = default(global::System.Threading.CancellationToken))
+      {
+        return StreamingFromClient(new grpc::CallOptions(headers, deadline, cancellationToken));
+      }
+      /// <summary>
+      /// Single-sided unbounded streaming from client to server
+      /// The server returns the client payload as-is once the client does WritesDone
+      /// </summary>
+      /// <param name="options">The options for the call.</param>
+      /// <returns>The call object.</returns>
+      public virtual grpc::AsyncClientStreamingCall<global::Grpc.Testing.SimpleRequest, global::Grpc.Testing.SimpleResponse> StreamingFromClient(grpc::CallOptions options)
+      {
+        return CallInvoker.AsyncClientStreamingCall(__Method_StreamingFromClient, null, options);
+      }
+      /// <summary>
+      /// Single-sided unbounded streaming from server to client
+      /// The server repeatedly returns the client payload as-is
+      /// </summary>
+      /// <param name="request">The request to send to the server.</param>
+      /// <param name="headers">The initial metadata to send with the call. This parameter is optional.</param>
+      /// <param name="deadline">An optional deadline for the call. The call will be cancelled if deadline is hit.</param>
+      /// <param name="cancellationToken">An optional token for canceling the call.</param>
+      /// <returns>The call object.</returns>
+      public virtual grpc::AsyncServerStreamingCall<global::Grpc.Testing.SimpleResponse> StreamingFromServer(global::Grpc.Testing.SimpleRequest request, grpc::Metadata headers = null, global::System.DateTime? deadline = null, global::System.Threading.CancellationToken cancellationToken = default(global::System.Threading.CancellationToken))
+      {
+        return StreamingFromServer(request, new grpc::CallOptions(headers, deadline, cancellationToken));
+      }
+      /// <summary>
+      /// Single-sided unbounded streaming from server to client
+      /// The server repeatedly returns the client payload as-is
+      /// </summary>
+      /// <param name="request">The request to send to the server.</param>
+      /// <param name="options">The options for the call.</param>
+      /// <returns>The call object.</returns>
+      public virtual grpc::AsyncServerStreamingCall<global::Grpc.Testing.SimpleResponse> StreamingFromServer(global::Grpc.Testing.SimpleRequest request, grpc::CallOptions options)
+      {
+        return CallInvoker.AsyncServerStreamingCall(__Method_StreamingFromServer, null, options, request);
+      }
+      /// <summary>
+      /// Two-sided unbounded streaming between server to client
+      /// Both sides send the content of their own choice to the other
+      /// </summary>
+      /// <param name="headers">The initial metadata to send with the call. This parameter is optional.</param>
+      /// <param name="deadline">An optional deadline for the call. The call will be cancelled if deadline is hit.</param>
+      /// <param name="cancellationToken">An optional token for canceling the call.</param>
+      /// <returns>The call object.</returns>
+      public virtual grpc::AsyncDuplexStreamingCall<global::Grpc.Testing.SimpleRequest, global::Grpc.Testing.SimpleResponse> StreamingBothWays(grpc::Metadata headers = null, global::System.DateTime? deadline = null, global::System.Threading.CancellationToken cancellationToken = default(global::System.Threading.CancellationToken))
+      {
+        return StreamingBothWays(new grpc::CallOptions(headers, deadline, cancellationToken));
+      }
+      /// <summary>
+      /// Two-sided unbounded streaming between server to client
+      /// Both sides send the content of their own choice to the other
+      /// </summary>
+      /// <param name="options">The options for the call.</param>
+      /// <returns>The call object.</returns>
+      public virtual grpc::AsyncDuplexStreamingCall<global::Grpc.Testing.SimpleRequest, global::Grpc.Testing.SimpleResponse> StreamingBothWays(grpc::CallOptions options)
+      {
+        return CallInvoker.AsyncDuplexStreamingCall(__Method_StreamingBothWays, null, options);
+      }
+      /// <summary>Creates a new instance of client from given <c>ClientBaseConfiguration</c>.</summary>
+      protected override BenchmarkServiceClient NewInstance(ClientBaseConfiguration configuration)
+      {
+        return new BenchmarkServiceClient(configuration);
+      }
+    }
+
+    /// <summary>Creates service definition that can be registered with a server</summary>
+    /// <param name="serviceImpl">An object implementing the server-side handling logic.</param>
+    public static grpc::ServerServiceDefinition BindService(BenchmarkServiceBase serviceImpl)
+    {
+      return grpc::ServerServiceDefinition.CreateBuilder()
+          .AddMethod(__Method_UnaryCall, serviceImpl.UnaryCall)
+          .AddMethod(__Method_StreamingCall, serviceImpl.StreamingCall)
+          .AddMethod(__Method_StreamingFromClient, serviceImpl.StreamingFromClient)
+          .AddMethod(__Method_StreamingFromServer, serviceImpl.StreamingFromServer)
+          .AddMethod(__Method_StreamingBothWays, serviceImpl.StreamingBothWays).Build();
+    }
+
+  }
+}
+#endregion
diff --git a/src/csharp/Grpc.IntegrationTesting/Control.cs b/src/csharp/Grpc.IntegrationTesting/Control.cs
index 8795728906..f3284a5390 100644
--- a/src/csharp/Grpc.IntegrationTesting/Control.cs
+++ b/src/csharp/Grpc.IntegrationTesting/Control.cs
@@ -1,5 +1,7 @@
-// Generated by the protocol buffer compiler.  DO NOT EDIT!
-// source: src/proto/grpc/testing/control.proto
+// <auto-generated>
+//     Generated by the protocol buffer compiler.  DO NOT EDIT!
+//     source: src/proto/grpc/testing/control.proto
+// </auto-generated>
 #pragma warning disable 1591, 0612, 3021
 #region Designer generated code
 
@@ -167,6 +169,7 @@ namespace Grpc.Testing {
   /// </summary>
   public sealed partial class PoissonParams : pb::IMessage<PoissonParams> {
     private static readonly pb::MessageParser<PoissonParams> _parser = new pb::MessageParser<PoissonParams>(() => new PoissonParams());
+    private pb::UnknownFieldSet _unknownFields;
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public static pb::MessageParser<PoissonParams> Parser { get { return _parser; } }
 
@@ -190,6 +193,7 @@ namespace Grpc.Testing {
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public PoissonParams(PoissonParams other) : this() {
       offeredLoad_ = other.offeredLoad_;
+      _unknownFields = pb::UnknownFieldSet.Clone(other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -224,14 +228,17 @@ namespace Grpc.Testing {
       if (ReferenceEquals(other, this)) {
         return true;
       }
-      if (OfferedLoad != other.OfferedLoad) return false;
-      return true;
+      if (!pbc::ProtobufEqualityComparers.BitwiseDoubleEqualityComparer.Equals(OfferedLoad, other.OfferedLoad)) return false;
+      return Equals(_unknownFields, other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public override int GetHashCode() {
       int hash = 1;
-      if (OfferedLoad != 0D) hash ^= OfferedLoad.GetHashCode();
+      if (OfferedLoad != 0D) hash ^= pbc::ProtobufEqualityComparers.BitwiseDoubleEqualityComparer.GetHashCode(OfferedLoad);
+      if (_unknownFields != null) {
+        hash ^= _unknownFields.GetHashCode();
+      }
       return hash;
     }
 
@@ -246,6 +253,9 @@ namespace Grpc.Testing {
         output.WriteRawTag(9);
         output.WriteDouble(OfferedLoad);
       }
+      if (_unknownFields != null) {
+        _unknownFields.WriteTo(output);
+      }
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -254,6 +264,9 @@ namespace Grpc.Testing {
       if (OfferedLoad != 0D) {
         size += 1 + 8;
       }
+      if (_unknownFields != null) {
+        size += _unknownFields.CalculateSize();
+      }
       return size;
     }
 
@@ -265,6 +278,7 @@ namespace Grpc.Testing {
       if (other.OfferedLoad != 0D) {
         OfferedLoad = other.OfferedLoad;
       }
+      _unknownFields = pb::UnknownFieldSet.MergeFrom(_unknownFields, other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -273,7 +287,7 @@ namespace Grpc.Testing {
       while ((tag = input.ReadTag()) != 0) {
         switch(tag) {
           default:
-            input.SkipLastField();
+            _unknownFields = pb::UnknownFieldSet.MergeFieldFrom(_unknownFields, input);
             break;
           case 9: {
             OfferedLoad = input.ReadDouble();
@@ -291,6 +305,7 @@ namespace Grpc.Testing {
   /// </summary>
   public sealed partial class ClosedLoopParams : pb::IMessage<ClosedLoopParams> {
     private static readonly pb::MessageParser<ClosedLoopParams> _parser = new pb::MessageParser<ClosedLoopParams>(() => new ClosedLoopParams());
+    private pb::UnknownFieldSet _unknownFields;
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public static pb::MessageParser<ClosedLoopParams> Parser { get { return _parser; } }
 
@@ -313,6 +328,7 @@ namespace Grpc.Testing {
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public ClosedLoopParams(ClosedLoopParams other) : this() {
+      _unknownFields = pb::UnknownFieldSet.Clone(other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -333,12 +349,15 @@ namespace Grpc.Testing {
       if (ReferenceEquals(other, this)) {
         return true;
       }
-      return true;
+      return Equals(_unknownFields, other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public override int GetHashCode() {
       int hash = 1;
+      if (_unknownFields != null) {
+        hash ^= _unknownFields.GetHashCode();
+      }
       return hash;
     }
 
@@ -349,11 +368,17 @@ namespace Grpc.Testing {
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public void WriteTo(pb::CodedOutputStream output) {
+      if (_unknownFields != null) {
+        _unknownFields.WriteTo(output);
+      }
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public int CalculateSize() {
       int size = 0;
+      if (_unknownFields != null) {
+        size += _unknownFields.CalculateSize();
+      }
       return size;
     }
 
@@ -362,6 +387,7 @@ namespace Grpc.Testing {
       if (other == null) {
         return;
       }
+      _unknownFields = pb::UnknownFieldSet.MergeFrom(_unknownFields, other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -370,7 +396,7 @@ namespace Grpc.Testing {
       while ((tag = input.ReadTag()) != 0) {
         switch(tag) {
           default:
-            input.SkipLastField();
+            _unknownFields = pb::UnknownFieldSet.MergeFieldFrom(_unknownFields, input);
             break;
         }
       }
@@ -380,6 +406,7 @@ namespace Grpc.Testing {
 
   public sealed partial class LoadParams : pb::IMessage<LoadParams> {
     private static readonly pb::MessageParser<LoadParams> _parser = new pb::MessageParser<LoadParams>(() => new LoadParams());
+    private pb::UnknownFieldSet _unknownFields;
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public static pb::MessageParser<LoadParams> Parser { get { return _parser; } }
 
@@ -411,6 +438,7 @@ namespace Grpc.Testing {
           break;
       }
 
+      _unknownFields = pb::UnknownFieldSet.Clone(other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -475,7 +503,7 @@ namespace Grpc.Testing {
       if (!object.Equals(ClosedLoop, other.ClosedLoop)) return false;
       if (!object.Equals(Poisson, other.Poisson)) return false;
       if (LoadCase != other.LoadCase) return false;
-      return true;
+      return Equals(_unknownFields, other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -484,6 +512,9 @@ namespace Grpc.Testing {
       if (loadCase_ == LoadOneofCase.ClosedLoop) hash ^= ClosedLoop.GetHashCode();
       if (loadCase_ == LoadOneofCase.Poisson) hash ^= Poisson.GetHashCode();
       hash ^= (int) loadCase_;
+      if (_unknownFields != null) {
+        hash ^= _unknownFields.GetHashCode();
+      }
       return hash;
     }
 
@@ -502,6 +533,9 @@ namespace Grpc.Testing {
         output.WriteRawTag(18);
         output.WriteMessage(Poisson);
       }
+      if (_unknownFields != null) {
+        _unknownFields.WriteTo(output);
+      }
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -513,6 +547,9 @@ namespace Grpc.Testing {
       if (loadCase_ == LoadOneofCase.Poisson) {
         size += 1 + pb::CodedOutputStream.ComputeMessageSize(Poisson);
       }
+      if (_unknownFields != null) {
+        size += _unknownFields.CalculateSize();
+      }
       return size;
     }
 
@@ -536,6 +573,7 @@ namespace Grpc.Testing {
           break;
       }
 
+      _unknownFields = pb::UnknownFieldSet.MergeFrom(_unknownFields, other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -544,7 +582,7 @@ namespace Grpc.Testing {
       while ((tag = input.ReadTag()) != 0) {
         switch(tag) {
           default:
-            input.SkipLastField();
+            _unknownFields = pb::UnknownFieldSet.MergeFieldFrom(_unknownFields, input);
             break;
           case 10: {
             global::Grpc.Testing.ClosedLoopParams subBuilder = new global::Grpc.Testing.ClosedLoopParams();
@@ -575,6 +613,7 @@ namespace Grpc.Testing {
   /// </summary>
   public sealed partial class SecurityParams : pb::IMessage<SecurityParams> {
     private static readonly pb::MessageParser<SecurityParams> _parser = new pb::MessageParser<SecurityParams>(() => new SecurityParams());
+    private pb::UnknownFieldSet _unknownFields;
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public static pb::MessageParser<SecurityParams> Parser { get { return _parser; } }
 
@@ -600,6 +639,7 @@ namespace Grpc.Testing {
       useTestCa_ = other.useTestCa_;
       serverHostOverride_ = other.serverHostOverride_;
       credType_ = other.credType_;
+      _unknownFields = pb::UnknownFieldSet.Clone(other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -656,7 +696,7 @@ namespace Grpc.Testing {
       if (UseTestCa != other.UseTestCa) return false;
       if (ServerHostOverride != other.ServerHostOverride) return false;
       if (CredType != other.CredType) return false;
-      return true;
+      return Equals(_unknownFields, other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -665,6 +705,9 @@ namespace Grpc.Testing {
       if (UseTestCa != false) hash ^= UseTestCa.GetHashCode();
       if (ServerHostOverride.Length != 0) hash ^= ServerHostOverride.GetHashCode();
       if (CredType.Length != 0) hash ^= CredType.GetHashCode();
+      if (_unknownFields != null) {
+        hash ^= _unknownFields.GetHashCode();
+      }
       return hash;
     }
 
@@ -687,6 +730,9 @@ namespace Grpc.Testing {
         output.WriteRawTag(26);
         output.WriteString(CredType);
       }
+      if (_unknownFields != null) {
+        _unknownFields.WriteTo(output);
+      }
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -701,6 +747,9 @@ namespace Grpc.Testing {
       if (CredType.Length != 0) {
         size += 1 + pb::CodedOutputStream.ComputeStringSize(CredType);
       }
+      if (_unknownFields != null) {
+        size += _unknownFields.CalculateSize();
+      }
       return size;
     }
 
@@ -718,6 +767,7 @@ namespace Grpc.Testing {
       if (other.CredType.Length != 0) {
         CredType = other.CredType;
       }
+      _unknownFields = pb::UnknownFieldSet.MergeFrom(_unknownFields, other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -726,7 +776,7 @@ namespace Grpc.Testing {
       while ((tag = input.ReadTag()) != 0) {
         switch(tag) {
           default:
-            input.SkipLastField();
+            _unknownFields = pb::UnknownFieldSet.MergeFieldFrom(_unknownFields, input);
             break;
           case 8: {
             UseTestCa = input.ReadBool();
@@ -748,6 +798,7 @@ namespace Grpc.Testing {
 
   public sealed partial class ChannelArg : pb::IMessage<ChannelArg> {
     private static readonly pb::MessageParser<ChannelArg> _parser = new pb::MessageParser<ChannelArg>(() => new ChannelArg());
+    private pb::UnknownFieldSet _unknownFields;
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public static pb::MessageParser<ChannelArg> Parser { get { return _parser; } }
 
@@ -780,6 +831,7 @@ namespace Grpc.Testing {
           break;
       }
 
+      _unknownFields = pb::UnknownFieldSet.Clone(other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -856,7 +908,7 @@ namespace Grpc.Testing {
       if (StrValue != other.StrValue) return false;
       if (IntValue != other.IntValue) return false;
       if (ValueCase != other.ValueCase) return false;
-      return true;
+      return Equals(_unknownFields, other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -866,6 +918,9 @@ namespace Grpc.Testing {
       if (valueCase_ == ValueOneofCase.StrValue) hash ^= StrValue.GetHashCode();
       if (valueCase_ == ValueOneofCase.IntValue) hash ^= IntValue.GetHashCode();
       hash ^= (int) valueCase_;
+      if (_unknownFields != null) {
+        hash ^= _unknownFields.GetHashCode();
+      }
       return hash;
     }
 
@@ -888,6 +943,9 @@ namespace Grpc.Testing {
         output.WriteRawTag(24);
         output.WriteInt32(IntValue);
       }
+      if (_unknownFields != null) {
+        _unknownFields.WriteTo(output);
+      }
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -902,6 +960,9 @@ namespace Grpc.Testing {
       if (valueCase_ == ValueOneofCase.IntValue) {
         size += 1 + pb::CodedOutputStream.ComputeInt32Size(IntValue);
       }
+      if (_unknownFields != null) {
+        size += _unknownFields.CalculateSize();
+      }
       return size;
     }
 
@@ -922,6 +983,7 @@ namespace Grpc.Testing {
           break;
       }
 
+      _unknownFields = pb::UnknownFieldSet.MergeFrom(_unknownFields, other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -930,7 +992,7 @@ namespace Grpc.Testing {
       while ((tag = input.ReadTag()) != 0) {
         switch(tag) {
           default:
-            input.SkipLastField();
+            _unknownFields = pb::UnknownFieldSet.MergeFieldFrom(_unknownFields, input);
             break;
           case 10: {
             Name = input.ReadString();
@@ -952,6 +1014,7 @@ namespace Grpc.Testing {
 
   public sealed partial class ClientConfig : pb::IMessage<ClientConfig> {
     private static readonly pb::MessageParser<ClientConfig> _parser = new pb::MessageParser<ClientConfig>(() => new ClientConfig());
+    private pb::UnknownFieldSet _unknownFields;
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public static pb::MessageParser<ClientConfig> Parser { get { return _parser; } }
 
@@ -991,6 +1054,7 @@ namespace Grpc.Testing {
       threadsPerCq_ = other.threadsPerCq_;
       messagesPerStream_ = other.messagesPerStream_;
       useCoalesceApi_ = other.useCoalesceApi_;
+      _unknownFields = pb::UnknownFieldSet.Clone(other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -1244,7 +1308,7 @@ namespace Grpc.Testing {
       if (ThreadsPerCq != other.ThreadsPerCq) return false;
       if (MessagesPerStream != other.MessagesPerStream) return false;
       if (UseCoalesceApi != other.UseCoalesceApi) return false;
-      return true;
+      return Equals(_unknownFields, other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -1267,6 +1331,9 @@ namespace Grpc.Testing {
       if (ThreadsPerCq != 0) hash ^= ThreadsPerCq.GetHashCode();
       if (MessagesPerStream != 0) hash ^= MessagesPerStream.GetHashCode();
       if (UseCoalesceApi != false) hash ^= UseCoalesceApi.GetHashCode();
+      if (_unknownFields != null) {
+        hash ^= _unknownFields.GetHashCode();
+      }
       return hash;
     }
 
@@ -1336,6 +1403,9 @@ namespace Grpc.Testing {
         output.WriteRawTag(152, 1);
         output.WriteBool(UseCoalesceApi);
       }
+      if (_unknownFields != null) {
+        _unknownFields.WriteTo(output);
+      }
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -1386,6 +1456,9 @@ namespace Grpc.Testing {
       if (UseCoalesceApi != false) {
         size += 2 + 1;
       }
+      if (_unknownFields != null) {
+        size += _unknownFields.CalculateSize();
+      }
       return size;
     }
 
@@ -1451,6 +1524,7 @@ namespace Grpc.Testing {
       if (other.UseCoalesceApi != false) {
         UseCoalesceApi = other.UseCoalesceApi;
       }
+      _unknownFields = pb::UnknownFieldSet.MergeFrom(_unknownFields, other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -1459,7 +1533,7 @@ namespace Grpc.Testing {
       while ((tag = input.ReadTag()) != 0) {
         switch(tag) {
           default:
-            input.SkipLastField();
+            _unknownFields = pb::UnknownFieldSet.MergeFieldFrom(_unknownFields, input);
             break;
           case 10: {
             serverTargets_.AddEntriesFrom(input, _repeated_serverTargets_codec);
@@ -1550,6 +1624,7 @@ namespace Grpc.Testing {
 
   public sealed partial class ClientStatus : pb::IMessage<ClientStatus> {
     private static readonly pb::MessageParser<ClientStatus> _parser = new pb::MessageParser<ClientStatus>(() => new ClientStatus());
+    private pb::UnknownFieldSet _unknownFields;
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public static pb::MessageParser<ClientStatus> Parser { get { return _parser; } }
 
@@ -1573,6 +1648,7 @@ namespace Grpc.Testing {
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public ClientStatus(ClientStatus other) : this() {
       Stats = other.stats_ != null ? other.Stats.Clone() : null;
+      _unknownFields = pb::UnknownFieldSet.Clone(other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -1605,13 +1681,16 @@ namespace Grpc.Testing {
         return true;
       }
       if (!object.Equals(Stats, other.Stats)) return false;
-      return true;
+      return Equals(_unknownFields, other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public override int GetHashCode() {
       int hash = 1;
       if (stats_ != null) hash ^= Stats.GetHashCode();
+      if (_unknownFields != null) {
+        hash ^= _unknownFields.GetHashCode();
+      }
       return hash;
     }
 
@@ -1626,6 +1705,9 @@ namespace Grpc.Testing {
         output.WriteRawTag(10);
         output.WriteMessage(Stats);
       }
+      if (_unknownFields != null) {
+        _unknownFields.WriteTo(output);
+      }
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -1634,6 +1716,9 @@ namespace Grpc.Testing {
       if (stats_ != null) {
         size += 1 + pb::CodedOutputStream.ComputeMessageSize(Stats);
       }
+      if (_unknownFields != null) {
+        size += _unknownFields.CalculateSize();
+      }
       return size;
     }
 
@@ -1648,6 +1733,7 @@ namespace Grpc.Testing {
         }
         Stats.MergeFrom(other.Stats);
       }
+      _unknownFields = pb::UnknownFieldSet.MergeFrom(_unknownFields, other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -1656,7 +1742,7 @@ namespace Grpc.Testing {
       while ((tag = input.ReadTag()) != 0) {
         switch(tag) {
           default:
-            input.SkipLastField();
+            _unknownFields = pb::UnknownFieldSet.MergeFieldFrom(_unknownFields, input);
             break;
           case 10: {
             if (stats_ == null) {
@@ -1676,6 +1762,7 @@ namespace Grpc.Testing {
   /// </summary>
   public sealed partial class Mark : pb::IMessage<Mark> {
     private static readonly pb::MessageParser<Mark> _parser = new pb::MessageParser<Mark>(() => new Mark());
+    private pb::UnknownFieldSet _unknownFields;
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public static pb::MessageParser<Mark> Parser { get { return _parser; } }
 
@@ -1699,6 +1786,7 @@ namespace Grpc.Testing {
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public Mark(Mark other) : this() {
       reset_ = other.reset_;
+      _unknownFields = pb::UnknownFieldSet.Clone(other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -1734,13 +1822,16 @@ namespace Grpc.Testing {
         return true;
       }
       if (Reset != other.Reset) return false;
-      return true;
+      return Equals(_unknownFields, other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public override int GetHashCode() {
       int hash = 1;
       if (Reset != false) hash ^= Reset.GetHashCode();
+      if (_unknownFields != null) {
+        hash ^= _unknownFields.GetHashCode();
+      }
       return hash;
     }
 
@@ -1755,6 +1846,9 @@ namespace Grpc.Testing {
         output.WriteRawTag(8);
         output.WriteBool(Reset);
       }
+      if (_unknownFields != null) {
+        _unknownFields.WriteTo(output);
+      }
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -1763,6 +1857,9 @@ namespace Grpc.Testing {
       if (Reset != false) {
         size += 1 + 1;
       }
+      if (_unknownFields != null) {
+        size += _unknownFields.CalculateSize();
+      }
       return size;
     }
 
@@ -1774,6 +1871,7 @@ namespace Grpc.Testing {
       if (other.Reset != false) {
         Reset = other.Reset;
       }
+      _unknownFields = pb::UnknownFieldSet.MergeFrom(_unknownFields, other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -1782,7 +1880,7 @@ namespace Grpc.Testing {
       while ((tag = input.ReadTag()) != 0) {
         switch(tag) {
           default:
-            input.SkipLastField();
+            _unknownFields = pb::UnknownFieldSet.MergeFieldFrom(_unknownFields, input);
             break;
           case 8: {
             Reset = input.ReadBool();
@@ -1796,6 +1894,7 @@ namespace Grpc.Testing {
 
   public sealed partial class ClientArgs : pb::IMessage<ClientArgs> {
     private static readonly pb::MessageParser<ClientArgs> _parser = new pb::MessageParser<ClientArgs>(() => new ClientArgs());
+    private pb::UnknownFieldSet _unknownFields;
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public static pb::MessageParser<ClientArgs> Parser { get { return _parser; } }
 
@@ -1827,6 +1926,7 @@ namespace Grpc.Testing {
           break;
       }
 
+      _unknownFields = pb::UnknownFieldSet.Clone(other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -1891,7 +1991,7 @@ namespace Grpc.Testing {
       if (!object.Equals(Setup, other.Setup)) return false;
       if (!object.Equals(Mark, other.Mark)) return false;
       if (ArgtypeCase != other.ArgtypeCase) return false;
-      return true;
+      return Equals(_unknownFields, other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -1900,6 +2000,9 @@ namespace Grpc.Testing {
       if (argtypeCase_ == ArgtypeOneofCase.Setup) hash ^= Setup.GetHashCode();
       if (argtypeCase_ == ArgtypeOneofCase.Mark) hash ^= Mark.GetHashCode();
       hash ^= (int) argtypeCase_;
+      if (_unknownFields != null) {
+        hash ^= _unknownFields.GetHashCode();
+      }
       return hash;
     }
 
@@ -1918,6 +2021,9 @@ namespace Grpc.Testing {
         output.WriteRawTag(18);
         output.WriteMessage(Mark);
       }
+      if (_unknownFields != null) {
+        _unknownFields.WriteTo(output);
+      }
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -1929,6 +2035,9 @@ namespace Grpc.Testing {
       if (argtypeCase_ == ArgtypeOneofCase.Mark) {
         size += 1 + pb::CodedOutputStream.ComputeMessageSize(Mark);
       }
+      if (_unknownFields != null) {
+        size += _unknownFields.CalculateSize();
+      }
       return size;
     }
 
@@ -1952,6 +2061,7 @@ namespace Grpc.Testing {
           break;
       }
 
+      _unknownFields = pb::UnknownFieldSet.MergeFrom(_unknownFields, other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -1960,7 +2070,7 @@ namespace Grpc.Testing {
       while ((tag = input.ReadTag()) != 0) {
         switch(tag) {
           default:
-            input.SkipLastField();
+            _unknownFields = pb::UnknownFieldSet.MergeFieldFrom(_unknownFields, input);
             break;
           case 10: {
             global::Grpc.Testing.ClientConfig subBuilder = new global::Grpc.Testing.ClientConfig();
@@ -1988,6 +2098,7 @@ namespace Grpc.Testing {
 
   public sealed partial class ServerConfig : pb::IMessage<ServerConfig> {
     private static readonly pb::MessageParser<ServerConfig> _parser = new pb::MessageParser<ServerConfig>(() => new ServerConfig());
+    private pb::UnknownFieldSet _unknownFields;
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public static pb::MessageParser<ServerConfig> Parser { get { return _parser; } }
 
@@ -2021,6 +2132,7 @@ namespace Grpc.Testing {
       threadsPerCq_ = other.threadsPerCq_;
       resourceQuotaSize_ = other.resourceQuotaSize_;
       channelArgs_ = other.channelArgs_.Clone();
+      _unknownFields = pb::UnknownFieldSet.Clone(other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -2198,7 +2310,7 @@ namespace Grpc.Testing {
       if (ThreadsPerCq != other.ThreadsPerCq) return false;
       if (ResourceQuotaSize != other.ResourceQuotaSize) return false;
       if(!channelArgs_.Equals(other.channelArgs_)) return false;
-      return true;
+      return Equals(_unknownFields, other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -2215,6 +2327,9 @@ namespace Grpc.Testing {
       if (ThreadsPerCq != 0) hash ^= ThreadsPerCq.GetHashCode();
       if (ResourceQuotaSize != 0) hash ^= ResourceQuotaSize.GetHashCode();
       hash ^= channelArgs_.GetHashCode();
+      if (_unknownFields != null) {
+        hash ^= _unknownFields.GetHashCode();
+      }
       return hash;
     }
 
@@ -2263,6 +2378,9 @@ namespace Grpc.Testing {
         output.WriteInt32(ResourceQuotaSize);
       }
       channelArgs_.WriteTo(output, _repeated_channelArgs_codec);
+      if (_unknownFields != null) {
+        _unknownFields.WriteTo(output);
+      }
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -2297,6 +2415,9 @@ namespace Grpc.Testing {
         size += 2 + pb::CodedOutputStream.ComputeInt32Size(ResourceQuotaSize);
       }
       size += channelArgs_.CalculateSize(_repeated_channelArgs_codec);
+      if (_unknownFields != null) {
+        size += _unknownFields.CalculateSize();
+      }
       return size;
     }
 
@@ -2340,6 +2461,7 @@ namespace Grpc.Testing {
         ResourceQuotaSize = other.ResourceQuotaSize;
       }
       channelArgs_.Add(other.channelArgs_);
+      _unknownFields = pb::UnknownFieldSet.MergeFrom(_unknownFields, other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -2348,7 +2470,7 @@ namespace Grpc.Testing {
       while ((tag = input.ReadTag()) != 0) {
         switch(tag) {
           default:
-            input.SkipLastField();
+            _unknownFields = pb::UnknownFieldSet.MergeFieldFrom(_unknownFields, input);
             break;
           case 8: {
             serverType_ = (global::Grpc.Testing.ServerType) input.ReadEnum();
@@ -2409,6 +2531,7 @@ namespace Grpc.Testing {
 
   public sealed partial class ServerArgs : pb::IMessage<ServerArgs> {
     private static readonly pb::MessageParser<ServerArgs> _parser = new pb::MessageParser<ServerArgs>(() => new ServerArgs());
+    private pb::UnknownFieldSet _unknownFields;
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public static pb::MessageParser<ServerArgs> Parser { get { return _parser; } }
 
@@ -2440,6 +2563,7 @@ namespace Grpc.Testing {
           break;
       }
 
+      _unknownFields = pb::UnknownFieldSet.Clone(other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -2504,7 +2628,7 @@ namespace Grpc.Testing {
       if (!object.Equals(Setup, other.Setup)) return false;
       if (!object.Equals(Mark, other.Mark)) return false;
       if (ArgtypeCase != other.ArgtypeCase) return false;
-      return true;
+      return Equals(_unknownFields, other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -2513,6 +2637,9 @@ namespace Grpc.Testing {
       if (argtypeCase_ == ArgtypeOneofCase.Setup) hash ^= Setup.GetHashCode();
       if (argtypeCase_ == ArgtypeOneofCase.Mark) hash ^= Mark.GetHashCode();
       hash ^= (int) argtypeCase_;
+      if (_unknownFields != null) {
+        hash ^= _unknownFields.GetHashCode();
+      }
       return hash;
     }
 
@@ -2531,6 +2658,9 @@ namespace Grpc.Testing {
         output.WriteRawTag(18);
         output.WriteMessage(Mark);
       }
+      if (_unknownFields != null) {
+        _unknownFields.WriteTo(output);
+      }
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -2542,6 +2672,9 @@ namespace Grpc.Testing {
       if (argtypeCase_ == ArgtypeOneofCase.Mark) {
         size += 1 + pb::CodedOutputStream.ComputeMessageSize(Mark);
       }
+      if (_unknownFields != null) {
+        size += _unknownFields.CalculateSize();
+      }
       return size;
     }
 
@@ -2565,6 +2698,7 @@ namespace Grpc.Testing {
           break;
       }
 
+      _unknownFields = pb::UnknownFieldSet.MergeFrom(_unknownFields, other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -2573,7 +2707,7 @@ namespace Grpc.Testing {
       while ((tag = input.ReadTag()) != 0) {
         switch(tag) {
           default:
-            input.SkipLastField();
+            _unknownFields = pb::UnknownFieldSet.MergeFieldFrom(_unknownFields, input);
             break;
           case 10: {
             global::Grpc.Testing.ServerConfig subBuilder = new global::Grpc.Testing.ServerConfig();
@@ -2601,6 +2735,7 @@ namespace Grpc.Testing {
 
   public sealed partial class ServerStatus : pb::IMessage<ServerStatus> {
     private static readonly pb::MessageParser<ServerStatus> _parser = new pb::MessageParser<ServerStatus>(() => new ServerStatus());
+    private pb::UnknownFieldSet _unknownFields;
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public static pb::MessageParser<ServerStatus> Parser { get { return _parser; } }
 
@@ -2626,6 +2761,7 @@ namespace Grpc.Testing {
       Stats = other.stats_ != null ? other.Stats.Clone() : null;
       port_ = other.port_;
       cores_ = other.cores_;
+      _unknownFields = pb::UnknownFieldSet.Clone(other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -2688,7 +2824,7 @@ namespace Grpc.Testing {
       if (!object.Equals(Stats, other.Stats)) return false;
       if (Port != other.Port) return false;
       if (Cores != other.Cores) return false;
-      return true;
+      return Equals(_unknownFields, other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -2697,6 +2833,9 @@ namespace Grpc.Testing {
       if (stats_ != null) hash ^= Stats.GetHashCode();
       if (Port != 0) hash ^= Port.GetHashCode();
       if (Cores != 0) hash ^= Cores.GetHashCode();
+      if (_unknownFields != null) {
+        hash ^= _unknownFields.GetHashCode();
+      }
       return hash;
     }
 
@@ -2719,6 +2858,9 @@ namespace Grpc.Testing {
         output.WriteRawTag(24);
         output.WriteInt32(Cores);
       }
+      if (_unknownFields != null) {
+        _unknownFields.WriteTo(output);
+      }
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -2733,6 +2875,9 @@ namespace Grpc.Testing {
       if (Cores != 0) {
         size += 1 + pb::CodedOutputStream.ComputeInt32Size(Cores);
       }
+      if (_unknownFields != null) {
+        size += _unknownFields.CalculateSize();
+      }
       return size;
     }
 
@@ -2753,6 +2898,7 @@ namespace Grpc.Testing {
       if (other.Cores != 0) {
         Cores = other.Cores;
       }
+      _unknownFields = pb::UnknownFieldSet.MergeFrom(_unknownFields, other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -2761,7 +2907,7 @@ namespace Grpc.Testing {
       while ((tag = input.ReadTag()) != 0) {
         switch(tag) {
           default:
-            input.SkipLastField();
+            _unknownFields = pb::UnknownFieldSet.MergeFieldFrom(_unknownFields, input);
             break;
           case 10: {
             if (stats_ == null) {
@@ -2786,6 +2932,7 @@ namespace Grpc.Testing {
 
   public sealed partial class CoreRequest : pb::IMessage<CoreRequest> {
     private static readonly pb::MessageParser<CoreRequest> _parser = new pb::MessageParser<CoreRequest>(() => new CoreRequest());
+    private pb::UnknownFieldSet _unknownFields;
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public static pb::MessageParser<CoreRequest> Parser { get { return _parser; } }
 
@@ -2808,6 +2955,7 @@ namespace Grpc.Testing {
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public CoreRequest(CoreRequest other) : this() {
+      _unknownFields = pb::UnknownFieldSet.Clone(other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -2828,12 +2976,15 @@ namespace Grpc.Testing {
       if (ReferenceEquals(other, this)) {
         return true;
       }
-      return true;
+      return Equals(_unknownFields, other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public override int GetHashCode() {
       int hash = 1;
+      if (_unknownFields != null) {
+        hash ^= _unknownFields.GetHashCode();
+      }
       return hash;
     }
 
@@ -2844,11 +2995,17 @@ namespace Grpc.Testing {
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public void WriteTo(pb::CodedOutputStream output) {
+      if (_unknownFields != null) {
+        _unknownFields.WriteTo(output);
+      }
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public int CalculateSize() {
       int size = 0;
+      if (_unknownFields != null) {
+        size += _unknownFields.CalculateSize();
+      }
       return size;
     }
 
@@ -2857,6 +3014,7 @@ namespace Grpc.Testing {
       if (other == null) {
         return;
       }
+      _unknownFields = pb::UnknownFieldSet.MergeFrom(_unknownFields, other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -2865,7 +3023,7 @@ namespace Grpc.Testing {
       while ((tag = input.ReadTag()) != 0) {
         switch(tag) {
           default:
-            input.SkipLastField();
+            _unknownFields = pb::UnknownFieldSet.MergeFieldFrom(_unknownFields, input);
             break;
         }
       }
@@ -2875,6 +3033,7 @@ namespace Grpc.Testing {
 
   public sealed partial class CoreResponse : pb::IMessage<CoreResponse> {
     private static readonly pb::MessageParser<CoreResponse> _parser = new pb::MessageParser<CoreResponse>(() => new CoreResponse());
+    private pb::UnknownFieldSet _unknownFields;
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public static pb::MessageParser<CoreResponse> Parser { get { return _parser; } }
 
@@ -2898,6 +3057,7 @@ namespace Grpc.Testing {
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public CoreResponse(CoreResponse other) : this() {
       cores_ = other.cores_;
+      _unknownFields = pb::UnknownFieldSet.Clone(other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -2933,13 +3093,16 @@ namespace Grpc.Testing {
         return true;
       }
       if (Cores != other.Cores) return false;
-      return true;
+      return Equals(_unknownFields, other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public override int GetHashCode() {
       int hash = 1;
       if (Cores != 0) hash ^= Cores.GetHashCode();
+      if (_unknownFields != null) {
+        hash ^= _unknownFields.GetHashCode();
+      }
       return hash;
     }
 
@@ -2954,6 +3117,9 @@ namespace Grpc.Testing {
         output.WriteRawTag(8);
         output.WriteInt32(Cores);
       }
+      if (_unknownFields != null) {
+        _unknownFields.WriteTo(output);
+      }
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -2962,6 +3128,9 @@ namespace Grpc.Testing {
       if (Cores != 0) {
         size += 1 + pb::CodedOutputStream.ComputeInt32Size(Cores);
       }
+      if (_unknownFields != null) {
+        size += _unknownFields.CalculateSize();
+      }
       return size;
     }
 
@@ -2973,6 +3142,7 @@ namespace Grpc.Testing {
       if (other.Cores != 0) {
         Cores = other.Cores;
       }
+      _unknownFields = pb::UnknownFieldSet.MergeFrom(_unknownFields, other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -2981,7 +3151,7 @@ namespace Grpc.Testing {
       while ((tag = input.ReadTag()) != 0) {
         switch(tag) {
           default:
-            input.SkipLastField();
+            _unknownFields = pb::UnknownFieldSet.MergeFieldFrom(_unknownFields, input);
             break;
           case 8: {
             Cores = input.ReadInt32();
@@ -2995,6 +3165,7 @@ namespace Grpc.Testing {
 
   public sealed partial class Void : pb::IMessage<Void> {
     private static readonly pb::MessageParser<Void> _parser = new pb::MessageParser<Void>(() => new Void());
+    private pb::UnknownFieldSet _unknownFields;
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public static pb::MessageParser<Void> Parser { get { return _parser; } }
 
@@ -3017,6 +3188,7 @@ namespace Grpc.Testing {
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public Void(Void other) : this() {
+      _unknownFields = pb::UnknownFieldSet.Clone(other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -3037,12 +3209,15 @@ namespace Grpc.Testing {
       if (ReferenceEquals(other, this)) {
         return true;
       }
-      return true;
+      return Equals(_unknownFields, other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public override int GetHashCode() {
       int hash = 1;
+      if (_unknownFields != null) {
+        hash ^= _unknownFields.GetHashCode();
+      }
       return hash;
     }
 
@@ -3053,11 +3228,17 @@ namespace Grpc.Testing {
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public void WriteTo(pb::CodedOutputStream output) {
+      if (_unknownFields != null) {
+        _unknownFields.WriteTo(output);
+      }
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public int CalculateSize() {
       int size = 0;
+      if (_unknownFields != null) {
+        size += _unknownFields.CalculateSize();
+      }
       return size;
     }
 
@@ -3066,6 +3247,7 @@ namespace Grpc.Testing {
       if (other == null) {
         return;
       }
+      _unknownFields = pb::UnknownFieldSet.MergeFrom(_unknownFields, other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -3074,7 +3256,7 @@ namespace Grpc.Testing {
       while ((tag = input.ReadTag()) != 0) {
         switch(tag) {
           default:
-            input.SkipLastField();
+            _unknownFields = pb::UnknownFieldSet.MergeFieldFrom(_unknownFields, input);
             break;
         }
       }
@@ -3087,6 +3269,7 @@ namespace Grpc.Testing {
   /// </summary>
   public sealed partial class Scenario : pb::IMessage<Scenario> {
     private static readonly pb::MessageParser<Scenario> _parser = new pb::MessageParser<Scenario>(() => new Scenario());
+    private pb::UnknownFieldSet _unknownFields;
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public static pb::MessageParser<Scenario> Parser { get { return _parser; } }
 
@@ -3117,6 +3300,7 @@ namespace Grpc.Testing {
       warmupSeconds_ = other.warmupSeconds_;
       benchmarkSeconds_ = other.benchmarkSeconds_;
       spawnLocalWorkerCount_ = other.spawnLocalWorkerCount_;
+      _unknownFields = pb::UnknownFieldSet.Clone(other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -3257,7 +3441,7 @@ namespace Grpc.Testing {
       if (WarmupSeconds != other.WarmupSeconds) return false;
       if (BenchmarkSeconds != other.BenchmarkSeconds) return false;
       if (SpawnLocalWorkerCount != other.SpawnLocalWorkerCount) return false;
-      return true;
+      return Equals(_unknownFields, other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -3271,6 +3455,9 @@ namespace Grpc.Testing {
       if (WarmupSeconds != 0) hash ^= WarmupSeconds.GetHashCode();
       if (BenchmarkSeconds != 0) hash ^= BenchmarkSeconds.GetHashCode();
       if (SpawnLocalWorkerCount != 0) hash ^= SpawnLocalWorkerCount.GetHashCode();
+      if (_unknownFields != null) {
+        hash ^= _unknownFields.GetHashCode();
+      }
       return hash;
     }
 
@@ -3313,6 +3500,9 @@ namespace Grpc.Testing {
         output.WriteRawTag(64);
         output.WriteInt32(SpawnLocalWorkerCount);
       }
+      if (_unknownFields != null) {
+        _unknownFields.WriteTo(output);
+      }
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -3342,6 +3532,9 @@ namespace Grpc.Testing {
       if (SpawnLocalWorkerCount != 0) {
         size += 1 + pb::CodedOutputStream.ComputeInt32Size(SpawnLocalWorkerCount);
       }
+      if (_unknownFields != null) {
+        size += _unknownFields.CalculateSize();
+      }
       return size;
     }
 
@@ -3380,6 +3573,7 @@ namespace Grpc.Testing {
       if (other.SpawnLocalWorkerCount != 0) {
         SpawnLocalWorkerCount = other.SpawnLocalWorkerCount;
       }
+      _unknownFields = pb::UnknownFieldSet.MergeFrom(_unknownFields, other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -3388,7 +3582,7 @@ namespace Grpc.Testing {
       while ((tag = input.ReadTag()) != 0) {
         switch(tag) {
           default:
-            input.SkipLastField();
+            _unknownFields = pb::UnknownFieldSet.MergeFieldFrom(_unknownFields, input);
             break;
           case 10: {
             Name = input.ReadString();
@@ -3439,6 +3633,7 @@ namespace Grpc.Testing {
   /// </summary>
   public sealed partial class Scenarios : pb::IMessage<Scenarios> {
     private static readonly pb::MessageParser<Scenarios> _parser = new pb::MessageParser<Scenarios>(() => new Scenarios());
+    private pb::UnknownFieldSet _unknownFields;
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public static pb::MessageParser<Scenarios> Parser { get { return _parser; } }
 
@@ -3462,6 +3657,7 @@ namespace Grpc.Testing {
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public Scenarios(Scenarios other) : this() {
       scenarios_ = other.scenarios_.Clone();
+      _unknownFields = pb::UnknownFieldSet.Clone(other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -3493,13 +3689,16 @@ namespace Grpc.Testing {
         return true;
       }
       if(!scenarios_.Equals(other.scenarios_)) return false;
-      return true;
+      return Equals(_unknownFields, other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public override int GetHashCode() {
       int hash = 1;
       hash ^= scenarios_.GetHashCode();
+      if (_unknownFields != null) {
+        hash ^= _unknownFields.GetHashCode();
+      }
       return hash;
     }
 
@@ -3511,12 +3710,18 @@ namespace Grpc.Testing {
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public void WriteTo(pb::CodedOutputStream output) {
       scenarios_.WriteTo(output, _repeated_scenarios_codec);
+      if (_unknownFields != null) {
+        _unknownFields.WriteTo(output);
+      }
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public int CalculateSize() {
       int size = 0;
       size += scenarios_.CalculateSize(_repeated_scenarios_codec);
+      if (_unknownFields != null) {
+        size += _unknownFields.CalculateSize();
+      }
       return size;
     }
 
@@ -3526,6 +3731,7 @@ namespace Grpc.Testing {
         return;
       }
       scenarios_.Add(other.scenarios_);
+      _unknownFields = pb::UnknownFieldSet.MergeFrom(_unknownFields, other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -3534,7 +3740,7 @@ namespace Grpc.Testing {
       while ((tag = input.ReadTag()) != 0) {
         switch(tag) {
           default:
-            input.SkipLastField();
+            _unknownFields = pb::UnknownFieldSet.MergeFieldFrom(_unknownFields, input);
             break;
           case 10: {
             scenarios_.AddEntriesFrom(input, _repeated_scenarios_codec);
@@ -3552,6 +3758,7 @@ namespace Grpc.Testing {
   /// </summary>
   public sealed partial class ScenarioResultSummary : pb::IMessage<ScenarioResultSummary> {
     private static readonly pb::MessageParser<ScenarioResultSummary> _parser = new pb::MessageParser<ScenarioResultSummary>(() => new ScenarioResultSummary());
+    private pb::UnknownFieldSet _unknownFields;
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public static pb::MessageParser<ScenarioResultSummary> Parser { get { return _parser; } }
 
@@ -3592,6 +3799,7 @@ namespace Grpc.Testing {
       serverPollsPerRequest_ = other.serverPollsPerRequest_;
       serverQueriesPerCpuSec_ = other.serverQueriesPerCpuSec_;
       clientQueriesPerCpuSec_ = other.clientQueriesPerCpuSec_;
+      _unknownFields = pb::UnknownFieldSet.Clone(other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -3843,48 +4051,51 @@ namespace Grpc.Testing {
       if (ReferenceEquals(other, this)) {
         return true;
       }
-      if (Qps != other.Qps) return false;
-      if (QpsPerServerCore != other.QpsPerServerCore) return false;
-      if (ServerSystemTime != other.ServerSystemTime) return false;
-      if (ServerUserTime != other.ServerUserTime) return false;
-      if (ClientSystemTime != other.ClientSystemTime) return false;
-      if (ClientUserTime != other.ClientUserTime) return false;
-      if (Latency50 != other.Latency50) return false;
-      if (Latency90 != other.Latency90) return false;
-      if (Latency95 != other.Latency95) return false;
-      if (Latency99 != other.Latency99) return false;
-      if (Latency999 != other.Latency999) return false;
-      if (ServerCpuUsage != other.ServerCpuUsage) return false;
-      if (SuccessfulRequestsPerSecond != other.SuccessfulRequestsPerSecond) return false;
-      if (FailedRequestsPerSecond != other.FailedRequestsPerSecond) return false;
-      if (ClientPollsPerRequest != other.ClientPollsPerRequest) return false;
-      if (ServerPollsPerRequest != other.ServerPollsPerRequest) return false;
-      if (ServerQueriesPerCpuSec != other.ServerQueriesPerCpuSec) return false;
-      if (ClientQueriesPerCpuSec != other.ClientQueriesPerCpuSec) return false;
-      return true;
+      if (!pbc::ProtobufEqualityComparers.BitwiseDoubleEqualityComparer.Equals(Qps, other.Qps)) return false;
+      if (!pbc::ProtobufEqualityComparers.BitwiseDoubleEqualityComparer.Equals(QpsPerServerCore, other.QpsPerServerCore)) return false;
+      if (!pbc::ProtobufEqualityComparers.BitwiseDoubleEqualityComparer.Equals(ServerSystemTime, other.ServerSystemTime)) return false;
+      if (!pbc::ProtobufEqualityComparers.BitwiseDoubleEqualityComparer.Equals(ServerUserTime, other.ServerUserTime)) return false;
+      if (!pbc::ProtobufEqualityComparers.BitwiseDoubleEqualityComparer.Equals(ClientSystemTime, other.ClientSystemTime)) return false;
+      if (!pbc::ProtobufEqualityComparers.BitwiseDoubleEqualityComparer.Equals(ClientUserTime, other.ClientUserTime)) return false;
+      if (!pbc::ProtobufEqualityComparers.BitwiseDoubleEqualityComparer.Equals(Latency50, other.Latency50)) return false;
+      if (!pbc::ProtobufEqualityComparers.BitwiseDoubleEqualityComparer.Equals(Latency90, other.Latency90)) return false;
+      if (!pbc::ProtobufEqualityComparers.BitwiseDoubleEqualityComparer.Equals(Latency95, other.Latency95)) return false;
+      if (!pbc::ProtobufEqualityComparers.BitwiseDoubleEqualityComparer.Equals(Latency99, other.Latency99)) return false;
+      if (!pbc::ProtobufEqualityComparers.BitwiseDoubleEqualityComparer.Equals(Latency999, other.Latency999)) return false;
+      if (!pbc::ProtobufEqualityComparers.BitwiseDoubleEqualityComparer.Equals(ServerCpuUsage, other.ServerCpuUsage)) return false;
+      if (!pbc::ProtobufEqualityComparers.BitwiseDoubleEqualityComparer.Equals(SuccessfulRequestsPerSecond, other.SuccessfulRequestsPerSecond)) return false;
+      if (!pbc::ProtobufEqualityComparers.BitwiseDoubleEqualityComparer.Equals(FailedRequestsPerSecond, other.FailedRequestsPerSecond)) return false;
+      if (!pbc::ProtobufEqualityComparers.BitwiseDoubleEqualityComparer.Equals(ClientPollsPerRequest, other.ClientPollsPerRequest)) return false;
+      if (!pbc::ProtobufEqualityComparers.BitwiseDoubleEqualityComparer.Equals(ServerPollsPerRequest, other.ServerPollsPerRequest)) return false;
+      if (!pbc::ProtobufEqualityComparers.BitwiseDoubleEqualityComparer.Equals(ServerQueriesPerCpuSec, other.ServerQueriesPerCpuSec)) return false;
+      if (!pbc::ProtobufEqualityComparers.BitwiseDoubleEqualityComparer.Equals(ClientQueriesPerCpuSec, other.ClientQueriesPerCpuSec)) return false;
+      return Equals(_unknownFields, other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public override int GetHashCode() {
       int hash = 1;
-      if (Qps != 0D) hash ^= Qps.GetHashCode();
-      if (QpsPerServerCore != 0D) hash ^= QpsPerServerCore.GetHashCode();
-      if (ServerSystemTime != 0D) hash ^= ServerSystemTime.GetHashCode();
-      if (ServerUserTime != 0D) hash ^= ServerUserTime.GetHashCode();
-      if (ClientSystemTime != 0D) hash ^= ClientSystemTime.GetHashCode();
-      if (ClientUserTime != 0D) hash ^= ClientUserTime.GetHashCode();
-      if (Latency50 != 0D) hash ^= Latency50.GetHashCode();
-      if (Latency90 != 0D) hash ^= Latency90.GetHashCode();
-      if (Latency95 != 0D) hash ^= Latency95.GetHashCode();
-      if (Latency99 != 0D) hash ^= Latency99.GetHashCode();
-      if (Latency999 != 0D) hash ^= Latency999.GetHashCode();
-      if (ServerCpuUsage != 0D) hash ^= ServerCpuUsage.GetHashCode();
-      if (SuccessfulRequestsPerSecond != 0D) hash ^= SuccessfulRequestsPerSecond.GetHashCode();
-      if (FailedRequestsPerSecond != 0D) hash ^= FailedRequestsPerSecond.GetHashCode();
-      if (ClientPollsPerRequest != 0D) hash ^= ClientPollsPerRequest.GetHashCode();
-      if (ServerPollsPerRequest != 0D) hash ^= ServerPollsPerRequest.GetHashCode();
-      if (ServerQueriesPerCpuSec != 0D) hash ^= ServerQueriesPerCpuSec.GetHashCode();
-      if (ClientQueriesPerCpuSec != 0D) hash ^= ClientQueriesPerCpuSec.GetHashCode();
+      if (Qps != 0D) hash ^= pbc::ProtobufEqualityComparers.BitwiseDoubleEqualityComparer.GetHashCode(Qps);
+      if (QpsPerServerCore != 0D) hash ^= pbc::ProtobufEqualityComparers.BitwiseDoubleEqualityComparer.GetHashCode(QpsPerServerCore);
+      if (ServerSystemTime != 0D) hash ^= pbc::ProtobufEqualityComparers.BitwiseDoubleEqualityComparer.GetHashCode(ServerSystemTime);
+      if (ServerUserTime != 0D) hash ^= pbc::ProtobufEqualityComparers.BitwiseDoubleEqualityComparer.GetHashCode(ServerUserTime);
+      if (ClientSystemTime != 0D) hash ^= pbc::ProtobufEqualityComparers.BitwiseDoubleEqualityComparer.GetHashCode(ClientSystemTime);
+      if (ClientUserTime != 0D) hash ^= pbc::ProtobufEqualityComparers.BitwiseDoubleEqualityComparer.GetHashCode(ClientUserTime);
+      if (Latency50 != 0D) hash ^= pbc::ProtobufEqualityComparers.BitwiseDoubleEqualityComparer.GetHashCode(Latency50);
+      if (Latency90 != 0D) hash ^= pbc::ProtobufEqualityComparers.BitwiseDoubleEqualityComparer.GetHashCode(Latency90);
+      if (Latency95 != 0D) hash ^= pbc::ProtobufEqualityComparers.BitwiseDoubleEqualityComparer.GetHashCode(Latency95);
+      if (Latency99 != 0D) hash ^= pbc::ProtobufEqualityComparers.BitwiseDoubleEqualityComparer.GetHashCode(Latency99);
+      if (Latency999 != 0D) hash ^= pbc::ProtobufEqualityComparers.BitwiseDoubleEqualityComparer.GetHashCode(Latency999);
+      if (ServerCpuUsage != 0D) hash ^= pbc::ProtobufEqualityComparers.BitwiseDoubleEqualityComparer.GetHashCode(ServerCpuUsage);
+      if (SuccessfulRequestsPerSecond != 0D) hash ^= pbc::ProtobufEqualityComparers.BitwiseDoubleEqualityComparer.GetHashCode(SuccessfulRequestsPerSecond);
+      if (FailedRequestsPerSecond != 0D) hash ^= pbc::ProtobufEqualityComparers.BitwiseDoubleEqualityComparer.GetHashCode(FailedRequestsPerSecond);
+      if (ClientPollsPerRequest != 0D) hash ^= pbc::ProtobufEqualityComparers.BitwiseDoubleEqualityComparer.GetHashCode(ClientPollsPerRequest);
+      if (ServerPollsPerRequest != 0D) hash ^= pbc::ProtobufEqualityComparers.BitwiseDoubleEqualityComparer.GetHashCode(ServerPollsPerRequest);
+      if (ServerQueriesPerCpuSec != 0D) hash ^= pbc::ProtobufEqualityComparers.BitwiseDoubleEqualityComparer.GetHashCode(ServerQueriesPerCpuSec);
+      if (ClientQueriesPerCpuSec != 0D) hash ^= pbc::ProtobufEqualityComparers.BitwiseDoubleEqualityComparer.GetHashCode(ClientQueriesPerCpuSec);
+      if (_unknownFields != null) {
+        hash ^= _unknownFields.GetHashCode();
+      }
       return hash;
     }
 
@@ -3967,6 +4178,9 @@ namespace Grpc.Testing {
         output.WriteRawTag(145, 1);
         output.WriteDouble(ClientQueriesPerCpuSec);
       }
+      if (_unknownFields != null) {
+        _unknownFields.WriteTo(output);
+      }
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -4026,6 +4240,9 @@ namespace Grpc.Testing {
       if (ClientQueriesPerCpuSec != 0D) {
         size += 2 + 8;
       }
+      if (_unknownFields != null) {
+        size += _unknownFields.CalculateSize();
+      }
       return size;
     }
 
@@ -4088,6 +4305,7 @@ namespace Grpc.Testing {
       if (other.ClientQueriesPerCpuSec != 0D) {
         ClientQueriesPerCpuSec = other.ClientQueriesPerCpuSec;
       }
+      _unknownFields = pb::UnknownFieldSet.MergeFrom(_unknownFields, other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -4096,7 +4314,7 @@ namespace Grpc.Testing {
       while ((tag = input.ReadTag()) != 0) {
         switch(tag) {
           default:
-            input.SkipLastField();
+            _unknownFields = pb::UnknownFieldSet.MergeFieldFrom(_unknownFields, input);
             break;
           case 9: {
             Qps = input.ReadDouble();
@@ -4181,6 +4399,7 @@ namespace Grpc.Testing {
   /// </summary>
   public sealed partial class ScenarioResult : pb::IMessage<ScenarioResult> {
     private static readonly pb::MessageParser<ScenarioResult> _parser = new pb::MessageParser<ScenarioResult>(() => new ScenarioResult());
+    private pb::UnknownFieldSet _unknownFields;
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public static pb::MessageParser<ScenarioResult> Parser { get { return _parser; } }
 
@@ -4212,6 +4431,7 @@ namespace Grpc.Testing {
       clientSuccess_ = other.clientSuccess_.Clone();
       serverSuccess_ = other.serverSuccess_.Clone();
       requestResults_ = other.requestResults_.Clone();
+      _unknownFields = pb::UnknownFieldSet.Clone(other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -4358,7 +4578,7 @@ namespace Grpc.Testing {
       if(!clientSuccess_.Equals(other.clientSuccess_)) return false;
       if(!serverSuccess_.Equals(other.serverSuccess_)) return false;
       if(!requestResults_.Equals(other.requestResults_)) return false;
-      return true;
+      return Equals(_unknownFields, other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -4373,6 +4593,9 @@ namespace Grpc.Testing {
       hash ^= clientSuccess_.GetHashCode();
       hash ^= serverSuccess_.GetHashCode();
       hash ^= requestResults_.GetHashCode();
+      if (_unknownFields != null) {
+        hash ^= _unknownFields.GetHashCode();
+      }
       return hash;
     }
 
@@ -4401,6 +4624,9 @@ namespace Grpc.Testing {
       clientSuccess_.WriteTo(output, _repeated_clientSuccess_codec);
       serverSuccess_.WriteTo(output, _repeated_serverSuccess_codec);
       requestResults_.WriteTo(output, _repeated_requestResults_codec);
+      if (_unknownFields != null) {
+        _unknownFields.WriteTo(output);
+      }
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -4421,6 +4647,9 @@ namespace Grpc.Testing {
       size += clientSuccess_.CalculateSize(_repeated_clientSuccess_codec);
       size += serverSuccess_.CalculateSize(_repeated_serverSuccess_codec);
       size += requestResults_.CalculateSize(_repeated_requestResults_codec);
+      if (_unknownFields != null) {
+        size += _unknownFields.CalculateSize();
+      }
       return size;
     }
 
@@ -4453,6 +4682,7 @@ namespace Grpc.Testing {
       clientSuccess_.Add(other.clientSuccess_);
       serverSuccess_.Add(other.serverSuccess_);
       requestResults_.Add(other.requestResults_);
+      _unknownFields = pb::UnknownFieldSet.MergeFrom(_unknownFields, other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -4461,7 +4691,7 @@ namespace Grpc.Testing {
       while ((tag = input.ReadTag()) != 0) {
         switch(tag) {
           default:
-            input.SkipLastField();
+            _unknownFields = pb::UnknownFieldSet.MergeFieldFrom(_unknownFields, input);
             break;
           case 10: {
             if (scenario_ == null) {
diff --git a/src/csharp/Grpc.IntegrationTesting/CoreStats/Stats.cs b/src/csharp/Grpc.IntegrationTesting/CoreStats/Stats.cs
index 380294e335..4ff56cd3ec 100644
--- a/src/csharp/Grpc.IntegrationTesting/CoreStats/Stats.cs
+++ b/src/csharp/Grpc.IntegrationTesting/CoreStats/Stats.cs
@@ -1,5 +1,7 @@
-// Generated by the protocol buffer compiler.  DO NOT EDIT!
-// source: grpc/core/stats.proto
+// <auto-generated>
+//     Generated by the protocol buffer compiler.  DO NOT EDIT!
+//     source: grpc/core/stats.proto
+// </auto-generated>
 #pragma warning disable 1591, 0612, 3021
 #region Designer generated code
 
@@ -43,6 +45,7 @@ namespace Grpc.Core {
   #region Messages
   public sealed partial class Bucket : pb::IMessage<Bucket> {
     private static readonly pb::MessageParser<Bucket> _parser = new pb::MessageParser<Bucket>(() => new Bucket());
+    private pb::UnknownFieldSet _unknownFields;
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public static pb::MessageParser<Bucket> Parser { get { return _parser; } }
 
@@ -67,6 +70,7 @@ namespace Grpc.Core {
     public Bucket(Bucket other) : this() {
       start_ = other.start_;
       count_ = other.count_;
+      _unknownFields = pb::UnknownFieldSet.Clone(other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -109,16 +113,19 @@ namespace Grpc.Core {
       if (ReferenceEquals(other, this)) {
         return true;
       }
-      if (Start != other.Start) return false;
+      if (!pbc::ProtobufEqualityComparers.BitwiseDoubleEqualityComparer.Equals(Start, other.Start)) return false;
       if (Count != other.Count) return false;
-      return true;
+      return Equals(_unknownFields, other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public override int GetHashCode() {
       int hash = 1;
-      if (Start != 0D) hash ^= Start.GetHashCode();
+      if (Start != 0D) hash ^= pbc::ProtobufEqualityComparers.BitwiseDoubleEqualityComparer.GetHashCode(Start);
       if (Count != 0UL) hash ^= Count.GetHashCode();
+      if (_unknownFields != null) {
+        hash ^= _unknownFields.GetHashCode();
+      }
       return hash;
     }
 
@@ -137,6 +144,9 @@ namespace Grpc.Core {
         output.WriteRawTag(16);
         output.WriteUInt64(Count);
       }
+      if (_unknownFields != null) {
+        _unknownFields.WriteTo(output);
+      }
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -148,6 +158,9 @@ namespace Grpc.Core {
       if (Count != 0UL) {
         size += 1 + pb::CodedOutputStream.ComputeUInt64Size(Count);
       }
+      if (_unknownFields != null) {
+        size += _unknownFields.CalculateSize();
+      }
       return size;
     }
 
@@ -162,6 +175,7 @@ namespace Grpc.Core {
       if (other.Count != 0UL) {
         Count = other.Count;
       }
+      _unknownFields = pb::UnknownFieldSet.MergeFrom(_unknownFields, other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -170,7 +184,7 @@ namespace Grpc.Core {
       while ((tag = input.ReadTag()) != 0) {
         switch(tag) {
           default:
-            input.SkipLastField();
+            _unknownFields = pb::UnknownFieldSet.MergeFieldFrom(_unknownFields, input);
             break;
           case 9: {
             Start = input.ReadDouble();
@@ -188,6 +202,7 @@ namespace Grpc.Core {
 
   public sealed partial class Histogram : pb::IMessage<Histogram> {
     private static readonly pb::MessageParser<Histogram> _parser = new pb::MessageParser<Histogram>(() => new Histogram());
+    private pb::UnknownFieldSet _unknownFields;
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public static pb::MessageParser<Histogram> Parser { get { return _parser; } }
 
@@ -211,6 +226,7 @@ namespace Grpc.Core {
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public Histogram(Histogram other) : this() {
       buckets_ = other.buckets_.Clone();
+      _unknownFields = pb::UnknownFieldSet.Clone(other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -242,13 +258,16 @@ namespace Grpc.Core {
         return true;
       }
       if(!buckets_.Equals(other.buckets_)) return false;
-      return true;
+      return Equals(_unknownFields, other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public override int GetHashCode() {
       int hash = 1;
       hash ^= buckets_.GetHashCode();
+      if (_unknownFields != null) {
+        hash ^= _unknownFields.GetHashCode();
+      }
       return hash;
     }
 
@@ -260,12 +279,18 @@ namespace Grpc.Core {
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public void WriteTo(pb::CodedOutputStream output) {
       buckets_.WriteTo(output, _repeated_buckets_codec);
+      if (_unknownFields != null) {
+        _unknownFields.WriteTo(output);
+      }
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public int CalculateSize() {
       int size = 0;
       size += buckets_.CalculateSize(_repeated_buckets_codec);
+      if (_unknownFields != null) {
+        size += _unknownFields.CalculateSize();
+      }
       return size;
     }
 
@@ -275,6 +300,7 @@ namespace Grpc.Core {
         return;
       }
       buckets_.Add(other.buckets_);
+      _unknownFields = pb::UnknownFieldSet.MergeFrom(_unknownFields, other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -283,7 +309,7 @@ namespace Grpc.Core {
       while ((tag = input.ReadTag()) != 0) {
         switch(tag) {
           default:
-            input.SkipLastField();
+            _unknownFields = pb::UnknownFieldSet.MergeFieldFrom(_unknownFields, input);
             break;
           case 10: {
             buckets_.AddEntriesFrom(input, _repeated_buckets_codec);
@@ -297,6 +323,7 @@ namespace Grpc.Core {
 
   public sealed partial class Metric : pb::IMessage<Metric> {
     private static readonly pb::MessageParser<Metric> _parser = new pb::MessageParser<Metric>(() => new Metric());
+    private pb::UnknownFieldSet _unknownFields;
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public static pb::MessageParser<Metric> Parser { get { return _parser; } }
 
@@ -329,6 +356,7 @@ namespace Grpc.Core {
           break;
       }
 
+      _unknownFields = pb::UnknownFieldSet.Clone(other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -405,7 +433,7 @@ namespace Grpc.Core {
       if (Count != other.Count) return false;
       if (!object.Equals(Histogram, other.Histogram)) return false;
       if (ValueCase != other.ValueCase) return false;
-      return true;
+      return Equals(_unknownFields, other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -415,6 +443,9 @@ namespace Grpc.Core {
       if (valueCase_ == ValueOneofCase.Count) hash ^= Count.GetHashCode();
       if (valueCase_ == ValueOneofCase.Histogram) hash ^= Histogram.GetHashCode();
       hash ^= (int) valueCase_;
+      if (_unknownFields != null) {
+        hash ^= _unknownFields.GetHashCode();
+      }
       return hash;
     }
 
@@ -437,6 +468,9 @@ namespace Grpc.Core {
         output.WriteRawTag(90);
         output.WriteMessage(Histogram);
       }
+      if (_unknownFields != null) {
+        _unknownFields.WriteTo(output);
+      }
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -451,6 +485,9 @@ namespace Grpc.Core {
       if (valueCase_ == ValueOneofCase.Histogram) {
         size += 1 + pb::CodedOutputStream.ComputeMessageSize(Histogram);
       }
+      if (_unknownFields != null) {
+        size += _unknownFields.CalculateSize();
+      }
       return size;
     }
 
@@ -474,6 +511,7 @@ namespace Grpc.Core {
           break;
       }
 
+      _unknownFields = pb::UnknownFieldSet.MergeFrom(_unknownFields, other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -482,7 +520,7 @@ namespace Grpc.Core {
       while ((tag = input.ReadTag()) != 0) {
         switch(tag) {
           default:
-            input.SkipLastField();
+            _unknownFields = pb::UnknownFieldSet.MergeFieldFrom(_unknownFields, input);
             break;
           case 10: {
             Name = input.ReadString();
@@ -509,6 +547,7 @@ namespace Grpc.Core {
 
   public sealed partial class Stats : pb::IMessage<Stats> {
     private static readonly pb::MessageParser<Stats> _parser = new pb::MessageParser<Stats>(() => new Stats());
+    private pb::UnknownFieldSet _unknownFields;
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public static pb::MessageParser<Stats> Parser { get { return _parser; } }
 
@@ -532,6 +571,7 @@ namespace Grpc.Core {
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public Stats(Stats other) : this() {
       metrics_ = other.metrics_.Clone();
+      _unknownFields = pb::UnknownFieldSet.Clone(other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -563,13 +603,16 @@ namespace Grpc.Core {
         return true;
       }
       if(!metrics_.Equals(other.metrics_)) return false;
-      return true;
+      return Equals(_unknownFields, other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public override int GetHashCode() {
       int hash = 1;
       hash ^= metrics_.GetHashCode();
+      if (_unknownFields != null) {
+        hash ^= _unknownFields.GetHashCode();
+      }
       return hash;
     }
 
@@ -581,12 +624,18 @@ namespace Grpc.Core {
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public void WriteTo(pb::CodedOutputStream output) {
       metrics_.WriteTo(output, _repeated_metrics_codec);
+      if (_unknownFields != null) {
+        _unknownFields.WriteTo(output);
+      }
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public int CalculateSize() {
       int size = 0;
       size += metrics_.CalculateSize(_repeated_metrics_codec);
+      if (_unknownFields != null) {
+        size += _unknownFields.CalculateSize();
+      }
       return size;
     }
 
@@ -596,6 +645,7 @@ namespace Grpc.Core {
         return;
       }
       metrics_.Add(other.metrics_);
+      _unknownFields = pb::UnknownFieldSet.MergeFrom(_unknownFields, other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -604,7 +654,7 @@ namespace Grpc.Core {
       while ((tag = input.ReadTag()) != 0) {
         switch(tag) {
           default:
-            input.SkipLastField();
+            _unknownFields = pb::UnknownFieldSet.MergeFieldFrom(_unknownFields, input);
             break;
           case 10: {
             metrics_.AddEntriesFrom(input, _repeated_metrics_codec);
diff --git a/src/csharp/Grpc.IntegrationTesting/EchoMessages.cs b/src/csharp/Grpc.IntegrationTesting/EchoMessages.cs
index 9581aded58..39c3d76ce8 100644
--- a/src/csharp/Grpc.IntegrationTesting/EchoMessages.cs
+++ b/src/csharp/Grpc.IntegrationTesting/EchoMessages.cs
@@ -1,5 +1,7 @@
-// Generated by the protocol buffer compiler.  DO NOT EDIT!
-// source: src/proto/grpc/testing/echo_messages.proto
+// <auto-generated>
+//     Generated by the protocol buffer compiler.  DO NOT EDIT!
+//     source: src/proto/grpc/testing/echo_messages.proto
+// </auto-generated>
 #pragma warning disable 1591, 0612, 3021
 #region Designer generated code
 
@@ -63,6 +65,7 @@ namespace Grpc.Testing {
   /// </summary>
   public sealed partial class DebugInfo : pb::IMessage<DebugInfo> {
     private static readonly pb::MessageParser<DebugInfo> _parser = new pb::MessageParser<DebugInfo>(() => new DebugInfo());
+    private pb::UnknownFieldSet _unknownFields;
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public static pb::MessageParser<DebugInfo> Parser { get { return _parser; } }
 
@@ -87,6 +90,7 @@ namespace Grpc.Testing {
     public DebugInfo(DebugInfo other) : this() {
       stackEntries_ = other.stackEntries_.Clone();
       detail_ = other.detail_;
+      _unknownFields = pb::UnknownFieldSet.Clone(other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -130,7 +134,7 @@ namespace Grpc.Testing {
       }
       if(!stackEntries_.Equals(other.stackEntries_)) return false;
       if (Detail != other.Detail) return false;
-      return true;
+      return Equals(_unknownFields, other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -138,6 +142,9 @@ namespace Grpc.Testing {
       int hash = 1;
       hash ^= stackEntries_.GetHashCode();
       if (Detail.Length != 0) hash ^= Detail.GetHashCode();
+      if (_unknownFields != null) {
+        hash ^= _unknownFields.GetHashCode();
+      }
       return hash;
     }
 
@@ -153,6 +160,9 @@ namespace Grpc.Testing {
         output.WriteRawTag(18);
         output.WriteString(Detail);
       }
+      if (_unknownFields != null) {
+        _unknownFields.WriteTo(output);
+      }
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -162,6 +172,9 @@ namespace Grpc.Testing {
       if (Detail.Length != 0) {
         size += 1 + pb::CodedOutputStream.ComputeStringSize(Detail);
       }
+      if (_unknownFields != null) {
+        size += _unknownFields.CalculateSize();
+      }
       return size;
     }
 
@@ -174,6 +187,7 @@ namespace Grpc.Testing {
       if (other.Detail.Length != 0) {
         Detail = other.Detail;
       }
+      _unknownFields = pb::UnknownFieldSet.MergeFrom(_unknownFields, other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -182,7 +196,7 @@ namespace Grpc.Testing {
       while ((tag = input.ReadTag()) != 0) {
         switch(tag) {
           default:
-            input.SkipLastField();
+            _unknownFields = pb::UnknownFieldSet.MergeFieldFrom(_unknownFields, input);
             break;
           case 10: {
             stackEntries_.AddEntriesFrom(input, _repeated_stackEntries_codec);
@@ -203,6 +217,7 @@ namespace Grpc.Testing {
   /// </summary>
   public sealed partial class ErrorStatus : pb::IMessage<ErrorStatus> {
     private static readonly pb::MessageParser<ErrorStatus> _parser = new pb::MessageParser<ErrorStatus>(() => new ErrorStatus());
+    private pb::UnknownFieldSet _unknownFields;
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public static pb::MessageParser<ErrorStatus> Parser { get { return _parser; } }
 
@@ -228,6 +243,7 @@ namespace Grpc.Testing {
       code_ = other.code_;
       errorMessage_ = other.errorMessage_;
       binaryErrorDetails_ = other.binaryErrorDetails_;
+      _unknownFields = pb::UnknownFieldSet.Clone(other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -284,7 +300,7 @@ namespace Grpc.Testing {
       if (Code != other.Code) return false;
       if (ErrorMessage != other.ErrorMessage) return false;
       if (BinaryErrorDetails != other.BinaryErrorDetails) return false;
-      return true;
+      return Equals(_unknownFields, other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -293,6 +309,9 @@ namespace Grpc.Testing {
       if (Code != 0) hash ^= Code.GetHashCode();
       if (ErrorMessage.Length != 0) hash ^= ErrorMessage.GetHashCode();
       if (BinaryErrorDetails.Length != 0) hash ^= BinaryErrorDetails.GetHashCode();
+      if (_unknownFields != null) {
+        hash ^= _unknownFields.GetHashCode();
+      }
       return hash;
     }
 
@@ -315,6 +334,9 @@ namespace Grpc.Testing {
         output.WriteRawTag(26);
         output.WriteString(BinaryErrorDetails);
       }
+      if (_unknownFields != null) {
+        _unknownFields.WriteTo(output);
+      }
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -329,6 +351,9 @@ namespace Grpc.Testing {
       if (BinaryErrorDetails.Length != 0) {
         size += 1 + pb::CodedOutputStream.ComputeStringSize(BinaryErrorDetails);
       }
+      if (_unknownFields != null) {
+        size += _unknownFields.CalculateSize();
+      }
       return size;
     }
 
@@ -346,6 +371,7 @@ namespace Grpc.Testing {
       if (other.BinaryErrorDetails.Length != 0) {
         BinaryErrorDetails = other.BinaryErrorDetails;
       }
+      _unknownFields = pb::UnknownFieldSet.MergeFrom(_unknownFields, other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -354,7 +380,7 @@ namespace Grpc.Testing {
       while ((tag = input.ReadTag()) != 0) {
         switch(tag) {
           default:
-            input.SkipLastField();
+            _unknownFields = pb::UnknownFieldSet.MergeFieldFrom(_unknownFields, input);
             break;
           case 8: {
             Code = input.ReadInt32();
@@ -376,6 +402,7 @@ namespace Grpc.Testing {
 
   public sealed partial class RequestParams : pb::IMessage<RequestParams> {
     private static readonly pb::MessageParser<RequestParams> _parser = new pb::MessageParser<RequestParams>(() => new RequestParams());
+    private pb::UnknownFieldSet _unknownFields;
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public static pb::MessageParser<RequestParams> Parser { get { return _parser; } }
 
@@ -413,6 +440,7 @@ namespace Grpc.Testing {
       binaryErrorDetails_ = other.binaryErrorDetails_;
       ExpectedError = other.expectedError_ != null ? other.ExpectedError.Clone() : null;
       serverSleepUs_ = other.serverSleepUs_;
+      _unknownFields = pb::UnknownFieldSet.Clone(other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -622,7 +650,7 @@ namespace Grpc.Testing {
       if (BinaryErrorDetails != other.BinaryErrorDetails) return false;
       if (!object.Equals(ExpectedError, other.ExpectedError)) return false;
       if (ServerSleepUs != other.ServerSleepUs) return false;
-      return true;
+      return Equals(_unknownFields, other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -643,6 +671,9 @@ namespace Grpc.Testing {
       if (BinaryErrorDetails.Length != 0) hash ^= BinaryErrorDetails.GetHashCode();
       if (expectedError_ != null) hash ^= ExpectedError.GetHashCode();
       if (ServerSleepUs != 0) hash ^= ServerSleepUs.GetHashCode();
+      if (_unknownFields != null) {
+        hash ^= _unknownFields.GetHashCode();
+      }
       return hash;
     }
 
@@ -713,6 +744,9 @@ namespace Grpc.Testing {
         output.WriteRawTag(120);
         output.WriteInt32(ServerSleepUs);
       }
+      if (_unknownFields != null) {
+        _unknownFields.WriteTo(output);
+      }
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -763,6 +797,9 @@ namespace Grpc.Testing {
       if (ServerSleepUs != 0) {
         size += 1 + pb::CodedOutputStream.ComputeInt32Size(ServerSleepUs);
       }
+      if (_unknownFields != null) {
+        size += _unknownFields.CalculateSize();
+      }
       return size;
     }
 
@@ -822,6 +859,7 @@ namespace Grpc.Testing {
       if (other.ServerSleepUs != 0) {
         ServerSleepUs = other.ServerSleepUs;
       }
+      _unknownFields = pb::UnknownFieldSet.MergeFrom(_unknownFields, other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -830,7 +868,7 @@ namespace Grpc.Testing {
       while ((tag = input.ReadTag()) != 0) {
         switch(tag) {
           default:
-            input.SkipLastField();
+            _unknownFields = pb::UnknownFieldSet.MergeFieldFrom(_unknownFields, input);
             break;
           case 8: {
             EchoDeadline = input.ReadBool();
@@ -906,6 +944,7 @@ namespace Grpc.Testing {
 
   public sealed partial class EchoRequest : pb::IMessage<EchoRequest> {
     private static readonly pb::MessageParser<EchoRequest> _parser = new pb::MessageParser<EchoRequest>(() => new EchoRequest());
+    private pb::UnknownFieldSet _unknownFields;
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public static pb::MessageParser<EchoRequest> Parser { get { return _parser; } }
 
@@ -930,6 +969,7 @@ namespace Grpc.Testing {
     public EchoRequest(EchoRequest other) : this() {
       message_ = other.message_;
       Param = other.param_ != null ? other.Param.Clone() : null;
+      _unknownFields = pb::UnknownFieldSet.Clone(other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -974,7 +1014,7 @@ namespace Grpc.Testing {
       }
       if (Message != other.Message) return false;
       if (!object.Equals(Param, other.Param)) return false;
-      return true;
+      return Equals(_unknownFields, other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -982,6 +1022,9 @@ namespace Grpc.Testing {
       int hash = 1;
       if (Message.Length != 0) hash ^= Message.GetHashCode();
       if (param_ != null) hash ^= Param.GetHashCode();
+      if (_unknownFields != null) {
+        hash ^= _unknownFields.GetHashCode();
+      }
       return hash;
     }
 
@@ -1000,6 +1043,9 @@ namespace Grpc.Testing {
         output.WriteRawTag(18);
         output.WriteMessage(Param);
       }
+      if (_unknownFields != null) {
+        _unknownFields.WriteTo(output);
+      }
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -1011,6 +1057,9 @@ namespace Grpc.Testing {
       if (param_ != null) {
         size += 1 + pb::CodedOutputStream.ComputeMessageSize(Param);
       }
+      if (_unknownFields != null) {
+        size += _unknownFields.CalculateSize();
+      }
       return size;
     }
 
@@ -1028,6 +1077,7 @@ namespace Grpc.Testing {
         }
         Param.MergeFrom(other.Param);
       }
+      _unknownFields = pb::UnknownFieldSet.MergeFrom(_unknownFields, other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -1036,7 +1086,7 @@ namespace Grpc.Testing {
       while ((tag = input.ReadTag()) != 0) {
         switch(tag) {
           default:
-            input.SkipLastField();
+            _unknownFields = pb::UnknownFieldSet.MergeFieldFrom(_unknownFields, input);
             break;
           case 10: {
             Message = input.ReadString();
@@ -1057,6 +1107,7 @@ namespace Grpc.Testing {
 
   public sealed partial class ResponseParams : pb::IMessage<ResponseParams> {
     private static readonly pb::MessageParser<ResponseParams> _parser = new pb::MessageParser<ResponseParams>(() => new ResponseParams());
+    private pb::UnknownFieldSet _unknownFields;
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public static pb::MessageParser<ResponseParams> Parser { get { return _parser; } }
 
@@ -1082,6 +1133,7 @@ namespace Grpc.Testing {
       requestDeadline_ = other.requestDeadline_;
       host_ = other.host_;
       peer_ = other.peer_;
+      _unknownFields = pb::UnknownFieldSet.Clone(other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -1138,7 +1190,7 @@ namespace Grpc.Testing {
       if (RequestDeadline != other.RequestDeadline) return false;
       if (Host != other.Host) return false;
       if (Peer != other.Peer) return false;
-      return true;
+      return Equals(_unknownFields, other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -1147,6 +1199,9 @@ namespace Grpc.Testing {
       if (RequestDeadline != 0L) hash ^= RequestDeadline.GetHashCode();
       if (Host.Length != 0) hash ^= Host.GetHashCode();
       if (Peer.Length != 0) hash ^= Peer.GetHashCode();
+      if (_unknownFields != null) {
+        hash ^= _unknownFields.GetHashCode();
+      }
       return hash;
     }
 
@@ -1169,6 +1224,9 @@ namespace Grpc.Testing {
         output.WriteRawTag(26);
         output.WriteString(Peer);
       }
+      if (_unknownFields != null) {
+        _unknownFields.WriteTo(output);
+      }
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -1183,6 +1241,9 @@ namespace Grpc.Testing {
       if (Peer.Length != 0) {
         size += 1 + pb::CodedOutputStream.ComputeStringSize(Peer);
       }
+      if (_unknownFields != null) {
+        size += _unknownFields.CalculateSize();
+      }
       return size;
     }
 
@@ -1200,6 +1261,7 @@ namespace Grpc.Testing {
       if (other.Peer.Length != 0) {
         Peer = other.Peer;
       }
+      _unknownFields = pb::UnknownFieldSet.MergeFrom(_unknownFields, other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -1208,7 +1270,7 @@ namespace Grpc.Testing {
       while ((tag = input.ReadTag()) != 0) {
         switch(tag) {
           default:
-            input.SkipLastField();
+            _unknownFields = pb::UnknownFieldSet.MergeFieldFrom(_unknownFields, input);
             break;
           case 8: {
             RequestDeadline = input.ReadInt64();
@@ -1230,6 +1292,7 @@ namespace Grpc.Testing {
 
   public sealed partial class EchoResponse : pb::IMessage<EchoResponse> {
     private static readonly pb::MessageParser<EchoResponse> _parser = new pb::MessageParser<EchoResponse>(() => new EchoResponse());
+    private pb::UnknownFieldSet _unknownFields;
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public static pb::MessageParser<EchoResponse> Parser { get { return _parser; } }
 
@@ -1254,6 +1317,7 @@ namespace Grpc.Testing {
     public EchoResponse(EchoResponse other) : this() {
       message_ = other.message_;
       Param = other.param_ != null ? other.Param.Clone() : null;
+      _unknownFields = pb::UnknownFieldSet.Clone(other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -1298,7 +1362,7 @@ namespace Grpc.Testing {
       }
       if (Message != other.Message) return false;
       if (!object.Equals(Param, other.Param)) return false;
-      return true;
+      return Equals(_unknownFields, other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -1306,6 +1370,9 @@ namespace Grpc.Testing {
       int hash = 1;
       if (Message.Length != 0) hash ^= Message.GetHashCode();
       if (param_ != null) hash ^= Param.GetHashCode();
+      if (_unknownFields != null) {
+        hash ^= _unknownFields.GetHashCode();
+      }
       return hash;
     }
 
@@ -1324,6 +1391,9 @@ namespace Grpc.Testing {
         output.WriteRawTag(18);
         output.WriteMessage(Param);
       }
+      if (_unknownFields != null) {
+        _unknownFields.WriteTo(output);
+      }
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -1335,6 +1405,9 @@ namespace Grpc.Testing {
       if (param_ != null) {
         size += 1 + pb::CodedOutputStream.ComputeMessageSize(Param);
       }
+      if (_unknownFields != null) {
+        size += _unknownFields.CalculateSize();
+      }
       return size;
     }
 
@@ -1352,6 +1425,7 @@ namespace Grpc.Testing {
         }
         Param.MergeFrom(other.Param);
       }
+      _unknownFields = pb::UnknownFieldSet.MergeFrom(_unknownFields, other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -1360,7 +1434,7 @@ namespace Grpc.Testing {
       while ((tag = input.ReadTag()) != 0) {
         switch(tag) {
           default:
-            input.SkipLastField();
+            _unknownFields = pb::UnknownFieldSet.MergeFieldFrom(_unknownFields, input);
             break;
           case 10: {
             Message = input.ReadString();
diff --git a/src/csharp/Grpc.IntegrationTesting/Empty.cs b/src/csharp/Grpc.IntegrationTesting/Empty.cs
index 24ffd61741..0d4c28bf7f 100644
--- a/src/csharp/Grpc.IntegrationTesting/Empty.cs
+++ b/src/csharp/Grpc.IntegrationTesting/Empty.cs
@@ -1,5 +1,7 @@
-// Generated by the protocol buffer compiler.  DO NOT EDIT!
-// source: src/proto/grpc/testing/empty.proto
+// <auto-generated>
+//     Generated by the protocol buffer compiler.  DO NOT EDIT!
+//     source: src/proto/grpc/testing/empty.proto
+// </auto-generated>
 #pragma warning disable 1591, 0612, 3021
 #region Designer generated code
 
@@ -45,6 +47,7 @@ namespace Grpc.Testing {
   /// </summary>
   public sealed partial class Empty : pb::IMessage<Empty> {
     private static readonly pb::MessageParser<Empty> _parser = new pb::MessageParser<Empty>(() => new Empty());
+    private pb::UnknownFieldSet _unknownFields;
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public static pb::MessageParser<Empty> Parser { get { return _parser; } }
 
@@ -67,6 +70,7 @@ namespace Grpc.Testing {
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public Empty(Empty other) : this() {
+      _unknownFields = pb::UnknownFieldSet.Clone(other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -87,12 +91,15 @@ namespace Grpc.Testing {
       if (ReferenceEquals(other, this)) {
         return true;
       }
-      return true;
+      return Equals(_unknownFields, other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public override int GetHashCode() {
       int hash = 1;
+      if (_unknownFields != null) {
+        hash ^= _unknownFields.GetHashCode();
+      }
       return hash;
     }
 
@@ -103,11 +110,17 @@ namespace Grpc.Testing {
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public void WriteTo(pb::CodedOutputStream output) {
+      if (_unknownFields != null) {
+        _unknownFields.WriteTo(output);
+      }
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public int CalculateSize() {
       int size = 0;
+      if (_unknownFields != null) {
+        size += _unknownFields.CalculateSize();
+      }
       return size;
     }
 
@@ -116,6 +129,7 @@ namespace Grpc.Testing {
       if (other == null) {
         return;
       }
+      _unknownFields = pb::UnknownFieldSet.MergeFrom(_unknownFields, other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -124,7 +138,7 @@ namespace Grpc.Testing {
       while ((tag = input.ReadTag()) != 0) {
         switch(tag) {
           default:
-            input.SkipLastField();
+            _unknownFields = pb::UnknownFieldSet.MergeFieldFrom(_unknownFields, input);
             break;
         }
       }
diff --git a/src/csharp/Grpc.IntegrationTesting/Messages.cs b/src/csharp/Grpc.IntegrationTesting/Messages.cs
index 278ef662e4..b5c93babd2 100644
--- a/src/csharp/Grpc.IntegrationTesting/Messages.cs
+++ b/src/csharp/Grpc.IntegrationTesting/Messages.cs
@@ -1,5 +1,7 @@
-// Generated by the protocol buffer compiler.  DO NOT EDIT!
-// source: src/proto/grpc/testing/messages.proto
+// <auto-generated>
+//     Generated by the protocol buffer compiler.  DO NOT EDIT!
+//     source: src/proto/grpc/testing/messages.proto
+// </auto-generated>
 #pragma warning disable 1591, 0612, 3021
 #region Designer generated code
 
@@ -95,6 +97,7 @@ namespace Grpc.Testing {
   /// </summary>
   public sealed partial class BoolValue : pb::IMessage<BoolValue> {
     private static readonly pb::MessageParser<BoolValue> _parser = new pb::MessageParser<BoolValue>(() => new BoolValue());
+    private pb::UnknownFieldSet _unknownFields;
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public static pb::MessageParser<BoolValue> Parser { get { return _parser; } }
 
@@ -118,6 +121,7 @@ namespace Grpc.Testing {
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public BoolValue(BoolValue other) : this() {
       value_ = other.value_;
+      _unknownFields = pb::UnknownFieldSet.Clone(other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -153,13 +157,16 @@ namespace Grpc.Testing {
         return true;
       }
       if (Value != other.Value) return false;
-      return true;
+      return Equals(_unknownFields, other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public override int GetHashCode() {
       int hash = 1;
       if (Value != false) hash ^= Value.GetHashCode();
+      if (_unknownFields != null) {
+        hash ^= _unknownFields.GetHashCode();
+      }
       return hash;
     }
 
@@ -174,6 +181,9 @@ namespace Grpc.Testing {
         output.WriteRawTag(8);
         output.WriteBool(Value);
       }
+      if (_unknownFields != null) {
+        _unknownFields.WriteTo(output);
+      }
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -182,6 +192,9 @@ namespace Grpc.Testing {
       if (Value != false) {
         size += 1 + 1;
       }
+      if (_unknownFields != null) {
+        size += _unknownFields.CalculateSize();
+      }
       return size;
     }
 
@@ -193,6 +206,7 @@ namespace Grpc.Testing {
       if (other.Value != false) {
         Value = other.Value;
       }
+      _unknownFields = pb::UnknownFieldSet.MergeFrom(_unknownFields, other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -201,7 +215,7 @@ namespace Grpc.Testing {
       while ((tag = input.ReadTag()) != 0) {
         switch(tag) {
           default:
-            input.SkipLastField();
+            _unknownFields = pb::UnknownFieldSet.MergeFieldFrom(_unknownFields, input);
             break;
           case 8: {
             Value = input.ReadBool();
@@ -218,6 +232,7 @@ namespace Grpc.Testing {
   /// </summary>
   public sealed partial class Payload : pb::IMessage<Payload> {
     private static readonly pb::MessageParser<Payload> _parser = new pb::MessageParser<Payload>(() => new Payload());
+    private pb::UnknownFieldSet _unknownFields;
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public static pb::MessageParser<Payload> Parser { get { return _parser; } }
 
@@ -242,6 +257,7 @@ namespace Grpc.Testing {
     public Payload(Payload other) : this() {
       type_ = other.type_;
       body_ = other.body_;
+      _unknownFields = pb::UnknownFieldSet.Clone(other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -293,7 +309,7 @@ namespace Grpc.Testing {
       }
       if (Type != other.Type) return false;
       if (Body != other.Body) return false;
-      return true;
+      return Equals(_unknownFields, other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -301,6 +317,9 @@ namespace Grpc.Testing {
       int hash = 1;
       if (Type != 0) hash ^= Type.GetHashCode();
       if (Body.Length != 0) hash ^= Body.GetHashCode();
+      if (_unknownFields != null) {
+        hash ^= _unknownFields.GetHashCode();
+      }
       return hash;
     }
 
@@ -319,6 +338,9 @@ namespace Grpc.Testing {
         output.WriteRawTag(18);
         output.WriteBytes(Body);
       }
+      if (_unknownFields != null) {
+        _unknownFields.WriteTo(output);
+      }
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -330,6 +352,9 @@ namespace Grpc.Testing {
       if (Body.Length != 0) {
         size += 1 + pb::CodedOutputStream.ComputeBytesSize(Body);
       }
+      if (_unknownFields != null) {
+        size += _unknownFields.CalculateSize();
+      }
       return size;
     }
 
@@ -344,6 +369,7 @@ namespace Grpc.Testing {
       if (other.Body.Length != 0) {
         Body = other.Body;
       }
+      _unknownFields = pb::UnknownFieldSet.MergeFrom(_unknownFields, other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -352,7 +378,7 @@ namespace Grpc.Testing {
       while ((tag = input.ReadTag()) != 0) {
         switch(tag) {
           default:
-            input.SkipLastField();
+            _unknownFields = pb::UnknownFieldSet.MergeFieldFrom(_unknownFields, input);
             break;
           case 8: {
             type_ = (global::Grpc.Testing.PayloadType) input.ReadEnum();
@@ -374,6 +400,7 @@ namespace Grpc.Testing {
   /// </summary>
   public sealed partial class EchoStatus : pb::IMessage<EchoStatus> {
     private static readonly pb::MessageParser<EchoStatus> _parser = new pb::MessageParser<EchoStatus>(() => new EchoStatus());
+    private pb::UnknownFieldSet _unknownFields;
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public static pb::MessageParser<EchoStatus> Parser { get { return _parser; } }
 
@@ -398,6 +425,7 @@ namespace Grpc.Testing {
     public EchoStatus(EchoStatus other) : this() {
       code_ = other.code_;
       message_ = other.message_;
+      _unknownFields = pb::UnknownFieldSet.Clone(other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -442,7 +470,7 @@ namespace Grpc.Testing {
       }
       if (Code != other.Code) return false;
       if (Message != other.Message) return false;
-      return true;
+      return Equals(_unknownFields, other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -450,6 +478,9 @@ namespace Grpc.Testing {
       int hash = 1;
       if (Code != 0) hash ^= Code.GetHashCode();
       if (Message.Length != 0) hash ^= Message.GetHashCode();
+      if (_unknownFields != null) {
+        hash ^= _unknownFields.GetHashCode();
+      }
       return hash;
     }
 
@@ -468,6 +499,9 @@ namespace Grpc.Testing {
         output.WriteRawTag(18);
         output.WriteString(Message);
       }
+      if (_unknownFields != null) {
+        _unknownFields.WriteTo(output);
+      }
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -479,6 +513,9 @@ namespace Grpc.Testing {
       if (Message.Length != 0) {
         size += 1 + pb::CodedOutputStream.ComputeStringSize(Message);
       }
+      if (_unknownFields != null) {
+        size += _unknownFields.CalculateSize();
+      }
       return size;
     }
 
@@ -493,6 +530,7 @@ namespace Grpc.Testing {
       if (other.Message.Length != 0) {
         Message = other.Message;
       }
+      _unknownFields = pb::UnknownFieldSet.MergeFrom(_unknownFields, other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -501,7 +539,7 @@ namespace Grpc.Testing {
       while ((tag = input.ReadTag()) != 0) {
         switch(tag) {
           default:
-            input.SkipLastField();
+            _unknownFields = pb::UnknownFieldSet.MergeFieldFrom(_unknownFields, input);
             break;
           case 8: {
             Code = input.ReadInt32();
@@ -522,6 +560,7 @@ namespace Grpc.Testing {
   /// </summary>
   public sealed partial class SimpleRequest : pb::IMessage<SimpleRequest> {
     private static readonly pb::MessageParser<SimpleRequest> _parser = new pb::MessageParser<SimpleRequest>(() => new SimpleRequest());
+    private pb::UnknownFieldSet _unknownFields;
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public static pb::MessageParser<SimpleRequest> Parser { get { return _parser; } }
 
@@ -552,6 +591,7 @@ namespace Grpc.Testing {
       ResponseCompressed = other.responseCompressed_ != null ? other.ResponseCompressed.Clone() : null;
       ResponseStatus = other.responseStatus_ != null ? other.ResponseStatus.Clone() : null;
       ExpectCompressed = other.expectCompressed_ != null ? other.ExpectCompressed.Clone() : null;
+      _unknownFields = pb::UnknownFieldSet.Clone(other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -697,7 +737,7 @@ namespace Grpc.Testing {
       if (!object.Equals(ResponseCompressed, other.ResponseCompressed)) return false;
       if (!object.Equals(ResponseStatus, other.ResponseStatus)) return false;
       if (!object.Equals(ExpectCompressed, other.ExpectCompressed)) return false;
-      return true;
+      return Equals(_unknownFields, other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -711,6 +751,9 @@ namespace Grpc.Testing {
       if (responseCompressed_ != null) hash ^= ResponseCompressed.GetHashCode();
       if (responseStatus_ != null) hash ^= ResponseStatus.GetHashCode();
       if (expectCompressed_ != null) hash ^= ExpectCompressed.GetHashCode();
+      if (_unknownFields != null) {
+        hash ^= _unknownFields.GetHashCode();
+      }
       return hash;
     }
 
@@ -753,6 +796,9 @@ namespace Grpc.Testing {
         output.WriteRawTag(66);
         output.WriteMessage(ExpectCompressed);
       }
+      if (_unknownFields != null) {
+        _unknownFields.WriteTo(output);
+      }
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -782,6 +828,9 @@ namespace Grpc.Testing {
       if (expectCompressed_ != null) {
         size += 1 + pb::CodedOutputStream.ComputeMessageSize(ExpectCompressed);
       }
+      if (_unknownFields != null) {
+        size += _unknownFields.CalculateSize();
+      }
       return size;
     }
 
@@ -826,6 +875,7 @@ namespace Grpc.Testing {
         }
         ExpectCompressed.MergeFrom(other.ExpectCompressed);
       }
+      _unknownFields = pb::UnknownFieldSet.MergeFrom(_unknownFields, other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -834,7 +884,7 @@ namespace Grpc.Testing {
       while ((tag = input.ReadTag()) != 0) {
         switch(tag) {
           default:
-            input.SkipLastField();
+            _unknownFields = pb::UnknownFieldSet.MergeFieldFrom(_unknownFields, input);
             break;
           case 8: {
             responseType_ = (global::Grpc.Testing.PayloadType) input.ReadEnum();
@@ -891,6 +941,7 @@ namespace Grpc.Testing {
   /// </summary>
   public sealed partial class SimpleResponse : pb::IMessage<SimpleResponse> {
     private static readonly pb::MessageParser<SimpleResponse> _parser = new pb::MessageParser<SimpleResponse>(() => new SimpleResponse());
+    private pb::UnknownFieldSet _unknownFields;
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public static pb::MessageParser<SimpleResponse> Parser { get { return _parser; } }
 
@@ -916,6 +967,7 @@ namespace Grpc.Testing {
       Payload = other.payload_ != null ? other.Payload.Clone() : null;
       username_ = other.username_;
       oauthScope_ = other.oauthScope_;
+      _unknownFields = pb::UnknownFieldSet.Clone(other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -982,7 +1034,7 @@ namespace Grpc.Testing {
       if (!object.Equals(Payload, other.Payload)) return false;
       if (Username != other.Username) return false;
       if (OauthScope != other.OauthScope) return false;
-      return true;
+      return Equals(_unknownFields, other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -991,6 +1043,9 @@ namespace Grpc.Testing {
       if (payload_ != null) hash ^= Payload.GetHashCode();
       if (Username.Length != 0) hash ^= Username.GetHashCode();
       if (OauthScope.Length != 0) hash ^= OauthScope.GetHashCode();
+      if (_unknownFields != null) {
+        hash ^= _unknownFields.GetHashCode();
+      }
       return hash;
     }
 
@@ -1013,6 +1068,9 @@ namespace Grpc.Testing {
         output.WriteRawTag(26);
         output.WriteString(OauthScope);
       }
+      if (_unknownFields != null) {
+        _unknownFields.WriteTo(output);
+      }
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -1027,6 +1085,9 @@ namespace Grpc.Testing {
       if (OauthScope.Length != 0) {
         size += 1 + pb::CodedOutputStream.ComputeStringSize(OauthScope);
       }
+      if (_unknownFields != null) {
+        size += _unknownFields.CalculateSize();
+      }
       return size;
     }
 
@@ -1047,6 +1108,7 @@ namespace Grpc.Testing {
       if (other.OauthScope.Length != 0) {
         OauthScope = other.OauthScope;
       }
+      _unknownFields = pb::UnknownFieldSet.MergeFrom(_unknownFields, other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -1055,7 +1117,7 @@ namespace Grpc.Testing {
       while ((tag = input.ReadTag()) != 0) {
         switch(tag) {
           default:
-            input.SkipLastField();
+            _unknownFields = pb::UnknownFieldSet.MergeFieldFrom(_unknownFields, input);
             break;
           case 10: {
             if (payload_ == null) {
@@ -1083,6 +1145,7 @@ namespace Grpc.Testing {
   /// </summary>
   public sealed partial class StreamingInputCallRequest : pb::IMessage<StreamingInputCallRequest> {
     private static readonly pb::MessageParser<StreamingInputCallRequest> _parser = new pb::MessageParser<StreamingInputCallRequest>(() => new StreamingInputCallRequest());
+    private pb::UnknownFieldSet _unknownFields;
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public static pb::MessageParser<StreamingInputCallRequest> Parser { get { return _parser; } }
 
@@ -1107,6 +1170,7 @@ namespace Grpc.Testing {
     public StreamingInputCallRequest(StreamingInputCallRequest other) : this() {
       Payload = other.payload_ != null ? other.Payload.Clone() : null;
       ExpectCompressed = other.expectCompressed_ != null ? other.ExpectCompressed.Clone() : null;
+      _unknownFields = pb::UnknownFieldSet.Clone(other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -1160,7 +1224,7 @@ namespace Grpc.Testing {
       }
       if (!object.Equals(Payload, other.Payload)) return false;
       if (!object.Equals(ExpectCompressed, other.ExpectCompressed)) return false;
-      return true;
+      return Equals(_unknownFields, other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -1168,6 +1232,9 @@ namespace Grpc.Testing {
       int hash = 1;
       if (payload_ != null) hash ^= Payload.GetHashCode();
       if (expectCompressed_ != null) hash ^= ExpectCompressed.GetHashCode();
+      if (_unknownFields != null) {
+        hash ^= _unknownFields.GetHashCode();
+      }
       return hash;
     }
 
@@ -1186,6 +1253,9 @@ namespace Grpc.Testing {
         output.WriteRawTag(18);
         output.WriteMessage(ExpectCompressed);
       }
+      if (_unknownFields != null) {
+        _unknownFields.WriteTo(output);
+      }
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -1197,6 +1267,9 @@ namespace Grpc.Testing {
       if (expectCompressed_ != null) {
         size += 1 + pb::CodedOutputStream.ComputeMessageSize(ExpectCompressed);
       }
+      if (_unknownFields != null) {
+        size += _unknownFields.CalculateSize();
+      }
       return size;
     }
 
@@ -1217,6 +1290,7 @@ namespace Grpc.Testing {
         }
         ExpectCompressed.MergeFrom(other.ExpectCompressed);
       }
+      _unknownFields = pb::UnknownFieldSet.MergeFrom(_unknownFields, other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -1225,7 +1299,7 @@ namespace Grpc.Testing {
       while ((tag = input.ReadTag()) != 0) {
         switch(tag) {
           default:
-            input.SkipLastField();
+            _unknownFields = pb::UnknownFieldSet.MergeFieldFrom(_unknownFields, input);
             break;
           case 10: {
             if (payload_ == null) {
@@ -1252,6 +1326,7 @@ namespace Grpc.Testing {
   /// </summary>
   public sealed partial class StreamingInputCallResponse : pb::IMessage<StreamingInputCallResponse> {
     private static readonly pb::MessageParser<StreamingInputCallResponse> _parser = new pb::MessageParser<StreamingInputCallResponse>(() => new StreamingInputCallResponse());
+    private pb::UnknownFieldSet _unknownFields;
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public static pb::MessageParser<StreamingInputCallResponse> Parser { get { return _parser; } }
 
@@ -1275,6 +1350,7 @@ namespace Grpc.Testing {
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public StreamingInputCallResponse(StreamingInputCallResponse other) : this() {
       aggregatedPayloadSize_ = other.aggregatedPayloadSize_;
+      _unknownFields = pb::UnknownFieldSet.Clone(other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -1310,13 +1386,16 @@ namespace Grpc.Testing {
         return true;
       }
       if (AggregatedPayloadSize != other.AggregatedPayloadSize) return false;
-      return true;
+      return Equals(_unknownFields, other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public override int GetHashCode() {
       int hash = 1;
       if (AggregatedPayloadSize != 0) hash ^= AggregatedPayloadSize.GetHashCode();
+      if (_unknownFields != null) {
+        hash ^= _unknownFields.GetHashCode();
+      }
       return hash;
     }
 
@@ -1331,6 +1410,9 @@ namespace Grpc.Testing {
         output.WriteRawTag(8);
         output.WriteInt32(AggregatedPayloadSize);
       }
+      if (_unknownFields != null) {
+        _unknownFields.WriteTo(output);
+      }
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -1339,6 +1421,9 @@ namespace Grpc.Testing {
       if (AggregatedPayloadSize != 0) {
         size += 1 + pb::CodedOutputStream.ComputeInt32Size(AggregatedPayloadSize);
       }
+      if (_unknownFields != null) {
+        size += _unknownFields.CalculateSize();
+      }
       return size;
     }
 
@@ -1350,6 +1435,7 @@ namespace Grpc.Testing {
       if (other.AggregatedPayloadSize != 0) {
         AggregatedPayloadSize = other.AggregatedPayloadSize;
       }
+      _unknownFields = pb::UnknownFieldSet.MergeFrom(_unknownFields, other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -1358,7 +1444,7 @@ namespace Grpc.Testing {
       while ((tag = input.ReadTag()) != 0) {
         switch(tag) {
           default:
-            input.SkipLastField();
+            _unknownFields = pb::UnknownFieldSet.MergeFieldFrom(_unknownFields, input);
             break;
           case 8: {
             AggregatedPayloadSize = input.ReadInt32();
@@ -1375,6 +1461,7 @@ namespace Grpc.Testing {
   /// </summary>
   public sealed partial class ResponseParameters : pb::IMessage<ResponseParameters> {
     private static readonly pb::MessageParser<ResponseParameters> _parser = new pb::MessageParser<ResponseParameters>(() => new ResponseParameters());
+    private pb::UnknownFieldSet _unknownFields;
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public static pb::MessageParser<ResponseParameters> Parser { get { return _parser; } }
 
@@ -1400,6 +1487,7 @@ namespace Grpc.Testing {
       size_ = other.size_;
       intervalUs_ = other.intervalUs_;
       Compressed = other.compressed_ != null ? other.Compressed.Clone() : null;
+      _unknownFields = pb::UnknownFieldSet.Clone(other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -1469,7 +1557,7 @@ namespace Grpc.Testing {
       if (Size != other.Size) return false;
       if (IntervalUs != other.IntervalUs) return false;
       if (!object.Equals(Compressed, other.Compressed)) return false;
-      return true;
+      return Equals(_unknownFields, other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -1478,6 +1566,9 @@ namespace Grpc.Testing {
       if (Size != 0) hash ^= Size.GetHashCode();
       if (IntervalUs != 0) hash ^= IntervalUs.GetHashCode();
       if (compressed_ != null) hash ^= Compressed.GetHashCode();
+      if (_unknownFields != null) {
+        hash ^= _unknownFields.GetHashCode();
+      }
       return hash;
     }
 
@@ -1500,6 +1591,9 @@ namespace Grpc.Testing {
         output.WriteRawTag(26);
         output.WriteMessage(Compressed);
       }
+      if (_unknownFields != null) {
+        _unknownFields.WriteTo(output);
+      }
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -1514,6 +1608,9 @@ namespace Grpc.Testing {
       if (compressed_ != null) {
         size += 1 + pb::CodedOutputStream.ComputeMessageSize(Compressed);
       }
+      if (_unknownFields != null) {
+        size += _unknownFields.CalculateSize();
+      }
       return size;
     }
 
@@ -1534,6 +1631,7 @@ namespace Grpc.Testing {
         }
         Compressed.MergeFrom(other.Compressed);
       }
+      _unknownFields = pb::UnknownFieldSet.MergeFrom(_unknownFields, other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -1542,7 +1640,7 @@ namespace Grpc.Testing {
       while ((tag = input.ReadTag()) != 0) {
         switch(tag) {
           default:
-            input.SkipLastField();
+            _unknownFields = pb::UnknownFieldSet.MergeFieldFrom(_unknownFields, input);
             break;
           case 8: {
             Size = input.ReadInt32();
@@ -1570,6 +1668,7 @@ namespace Grpc.Testing {
   /// </summary>
   public sealed partial class StreamingOutputCallRequest : pb::IMessage<StreamingOutputCallRequest> {
     private static readonly pb::MessageParser<StreamingOutputCallRequest> _parser = new pb::MessageParser<StreamingOutputCallRequest>(() => new StreamingOutputCallRequest());
+    private pb::UnknownFieldSet _unknownFields;
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public static pb::MessageParser<StreamingOutputCallRequest> Parser { get { return _parser; } }
 
@@ -1596,6 +1695,7 @@ namespace Grpc.Testing {
       responseParameters_ = other.responseParameters_.Clone();
       Payload = other.payload_ != null ? other.Payload.Clone() : null;
       ResponseStatus = other.responseStatus_ != null ? other.ResponseStatus.Clone() : null;
+      _unknownFields = pb::UnknownFieldSet.Clone(other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -1679,7 +1779,7 @@ namespace Grpc.Testing {
       if(!responseParameters_.Equals(other.responseParameters_)) return false;
       if (!object.Equals(Payload, other.Payload)) return false;
       if (!object.Equals(ResponseStatus, other.ResponseStatus)) return false;
-      return true;
+      return Equals(_unknownFields, other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -1689,6 +1789,9 @@ namespace Grpc.Testing {
       hash ^= responseParameters_.GetHashCode();
       if (payload_ != null) hash ^= Payload.GetHashCode();
       if (responseStatus_ != null) hash ^= ResponseStatus.GetHashCode();
+      if (_unknownFields != null) {
+        hash ^= _unknownFields.GetHashCode();
+      }
       return hash;
     }
 
@@ -1712,6 +1815,9 @@ namespace Grpc.Testing {
         output.WriteRawTag(58);
         output.WriteMessage(ResponseStatus);
       }
+      if (_unknownFields != null) {
+        _unknownFields.WriteTo(output);
+      }
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -1727,6 +1833,9 @@ namespace Grpc.Testing {
       if (responseStatus_ != null) {
         size += 1 + pb::CodedOutputStream.ComputeMessageSize(ResponseStatus);
       }
+      if (_unknownFields != null) {
+        size += _unknownFields.CalculateSize();
+      }
       return size;
     }
 
@@ -1751,6 +1860,7 @@ namespace Grpc.Testing {
         }
         ResponseStatus.MergeFrom(other.ResponseStatus);
       }
+      _unknownFields = pb::UnknownFieldSet.MergeFrom(_unknownFields, other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -1759,7 +1869,7 @@ namespace Grpc.Testing {
       while ((tag = input.ReadTag()) != 0) {
         switch(tag) {
           default:
-            input.SkipLastField();
+            _unknownFields = pb::UnknownFieldSet.MergeFieldFrom(_unknownFields, input);
             break;
           case 8: {
             responseType_ = (global::Grpc.Testing.PayloadType) input.ReadEnum();
@@ -1794,6 +1904,7 @@ namespace Grpc.Testing {
   /// </summary>
   public sealed partial class StreamingOutputCallResponse : pb::IMessage<StreamingOutputCallResponse> {
     private static readonly pb::MessageParser<StreamingOutputCallResponse> _parser = new pb::MessageParser<StreamingOutputCallResponse>(() => new StreamingOutputCallResponse());
+    private pb::UnknownFieldSet _unknownFields;
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public static pb::MessageParser<StreamingOutputCallResponse> Parser { get { return _parser; } }
 
@@ -1817,6 +1928,7 @@ namespace Grpc.Testing {
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public StreamingOutputCallResponse(StreamingOutputCallResponse other) : this() {
       Payload = other.payload_ != null ? other.Payload.Clone() : null;
+      _unknownFields = pb::UnknownFieldSet.Clone(other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -1852,13 +1964,16 @@ namespace Grpc.Testing {
         return true;
       }
       if (!object.Equals(Payload, other.Payload)) return false;
-      return true;
+      return Equals(_unknownFields, other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public override int GetHashCode() {
       int hash = 1;
       if (payload_ != null) hash ^= Payload.GetHashCode();
+      if (_unknownFields != null) {
+        hash ^= _unknownFields.GetHashCode();
+      }
       return hash;
     }
 
@@ -1873,6 +1988,9 @@ namespace Grpc.Testing {
         output.WriteRawTag(10);
         output.WriteMessage(Payload);
       }
+      if (_unknownFields != null) {
+        _unknownFields.WriteTo(output);
+      }
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -1881,6 +1999,9 @@ namespace Grpc.Testing {
       if (payload_ != null) {
         size += 1 + pb::CodedOutputStream.ComputeMessageSize(Payload);
       }
+      if (_unknownFields != null) {
+        size += _unknownFields.CalculateSize();
+      }
       return size;
     }
 
@@ -1895,6 +2016,7 @@ namespace Grpc.Testing {
         }
         Payload.MergeFrom(other.Payload);
       }
+      _unknownFields = pb::UnknownFieldSet.MergeFrom(_unknownFields, other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -1903,7 +2025,7 @@ namespace Grpc.Testing {
       while ((tag = input.ReadTag()) != 0) {
         switch(tag) {
           default:
-            input.SkipLastField();
+            _unknownFields = pb::UnknownFieldSet.MergeFieldFrom(_unknownFields, input);
             break;
           case 10: {
             if (payload_ == null) {
@@ -1924,6 +2046,7 @@ namespace Grpc.Testing {
   /// </summary>
   public sealed partial class ReconnectParams : pb::IMessage<ReconnectParams> {
     private static readonly pb::MessageParser<ReconnectParams> _parser = new pb::MessageParser<ReconnectParams>(() => new ReconnectParams());
+    private pb::UnknownFieldSet _unknownFields;
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public static pb::MessageParser<ReconnectParams> Parser { get { return _parser; } }
 
@@ -1947,6 +2070,7 @@ namespace Grpc.Testing {
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public ReconnectParams(ReconnectParams other) : this() {
       maxReconnectBackoffMs_ = other.maxReconnectBackoffMs_;
+      _unknownFields = pb::UnknownFieldSet.Clone(other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -1979,13 +2103,16 @@ namespace Grpc.Testing {
         return true;
       }
       if (MaxReconnectBackoffMs != other.MaxReconnectBackoffMs) return false;
-      return true;
+      return Equals(_unknownFields, other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public override int GetHashCode() {
       int hash = 1;
       if (MaxReconnectBackoffMs != 0) hash ^= MaxReconnectBackoffMs.GetHashCode();
+      if (_unknownFields != null) {
+        hash ^= _unknownFields.GetHashCode();
+      }
       return hash;
     }
 
@@ -2000,6 +2127,9 @@ namespace Grpc.Testing {
         output.WriteRawTag(8);
         output.WriteInt32(MaxReconnectBackoffMs);
       }
+      if (_unknownFields != null) {
+        _unknownFields.WriteTo(output);
+      }
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -2008,6 +2138,9 @@ namespace Grpc.Testing {
       if (MaxReconnectBackoffMs != 0) {
         size += 1 + pb::CodedOutputStream.ComputeInt32Size(MaxReconnectBackoffMs);
       }
+      if (_unknownFields != null) {
+        size += _unknownFields.CalculateSize();
+      }
       return size;
     }
 
@@ -2019,6 +2152,7 @@ namespace Grpc.Testing {
       if (other.MaxReconnectBackoffMs != 0) {
         MaxReconnectBackoffMs = other.MaxReconnectBackoffMs;
       }
+      _unknownFields = pb::UnknownFieldSet.MergeFrom(_unknownFields, other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -2027,7 +2161,7 @@ namespace Grpc.Testing {
       while ((tag = input.ReadTag()) != 0) {
         switch(tag) {
           default:
-            input.SkipLastField();
+            _unknownFields = pb::UnknownFieldSet.MergeFieldFrom(_unknownFields, input);
             break;
           case 8: {
             MaxReconnectBackoffMs = input.ReadInt32();
@@ -2046,6 +2180,7 @@ namespace Grpc.Testing {
   /// </summary>
   public sealed partial class ReconnectInfo : pb::IMessage<ReconnectInfo> {
     private static readonly pb::MessageParser<ReconnectInfo> _parser = new pb::MessageParser<ReconnectInfo>(() => new ReconnectInfo());
+    private pb::UnknownFieldSet _unknownFields;
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public static pb::MessageParser<ReconnectInfo> Parser { get { return _parser; } }
 
@@ -2070,6 +2205,7 @@ namespace Grpc.Testing {
     public ReconnectInfo(ReconnectInfo other) : this() {
       passed_ = other.passed_;
       backoffMs_ = other.backoffMs_.Clone();
+      _unknownFields = pb::UnknownFieldSet.Clone(other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -2113,7 +2249,7 @@ namespace Grpc.Testing {
       }
       if (Passed != other.Passed) return false;
       if(!backoffMs_.Equals(other.backoffMs_)) return false;
-      return true;
+      return Equals(_unknownFields, other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -2121,6 +2257,9 @@ namespace Grpc.Testing {
       int hash = 1;
       if (Passed != false) hash ^= Passed.GetHashCode();
       hash ^= backoffMs_.GetHashCode();
+      if (_unknownFields != null) {
+        hash ^= _unknownFields.GetHashCode();
+      }
       return hash;
     }
 
@@ -2136,6 +2275,9 @@ namespace Grpc.Testing {
         output.WriteBool(Passed);
       }
       backoffMs_.WriteTo(output, _repeated_backoffMs_codec);
+      if (_unknownFields != null) {
+        _unknownFields.WriteTo(output);
+      }
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -2145,6 +2287,9 @@ namespace Grpc.Testing {
         size += 1 + 1;
       }
       size += backoffMs_.CalculateSize(_repeated_backoffMs_codec);
+      if (_unknownFields != null) {
+        size += _unknownFields.CalculateSize();
+      }
       return size;
     }
 
@@ -2157,6 +2302,7 @@ namespace Grpc.Testing {
         Passed = other.Passed;
       }
       backoffMs_.Add(other.backoffMs_);
+      _unknownFields = pb::UnknownFieldSet.MergeFrom(_unknownFields, other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -2165,7 +2311,7 @@ namespace Grpc.Testing {
       while ((tag = input.ReadTag()) != 0) {
         switch(tag) {
           default:
-            input.SkipLastField();
+            _unknownFields = pb::UnknownFieldSet.MergeFieldFrom(_unknownFields, input);
             break;
           case 8: {
             Passed = input.ReadBool();
diff --git a/src/csharp/Grpc.IntegrationTesting/Metrics.cs b/src/csharp/Grpc.IntegrationTesting/Metrics.cs
index 84eb09af4f..b5d8b87a68 100644
--- a/src/csharp/Grpc.IntegrationTesting/Metrics.cs
+++ b/src/csharp/Grpc.IntegrationTesting/Metrics.cs
@@ -1,5 +1,7 @@
-// Generated by the protocol buffer compiler.  DO NOT EDIT!
-// source: src/proto/grpc/testing/metrics.proto
+// <auto-generated>
+//     Generated by the protocol buffer compiler.  DO NOT EDIT!
+//     source: src/proto/grpc/testing/metrics.proto
+// </auto-generated>
 #pragma warning disable 1591, 0612, 3021
 #region Designer generated code
 
@@ -48,6 +50,7 @@ namespace Grpc.Testing {
   /// </summary>
   public sealed partial class GaugeResponse : pb::IMessage<GaugeResponse> {
     private static readonly pb::MessageParser<GaugeResponse> _parser = new pb::MessageParser<GaugeResponse>(() => new GaugeResponse());
+    private pb::UnknownFieldSet _unknownFields;
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public static pb::MessageParser<GaugeResponse> Parser { get { return _parser; } }
 
@@ -83,6 +86,7 @@ namespace Grpc.Testing {
           break;
       }
 
+      _unknownFields = pb::UnknownFieldSet.Clone(other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -169,10 +173,10 @@ namespace Grpc.Testing {
       }
       if (Name != other.Name) return false;
       if (LongValue != other.LongValue) return false;
-      if (DoubleValue != other.DoubleValue) return false;
+      if (!pbc::ProtobufEqualityComparers.BitwiseDoubleEqualityComparer.Equals(DoubleValue, other.DoubleValue)) return false;
       if (StringValue != other.StringValue) return false;
       if (ValueCase != other.ValueCase) return false;
-      return true;
+      return Equals(_unknownFields, other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -180,9 +184,12 @@ namespace Grpc.Testing {
       int hash = 1;
       if (Name.Length != 0) hash ^= Name.GetHashCode();
       if (valueCase_ == ValueOneofCase.LongValue) hash ^= LongValue.GetHashCode();
-      if (valueCase_ == ValueOneofCase.DoubleValue) hash ^= DoubleValue.GetHashCode();
+      if (valueCase_ == ValueOneofCase.DoubleValue) hash ^= pbc::ProtobufEqualityComparers.BitwiseDoubleEqualityComparer.GetHashCode(DoubleValue);
       if (valueCase_ == ValueOneofCase.StringValue) hash ^= StringValue.GetHashCode();
       hash ^= (int) valueCase_;
+      if (_unknownFields != null) {
+        hash ^= _unknownFields.GetHashCode();
+      }
       return hash;
     }
 
@@ -209,6 +216,9 @@ namespace Grpc.Testing {
         output.WriteRawTag(34);
         output.WriteString(StringValue);
       }
+      if (_unknownFields != null) {
+        _unknownFields.WriteTo(output);
+      }
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -226,6 +236,9 @@ namespace Grpc.Testing {
       if (valueCase_ == ValueOneofCase.StringValue) {
         size += 1 + pb::CodedOutputStream.ComputeStringSize(StringValue);
       }
+      if (_unknownFields != null) {
+        size += _unknownFields.CalculateSize();
+      }
       return size;
     }
 
@@ -249,6 +262,7 @@ namespace Grpc.Testing {
           break;
       }
 
+      _unknownFields = pb::UnknownFieldSet.MergeFrom(_unknownFields, other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -257,7 +271,7 @@ namespace Grpc.Testing {
       while ((tag = input.ReadTag()) != 0) {
         switch(tag) {
           default:
-            input.SkipLastField();
+            _unknownFields = pb::UnknownFieldSet.MergeFieldFrom(_unknownFields, input);
             break;
           case 10: {
             Name = input.ReadString();
@@ -286,6 +300,7 @@ namespace Grpc.Testing {
   /// </summary>
   public sealed partial class GaugeRequest : pb::IMessage<GaugeRequest> {
     private static readonly pb::MessageParser<GaugeRequest> _parser = new pb::MessageParser<GaugeRequest>(() => new GaugeRequest());
+    private pb::UnknownFieldSet _unknownFields;
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public static pb::MessageParser<GaugeRequest> Parser { get { return _parser; } }
 
@@ -309,6 +324,7 @@ namespace Grpc.Testing {
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public GaugeRequest(GaugeRequest other) : this() {
       name_ = other.name_;
+      _unknownFields = pb::UnknownFieldSet.Clone(other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -341,13 +357,16 @@ namespace Grpc.Testing {
         return true;
       }
       if (Name != other.Name) return false;
-      return true;
+      return Equals(_unknownFields, other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public override int GetHashCode() {
       int hash = 1;
       if (Name.Length != 0) hash ^= Name.GetHashCode();
+      if (_unknownFields != null) {
+        hash ^= _unknownFields.GetHashCode();
+      }
       return hash;
     }
 
@@ -362,6 +381,9 @@ namespace Grpc.Testing {
         output.WriteRawTag(10);
         output.WriteString(Name);
       }
+      if (_unknownFields != null) {
+        _unknownFields.WriteTo(output);
+      }
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -370,6 +392,9 @@ namespace Grpc.Testing {
       if (Name.Length != 0) {
         size += 1 + pb::CodedOutputStream.ComputeStringSize(Name);
       }
+      if (_unknownFields != null) {
+        size += _unknownFields.CalculateSize();
+      }
       return size;
     }
 
@@ -381,6 +406,7 @@ namespace Grpc.Testing {
       if (other.Name.Length != 0) {
         Name = other.Name;
       }
+      _unknownFields = pb::UnknownFieldSet.MergeFrom(_unknownFields, other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -389,7 +415,7 @@ namespace Grpc.Testing {
       while ((tag = input.ReadTag()) != 0) {
         switch(tag) {
           default:
-            input.SkipLastField();
+            _unknownFields = pb::UnknownFieldSet.MergeFieldFrom(_unknownFields, input);
             break;
           case 10: {
             Name = input.ReadString();
@@ -403,6 +429,7 @@ namespace Grpc.Testing {
 
   public sealed partial class EmptyMessage : pb::IMessage<EmptyMessage> {
     private static readonly pb::MessageParser<EmptyMessage> _parser = new pb::MessageParser<EmptyMessage>(() => new EmptyMessage());
+    private pb::UnknownFieldSet _unknownFields;
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public static pb::MessageParser<EmptyMessage> Parser { get { return _parser; } }
 
@@ -425,6 +452,7 @@ namespace Grpc.Testing {
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public EmptyMessage(EmptyMessage other) : this() {
+      _unknownFields = pb::UnknownFieldSet.Clone(other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -445,12 +473,15 @@ namespace Grpc.Testing {
       if (ReferenceEquals(other, this)) {
         return true;
       }
-      return true;
+      return Equals(_unknownFields, other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public override int GetHashCode() {
       int hash = 1;
+      if (_unknownFields != null) {
+        hash ^= _unknownFields.GetHashCode();
+      }
       return hash;
     }
 
@@ -461,11 +492,17 @@ namespace Grpc.Testing {
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public void WriteTo(pb::CodedOutputStream output) {
+      if (_unknownFields != null) {
+        _unknownFields.WriteTo(output);
+      }
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public int CalculateSize() {
       int size = 0;
+      if (_unknownFields != null) {
+        size += _unknownFields.CalculateSize();
+      }
       return size;
     }
 
@@ -474,6 +511,7 @@ namespace Grpc.Testing {
       if (other == null) {
         return;
       }
+      _unknownFields = pb::UnknownFieldSet.MergeFrom(_unknownFields, other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -482,7 +520,7 @@ namespace Grpc.Testing {
       while ((tag = input.ReadTag()) != 0) {
         switch(tag) {
           default:
-            input.SkipLastField();
+            _unknownFields = pb::UnknownFieldSet.MergeFieldFrom(_unknownFields, input);
             break;
         }
       }
diff --git a/src/csharp/Grpc.IntegrationTesting/Payloads.cs b/src/csharp/Grpc.IntegrationTesting/Payloads.cs
index fca8cda6f6..25f34ff05e 100644
--- a/src/csharp/Grpc.IntegrationTesting/Payloads.cs
+++ b/src/csharp/Grpc.IntegrationTesting/Payloads.cs
@@ -1,5 +1,7 @@
-// Generated by the protocol buffer compiler.  DO NOT EDIT!
-// source: src/proto/grpc/testing/payloads.proto
+// <auto-generated>
+//     Generated by the protocol buffer compiler.  DO NOT EDIT!
+//     source: src/proto/grpc/testing/payloads.proto
+// </auto-generated>
 #pragma warning disable 1591, 0612, 3021
 #region Designer generated code
 
@@ -46,6 +48,7 @@ namespace Grpc.Testing {
   #region Messages
   public sealed partial class ByteBufferParams : pb::IMessage<ByteBufferParams> {
     private static readonly pb::MessageParser<ByteBufferParams> _parser = new pb::MessageParser<ByteBufferParams>(() => new ByteBufferParams());
+    private pb::UnknownFieldSet _unknownFields;
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public static pb::MessageParser<ByteBufferParams> Parser { get { return _parser; } }
 
@@ -70,6 +73,7 @@ namespace Grpc.Testing {
     public ByteBufferParams(ByteBufferParams other) : this() {
       reqSize_ = other.reqSize_;
       respSize_ = other.respSize_;
+      _unknownFields = pb::UnknownFieldSet.Clone(other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -114,7 +118,7 @@ namespace Grpc.Testing {
       }
       if (ReqSize != other.ReqSize) return false;
       if (RespSize != other.RespSize) return false;
-      return true;
+      return Equals(_unknownFields, other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -122,6 +126,9 @@ namespace Grpc.Testing {
       int hash = 1;
       if (ReqSize != 0) hash ^= ReqSize.GetHashCode();
       if (RespSize != 0) hash ^= RespSize.GetHashCode();
+      if (_unknownFields != null) {
+        hash ^= _unknownFields.GetHashCode();
+      }
       return hash;
     }
 
@@ -140,6 +147,9 @@ namespace Grpc.Testing {
         output.WriteRawTag(16);
         output.WriteInt32(RespSize);
       }
+      if (_unknownFields != null) {
+        _unknownFields.WriteTo(output);
+      }
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -151,6 +161,9 @@ namespace Grpc.Testing {
       if (RespSize != 0) {
         size += 1 + pb::CodedOutputStream.ComputeInt32Size(RespSize);
       }
+      if (_unknownFields != null) {
+        size += _unknownFields.CalculateSize();
+      }
       return size;
     }
 
@@ -165,6 +178,7 @@ namespace Grpc.Testing {
       if (other.RespSize != 0) {
         RespSize = other.RespSize;
       }
+      _unknownFields = pb::UnknownFieldSet.MergeFrom(_unknownFields, other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -173,7 +187,7 @@ namespace Grpc.Testing {
       while ((tag = input.ReadTag()) != 0) {
         switch(tag) {
           default:
-            input.SkipLastField();
+            _unknownFields = pb::UnknownFieldSet.MergeFieldFrom(_unknownFields, input);
             break;
           case 8: {
             ReqSize = input.ReadInt32();
@@ -191,6 +205,7 @@ namespace Grpc.Testing {
 
   public sealed partial class SimpleProtoParams : pb::IMessage<SimpleProtoParams> {
     private static readonly pb::MessageParser<SimpleProtoParams> _parser = new pb::MessageParser<SimpleProtoParams>(() => new SimpleProtoParams());
+    private pb::UnknownFieldSet _unknownFields;
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public static pb::MessageParser<SimpleProtoParams> Parser { get { return _parser; } }
 
@@ -215,6 +230,7 @@ namespace Grpc.Testing {
     public SimpleProtoParams(SimpleProtoParams other) : this() {
       reqSize_ = other.reqSize_;
       respSize_ = other.respSize_;
+      _unknownFields = pb::UnknownFieldSet.Clone(other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -259,7 +275,7 @@ namespace Grpc.Testing {
       }
       if (ReqSize != other.ReqSize) return false;
       if (RespSize != other.RespSize) return false;
-      return true;
+      return Equals(_unknownFields, other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -267,6 +283,9 @@ namespace Grpc.Testing {
       int hash = 1;
       if (ReqSize != 0) hash ^= ReqSize.GetHashCode();
       if (RespSize != 0) hash ^= RespSize.GetHashCode();
+      if (_unknownFields != null) {
+        hash ^= _unknownFields.GetHashCode();
+      }
       return hash;
     }
 
@@ -285,6 +304,9 @@ namespace Grpc.Testing {
         output.WriteRawTag(16);
         output.WriteInt32(RespSize);
       }
+      if (_unknownFields != null) {
+        _unknownFields.WriteTo(output);
+      }
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -296,6 +318,9 @@ namespace Grpc.Testing {
       if (RespSize != 0) {
         size += 1 + pb::CodedOutputStream.ComputeInt32Size(RespSize);
       }
+      if (_unknownFields != null) {
+        size += _unknownFields.CalculateSize();
+      }
       return size;
     }
 
@@ -310,6 +335,7 @@ namespace Grpc.Testing {
       if (other.RespSize != 0) {
         RespSize = other.RespSize;
       }
+      _unknownFields = pb::UnknownFieldSet.MergeFrom(_unknownFields, other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -318,7 +344,7 @@ namespace Grpc.Testing {
       while ((tag = input.ReadTag()) != 0) {
         switch(tag) {
           default:
-            input.SkipLastField();
+            _unknownFields = pb::UnknownFieldSet.MergeFieldFrom(_unknownFields, input);
             break;
           case 8: {
             ReqSize = input.ReadInt32();
@@ -340,6 +366,7 @@ namespace Grpc.Testing {
   /// </summary>
   public sealed partial class ComplexProtoParams : pb::IMessage<ComplexProtoParams> {
     private static readonly pb::MessageParser<ComplexProtoParams> _parser = new pb::MessageParser<ComplexProtoParams>(() => new ComplexProtoParams());
+    private pb::UnknownFieldSet _unknownFields;
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public static pb::MessageParser<ComplexProtoParams> Parser { get { return _parser; } }
 
@@ -362,6 +389,7 @@ namespace Grpc.Testing {
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public ComplexProtoParams(ComplexProtoParams other) : this() {
+      _unknownFields = pb::UnknownFieldSet.Clone(other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -382,12 +410,15 @@ namespace Grpc.Testing {
       if (ReferenceEquals(other, this)) {
         return true;
       }
-      return true;
+      return Equals(_unknownFields, other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public override int GetHashCode() {
       int hash = 1;
+      if (_unknownFields != null) {
+        hash ^= _unknownFields.GetHashCode();
+      }
       return hash;
     }
 
@@ -398,11 +429,17 @@ namespace Grpc.Testing {
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public void WriteTo(pb::CodedOutputStream output) {
+      if (_unknownFields != null) {
+        _unknownFields.WriteTo(output);
+      }
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public int CalculateSize() {
       int size = 0;
+      if (_unknownFields != null) {
+        size += _unknownFields.CalculateSize();
+      }
       return size;
     }
 
@@ -411,6 +448,7 @@ namespace Grpc.Testing {
       if (other == null) {
         return;
       }
+      _unknownFields = pb::UnknownFieldSet.MergeFrom(_unknownFields, other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -419,7 +457,7 @@ namespace Grpc.Testing {
       while ((tag = input.ReadTag()) != 0) {
         switch(tag) {
           default:
-            input.SkipLastField();
+            _unknownFields = pb::UnknownFieldSet.MergeFieldFrom(_unknownFields, input);
             break;
         }
       }
@@ -429,6 +467,7 @@ namespace Grpc.Testing {
 
   public sealed partial class PayloadConfig : pb::IMessage<PayloadConfig> {
     private static readonly pb::MessageParser<PayloadConfig> _parser = new pb::MessageParser<PayloadConfig>(() => new PayloadConfig());
+    private pb::UnknownFieldSet _unknownFields;
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public static pb::MessageParser<PayloadConfig> Parser { get { return _parser; } }
 
@@ -463,6 +502,7 @@ namespace Grpc.Testing {
           break;
       }
 
+      _unknownFields = pb::UnknownFieldSet.Clone(other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -540,7 +580,7 @@ namespace Grpc.Testing {
       if (!object.Equals(SimpleParams, other.SimpleParams)) return false;
       if (!object.Equals(ComplexParams, other.ComplexParams)) return false;
       if (PayloadCase != other.PayloadCase) return false;
-      return true;
+      return Equals(_unknownFields, other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -550,6 +590,9 @@ namespace Grpc.Testing {
       if (payloadCase_ == PayloadOneofCase.SimpleParams) hash ^= SimpleParams.GetHashCode();
       if (payloadCase_ == PayloadOneofCase.ComplexParams) hash ^= ComplexParams.GetHashCode();
       hash ^= (int) payloadCase_;
+      if (_unknownFields != null) {
+        hash ^= _unknownFields.GetHashCode();
+      }
       return hash;
     }
 
@@ -572,6 +615,9 @@ namespace Grpc.Testing {
         output.WriteRawTag(26);
         output.WriteMessage(ComplexParams);
       }
+      if (_unknownFields != null) {
+        _unknownFields.WriteTo(output);
+      }
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -586,6 +632,9 @@ namespace Grpc.Testing {
       if (payloadCase_ == PayloadOneofCase.ComplexParams) {
         size += 1 + pb::CodedOutputStream.ComputeMessageSize(ComplexParams);
       }
+      if (_unknownFields != null) {
+        size += _unknownFields.CalculateSize();
+      }
       return size;
     }
 
@@ -615,6 +664,7 @@ namespace Grpc.Testing {
           break;
       }
 
+      _unknownFields = pb::UnknownFieldSet.MergeFrom(_unknownFields, other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -623,7 +673,7 @@ namespace Grpc.Testing {
       while ((tag = input.ReadTag()) != 0) {
         switch(tag) {
           default:
-            input.SkipLastField();
+            _unknownFields = pb::UnknownFieldSet.MergeFieldFrom(_unknownFields, input);
             break;
           case 10: {
             global::Grpc.Testing.ByteBufferParams subBuilder = new global::Grpc.Testing.ByteBufferParams();
diff --git a/src/csharp/Grpc.IntegrationTesting/ReportQpsScenarioService.cs b/src/csharp/Grpc.IntegrationTesting/ReportQpsScenarioService.cs
new file mode 100644
index 0000000000..707c443497
--- /dev/null
+++ b/src/csharp/Grpc.IntegrationTesting/ReportQpsScenarioService.cs
@@ -0,0 +1,41 @@
+// <auto-generated>
+//     Generated by the protocol buffer compiler.  DO NOT EDIT!
+//     source: src/proto/grpc/testing/report_qps_scenario_service.proto
+// </auto-generated>
+#pragma warning disable 1591, 0612, 3021
+#region Designer generated code
+
+using pb = global::Google.Protobuf;
+using pbc = global::Google.Protobuf.Collections;
+using pbr = global::Google.Protobuf.Reflection;
+using scg = global::System.Collections.Generic;
+namespace Grpc.Testing {
+
+  /// <summary>Holder for reflection information generated from src/proto/grpc/testing/report_qps_scenario_service.proto</summary>
+  public static partial class ReportQpsScenarioServiceReflection {
+
+    #region Descriptor
+    /// <summary>File descriptor for src/proto/grpc/testing/report_qps_scenario_service.proto</summary>
+    public static pbr::FileDescriptor Descriptor {
+      get { return descriptor; }
+    }
+    private static pbr::FileDescriptor descriptor;
+
+    static ReportQpsScenarioServiceReflection() {
+      byte[] descriptorData = global::System.Convert.FromBase64String(
+          string.Concat(
+            "CjhzcmMvcHJvdG8vZ3JwYy90ZXN0aW5nL3JlcG9ydF9xcHNfc2NlbmFyaW9f",
+            "c2VydmljZS5wcm90bxIMZ3JwYy50ZXN0aW5nGiRzcmMvcHJvdG8vZ3JwYy90",
+            "ZXN0aW5nL2NvbnRyb2wucHJvdG8yXgoYUmVwb3J0UXBzU2NlbmFyaW9TZXJ2",
+            "aWNlEkIKDlJlcG9ydFNjZW5hcmlvEhwuZ3JwYy50ZXN0aW5nLlNjZW5hcmlv",
+            "UmVzdWx0GhIuZ3JwYy50ZXN0aW5nLlZvaWRiBnByb3RvMw=="));
+      descriptor = pbr::FileDescriptor.FromGeneratedCode(descriptorData,
+          new pbr::FileDescriptor[] { global::Grpc.Testing.ControlReflection.Descriptor, },
+          new pbr::GeneratedClrTypeInfo(null, null));
+    }
+    #endregion
+
+  }
+}
+
+#endregion Designer generated code
diff --git a/src/csharp/Grpc.IntegrationTesting/ReportQpsScenarioServiceGrpc.cs b/src/csharp/Grpc.IntegrationTesting/ReportQpsScenarioServiceGrpc.cs
new file mode 100644
index 0000000000..c9c6f75c8c
--- /dev/null
+++ b/src/csharp/Grpc.IntegrationTesting/ReportQpsScenarioServiceGrpc.cs
@@ -0,0 +1,148 @@
+// <auto-generated>
+//     Generated by the protocol buffer compiler.  DO NOT EDIT!
+//     source: src/proto/grpc/testing/report_qps_scenario_service.proto
+// </auto-generated>
+// Original file comments:
+// Copyright 2015 gRPC authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+// An integration test service that covers all the method signature permutations
+// of unary/streaming requests/responses.
+#pragma warning disable 1591
+#region Designer generated code
+
+using grpc = global::Grpc.Core;
+
+namespace Grpc.Testing {
+  public static partial class ReportQpsScenarioService
+  {
+    static readonly string __ServiceName = "grpc.testing.ReportQpsScenarioService";
+
+    static readonly grpc::Marshaller<global::Grpc.Testing.ScenarioResult> __Marshaller_ScenarioResult = grpc::Marshallers.Create((arg) => global::Google.Protobuf.MessageExtensions.ToByteArray(arg), global::Grpc.Testing.ScenarioResult.Parser.ParseFrom);
+    static readonly grpc::Marshaller<global::Grpc.Testing.Void> __Marshaller_Void = grpc::Marshallers.Create((arg) => global::Google.Protobuf.MessageExtensions.ToByteArray(arg), global::Grpc.Testing.Void.Parser.ParseFrom);
+
+    static readonly grpc::Method<global::Grpc.Testing.ScenarioResult, global::Grpc.Testing.Void> __Method_ReportScenario = new grpc::Method<global::Grpc.Testing.ScenarioResult, global::Grpc.Testing.Void>(
+        grpc::MethodType.Unary,
+        __ServiceName,
+        "ReportScenario",
+        __Marshaller_ScenarioResult,
+        __Marshaller_Void);
+
+    /// <summary>Service descriptor</summary>
+    public static global::Google.Protobuf.Reflection.ServiceDescriptor Descriptor
+    {
+      get { return global::Grpc.Testing.ReportQpsScenarioServiceReflection.Descriptor.Services[0]; }
+    }
+
+    /// <summary>Base class for server-side implementations of ReportQpsScenarioService</summary>
+    public abstract partial class ReportQpsScenarioServiceBase
+    {
+      /// <summary>
+      /// Report results of a QPS test benchmark scenario.
+      /// </summary>
+      /// <param name="request">The request received from the client.</param>
+      /// <param name="context">The context of the server-side call handler being invoked.</param>
+      /// <returns>The response to send back to the client (wrapped by a task).</returns>
+      public virtual global::System.Threading.Tasks.Task<global::Grpc.Testing.Void> ReportScenario(global::Grpc.Testing.ScenarioResult request, grpc::ServerCallContext context)
+      {
+        throw new grpc::RpcException(new grpc::Status(grpc::StatusCode.Unimplemented, ""));
+      }
+
+    }
+
+    /// <summary>Client for ReportQpsScenarioService</summary>
+    public partial class ReportQpsScenarioServiceClient : grpc::ClientBase<ReportQpsScenarioServiceClient>
+    {
+      /// <summary>Creates a new client for ReportQpsScenarioService</summary>
+      /// <param name="channel">The channel to use to make remote calls.</param>
+      public ReportQpsScenarioServiceClient(grpc::Channel channel) : base(channel)
+      {
+      }
+      /// <summary>Creates a new client for ReportQpsScenarioService that uses a custom <c>CallInvoker</c>.</summary>
+      /// <param name="callInvoker">The callInvoker to use to make remote calls.</param>
+      public ReportQpsScenarioServiceClient(grpc::CallInvoker callInvoker) : base(callInvoker)
+      {
+      }
+      /// <summary>Protected parameterless constructor to allow creation of test doubles.</summary>
+      protected ReportQpsScenarioServiceClient() : base()
+      {
+      }
+      /// <summary>Protected constructor to allow creation of configured clients.</summary>
+      /// <param name="configuration">The client configuration.</param>
+      protected ReportQpsScenarioServiceClient(ClientBaseConfiguration configuration) : base(configuration)
+      {
+      }
+
+      /// <summary>
+      /// Report results of a QPS test benchmark scenario.
+      /// </summary>
+      /// <param name="request">The request to send to the server.</param>
+      /// <param name="headers">The initial metadata to send with the call. This parameter is optional.</param>
+      /// <param name="deadline">An optional deadline for the call. The call will be cancelled if deadline is hit.</param>
+      /// <param name="cancellationToken">An optional token for canceling the call.</param>
+      /// <returns>The response received from the server.</returns>
+      public virtual global::Grpc.Testing.Void ReportScenario(global::Grpc.Testing.ScenarioResult request, grpc::Metadata headers = null, global::System.DateTime? deadline = null, global::System.Threading.CancellationToken cancellationToken = default(global::System.Threading.CancellationToken))
+      {
+        return ReportScenario(request, new grpc::CallOptions(headers, deadline, cancellationToken));
+      }
+      /// <summary>
+      /// Report results of a QPS test benchmark scenario.
+      /// </summary>
+      /// <param name="request">The request to send to the server.</param>
+      /// <param name="options">The options for the call.</param>
+      /// <returns>The response received from the server.</returns>
+      public virtual global::Grpc.Testing.Void ReportScenario(global::Grpc.Testing.ScenarioResult request, grpc::CallOptions options)
+      {
+        return CallInvoker.BlockingUnaryCall(__Method_ReportScenario, null, options, request);
+      }
+      /// <summary>
+      /// Report results of a QPS test benchmark scenario.
+      /// </summary>
+      /// <param name="request">The request to send to the server.</param>
+      /// <param name="headers">The initial metadata to send with the call. This parameter is optional.</param>
+      /// <param name="deadline">An optional deadline for the call. The call will be cancelled if deadline is hit.</param>
+      /// <param name="cancellationToken">An optional token for canceling the call.</param>
+      /// <returns>The call object.</returns>
+      public virtual grpc::AsyncUnaryCall<global::Grpc.Testing.Void> ReportScenarioAsync(global::Grpc.Testing.ScenarioResult request, grpc::Metadata headers = null, global::System.DateTime? deadline = null, global::System.Threading.CancellationToken cancellationToken = default(global::System.Threading.CancellationToken))
+      {
+        return ReportScenarioAsync(request, new grpc::CallOptions(headers, deadline, cancellationToken));
+      }
+      /// <summary>
+      /// Report results of a QPS test benchmark scenario.
+      /// </summary>
+      /// <param name="request">The request to send to the server.</param>
+      /// <param name="options">The options for the call.</param>
+      /// <returns>The call object.</returns>
+      public virtual grpc::AsyncUnaryCall<global::Grpc.Testing.Void> ReportScenarioAsync(global::Grpc.Testing.ScenarioResult request, grpc::CallOptions options)
+      {
+        return CallInvoker.AsyncUnaryCall(__Method_ReportScenario, null, options, request);
+      }
+      /// <summary>Creates a new instance of client from given <c>ClientBaseConfiguration</c>.</summary>
+      protected override ReportQpsScenarioServiceClient NewInstance(ClientBaseConfiguration configuration)
+      {
+        return new ReportQpsScenarioServiceClient(configuration);
+      }
+    }
+
+    /// <summary>Creates service definition that can be registered with a server</summary>
+    /// <param name="serviceImpl">An object implementing the server-side handling logic.</param>
+    public static grpc::ServerServiceDefinition BindService(ReportQpsScenarioServiceBase serviceImpl)
+    {
+      return grpc::ServerServiceDefinition.CreateBuilder()
+          .AddMethod(__Method_ReportScenario, serviceImpl.ReportScenario).Build();
+    }
+
+  }
+}
+#endregion
diff --git a/src/csharp/Grpc.IntegrationTesting/Services.cs b/src/csharp/Grpc.IntegrationTesting/Services.cs
deleted file mode 100644
index 4b761706ed..0000000000
--- a/src/csharp/Grpc.IntegrationTesting/Services.cs
+++ /dev/null
@@ -1,55 +0,0 @@
-// Generated by the protocol buffer compiler.  DO NOT EDIT!
-// source: src/proto/grpc/testing/services.proto
-#pragma warning disable 1591, 0612, 3021
-#region Designer generated code
-
-using pb = global::Google.Protobuf;
-using pbc = global::Google.Protobuf.Collections;
-using pbr = global::Google.Protobuf.Reflection;
-using scg = global::System.Collections.Generic;
-namespace Grpc.Testing {
-
-  /// <summary>Holder for reflection information generated from src/proto/grpc/testing/services.proto</summary>
-  public static partial class ServicesReflection {
-
-    #region Descriptor
-    /// <summary>File descriptor for src/proto/grpc/testing/services.proto</summary>
-    public static pbr::FileDescriptor Descriptor {
-      get { return descriptor; }
-    }
-    private static pbr::FileDescriptor descriptor;
-
-    static ServicesReflection() {
-      byte[] descriptorData = global::System.Convert.FromBase64String(
-          string.Concat(
-            "CiVzcmMvcHJvdG8vZ3JwYy90ZXN0aW5nL3NlcnZpY2VzLnByb3RvEgxncnBj",
-            "LnRlc3RpbmcaJXNyYy9wcm90by9ncnBjL3Rlc3RpbmcvbWVzc2FnZXMucHJv",
-            "dG8aJHNyYy9wcm90by9ncnBjL3Rlc3RpbmcvY29udHJvbC5wcm90bzKmAwoQ",
-            "QmVuY2htYXJrU2VydmljZRJGCglVbmFyeUNhbGwSGy5ncnBjLnRlc3Rpbmcu",
-            "U2ltcGxlUmVxdWVzdBocLmdycGMudGVzdGluZy5TaW1wbGVSZXNwb25zZRJO",
-            "Cg1TdHJlYW1pbmdDYWxsEhsuZ3JwYy50ZXN0aW5nLlNpbXBsZVJlcXVlc3Qa",
-            "HC5ncnBjLnRlc3RpbmcuU2ltcGxlUmVzcG9uc2UoATABElIKE1N0cmVhbWlu",
-            "Z0Zyb21DbGllbnQSGy5ncnBjLnRlc3RpbmcuU2ltcGxlUmVxdWVzdBocLmdy",
-            "cGMudGVzdGluZy5TaW1wbGVSZXNwb25zZSgBElIKE1N0cmVhbWluZ0Zyb21T",
-            "ZXJ2ZXISGy5ncnBjLnRlc3RpbmcuU2ltcGxlUmVxdWVzdBocLmdycGMudGVz",
-            "dGluZy5TaW1wbGVSZXNwb25zZTABElIKEVN0cmVhbWluZ0JvdGhXYXlzEhsu",
-            "Z3JwYy50ZXN0aW5nLlNpbXBsZVJlcXVlc3QaHC5ncnBjLnRlc3RpbmcuU2lt",
-            "cGxlUmVzcG9uc2UoATABMpcCCg1Xb3JrZXJTZXJ2aWNlEkUKCVJ1blNlcnZl",
-            "chIYLmdycGMudGVzdGluZy5TZXJ2ZXJBcmdzGhouZ3JwYy50ZXN0aW5nLlNl",
-            "cnZlclN0YXR1cygBMAESRQoJUnVuQ2xpZW50EhguZ3JwYy50ZXN0aW5nLkNs",
-            "aWVudEFyZ3MaGi5ncnBjLnRlc3RpbmcuQ2xpZW50U3RhdHVzKAEwARJCCglD",
-            "b3JlQ291bnQSGS5ncnBjLnRlc3RpbmcuQ29yZVJlcXVlc3QaGi5ncnBjLnRl",
-            "c3RpbmcuQ29yZVJlc3BvbnNlEjQKClF1aXRXb3JrZXISEi5ncnBjLnRlc3Rp",
-            "bmcuVm9pZBoSLmdycGMudGVzdGluZy5Wb2lkMl4KGFJlcG9ydFFwc1NjZW5h",
-            "cmlvU2VydmljZRJCCg5SZXBvcnRTY2VuYXJpbxIcLmdycGMudGVzdGluZy5T",
-            "Y2VuYXJpb1Jlc3VsdBoSLmdycGMudGVzdGluZy5Wb2lkYgZwcm90bzM="));
-      descriptor = pbr::FileDescriptor.FromGeneratedCode(descriptorData,
-          new pbr::FileDescriptor[] { global::Grpc.Testing.MessagesReflection.Descriptor, global::Grpc.Testing.ControlReflection.Descriptor, },
-          new pbr::GeneratedClrTypeInfo(null, null));
-    }
-    #endregion
-
-  }
-}
-
-#endregion Designer generated code
diff --git a/src/csharp/Grpc.IntegrationTesting/ServicesGrpc.cs b/src/csharp/Grpc.IntegrationTesting/ServicesGrpc.cs
deleted file mode 100644
index 46b328a773..0000000000
--- a/src/csharp/Grpc.IntegrationTesting/ServicesGrpc.cs
+++ /dev/null
@@ -1,745 +0,0 @@
-// <auto-generated>
-//     Generated by the protocol buffer compiler.  DO NOT EDIT!
-//     source: src/proto/grpc/testing/services.proto
-// </auto-generated>
-// Original file comments:
-// Copyright 2015 gRPC authors.
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-//     http://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
-//
-// An integration test service that covers all the method signature permutations
-// of unary/streaming requests/responses.
-#pragma warning disable 1591
-#region Designer generated code
-
-using grpc = global::Grpc.Core;
-
-namespace Grpc.Testing {
-  public static partial class BenchmarkService
-  {
-    static readonly string __ServiceName = "grpc.testing.BenchmarkService";
-
-    static readonly grpc::Marshaller<global::Grpc.Testing.SimpleRequest> __Marshaller_SimpleRequest = grpc::Marshallers.Create((arg) => global::Google.Protobuf.MessageExtensions.ToByteArray(arg), global::Grpc.Testing.SimpleRequest.Parser.ParseFrom);
-    static readonly grpc::Marshaller<global::Grpc.Testing.SimpleResponse> __Marshaller_SimpleResponse = grpc::Marshallers.Create((arg) => global::Google.Protobuf.MessageExtensions.ToByteArray(arg), global::Grpc.Testing.SimpleResponse.Parser.ParseFrom);
-
-    static readonly grpc::Method<global::Grpc.Testing.SimpleRequest, global::Grpc.Testing.SimpleResponse> __Method_UnaryCall = new grpc::Method<global::Grpc.Testing.SimpleRequest, global::Grpc.Testing.SimpleResponse>(
-        grpc::MethodType.Unary,
-        __ServiceName,
-        "UnaryCall",
-        __Marshaller_SimpleRequest,
-        __Marshaller_SimpleResponse);
-
-    static readonly grpc::Method<global::Grpc.Testing.SimpleRequest, global::Grpc.Testing.SimpleResponse> __Method_StreamingCall = new grpc::Method<global::Grpc.Testing.SimpleRequest, global::Grpc.Testing.SimpleResponse>(
-        grpc::MethodType.DuplexStreaming,
-        __ServiceName,
-        "StreamingCall",
-        __Marshaller_SimpleRequest,
-        __Marshaller_SimpleResponse);
-
-    static readonly grpc::Method<global::Grpc.Testing.SimpleRequest, global::Grpc.Testing.SimpleResponse> __Method_StreamingFromClient = new grpc::Method<global::Grpc.Testing.SimpleRequest, global::Grpc.Testing.SimpleResponse>(
-        grpc::MethodType.ClientStreaming,
-        __ServiceName,
-        "StreamingFromClient",
-        __Marshaller_SimpleRequest,
-        __Marshaller_SimpleResponse);
-
-    static readonly grpc::Method<global::Grpc.Testing.SimpleRequest, global::Grpc.Testing.SimpleResponse> __Method_StreamingFromServer = new grpc::Method<global::Grpc.Testing.SimpleRequest, global::Grpc.Testing.SimpleResponse>(
-        grpc::MethodType.ServerStreaming,
-        __ServiceName,
-        "StreamingFromServer",
-        __Marshaller_SimpleRequest,
-        __Marshaller_SimpleResponse);
-
-    static readonly grpc::Method<global::Grpc.Testing.SimpleRequest, global::Grpc.Testing.SimpleResponse> __Method_StreamingBothWays = new grpc::Method<global::Grpc.Testing.SimpleRequest, global::Grpc.Testing.SimpleResponse>(
-        grpc::MethodType.DuplexStreaming,
-        __ServiceName,
-        "StreamingBothWays",
-        __Marshaller_SimpleRequest,
-        __Marshaller_SimpleResponse);
-
-    /// <summary>Service descriptor</summary>
-    public static global::Google.Protobuf.Reflection.ServiceDescriptor Descriptor
-    {
-      get { return global::Grpc.Testing.ServicesReflection.Descriptor.Services[0]; }
-    }
-
-    /// <summary>Base class for server-side implementations of BenchmarkService</summary>
-    public abstract partial class BenchmarkServiceBase
-    {
-      /// <summary>
-      /// One request followed by one response.
-      /// The server returns the client payload as-is.
-      /// </summary>
-      /// <param name="request">The request received from the client.</param>
-      /// <param name="context">The context of the server-side call handler being invoked.</param>
-      /// <returns>The response to send back to the client (wrapped by a task).</returns>
-      public virtual global::System.Threading.Tasks.Task<global::Grpc.Testing.SimpleResponse> UnaryCall(global::Grpc.Testing.SimpleRequest request, grpc::ServerCallContext context)
-      {
-        throw new grpc::RpcException(new grpc::Status(grpc::StatusCode.Unimplemented, ""));
-      }
-
-      /// <summary>
-      /// Repeated sequence of one request followed by one response.
-      /// Should be called streaming ping-pong
-      /// The server returns the client payload as-is on each response
-      /// </summary>
-      /// <param name="requestStream">Used for reading requests from the client.</param>
-      /// <param name="responseStream">Used for sending responses back to the client.</param>
-      /// <param name="context">The context of the server-side call handler being invoked.</param>
-      /// <returns>A task indicating completion of the handler.</returns>
-      public virtual global::System.Threading.Tasks.Task StreamingCall(grpc::IAsyncStreamReader<global::Grpc.Testing.SimpleRequest> requestStream, grpc::IServerStreamWriter<global::Grpc.Testing.SimpleResponse> responseStream, grpc::ServerCallContext context)
-      {
-        throw new grpc::RpcException(new grpc::Status(grpc::StatusCode.Unimplemented, ""));
-      }
-
-      /// <summary>
-      /// Single-sided unbounded streaming from client to server
-      /// The server returns the client payload as-is once the client does WritesDone
-      /// </summary>
-      /// <param name="requestStream">Used for reading requests from the client.</param>
-      /// <param name="context">The context of the server-side call handler being invoked.</param>
-      /// <returns>The response to send back to the client (wrapped by a task).</returns>
-      public virtual global::System.Threading.Tasks.Task<global::Grpc.Testing.SimpleResponse> StreamingFromClient(grpc::IAsyncStreamReader<global::Grpc.Testing.SimpleRequest> requestStream, grpc::ServerCallContext context)
-      {
-        throw new grpc::RpcException(new grpc::Status(grpc::StatusCode.Unimplemented, ""));
-      }
-
-      /// <summary>
-      /// Single-sided unbounded streaming from server to client
-      /// The server repeatedly returns the client payload as-is
-      /// </summary>
-      /// <param name="request">The request received from the client.</param>
-      /// <param name="responseStream">Used for sending responses back to the client.</param>
-      /// <param name="context">The context of the server-side call handler being invoked.</param>
-      /// <returns>A task indicating completion of the handler.</returns>
-      public virtual global::System.Threading.Tasks.Task StreamingFromServer(global::Grpc.Testing.SimpleRequest request, grpc::IServerStreamWriter<global::Grpc.Testing.SimpleResponse> responseStream, grpc::ServerCallContext context)
-      {
-        throw new grpc::RpcException(new grpc::Status(grpc::StatusCode.Unimplemented, ""));
-      }
-
-      /// <summary>
-      /// Two-sided unbounded streaming between server to client
-      /// Both sides send the content of their own choice to the other
-      /// </summary>
-      /// <param name="requestStream">Used for reading requests from the client.</param>
-      /// <param name="responseStream">Used for sending responses back to the client.</param>
-      /// <param name="context">The context of the server-side call handler being invoked.</param>
-      /// <returns>A task indicating completion of the handler.</returns>
-      public virtual global::System.Threading.Tasks.Task StreamingBothWays(grpc::IAsyncStreamReader<global::Grpc.Testing.SimpleRequest> requestStream, grpc::IServerStreamWriter<global::Grpc.Testing.SimpleResponse> responseStream, grpc::ServerCallContext context)
-      {
-        throw new grpc::RpcException(new grpc::Status(grpc::StatusCode.Unimplemented, ""));
-      }
-
-    }
-
-    /// <summary>Client for BenchmarkService</summary>
-    public partial class BenchmarkServiceClient : grpc::ClientBase<BenchmarkServiceClient>
-    {
-      /// <summary>Creates a new client for BenchmarkService</summary>
-      /// <param name="channel">The channel to use to make remote calls.</param>
-      public BenchmarkServiceClient(grpc::Channel channel) : base(channel)
-      {
-      }
-      /// <summary>Creates a new client for BenchmarkService that uses a custom <c>CallInvoker</c>.</summary>
-      /// <param name="callInvoker">The callInvoker to use to make remote calls.</param>
-      public BenchmarkServiceClient(grpc::CallInvoker callInvoker) : base(callInvoker)
-      {
-      }
-      /// <summary>Protected parameterless constructor to allow creation of test doubles.</summary>
-      protected BenchmarkServiceClient() : base()
-      {
-      }
-      /// <summary>Protected constructor to allow creation of configured clients.</summary>
-      /// <param name="configuration">The client configuration.</param>
-      protected BenchmarkServiceClient(ClientBaseConfiguration configuration) : base(configuration)
-      {
-      }
-
-      /// <summary>
-      /// One request followed by one response.
-      /// The server returns the client payload as-is.
-      /// </summary>
-      /// <param name="request">The request to send to the server.</param>
-      /// <param name="headers">The initial metadata to send with the call. This parameter is optional.</param>
-      /// <param name="deadline">An optional deadline for the call. The call will be cancelled if deadline is hit.</param>
-      /// <param name="cancellationToken">An optional token for canceling the call.</param>
-      /// <returns>The response received from the server.</returns>
-      public virtual global::Grpc.Testing.SimpleResponse UnaryCall(global::Grpc.Testing.SimpleRequest request, grpc::Metadata headers = null, global::System.DateTime? deadline = null, global::System.Threading.CancellationToken cancellationToken = default(global::System.Threading.CancellationToken))
-      {
-        return UnaryCall(request, new grpc::CallOptions(headers, deadline, cancellationToken));
-      }
-      /// <summary>
-      /// One request followed by one response.
-      /// The server returns the client payload as-is.
-      /// </summary>
-      /// <param name="request">The request to send to the server.</param>
-      /// <param name="options">The options for the call.</param>
-      /// <returns>The response received from the server.</returns>
-      public virtual global::Grpc.Testing.SimpleResponse UnaryCall(global::Grpc.Testing.SimpleRequest request, grpc::CallOptions options)
-      {
-        return CallInvoker.BlockingUnaryCall(__Method_UnaryCall, null, options, request);
-      }
-      /// <summary>
-      /// One request followed by one response.
-      /// The server returns the client payload as-is.
-      /// </summary>
-      /// <param name="request">The request to send to the server.</param>
-      /// <param name="headers">The initial metadata to send with the call. This parameter is optional.</param>
-      /// <param name="deadline">An optional deadline for the call. The call will be cancelled if deadline is hit.</param>
-      /// <param name="cancellationToken">An optional token for canceling the call.</param>
-      /// <returns>The call object.</returns>
-      public virtual grpc::AsyncUnaryCall<global::Grpc.Testing.SimpleResponse> UnaryCallAsync(global::Grpc.Testing.SimpleRequest request, grpc::Metadata headers = null, global::System.DateTime? deadline = null, global::System.Threading.CancellationToken cancellationToken = default(global::System.Threading.CancellationToken))
-      {
-        return UnaryCallAsync(request, new grpc::CallOptions(headers, deadline, cancellationToken));
-      }
-      /// <summary>
-      /// One request followed by one response.
-      /// The server returns the client payload as-is.
-      /// </summary>
-      /// <param name="request">The request to send to the server.</param>
-      /// <param name="options">The options for the call.</param>
-      /// <returns>The call object.</returns>
-      public virtual grpc::AsyncUnaryCall<global::Grpc.Testing.SimpleResponse> UnaryCallAsync(global::Grpc.Testing.SimpleRequest request, grpc::CallOptions options)
-      {
-        return CallInvoker.AsyncUnaryCall(__Method_UnaryCall, null, options, request);
-      }
-      /// <summary>
-      /// Repeated sequence of one request followed by one response.
-      /// Should be called streaming ping-pong
-      /// The server returns the client payload as-is on each response
-      /// </summary>
-      /// <param name="headers">The initial metadata to send with the call. This parameter is optional.</param>
-      /// <param name="deadline">An optional deadline for the call. The call will be cancelled if deadline is hit.</param>
-      /// <param name="cancellationToken">An optional token for canceling the call.</param>
-      /// <returns>The call object.</returns>
-      public virtual grpc::AsyncDuplexStreamingCall<global::Grpc.Testing.SimpleRequest, global::Grpc.Testing.SimpleResponse> StreamingCall(grpc::Metadata headers = null, global::System.DateTime? deadline = null, global::System.Threading.CancellationToken cancellationToken = default(global::System.Threading.CancellationToken))
-      {
-        return StreamingCall(new grpc::CallOptions(headers, deadline, cancellationToken));
-      }
-      /// <summary>
-      /// Repeated sequence of one request followed by one response.
-      /// Should be called streaming ping-pong
-      /// The server returns the client payload as-is on each response
-      /// </summary>
-      /// <param name="options">The options for the call.</param>
-      /// <returns>The call object.</returns>
-      public virtual grpc::AsyncDuplexStreamingCall<global::Grpc.Testing.SimpleRequest, global::Grpc.Testing.SimpleResponse> StreamingCall(grpc::CallOptions options)
-      {
-        return CallInvoker.AsyncDuplexStreamingCall(__Method_StreamingCall, null, options);
-      }
-      /// <summary>
-      /// Single-sided unbounded streaming from client to server
-      /// The server returns the client payload as-is once the client does WritesDone
-      /// </summary>
-      /// <param name="headers">The initial metadata to send with the call. This parameter is optional.</param>
-      /// <param name="deadline">An optional deadline for the call. The call will be cancelled if deadline is hit.</param>
-      /// <param name="cancellationToken">An optional token for canceling the call.</param>
-      /// <returns>The call object.</returns>
-      public virtual grpc::AsyncClientStreamingCall<global::Grpc.Testing.SimpleRequest, global::Grpc.Testing.SimpleResponse> StreamingFromClient(grpc::Metadata headers = null, global::System.DateTime? deadline = null, global::System.Threading.CancellationToken cancellationToken = default(global::System.Threading.CancellationToken))
-      {
-        return StreamingFromClient(new grpc::CallOptions(headers, deadline, cancellationToken));
-      }
-      /// <summary>
-      /// Single-sided unbounded streaming from client to server
-      /// The server returns the client payload as-is once the client does WritesDone
-      /// </summary>
-      /// <param name="options">The options for the call.</param>
-      /// <returns>The call object.</returns>
-      public virtual grpc::AsyncClientStreamingCall<global::Grpc.Testing.SimpleRequest, global::Grpc.Testing.SimpleResponse> StreamingFromClient(grpc::CallOptions options)
-      {
-        return CallInvoker.AsyncClientStreamingCall(__Method_StreamingFromClient, null, options);
-      }
-      /// <summary>
-      /// Single-sided unbounded streaming from server to client
-      /// The server repeatedly returns the client payload as-is
-      /// </summary>
-      /// <param name="request">The request to send to the server.</param>
-      /// <param name="headers">The initial metadata to send with the call. This parameter is optional.</param>
-      /// <param name="deadline">An optional deadline for the call. The call will be cancelled if deadline is hit.</param>
-      /// <param name="cancellationToken">An optional token for canceling the call.</param>
-      /// <returns>The call object.</returns>
-      public virtual grpc::AsyncServerStreamingCall<global::Grpc.Testing.SimpleResponse> StreamingFromServer(global::Grpc.Testing.SimpleRequest request, grpc::Metadata headers = null, global::System.DateTime? deadline = null, global::System.Threading.CancellationToken cancellationToken = default(global::System.Threading.CancellationToken))
-      {
-        return StreamingFromServer(request, new grpc::CallOptions(headers, deadline, cancellationToken));
-      }
-      /// <summary>
-      /// Single-sided unbounded streaming from server to client
-      /// The server repeatedly returns the client payload as-is
-      /// </summary>
-      /// <param name="request">The request to send to the server.</param>
-      /// <param name="options">The options for the call.</param>
-      /// <returns>The call object.</returns>
-      public virtual grpc::AsyncServerStreamingCall<global::Grpc.Testing.SimpleResponse> StreamingFromServer(global::Grpc.Testing.SimpleRequest request, grpc::CallOptions options)
-      {
-        return CallInvoker.AsyncServerStreamingCall(__Method_StreamingFromServer, null, options, request);
-      }
-      /// <summary>
-      /// Two-sided unbounded streaming between server to client
-      /// Both sides send the content of their own choice to the other
-      /// </summary>
-      /// <param name="headers">The initial metadata to send with the call. This parameter is optional.</param>
-      /// <param name="deadline">An optional deadline for the call. The call will be cancelled if deadline is hit.</param>
-      /// <param name="cancellationToken">An optional token for canceling the call.</param>
-      /// <returns>The call object.</returns>
-      public virtual grpc::AsyncDuplexStreamingCall<global::Grpc.Testing.SimpleRequest, global::Grpc.Testing.SimpleResponse> StreamingBothWays(grpc::Metadata headers = null, global::System.DateTime? deadline = null, global::System.Threading.CancellationToken cancellationToken = default(global::System.Threading.CancellationToken))
-      {
-        return StreamingBothWays(new grpc::CallOptions(headers, deadline, cancellationToken));
-      }
-      /// <summary>
-      /// Two-sided unbounded streaming between server to client
-      /// Both sides send the content of their own choice to the other
-      /// </summary>
-      /// <param name="options">The options for the call.</param>
-      /// <returns>The call object.</returns>
-      public virtual grpc::AsyncDuplexStreamingCall<global::Grpc.Testing.SimpleRequest, global::Grpc.Testing.SimpleResponse> StreamingBothWays(grpc::CallOptions options)
-      {
-        return CallInvoker.AsyncDuplexStreamingCall(__Method_StreamingBothWays, null, options);
-      }
-      /// <summary>Creates a new instance of client from given <c>ClientBaseConfiguration</c>.</summary>
-      protected override BenchmarkServiceClient NewInstance(ClientBaseConfiguration configuration)
-      {
-        return new BenchmarkServiceClient(configuration);
-      }
-    }
-
-    /// <summary>Creates service definition that can be registered with a server</summary>
-    /// <param name="serviceImpl">An object implementing the server-side handling logic.</param>
-    public static grpc::ServerServiceDefinition BindService(BenchmarkServiceBase serviceImpl)
-    {
-      return grpc::ServerServiceDefinition.CreateBuilder()
-          .AddMethod(__Method_UnaryCall, serviceImpl.UnaryCall)
-          .AddMethod(__Method_StreamingCall, serviceImpl.StreamingCall)
-          .AddMethod(__Method_StreamingFromClient, serviceImpl.StreamingFromClient)
-          .AddMethod(__Method_StreamingFromServer, serviceImpl.StreamingFromServer)
-          .AddMethod(__Method_StreamingBothWays, serviceImpl.StreamingBothWays).Build();
-    }
-
-  }
-  public static partial class WorkerService
-  {
-    static readonly string __ServiceName = "grpc.testing.WorkerService";
-
-    static readonly grpc::Marshaller<global::Grpc.Testing.ServerArgs> __Marshaller_ServerArgs = grpc::Marshallers.Create((arg) => global::Google.Protobuf.MessageExtensions.ToByteArray(arg), global::Grpc.Testing.ServerArgs.Parser.ParseFrom);
-    static readonly grpc::Marshaller<global::Grpc.Testing.ServerStatus> __Marshaller_ServerStatus = grpc::Marshallers.Create((arg) => global::Google.Protobuf.MessageExtensions.ToByteArray(arg), global::Grpc.Testing.ServerStatus.Parser.ParseFrom);
-    static readonly grpc::Marshaller<global::Grpc.Testing.ClientArgs> __Marshaller_ClientArgs = grpc::Marshallers.Create((arg) => global::Google.Protobuf.MessageExtensions.ToByteArray(arg), global::Grpc.Testing.ClientArgs.Parser.ParseFrom);
-    static readonly grpc::Marshaller<global::Grpc.Testing.ClientStatus> __Marshaller_ClientStatus = grpc::Marshallers.Create((arg) => global::Google.Protobuf.MessageExtensions.ToByteArray(arg), global::Grpc.Testing.ClientStatus.Parser.ParseFrom);
-    static readonly grpc::Marshaller<global::Grpc.Testing.CoreRequest> __Marshaller_CoreRequest = grpc::Marshallers.Create((arg) => global::Google.Protobuf.MessageExtensions.ToByteArray(arg), global::Grpc.Testing.CoreRequest.Parser.ParseFrom);
-    static readonly grpc::Marshaller<global::Grpc.Testing.CoreResponse> __Marshaller_CoreResponse = grpc::Marshallers.Create((arg) => global::Google.Protobuf.MessageExtensions.ToByteArray(arg), global::Grpc.Testing.CoreResponse.Parser.ParseFrom);
-    static readonly grpc::Marshaller<global::Grpc.Testing.Void> __Marshaller_Void = grpc::Marshallers.Create((arg) => global::Google.Protobuf.MessageExtensions.ToByteArray(arg), global::Grpc.Testing.Void.Parser.ParseFrom);
-
-    static readonly grpc::Method<global::Grpc.Testing.ServerArgs, global::Grpc.Testing.ServerStatus> __Method_RunServer = new grpc::Method<global::Grpc.Testing.ServerArgs, global::Grpc.Testing.ServerStatus>(
-        grpc::MethodType.DuplexStreaming,
-        __ServiceName,
-        "RunServer",
-        __Marshaller_ServerArgs,
-        __Marshaller_ServerStatus);
-
-    static readonly grpc::Method<global::Grpc.Testing.ClientArgs, global::Grpc.Testing.ClientStatus> __Method_RunClient = new grpc::Method<global::Grpc.Testing.ClientArgs, global::Grpc.Testing.ClientStatus>(
-        grpc::MethodType.DuplexStreaming,
-        __ServiceName,
-        "RunClient",
-        __Marshaller_ClientArgs,
-        __Marshaller_ClientStatus);
-
-    static readonly grpc::Method<global::Grpc.Testing.CoreRequest, global::Grpc.Testing.CoreResponse> __Method_CoreCount = new grpc::Method<global::Grpc.Testing.CoreRequest, global::Grpc.Testing.CoreResponse>(
-        grpc::MethodType.Unary,
-        __ServiceName,
-        "CoreCount",
-        __Marshaller_CoreRequest,
-        __Marshaller_CoreResponse);
-
-    static readonly grpc::Method<global::Grpc.Testing.Void, global::Grpc.Testing.Void> __Method_QuitWorker = new grpc::Method<global::Grpc.Testing.Void, global::Grpc.Testing.Void>(
-        grpc::MethodType.Unary,
-        __ServiceName,
-        "QuitWorker",
-        __Marshaller_Void,
-        __Marshaller_Void);
-
-    /// <summary>Service descriptor</summary>
-    public static global::Google.Protobuf.Reflection.ServiceDescriptor Descriptor
-    {
-      get { return global::Grpc.Testing.ServicesReflection.Descriptor.Services[1]; }
-    }
-
-    /// <summary>Base class for server-side implementations of WorkerService</summary>
-    public abstract partial class WorkerServiceBase
-    {
-      /// <summary>
-      /// Start server with specified workload.
-      /// First request sent specifies the ServerConfig followed by ServerStatus
-      /// response. After that, a "Mark" can be sent anytime to request the latest
-      /// stats. Closing the stream will initiate shutdown of the test server
-      /// and once the shutdown has finished, the OK status is sent to terminate
-      /// this RPC.
-      /// </summary>
-      /// <param name="requestStream">Used for reading requests from the client.</param>
-      /// <param name="responseStream">Used for sending responses back to the client.</param>
-      /// <param name="context">The context of the server-side call handler being invoked.</param>
-      /// <returns>A task indicating completion of the handler.</returns>
-      public virtual global::System.Threading.Tasks.Task RunServer(grpc::IAsyncStreamReader<global::Grpc.Testing.ServerArgs> requestStream, grpc::IServerStreamWriter<global::Grpc.Testing.ServerStatus> responseStream, grpc::ServerCallContext context)
-      {
-        throw new grpc::RpcException(new grpc::Status(grpc::StatusCode.Unimplemented, ""));
-      }
-
-      /// <summary>
-      /// Start client with specified workload.
-      /// First request sent specifies the ClientConfig followed by ClientStatus
-      /// response. After that, a "Mark" can be sent anytime to request the latest
-      /// stats. Closing the stream will initiate shutdown of the test client
-      /// and once the shutdown has finished, the OK status is sent to terminate
-      /// this RPC.
-      /// </summary>
-      /// <param name="requestStream">Used for reading requests from the client.</param>
-      /// <param name="responseStream">Used for sending responses back to the client.</param>
-      /// <param name="context">The context of the server-side call handler being invoked.</param>
-      /// <returns>A task indicating completion of the handler.</returns>
-      public virtual global::System.Threading.Tasks.Task RunClient(grpc::IAsyncStreamReader<global::Grpc.Testing.ClientArgs> requestStream, grpc::IServerStreamWriter<global::Grpc.Testing.ClientStatus> responseStream, grpc::ServerCallContext context)
-      {
-        throw new grpc::RpcException(new grpc::Status(grpc::StatusCode.Unimplemented, ""));
-      }
-
-      /// <summary>
-      /// Just return the core count - unary call
-      /// </summary>
-      /// <param name="request">The request received from the client.</param>
-      /// <param name="context">The context of the server-side call handler being invoked.</param>
-      /// <returns>The response to send back to the client (wrapped by a task).</returns>
-      public virtual global::System.Threading.Tasks.Task<global::Grpc.Testing.CoreResponse> CoreCount(global::Grpc.Testing.CoreRequest request, grpc::ServerCallContext context)
-      {
-        throw new grpc::RpcException(new grpc::Status(grpc::StatusCode.Unimplemented, ""));
-      }
-
-      /// <summary>
-      /// Quit this worker
-      /// </summary>
-      /// <param name="request">The request received from the client.</param>
-      /// <param name="context">The context of the server-side call handler being invoked.</param>
-      /// <returns>The response to send back to the client (wrapped by a task).</returns>
-      public virtual global::System.Threading.Tasks.Task<global::Grpc.Testing.Void> QuitWorker(global::Grpc.Testing.Void request, grpc::ServerCallContext context)
-      {
-        throw new grpc::RpcException(new grpc::Status(grpc::StatusCode.Unimplemented, ""));
-      }
-
-    }
-
-    /// <summary>Client for WorkerService</summary>
-    public partial class WorkerServiceClient : grpc::ClientBase<WorkerServiceClient>
-    {
-      /// <summary>Creates a new client for WorkerService</summary>
-      /// <param name="channel">The channel to use to make remote calls.</param>
-      public WorkerServiceClient(grpc::Channel channel) : base(channel)
-      {
-      }
-      /// <summary>Creates a new client for WorkerService that uses a custom <c>CallInvoker</c>.</summary>
-      /// <param name="callInvoker">The callInvoker to use to make remote calls.</param>
-      public WorkerServiceClient(grpc::CallInvoker callInvoker) : base(callInvoker)
-      {
-      }
-      /// <summary>Protected parameterless constructor to allow creation of test doubles.</summary>
-      protected WorkerServiceClient() : base()
-      {
-      }
-      /// <summary>Protected constructor to allow creation of configured clients.</summary>
-      /// <param name="configuration">The client configuration.</param>
-      protected WorkerServiceClient(ClientBaseConfiguration configuration) : base(configuration)
-      {
-      }
-
-      /// <summary>
-      /// Start server with specified workload.
-      /// First request sent specifies the ServerConfig followed by ServerStatus
-      /// response. After that, a "Mark" can be sent anytime to request the latest
-      /// stats. Closing the stream will initiate shutdown of the test server
-      /// and once the shutdown has finished, the OK status is sent to terminate
-      /// this RPC.
-      /// </summary>
-      /// <param name="headers">The initial metadata to send with the call. This parameter is optional.</param>
-      /// <param name="deadline">An optional deadline for the call. The call will be cancelled if deadline is hit.</param>
-      /// <param name="cancellationToken">An optional token for canceling the call.</param>
-      /// <returns>The call object.</returns>
-      public virtual grpc::AsyncDuplexStreamingCall<global::Grpc.Testing.ServerArgs, global::Grpc.Testing.ServerStatus> RunServer(grpc::Metadata headers = null, global::System.DateTime? deadline = null, global::System.Threading.CancellationToken cancellationToken = default(global::System.Threading.CancellationToken))
-      {
-        return RunServer(new grpc::CallOptions(headers, deadline, cancellationToken));
-      }
-      /// <summary>
-      /// Start server with specified workload.
-      /// First request sent specifies the ServerConfig followed by ServerStatus
-      /// response. After that, a "Mark" can be sent anytime to request the latest
-      /// stats. Closing the stream will initiate shutdown of the test server
-      /// and once the shutdown has finished, the OK status is sent to terminate
-      /// this RPC.
-      /// </summary>
-      /// <param name="options">The options for the call.</param>
-      /// <returns>The call object.</returns>
-      public virtual grpc::AsyncDuplexStreamingCall<global::Grpc.Testing.ServerArgs, global::Grpc.Testing.ServerStatus> RunServer(grpc::CallOptions options)
-      {
-        return CallInvoker.AsyncDuplexStreamingCall(__Method_RunServer, null, options);
-      }
-      /// <summary>
-      /// Start client with specified workload.
-      /// First request sent specifies the ClientConfig followed by ClientStatus
-      /// response. After that, a "Mark" can be sent anytime to request the latest
-      /// stats. Closing the stream will initiate shutdown of the test client
-      /// and once the shutdown has finished, the OK status is sent to terminate
-      /// this RPC.
-      /// </summary>
-      /// <param name="headers">The initial metadata to send with the call. This parameter is optional.</param>
-      /// <param name="deadline">An optional deadline for the call. The call will be cancelled if deadline is hit.</param>
-      /// <param name="cancellationToken">An optional token for canceling the call.</param>
-      /// <returns>The call object.</returns>
-      public virtual grpc::AsyncDuplexStreamingCall<global::Grpc.Testing.ClientArgs, global::Grpc.Testing.ClientStatus> RunClient(grpc::Metadata headers = null, global::System.DateTime? deadline = null, global::System.Threading.CancellationToken cancellationToken = default(global::System.Threading.CancellationToken))
-      {
-        return RunClient(new grpc::CallOptions(headers, deadline, cancellationToken));
-      }
-      /// <summary>
-      /// Start client with specified workload.
-      /// First request sent specifies the ClientConfig followed by ClientStatus
-      /// response. After that, a "Mark" can be sent anytime to request the latest
-      /// stats. Closing the stream will initiate shutdown of the test client
-      /// and once the shutdown has finished, the OK status is sent to terminate
-      /// this RPC.
-      /// </summary>
-      /// <param name="options">The options for the call.</param>
-      /// <returns>The call object.</returns>
-      public virtual grpc::AsyncDuplexStreamingCall<global::Grpc.Testing.ClientArgs, global::Grpc.Testing.ClientStatus> RunClient(grpc::CallOptions options)
-      {
-        return CallInvoker.AsyncDuplexStreamingCall(__Method_RunClient, null, options);
-      }
-      /// <summary>
-      /// Just return the core count - unary call
-      /// </summary>
-      /// <param name="request">The request to send to the server.</param>
-      /// <param name="headers">The initial metadata to send with the call. This parameter is optional.</param>
-      /// <param name="deadline">An optional deadline for the call. The call will be cancelled if deadline is hit.</param>
-      /// <param name="cancellationToken">An optional token for canceling the call.</param>
-      /// <returns>The response received from the server.</returns>
-      public virtual global::Grpc.Testing.CoreResponse CoreCount(global::Grpc.Testing.CoreRequest request, grpc::Metadata headers = null, global::System.DateTime? deadline = null, global::System.Threading.CancellationToken cancellationToken = default(global::System.Threading.CancellationToken))
-      {
-        return CoreCount(request, new grpc::CallOptions(headers, deadline, cancellationToken));
-      }
-      /// <summary>
-      /// Just return the core count - unary call
-      /// </summary>
-      /// <param name="request">The request to send to the server.</param>
-      /// <param name="options">The options for the call.</param>
-      /// <returns>The response received from the server.</returns>
-      public virtual global::Grpc.Testing.CoreResponse CoreCount(global::Grpc.Testing.CoreRequest request, grpc::CallOptions options)
-      {
-        return CallInvoker.BlockingUnaryCall(__Method_CoreCount, null, options, request);
-      }
-      /// <summary>
-      /// Just return the core count - unary call
-      /// </summary>
-      /// <param name="request">The request to send to the server.</param>
-      /// <param name="headers">The initial metadata to send with the call. This parameter is optional.</param>
-      /// <param name="deadline">An optional deadline for the call. The call will be cancelled if deadline is hit.</param>
-      /// <param name="cancellationToken">An optional token for canceling the call.</param>
-      /// <returns>The call object.</returns>
-      public virtual grpc::AsyncUnaryCall<global::Grpc.Testing.CoreResponse> CoreCountAsync(global::Grpc.Testing.CoreRequest request, grpc::Metadata headers = null, global::System.DateTime? deadline = null, global::System.Threading.CancellationToken cancellationToken = default(global::System.Threading.CancellationToken))
-      {
-        return CoreCountAsync(request, new grpc::CallOptions(headers, deadline, cancellationToken));
-      }
-      /// <summary>
-      /// Just return the core count - unary call
-      /// </summary>
-      /// <param name="request">The request to send to the server.</param>
-      /// <param name="options">The options for the call.</param>
-      /// <returns>The call object.</returns>
-      public virtual grpc::AsyncUnaryCall<global::Grpc.Testing.CoreResponse> CoreCountAsync(global::Grpc.Testing.CoreRequest request, grpc::CallOptions options)
-      {
-        return CallInvoker.AsyncUnaryCall(__Method_CoreCount, null, options, request);
-      }
-      /// <summary>
-      /// Quit this worker
-      /// </summary>
-      /// <param name="request">The request to send to the server.</param>
-      /// <param name="headers">The initial metadata to send with the call. This parameter is optional.</param>
-      /// <param name="deadline">An optional deadline for the call. The call will be cancelled if deadline is hit.</param>
-      /// <param name="cancellationToken">An optional token for canceling the call.</param>
-      /// <returns>The response received from the server.</returns>
-      public virtual global::Grpc.Testing.Void QuitWorker(global::Grpc.Testing.Void request, grpc::Metadata headers = null, global::System.DateTime? deadline = null, global::System.Threading.CancellationToken cancellationToken = default(global::System.Threading.CancellationToken))
-      {
-        return QuitWorker(request, new grpc::CallOptions(headers, deadline, cancellationToken));
-      }
-      /// <summary>
-      /// Quit this worker
-      /// </summary>
-      /// <param name="request">The request to send to the server.</param>
-      /// <param name="options">The options for the call.</param>
-      /// <returns>The response received from the server.</returns>
-      public virtual global::Grpc.Testing.Void QuitWorker(global::Grpc.Testing.Void request, grpc::CallOptions options)
-      {
-        return CallInvoker.BlockingUnaryCall(__Method_QuitWorker, null, options, request);
-      }
-      /// <summary>
-      /// Quit this worker
-      /// </summary>
-      /// <param name="request">The request to send to the server.</param>
-      /// <param name="headers">The initial metadata to send with the call. This parameter is optional.</param>
-      /// <param name="deadline">An optional deadline for the call. The call will be cancelled if deadline is hit.</param>
-      /// <param name="cancellationToken">An optional token for canceling the call.</param>
-      /// <returns>The call object.</returns>
-      public virtual grpc::AsyncUnaryCall<global::Grpc.Testing.Void> QuitWorkerAsync(global::Grpc.Testing.Void request, grpc::Metadata headers = null, global::System.DateTime? deadline = null, global::System.Threading.CancellationToken cancellationToken = default(global::System.Threading.CancellationToken))
-      {
-        return QuitWorkerAsync(request, new grpc::CallOptions(headers, deadline, cancellationToken));
-      }
-      /// <summary>
-      /// Quit this worker
-      /// </summary>
-      /// <param name="request">The request to send to the server.</param>
-      /// <param name="options">The options for the call.</param>
-      /// <returns>The call object.</returns>
-      public virtual grpc::AsyncUnaryCall<global::Grpc.Testing.Void> QuitWorkerAsync(global::Grpc.Testing.Void request, grpc::CallOptions options)
-      {
-        return CallInvoker.AsyncUnaryCall(__Method_QuitWorker, null, options, request);
-      }
-      /// <summary>Creates a new instance of client from given <c>ClientBaseConfiguration</c>.</summary>
-      protected override WorkerServiceClient NewInstance(ClientBaseConfiguration configuration)
-      {
-        return new WorkerServiceClient(configuration);
-      }
-    }
-
-    /// <summary>Creates service definition that can be registered with a server</summary>
-    /// <param name="serviceImpl">An object implementing the server-side handling logic.</param>
-    public static grpc::ServerServiceDefinition BindService(WorkerServiceBase serviceImpl)
-    {
-      return grpc::ServerServiceDefinition.CreateBuilder()
-          .AddMethod(__Method_RunServer, serviceImpl.RunServer)
-          .AddMethod(__Method_RunClient, serviceImpl.RunClient)
-          .AddMethod(__Method_CoreCount, serviceImpl.CoreCount)
-          .AddMethod(__Method_QuitWorker, serviceImpl.QuitWorker).Build();
-    }
-
-  }
-  public static partial class ReportQpsScenarioService
-  {
-    static readonly string __ServiceName = "grpc.testing.ReportQpsScenarioService";
-
-    static readonly grpc::Marshaller<global::Grpc.Testing.ScenarioResult> __Marshaller_ScenarioResult = grpc::Marshallers.Create((arg) => global::Google.Protobuf.MessageExtensions.ToByteArray(arg), global::Grpc.Testing.ScenarioResult.Parser.ParseFrom);
-    static readonly grpc::Marshaller<global::Grpc.Testing.Void> __Marshaller_Void = grpc::Marshallers.Create((arg) => global::Google.Protobuf.MessageExtensions.ToByteArray(arg), global::Grpc.Testing.Void.Parser.ParseFrom);
-
-    static readonly grpc::Method<global::Grpc.Testing.ScenarioResult, global::Grpc.Testing.Void> __Method_ReportScenario = new grpc::Method<global::Grpc.Testing.ScenarioResult, global::Grpc.Testing.Void>(
-        grpc::MethodType.Unary,
-        __ServiceName,
-        "ReportScenario",
-        __Marshaller_ScenarioResult,
-        __Marshaller_Void);
-
-    /// <summary>Service descriptor</summary>
-    public static global::Google.Protobuf.Reflection.ServiceDescriptor Descriptor
-    {
-      get { return global::Grpc.Testing.ServicesReflection.Descriptor.Services[2]; }
-    }
-
-    /// <summary>Base class for server-side implementations of ReportQpsScenarioService</summary>
-    public abstract partial class ReportQpsScenarioServiceBase
-    {
-      /// <summary>
-      /// Report results of a QPS test benchmark scenario.
-      /// </summary>
-      /// <param name="request">The request received from the client.</param>
-      /// <param name="context">The context of the server-side call handler being invoked.</param>
-      /// <returns>The response to send back to the client (wrapped by a task).</returns>
-      public virtual global::System.Threading.Tasks.Task<global::Grpc.Testing.Void> ReportScenario(global::Grpc.Testing.ScenarioResult request, grpc::ServerCallContext context)
-      {
-        throw new grpc::RpcException(new grpc::Status(grpc::StatusCode.Unimplemented, ""));
-      }
-
-    }
-
-    /// <summary>Client for ReportQpsScenarioService</summary>
-    public partial class ReportQpsScenarioServiceClient : grpc::ClientBase<ReportQpsScenarioServiceClient>
-    {
-      /// <summary>Creates a new client for ReportQpsScenarioService</summary>
-      /// <param name="channel">The channel to use to make remote calls.</param>
-      public ReportQpsScenarioServiceClient(grpc::Channel channel) : base(channel)
-      {
-      }
-      /// <summary>Creates a new client for ReportQpsScenarioService that uses a custom <c>CallInvoker</c>.</summary>
-      /// <param name="callInvoker">The callInvoker to use to make remote calls.</param>
-      public ReportQpsScenarioServiceClient(grpc::CallInvoker callInvoker) : base(callInvoker)
-      {
-      }
-      /// <summary>Protected parameterless constructor to allow creation of test doubles.</summary>
-      protected ReportQpsScenarioServiceClient() : base()
-      {
-      }
-      /// <summary>Protected constructor to allow creation of configured clients.</summary>
-      /// <param name="configuration">The client configuration.</param>
-      protected ReportQpsScenarioServiceClient(ClientBaseConfiguration configuration) : base(configuration)
-      {
-      }
-
-      /// <summary>
-      /// Report results of a QPS test benchmark scenario.
-      /// </summary>
-      /// <param name="request">The request to send to the server.</param>
-      /// <param name="headers">The initial metadata to send with the call. This parameter is optional.</param>
-      /// <param name="deadline">An optional deadline for the call. The call will be cancelled if deadline is hit.</param>
-      /// <param name="cancellationToken">An optional token for canceling the call.</param>
-      /// <returns>The response received from the server.</returns>
-      public virtual global::Grpc.Testing.Void ReportScenario(global::Grpc.Testing.ScenarioResult request, grpc::Metadata headers = null, global::System.DateTime? deadline = null, global::System.Threading.CancellationToken cancellationToken = default(global::System.Threading.CancellationToken))
-      {
-        return ReportScenario(request, new grpc::CallOptions(headers, deadline, cancellationToken));
-      }
-      /// <summary>
-      /// Report results of a QPS test benchmark scenario.
-      /// </summary>
-      /// <param name="request">The request to send to the server.</param>
-      /// <param name="options">The options for the call.</param>
-      /// <returns>The response received from the server.</returns>
-      public virtual global::Grpc.Testing.Void ReportScenario(global::Grpc.Testing.ScenarioResult request, grpc::CallOptions options)
-      {
-        return CallInvoker.BlockingUnaryCall(__Method_ReportScenario, null, options, request);
-      }
-      /// <summary>
-      /// Report results of a QPS test benchmark scenario.
-      /// </summary>
-      /// <param name="request">The request to send to the server.</param>
-      /// <param name="headers">The initial metadata to send with the call. This parameter is optional.</param>
-      /// <param name="deadline">An optional deadline for the call. The call will be cancelled if deadline is hit.</param>
-      /// <param name="cancellationToken">An optional token for canceling the call.</param>
-      /// <returns>The call object.</returns>
-      public virtual grpc::AsyncUnaryCall<global::Grpc.Testing.Void> ReportScenarioAsync(global::Grpc.Testing.ScenarioResult request, grpc::Metadata headers = null, global::System.DateTime? deadline = null, global::System.Threading.CancellationToken cancellationToken = default(global::System.Threading.CancellationToken))
-      {
-        return ReportScenarioAsync(request, new grpc::CallOptions(headers, deadline, cancellationToken));
-      }
-      /// <summary>
-      /// Report results of a QPS test benchmark scenario.
-      /// </summary>
-      /// <param name="request">The request to send to the server.</param>
-      /// <param name="options">The options for the call.</param>
-      /// <returns>The call object.</returns>
-      public virtual grpc::AsyncUnaryCall<global::Grpc.Testing.Void> ReportScenarioAsync(global::Grpc.Testing.ScenarioResult request, grpc::CallOptions options)
-      {
-        return CallInvoker.AsyncUnaryCall(__Method_ReportScenario, null, options, request);
-      }
-      /// <summary>Creates a new instance of client from given <c>ClientBaseConfiguration</c>.</summary>
-      protected override ReportQpsScenarioServiceClient NewInstance(ClientBaseConfiguration configuration)
-      {
-        return new ReportQpsScenarioServiceClient(configuration);
-      }
-    }
-
-    /// <summary>Creates service definition that can be registered with a server</summary>
-    /// <param name="serviceImpl">An object implementing the server-side handling logic.</param>
-    public static grpc::ServerServiceDefinition BindService(ReportQpsScenarioServiceBase serviceImpl)
-    {
-      return grpc::ServerServiceDefinition.CreateBuilder()
-          .AddMethod(__Method_ReportScenario, serviceImpl.ReportScenario).Build();
-    }
-
-  }
-}
-#endregion
diff --git a/src/csharp/Grpc.IntegrationTesting/Stats.cs b/src/csharp/Grpc.IntegrationTesting/Stats.cs
index e082ae7719..8160646215 100644
--- a/src/csharp/Grpc.IntegrationTesting/Stats.cs
+++ b/src/csharp/Grpc.IntegrationTesting/Stats.cs
@@ -1,5 +1,7 @@
-// Generated by the protocol buffer compiler.  DO NOT EDIT!
-// source: src/proto/grpc/testing/stats.proto
+// <auto-generated>
+//     Generated by the protocol buffer compiler.  DO NOT EDIT!
+//     source: src/proto/grpc/testing/stats.proto
+// </auto-generated>
 #pragma warning disable 1591, 0612, 3021
 #region Designer generated code
 
@@ -55,6 +57,7 @@ namespace Grpc.Testing {
   #region Messages
   public sealed partial class ServerStats : pb::IMessage<ServerStats> {
     private static readonly pb::MessageParser<ServerStats> _parser = new pb::MessageParser<ServerStats>(() => new ServerStats());
+    private pb::UnknownFieldSet _unknownFields;
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public static pb::MessageParser<ServerStats> Parser { get { return _parser; } }
 
@@ -84,6 +87,7 @@ namespace Grpc.Testing {
       idleCpuTime_ = other.idleCpuTime_;
       cqPollCount_ = other.cqPollCount_;
       CoreStats = other.coreStats_ != null ? other.CoreStats.Clone() : null;
+      _unknownFields = pb::UnknownFieldSet.Clone(other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -203,26 +207,29 @@ namespace Grpc.Testing {
       if (ReferenceEquals(other, this)) {
         return true;
       }
-      if (TimeElapsed != other.TimeElapsed) return false;
-      if (TimeUser != other.TimeUser) return false;
-      if (TimeSystem != other.TimeSystem) return false;
+      if (!pbc::ProtobufEqualityComparers.BitwiseDoubleEqualityComparer.Equals(TimeElapsed, other.TimeElapsed)) return false;
+      if (!pbc::ProtobufEqualityComparers.BitwiseDoubleEqualityComparer.Equals(TimeUser, other.TimeUser)) return false;
+      if (!pbc::ProtobufEqualityComparers.BitwiseDoubleEqualityComparer.Equals(TimeSystem, other.TimeSystem)) return false;
       if (TotalCpuTime != other.TotalCpuTime) return false;
       if (IdleCpuTime != other.IdleCpuTime) return false;
       if (CqPollCount != other.CqPollCount) return false;
       if (!object.Equals(CoreStats, other.CoreStats)) return false;
-      return true;
+      return Equals(_unknownFields, other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public override int GetHashCode() {
       int hash = 1;
-      if (TimeElapsed != 0D) hash ^= TimeElapsed.GetHashCode();
-      if (TimeUser != 0D) hash ^= TimeUser.GetHashCode();
-      if (TimeSystem != 0D) hash ^= TimeSystem.GetHashCode();
+      if (TimeElapsed != 0D) hash ^= pbc::ProtobufEqualityComparers.BitwiseDoubleEqualityComparer.GetHashCode(TimeElapsed);
+      if (TimeUser != 0D) hash ^= pbc::ProtobufEqualityComparers.BitwiseDoubleEqualityComparer.GetHashCode(TimeUser);
+      if (TimeSystem != 0D) hash ^= pbc::ProtobufEqualityComparers.BitwiseDoubleEqualityComparer.GetHashCode(TimeSystem);
       if (TotalCpuTime != 0UL) hash ^= TotalCpuTime.GetHashCode();
       if (IdleCpuTime != 0UL) hash ^= IdleCpuTime.GetHashCode();
       if (CqPollCount != 0UL) hash ^= CqPollCount.GetHashCode();
       if (coreStats_ != null) hash ^= CoreStats.GetHashCode();
+      if (_unknownFields != null) {
+        hash ^= _unknownFields.GetHashCode();
+      }
       return hash;
     }
 
@@ -261,6 +268,9 @@ namespace Grpc.Testing {
         output.WriteRawTag(58);
         output.WriteMessage(CoreStats);
       }
+      if (_unknownFields != null) {
+        _unknownFields.WriteTo(output);
+      }
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -287,6 +297,9 @@ namespace Grpc.Testing {
       if (coreStats_ != null) {
         size += 1 + pb::CodedOutputStream.ComputeMessageSize(CoreStats);
       }
+      if (_unknownFields != null) {
+        size += _unknownFields.CalculateSize();
+      }
       return size;
     }
 
@@ -319,6 +332,7 @@ namespace Grpc.Testing {
         }
         CoreStats.MergeFrom(other.CoreStats);
       }
+      _unknownFields = pb::UnknownFieldSet.MergeFrom(_unknownFields, other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -327,7 +341,7 @@ namespace Grpc.Testing {
       while ((tag = input.ReadTag()) != 0) {
         switch(tag) {
           default:
-            input.SkipLastField();
+            _unknownFields = pb::UnknownFieldSet.MergeFieldFrom(_unknownFields, input);
             break;
           case 9: {
             TimeElapsed = input.ReadDouble();
@@ -371,6 +385,7 @@ namespace Grpc.Testing {
   /// </summary>
   public sealed partial class HistogramParams : pb::IMessage<HistogramParams> {
     private static readonly pb::MessageParser<HistogramParams> _parser = new pb::MessageParser<HistogramParams>(() => new HistogramParams());
+    private pb::UnknownFieldSet _unknownFields;
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public static pb::MessageParser<HistogramParams> Parser { get { return _parser; } }
 
@@ -395,6 +410,7 @@ namespace Grpc.Testing {
     public HistogramParams(HistogramParams other) : this() {
       resolution_ = other.resolution_;
       maxPossible_ = other.maxPossible_;
+      _unknownFields = pb::UnknownFieldSet.Clone(other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -443,16 +459,19 @@ namespace Grpc.Testing {
       if (ReferenceEquals(other, this)) {
         return true;
       }
-      if (Resolution != other.Resolution) return false;
-      if (MaxPossible != other.MaxPossible) return false;
-      return true;
+      if (!pbc::ProtobufEqualityComparers.BitwiseDoubleEqualityComparer.Equals(Resolution, other.Resolution)) return false;
+      if (!pbc::ProtobufEqualityComparers.BitwiseDoubleEqualityComparer.Equals(MaxPossible, other.MaxPossible)) return false;
+      return Equals(_unknownFields, other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public override int GetHashCode() {
       int hash = 1;
-      if (Resolution != 0D) hash ^= Resolution.GetHashCode();
-      if (MaxPossible != 0D) hash ^= MaxPossible.GetHashCode();
+      if (Resolution != 0D) hash ^= pbc::ProtobufEqualityComparers.BitwiseDoubleEqualityComparer.GetHashCode(Resolution);
+      if (MaxPossible != 0D) hash ^= pbc::ProtobufEqualityComparers.BitwiseDoubleEqualityComparer.GetHashCode(MaxPossible);
+      if (_unknownFields != null) {
+        hash ^= _unknownFields.GetHashCode();
+      }
       return hash;
     }
 
@@ -471,6 +490,9 @@ namespace Grpc.Testing {
         output.WriteRawTag(17);
         output.WriteDouble(MaxPossible);
       }
+      if (_unknownFields != null) {
+        _unknownFields.WriteTo(output);
+      }
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -482,6 +504,9 @@ namespace Grpc.Testing {
       if (MaxPossible != 0D) {
         size += 1 + 8;
       }
+      if (_unknownFields != null) {
+        size += _unknownFields.CalculateSize();
+      }
       return size;
     }
 
@@ -496,6 +521,7 @@ namespace Grpc.Testing {
       if (other.MaxPossible != 0D) {
         MaxPossible = other.MaxPossible;
       }
+      _unknownFields = pb::UnknownFieldSet.MergeFrom(_unknownFields, other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -504,7 +530,7 @@ namespace Grpc.Testing {
       while ((tag = input.ReadTag()) != 0) {
         switch(tag) {
           default:
-            input.SkipLastField();
+            _unknownFields = pb::UnknownFieldSet.MergeFieldFrom(_unknownFields, input);
             break;
           case 9: {
             Resolution = input.ReadDouble();
@@ -525,6 +551,7 @@ namespace Grpc.Testing {
   /// </summary>
   public sealed partial class HistogramData : pb::IMessage<HistogramData> {
     private static readonly pb::MessageParser<HistogramData> _parser = new pb::MessageParser<HistogramData>(() => new HistogramData());
+    private pb::UnknownFieldSet _unknownFields;
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public static pb::MessageParser<HistogramData> Parser { get { return _parser; } }
 
@@ -553,6 +580,7 @@ namespace Grpc.Testing {
       sum_ = other.sum_;
       sumOfSquares_ = other.sumOfSquares_;
       count_ = other.count_;
+      _unknownFields = pb::UnknownFieldSet.Clone(other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -639,23 +667,26 @@ namespace Grpc.Testing {
         return true;
       }
       if(!bucket_.Equals(other.bucket_)) return false;
-      if (MinSeen != other.MinSeen) return false;
-      if (MaxSeen != other.MaxSeen) return false;
-      if (Sum != other.Sum) return false;
-      if (SumOfSquares != other.SumOfSquares) return false;
-      if (Count != other.Count) return false;
-      return true;
+      if (!pbc::ProtobufEqualityComparers.BitwiseDoubleEqualityComparer.Equals(MinSeen, other.MinSeen)) return false;
+      if (!pbc::ProtobufEqualityComparers.BitwiseDoubleEqualityComparer.Equals(MaxSeen, other.MaxSeen)) return false;
+      if (!pbc::ProtobufEqualityComparers.BitwiseDoubleEqualityComparer.Equals(Sum, other.Sum)) return false;
+      if (!pbc::ProtobufEqualityComparers.BitwiseDoubleEqualityComparer.Equals(SumOfSquares, other.SumOfSquares)) return false;
+      if (!pbc::ProtobufEqualityComparers.BitwiseDoubleEqualityComparer.Equals(Count, other.Count)) return false;
+      return Equals(_unknownFields, other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public override int GetHashCode() {
       int hash = 1;
       hash ^= bucket_.GetHashCode();
-      if (MinSeen != 0D) hash ^= MinSeen.GetHashCode();
-      if (MaxSeen != 0D) hash ^= MaxSeen.GetHashCode();
-      if (Sum != 0D) hash ^= Sum.GetHashCode();
-      if (SumOfSquares != 0D) hash ^= SumOfSquares.GetHashCode();
-      if (Count != 0D) hash ^= Count.GetHashCode();
+      if (MinSeen != 0D) hash ^= pbc::ProtobufEqualityComparers.BitwiseDoubleEqualityComparer.GetHashCode(MinSeen);
+      if (MaxSeen != 0D) hash ^= pbc::ProtobufEqualityComparers.BitwiseDoubleEqualityComparer.GetHashCode(MaxSeen);
+      if (Sum != 0D) hash ^= pbc::ProtobufEqualityComparers.BitwiseDoubleEqualityComparer.GetHashCode(Sum);
+      if (SumOfSquares != 0D) hash ^= pbc::ProtobufEqualityComparers.BitwiseDoubleEqualityComparer.GetHashCode(SumOfSquares);
+      if (Count != 0D) hash ^= pbc::ProtobufEqualityComparers.BitwiseDoubleEqualityComparer.GetHashCode(Count);
+      if (_unknownFields != null) {
+        hash ^= _unknownFields.GetHashCode();
+      }
       return hash;
     }
 
@@ -687,6 +718,9 @@ namespace Grpc.Testing {
         output.WriteRawTag(49);
         output.WriteDouble(Count);
       }
+      if (_unknownFields != null) {
+        _unknownFields.WriteTo(output);
+      }
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -708,6 +742,9 @@ namespace Grpc.Testing {
       if (Count != 0D) {
         size += 1 + 8;
       }
+      if (_unknownFields != null) {
+        size += _unknownFields.CalculateSize();
+      }
       return size;
     }
 
@@ -732,6 +769,7 @@ namespace Grpc.Testing {
       if (other.Count != 0D) {
         Count = other.Count;
       }
+      _unknownFields = pb::UnknownFieldSet.MergeFrom(_unknownFields, other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -740,7 +778,7 @@ namespace Grpc.Testing {
       while ((tag = input.ReadTag()) != 0) {
         switch(tag) {
           default:
-            input.SkipLastField();
+            _unknownFields = pb::UnknownFieldSet.MergeFieldFrom(_unknownFields, input);
             break;
           case 10:
           case 8: {
@@ -775,6 +813,7 @@ namespace Grpc.Testing {
 
   public sealed partial class RequestResultCount : pb::IMessage<RequestResultCount> {
     private static readonly pb::MessageParser<RequestResultCount> _parser = new pb::MessageParser<RequestResultCount>(() => new RequestResultCount());
+    private pb::UnknownFieldSet _unknownFields;
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public static pb::MessageParser<RequestResultCount> Parser { get { return _parser; } }
 
@@ -799,6 +838,7 @@ namespace Grpc.Testing {
     public RequestResultCount(RequestResultCount other) : this() {
       statusCode_ = other.statusCode_;
       count_ = other.count_;
+      _unknownFields = pb::UnknownFieldSet.Clone(other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -843,7 +883,7 @@ namespace Grpc.Testing {
       }
       if (StatusCode != other.StatusCode) return false;
       if (Count != other.Count) return false;
-      return true;
+      return Equals(_unknownFields, other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -851,6 +891,9 @@ namespace Grpc.Testing {
       int hash = 1;
       if (StatusCode != 0) hash ^= StatusCode.GetHashCode();
       if (Count != 0L) hash ^= Count.GetHashCode();
+      if (_unknownFields != null) {
+        hash ^= _unknownFields.GetHashCode();
+      }
       return hash;
     }
 
@@ -869,6 +912,9 @@ namespace Grpc.Testing {
         output.WriteRawTag(16);
         output.WriteInt64(Count);
       }
+      if (_unknownFields != null) {
+        _unknownFields.WriteTo(output);
+      }
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -880,6 +926,9 @@ namespace Grpc.Testing {
       if (Count != 0L) {
         size += 1 + pb::CodedOutputStream.ComputeInt64Size(Count);
       }
+      if (_unknownFields != null) {
+        size += _unknownFields.CalculateSize();
+      }
       return size;
     }
 
@@ -894,6 +943,7 @@ namespace Grpc.Testing {
       if (other.Count != 0L) {
         Count = other.Count;
       }
+      _unknownFields = pb::UnknownFieldSet.MergeFrom(_unknownFields, other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -902,7 +952,7 @@ namespace Grpc.Testing {
       while ((tag = input.ReadTag()) != 0) {
         switch(tag) {
           default:
-            input.SkipLastField();
+            _unknownFields = pb::UnknownFieldSet.MergeFieldFrom(_unknownFields, input);
             break;
           case 8: {
             StatusCode = input.ReadInt32();
@@ -920,6 +970,7 @@ namespace Grpc.Testing {
 
   public sealed partial class ClientStats : pb::IMessage<ClientStats> {
     private static readonly pb::MessageParser<ClientStats> _parser = new pb::MessageParser<ClientStats>(() => new ClientStats());
+    private pb::UnknownFieldSet _unknownFields;
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public static pb::MessageParser<ClientStats> Parser { get { return _parser; } }
 
@@ -949,6 +1000,7 @@ namespace Grpc.Testing {
       requestResults_ = other.requestResults_.Clone();
       cqPollCount_ = other.cqPollCount_;
       CoreStats = other.coreStats_ != null ? other.CoreStats.Clone() : null;
+      _unknownFields = pb::UnknownFieldSet.Clone(other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -1061,25 +1113,28 @@ namespace Grpc.Testing {
         return true;
       }
       if (!object.Equals(Latencies, other.Latencies)) return false;
-      if (TimeElapsed != other.TimeElapsed) return false;
-      if (TimeUser != other.TimeUser) return false;
-      if (TimeSystem != other.TimeSystem) return false;
+      if (!pbc::ProtobufEqualityComparers.BitwiseDoubleEqualityComparer.Equals(TimeElapsed, other.TimeElapsed)) return false;
+      if (!pbc::ProtobufEqualityComparers.BitwiseDoubleEqualityComparer.Equals(TimeUser, other.TimeUser)) return false;
+      if (!pbc::ProtobufEqualityComparers.BitwiseDoubleEqualityComparer.Equals(TimeSystem, other.TimeSystem)) return false;
       if(!requestResults_.Equals(other.requestResults_)) return false;
       if (CqPollCount != other.CqPollCount) return false;
       if (!object.Equals(CoreStats, other.CoreStats)) return false;
-      return true;
+      return Equals(_unknownFields, other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public override int GetHashCode() {
       int hash = 1;
       if (latencies_ != null) hash ^= Latencies.GetHashCode();
-      if (TimeElapsed != 0D) hash ^= TimeElapsed.GetHashCode();
-      if (TimeUser != 0D) hash ^= TimeUser.GetHashCode();
-      if (TimeSystem != 0D) hash ^= TimeSystem.GetHashCode();
+      if (TimeElapsed != 0D) hash ^= pbc::ProtobufEqualityComparers.BitwiseDoubleEqualityComparer.GetHashCode(TimeElapsed);
+      if (TimeUser != 0D) hash ^= pbc::ProtobufEqualityComparers.BitwiseDoubleEqualityComparer.GetHashCode(TimeUser);
+      if (TimeSystem != 0D) hash ^= pbc::ProtobufEqualityComparers.BitwiseDoubleEqualityComparer.GetHashCode(TimeSystem);
       hash ^= requestResults_.GetHashCode();
       if (CqPollCount != 0UL) hash ^= CqPollCount.GetHashCode();
       if (coreStats_ != null) hash ^= CoreStats.GetHashCode();
+      if (_unknownFields != null) {
+        hash ^= _unknownFields.GetHashCode();
+      }
       return hash;
     }
 
@@ -1115,6 +1170,9 @@ namespace Grpc.Testing {
         output.WriteRawTag(58);
         output.WriteMessage(CoreStats);
       }
+      if (_unknownFields != null) {
+        _unknownFields.WriteTo(output);
+      }
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -1139,6 +1197,9 @@ namespace Grpc.Testing {
       if (coreStats_ != null) {
         size += 1 + pb::CodedOutputStream.ComputeMessageSize(CoreStats);
       }
+      if (_unknownFields != null) {
+        size += _unknownFields.CalculateSize();
+      }
       return size;
     }
 
@@ -1172,6 +1233,7 @@ namespace Grpc.Testing {
         }
         CoreStats.MergeFrom(other.CoreStats);
       }
+      _unknownFields = pb::UnknownFieldSet.MergeFrom(_unknownFields, other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -1180,7 +1242,7 @@ namespace Grpc.Testing {
       while ((tag = input.ReadTag()) != 0) {
         switch(tag) {
           default:
-            input.SkipLastField();
+            _unknownFields = pb::UnknownFieldSet.MergeFieldFrom(_unknownFields, input);
             break;
           case 10: {
             if (latencies_ == null) {
diff --git a/src/csharp/Grpc.IntegrationTesting/Test.cs b/src/csharp/Grpc.IntegrationTesting/Test.cs
index d2fa9f8013..03f92c7657 100644
--- a/src/csharp/Grpc.IntegrationTesting/Test.cs
+++ b/src/csharp/Grpc.IntegrationTesting/Test.cs
@@ -1,5 +1,7 @@
-// Generated by the protocol buffer compiler.  DO NOT EDIT!
-// source: src/proto/grpc/testing/test.proto
+// <auto-generated>
+//     Generated by the protocol buffer compiler.  DO NOT EDIT!
+//     source: src/proto/grpc/testing/test.proto
+// </auto-generated>
 #pragma warning disable 1591, 0612, 3021
 #region Designer generated code
 
diff --git a/src/csharp/Grpc.IntegrationTesting/WorkerService.cs b/src/csharp/Grpc.IntegrationTesting/WorkerService.cs
new file mode 100644
index 0000000000..6de3193d82
--- /dev/null
+++ b/src/csharp/Grpc.IntegrationTesting/WorkerService.cs
@@ -0,0 +1,45 @@
+// <auto-generated>
+//     Generated by the protocol buffer compiler.  DO NOT EDIT!
+//     source: src/proto/grpc/testing/worker_service.proto
+// </auto-generated>
+#pragma warning disable 1591, 0612, 3021
+#region Designer generated code
+
+using pb = global::Google.Protobuf;
+using pbc = global::Google.Protobuf.Collections;
+using pbr = global::Google.Protobuf.Reflection;
+using scg = global::System.Collections.Generic;
+namespace Grpc.Testing {
+
+  /// <summary>Holder for reflection information generated from src/proto/grpc/testing/worker_service.proto</summary>
+  public static partial class WorkerServiceReflection {
+
+    #region Descriptor
+    /// <summary>File descriptor for src/proto/grpc/testing/worker_service.proto</summary>
+    public static pbr::FileDescriptor Descriptor {
+      get { return descriptor; }
+    }
+    private static pbr::FileDescriptor descriptor;
+
+    static WorkerServiceReflection() {
+      byte[] descriptorData = global::System.Convert.FromBase64String(
+          string.Concat(
+            "CitzcmMvcHJvdG8vZ3JwYy90ZXN0aW5nL3dvcmtlcl9zZXJ2aWNlLnByb3Rv",
+            "EgxncnBjLnRlc3RpbmcaJHNyYy9wcm90by9ncnBjL3Rlc3RpbmcvY29udHJv",
+            "bC5wcm90bzKXAgoNV29ya2VyU2VydmljZRJFCglSdW5TZXJ2ZXISGC5ncnBj",
+            "LnRlc3RpbmcuU2VydmVyQXJncxoaLmdycGMudGVzdGluZy5TZXJ2ZXJTdGF0",
+            "dXMoATABEkUKCVJ1bkNsaWVudBIYLmdycGMudGVzdGluZy5DbGllbnRBcmdz",
+            "GhouZ3JwYy50ZXN0aW5nLkNsaWVudFN0YXR1cygBMAESQgoJQ29yZUNvdW50",
+            "EhkuZ3JwYy50ZXN0aW5nLkNvcmVSZXF1ZXN0GhouZ3JwYy50ZXN0aW5nLkNv",
+            "cmVSZXNwb25zZRI0CgpRdWl0V29ya2VyEhIuZ3JwYy50ZXN0aW5nLlZvaWQa",
+            "Ei5ncnBjLnRlc3RpbmcuVm9pZGIGcHJvdG8z"));
+      descriptor = pbr::FileDescriptor.FromGeneratedCode(descriptorData,
+          new pbr::FileDescriptor[] { global::Grpc.Testing.ControlReflection.Descriptor, },
+          new pbr::GeneratedClrTypeInfo(null, null));
+    }
+    #endregion
+
+  }
+}
+
+#endregion Designer generated code
diff --git a/src/csharp/Grpc.IntegrationTesting/WorkerServiceGrpc.cs b/src/csharp/Grpc.IntegrationTesting/WorkerServiceGrpc.cs
new file mode 100644
index 0000000000..ede3ace461
--- /dev/null
+++ b/src/csharp/Grpc.IntegrationTesting/WorkerServiceGrpc.cs
@@ -0,0 +1,326 @@
+// <auto-generated>
+//     Generated by the protocol buffer compiler.  DO NOT EDIT!
+//     source: src/proto/grpc/testing/worker_service.proto
+// </auto-generated>
+// Original file comments:
+// Copyright 2015 gRPC authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+// An integration test service that covers all the method signature permutations
+// of unary/streaming requests/responses.
+#pragma warning disable 1591
+#region Designer generated code
+
+using grpc = global::Grpc.Core;
+
+namespace Grpc.Testing {
+  public static partial class WorkerService
+  {
+    static readonly string __ServiceName = "grpc.testing.WorkerService";
+
+    static readonly grpc::Marshaller<global::Grpc.Testing.ServerArgs> __Marshaller_ServerArgs = grpc::Marshallers.Create((arg) => global::Google.Protobuf.MessageExtensions.ToByteArray(arg), global::Grpc.Testing.ServerArgs.Parser.ParseFrom);
+    static readonly grpc::Marshaller<global::Grpc.Testing.ServerStatus> __Marshaller_ServerStatus = grpc::Marshallers.Create((arg) => global::Google.Protobuf.MessageExtensions.ToByteArray(arg), global::Grpc.Testing.ServerStatus.Parser.ParseFrom);
+    static readonly grpc::Marshaller<global::Grpc.Testing.ClientArgs> __Marshaller_ClientArgs = grpc::Marshallers.Create((arg) => global::Google.Protobuf.MessageExtensions.ToByteArray(arg), global::Grpc.Testing.ClientArgs.Parser.ParseFrom);
+    static readonly grpc::Marshaller<global::Grpc.Testing.ClientStatus> __Marshaller_ClientStatus = grpc::Marshallers.Create((arg) => global::Google.Protobuf.MessageExtensions.ToByteArray(arg), global::Grpc.Testing.ClientStatus.Parser.ParseFrom);
+    static readonly grpc::Marshaller<global::Grpc.Testing.CoreRequest> __Marshaller_CoreRequest = grpc::Marshallers.Create((arg) => global::Google.Protobuf.MessageExtensions.ToByteArray(arg), global::Grpc.Testing.CoreRequest.Parser.ParseFrom);
+    static readonly grpc::Marshaller<global::Grpc.Testing.CoreResponse> __Marshaller_CoreResponse = grpc::Marshallers.Create((arg) => global::Google.Protobuf.MessageExtensions.ToByteArray(arg), global::Grpc.Testing.CoreResponse.Parser.ParseFrom);
+    static readonly grpc::Marshaller<global::Grpc.Testing.Void> __Marshaller_Void = grpc::Marshallers.Create((arg) => global::Google.Protobuf.MessageExtensions.ToByteArray(arg), global::Grpc.Testing.Void.Parser.ParseFrom);
+
+    static readonly grpc::Method<global::Grpc.Testing.ServerArgs, global::Grpc.Testing.ServerStatus> __Method_RunServer = new grpc::Method<global::Grpc.Testing.ServerArgs, global::Grpc.Testing.ServerStatus>(
+        grpc::MethodType.DuplexStreaming,
+        __ServiceName,
+        "RunServer",
+        __Marshaller_ServerArgs,
+        __Marshaller_ServerStatus);
+
+    static readonly grpc::Method<global::Grpc.Testing.ClientArgs, global::Grpc.Testing.ClientStatus> __Method_RunClient = new grpc::Method<global::Grpc.Testing.ClientArgs, global::Grpc.Testing.ClientStatus>(
+        grpc::MethodType.DuplexStreaming,
+        __ServiceName,
+        "RunClient",
+        __Marshaller_ClientArgs,
+        __Marshaller_ClientStatus);
+
+    static readonly grpc::Method<global::Grpc.Testing.CoreRequest, global::Grpc.Testing.CoreResponse> __Method_CoreCount = new grpc::Method<global::Grpc.Testing.CoreRequest, global::Grpc.Testing.CoreResponse>(
+        grpc::MethodType.Unary,
+        __ServiceName,
+        "CoreCount",
+        __Marshaller_CoreRequest,
+        __Marshaller_CoreResponse);
+
+    static readonly grpc::Method<global::Grpc.Testing.Void, global::Grpc.Testing.Void> __Method_QuitWorker = new grpc::Method<global::Grpc.Testing.Void, global::Grpc.Testing.Void>(
+        grpc::MethodType.Unary,
+        __ServiceName,
+        "QuitWorker",
+        __Marshaller_Void,
+        __Marshaller_Void);
+
+    /// <summary>Service descriptor</summary>
+    public static global::Google.Protobuf.Reflection.ServiceDescriptor Descriptor
+    {
+      get { return global::Grpc.Testing.WorkerServiceReflection.Descriptor.Services[0]; }
+    }
+
+    /// <summary>Base class for server-side implementations of WorkerService</summary>
+    public abstract partial class WorkerServiceBase
+    {
+      /// <summary>
+      /// Start server with specified workload.
+      /// First request sent specifies the ServerConfig followed by ServerStatus
+      /// response. After that, a "Mark" can be sent anytime to request the latest
+      /// stats. Closing the stream will initiate shutdown of the test server
+      /// and once the shutdown has finished, the OK status is sent to terminate
+      /// this RPC.
+      /// </summary>
+      /// <param name="requestStream">Used for reading requests from the client.</param>
+      /// <param name="responseStream">Used for sending responses back to the client.</param>
+      /// <param name="context">The context of the server-side call handler being invoked.</param>
+      /// <returns>A task indicating completion of the handler.</returns>
+      public virtual global::System.Threading.Tasks.Task RunServer(grpc::IAsyncStreamReader<global::Grpc.Testing.ServerArgs> requestStream, grpc::IServerStreamWriter<global::Grpc.Testing.ServerStatus> responseStream, grpc::ServerCallContext context)
+      {
+        throw new grpc::RpcException(new grpc::Status(grpc::StatusCode.Unimplemented, ""));
+      }
+
+      /// <summary>
+      /// Start client with specified workload.
+      /// First request sent specifies the ClientConfig followed by ClientStatus
+      /// response. After that, a "Mark" can be sent anytime to request the latest
+      /// stats. Closing the stream will initiate shutdown of the test client
+      /// and once the shutdown has finished, the OK status is sent to terminate
+      /// this RPC.
+      /// </summary>
+      /// <param name="requestStream">Used for reading requests from the client.</param>
+      /// <param name="responseStream">Used for sending responses back to the client.</param>
+      /// <param name="context">The context of the server-side call handler being invoked.</param>
+      /// <returns>A task indicating completion of the handler.</returns>
+      public virtual global::System.Threading.Tasks.Task RunClient(grpc::IAsyncStreamReader<global::Grpc.Testing.ClientArgs> requestStream, grpc::IServerStreamWriter<global::Grpc.Testing.ClientStatus> responseStream, grpc::ServerCallContext context)
+      {
+        throw new grpc::RpcException(new grpc::Status(grpc::StatusCode.Unimplemented, ""));
+      }
+
+      /// <summary>
+      /// Just return the core count - unary call
+      /// </summary>
+      /// <param name="request">The request received from the client.</param>
+      /// <param name="context">The context of the server-side call handler being invoked.</param>
+      /// <returns>The response to send back to the client (wrapped by a task).</returns>
+      public virtual global::System.Threading.Tasks.Task<global::Grpc.Testing.CoreResponse> CoreCount(global::Grpc.Testing.CoreRequest request, grpc::ServerCallContext context)
+      {
+        throw new grpc::RpcException(new grpc::Status(grpc::StatusCode.Unimplemented, ""));
+      }
+
+      /// <summary>
+      /// Quit this worker
+      /// </summary>
+      /// <param name="request">The request received from the client.</param>
+      /// <param name="context">The context of the server-side call handler being invoked.</param>
+      /// <returns>The response to send back to the client (wrapped by a task).</returns>
+      public virtual global::System.Threading.Tasks.Task<global::Grpc.Testing.Void> QuitWorker(global::Grpc.Testing.Void request, grpc::ServerCallContext context)
+      {
+        throw new grpc::RpcException(new grpc::Status(grpc::StatusCode.Unimplemented, ""));
+      }
+
+    }
+
+    /// <summary>Client for WorkerService</summary>
+    public partial class WorkerServiceClient : grpc::ClientBase<WorkerServiceClient>
+    {
+      /// <summary>Creates a new client for WorkerService</summary>
+      /// <param name="channel">The channel to use to make remote calls.</param>
+      public WorkerServiceClient(grpc::Channel channel) : base(channel)
+      {
+      }
+      /// <summary>Creates a new client for WorkerService that uses a custom <c>CallInvoker</c>.</summary>
+      /// <param name="callInvoker">The callInvoker to use to make remote calls.</param>
+      public WorkerServiceClient(grpc::CallInvoker callInvoker) : base(callInvoker)
+      {
+      }
+      /// <summary>Protected parameterless constructor to allow creation of test doubles.</summary>
+      protected WorkerServiceClient() : base()
+      {
+      }
+      /// <summary>Protected constructor to allow creation of configured clients.</summary>
+      /// <param name="configuration">The client configuration.</param>
+      protected WorkerServiceClient(ClientBaseConfiguration configuration) : base(configuration)
+      {
+      }
+
+      /// <summary>
+      /// Start server with specified workload.
+      /// First request sent specifies the ServerConfig followed by ServerStatus
+      /// response. After that, a "Mark" can be sent anytime to request the latest
+      /// stats. Closing the stream will initiate shutdown of the test server
+      /// and once the shutdown has finished, the OK status is sent to terminate
+      /// this RPC.
+      /// </summary>
+      /// <param name="headers">The initial metadata to send with the call. This parameter is optional.</param>
+      /// <param name="deadline">An optional deadline for the call. The call will be cancelled if deadline is hit.</param>
+      /// <param name="cancellationToken">An optional token for canceling the call.</param>
+      /// <returns>The call object.</returns>
+      public virtual grpc::AsyncDuplexStreamingCall<global::Grpc.Testing.ServerArgs, global::Grpc.Testing.ServerStatus> RunServer(grpc::Metadata headers = null, global::System.DateTime? deadline = null, global::System.Threading.CancellationToken cancellationToken = default(global::System.Threading.CancellationToken))
+      {
+        return RunServer(new grpc::CallOptions(headers, deadline, cancellationToken));
+      }
+      /// <summary>
+      /// Start server with specified workload.
+      /// First request sent specifies the ServerConfig followed by ServerStatus
+      /// response. After that, a "Mark" can be sent anytime to request the latest
+      /// stats. Closing the stream will initiate shutdown of the test server
+      /// and once the shutdown has finished, the OK status is sent to terminate
+      /// this RPC.
+      /// </summary>
+      /// <param name="options">The options for the call.</param>
+      /// <returns>The call object.</returns>
+      public virtual grpc::AsyncDuplexStreamingCall<global::Grpc.Testing.ServerArgs, global::Grpc.Testing.ServerStatus> RunServer(grpc::CallOptions options)
+      {
+        return CallInvoker.AsyncDuplexStreamingCall(__Method_RunServer, null, options);
+      }
+      /// <summary>
+      /// Start client with specified workload.
+      /// First request sent specifies the ClientConfig followed by ClientStatus
+      /// response. After that, a "Mark" can be sent anytime to request the latest
+      /// stats. Closing the stream will initiate shutdown of the test client
+      /// and once the shutdown has finished, the OK status is sent to terminate
+      /// this RPC.
+      /// </summary>
+      /// <param name="headers">The initial metadata to send with the call. This parameter is optional.</param>
+      /// <param name="deadline">An optional deadline for the call. The call will be cancelled if deadline is hit.</param>
+      /// <param name="cancellationToken">An optional token for canceling the call.</param>
+      /// <returns>The call object.</returns>
+      public virtual grpc::AsyncDuplexStreamingCall<global::Grpc.Testing.ClientArgs, global::Grpc.Testing.ClientStatus> RunClient(grpc::Metadata headers = null, global::System.DateTime? deadline = null, global::System.Threading.CancellationToken cancellationToken = default(global::System.Threading.CancellationToken))
+      {
+        return RunClient(new grpc::CallOptions(headers, deadline, cancellationToken));
+      }
+      /// <summary>
+      /// Start client with specified workload.
+      /// First request sent specifies the ClientConfig followed by ClientStatus
+      /// response. After that, a "Mark" can be sent anytime to request the latest
+      /// stats. Closing the stream will initiate shutdown of the test client
+      /// and once the shutdown has finished, the OK status is sent to terminate
+      /// this RPC.
+      /// </summary>
+      /// <param name="options">The options for the call.</param>
+      /// <returns>The call object.</returns>
+      public virtual grpc::AsyncDuplexStreamingCall<global::Grpc.Testing.ClientArgs, global::Grpc.Testing.ClientStatus> RunClient(grpc::CallOptions options)
+      {
+        return CallInvoker.AsyncDuplexStreamingCall(__Method_RunClient, null, options);
+      }
+      /// <summary>
+      /// Just return the core count - unary call
+      /// </summary>
+      /// <param name="request">The request to send to the server.</param>
+      /// <param name="headers">The initial metadata to send with the call. This parameter is optional.</param>
+      /// <param name="deadline">An optional deadline for the call. The call will be cancelled if deadline is hit.</param>
+      /// <param name="cancellationToken">An optional token for canceling the call.</param>
+      /// <returns>The response received from the server.</returns>
+      public virtual global::Grpc.Testing.CoreResponse CoreCount(global::Grpc.Testing.CoreRequest request, grpc::Metadata headers = null, global::System.DateTime? deadline = null, global::System.Threading.CancellationToken cancellationToken = default(global::System.Threading.CancellationToken))
+      {
+        return CoreCount(request, new grpc::CallOptions(headers, deadline, cancellationToken));
+      }
+      /// <summary>
+      /// Just return the core count - unary call
+      /// </summary>
+      /// <param name="request">The request to send to the server.</param>
+      /// <param name="options">The options for the call.</param>
+      /// <returns>The response received from the server.</returns>
+      public virtual global::Grpc.Testing.CoreResponse CoreCount(global::Grpc.Testing.CoreRequest request, grpc::CallOptions options)
+      {
+        return CallInvoker.BlockingUnaryCall(__Method_CoreCount, null, options, request);
+      }
+      /// <summary>
+      /// Just return the core count - unary call
+      /// </summary>
+      /// <param name="request">The request to send to the server.</param>
+      /// <param name="headers">The initial metadata to send with the call. This parameter is optional.</param>
+      /// <param name="deadline">An optional deadline for the call. The call will be cancelled if deadline is hit.</param>
+      /// <param name="cancellationToken">An optional token for canceling the call.</param>
+      /// <returns>The call object.</returns>
+      public virtual grpc::AsyncUnaryCall<global::Grpc.Testing.CoreResponse> CoreCountAsync(global::Grpc.Testing.CoreRequest request, grpc::Metadata headers = null, global::System.DateTime? deadline = null, global::System.Threading.CancellationToken cancellationToken = default(global::System.Threading.CancellationToken))
+      {
+        return CoreCountAsync(request, new grpc::CallOptions(headers, deadline, cancellationToken));
+      }
+      /// <summary>
+      /// Just return the core count - unary call
+      /// </summary>
+      /// <param name="request">The request to send to the server.</param>
+      /// <param name="options">The options for the call.</param>
+      /// <returns>The call object.</returns>
+      public virtual grpc::AsyncUnaryCall<global::Grpc.Testing.CoreResponse> CoreCountAsync(global::Grpc.Testing.CoreRequest request, grpc::CallOptions options)
+      {
+        return CallInvoker.AsyncUnaryCall(__Method_CoreCount, null, options, request);
+      }
+      /// <summary>
+      /// Quit this worker
+      /// </summary>
+      /// <param name="request">The request to send to the server.</param>
+      /// <param name="headers">The initial metadata to send with the call. This parameter is optional.</param>
+      /// <param name="deadline">An optional deadline for the call. The call will be cancelled if deadline is hit.</param>
+      /// <param name="cancellationToken">An optional token for canceling the call.</param>
+      /// <returns>The response received from the server.</returns>
+      public virtual global::Grpc.Testing.Void QuitWorker(global::Grpc.Testing.Void request, grpc::Metadata headers = null, global::System.DateTime? deadline = null, global::System.Threading.CancellationToken cancellationToken = default(global::System.Threading.CancellationToken))
+      {
+        return QuitWorker(request, new grpc::CallOptions(headers, deadline, cancellationToken));
+      }
+      /// <summary>
+      /// Quit this worker
+      /// </summary>
+      /// <param name="request">The request to send to the server.</param>
+      /// <param name="options">The options for the call.</param>
+      /// <returns>The response received from the server.</returns>
+      public virtual global::Grpc.Testing.Void QuitWorker(global::Grpc.Testing.Void request, grpc::CallOptions options)
+      {
+        return CallInvoker.BlockingUnaryCall(__Method_QuitWorker, null, options, request);
+      }
+      /// <summary>
+      /// Quit this worker
+      /// </summary>
+      /// <param name="request">The request to send to the server.</param>
+      /// <param name="headers">The initial metadata to send with the call. This parameter is optional.</param>
+      /// <param name="deadline">An optional deadline for the call. The call will be cancelled if deadline is hit.</param>
+      /// <param name="cancellationToken">An optional token for canceling the call.</param>
+      /// <returns>The call object.</returns>
+      public virtual grpc::AsyncUnaryCall<global::Grpc.Testing.Void> QuitWorkerAsync(global::Grpc.Testing.Void request, grpc::Metadata headers = null, global::System.DateTime? deadline = null, global::System.Threading.CancellationToken cancellationToken = default(global::System.Threading.CancellationToken))
+      {
+        return QuitWorkerAsync(request, new grpc::CallOptions(headers, deadline, cancellationToken));
+      }
+      /// <summary>
+      /// Quit this worker
+      /// </summary>
+      /// <param name="request">The request to send to the server.</param>
+      /// <param name="options">The options for the call.</param>
+      /// <returns>The call object.</returns>
+      public virtual grpc::AsyncUnaryCall<global::Grpc.Testing.Void> QuitWorkerAsync(global::Grpc.Testing.Void request, grpc::CallOptions options)
+      {
+        return CallInvoker.AsyncUnaryCall(__Method_QuitWorker, null, options, request);
+      }
+      /// <summary>Creates a new instance of client from given <c>ClientBaseConfiguration</c>.</summary>
+      protected override WorkerServiceClient NewInstance(ClientBaseConfiguration configuration)
+      {
+        return new WorkerServiceClient(configuration);
+      }
+    }
+
+    /// <summary>Creates service definition that can be registered with a server</summary>
+    /// <param name="serviceImpl">An object implementing the server-side handling logic.</param>
+    public static grpc::ServerServiceDefinition BindService(WorkerServiceBase serviceImpl)
+    {
+      return grpc::ServerServiceDefinition.CreateBuilder()
+          .AddMethod(__Method_RunServer, serviceImpl.RunServer)
+          .AddMethod(__Method_RunClient, serviceImpl.RunClient)
+          .AddMethod(__Method_CoreCount, serviceImpl.CoreCount)
+          .AddMethod(__Method_QuitWorker, serviceImpl.QuitWorker).Build();
+    }
+
+  }
+}
+#endregion
diff --git a/src/csharp/Grpc.Reflection/Reflection.cs b/src/csharp/Grpc.Reflection/Reflection.cs
index 60090e5364..84b2a0a842 100644
--- a/src/csharp/Grpc.Reflection/Reflection.cs
+++ b/src/csharp/Grpc.Reflection/Reflection.cs
@@ -1,5 +1,7 @@
-// Generated by the protocol buffer compiler.  DO NOT EDIT!
-// source: grpc/reflection/v1alpha/reflection.proto
+// <auto-generated>
+//     Generated by the protocol buffer compiler.  DO NOT EDIT!
+//     source: grpc/reflection/v1alpha/reflection.proto
+// </auto-generated>
 #pragma warning disable 1591, 0612, 3021
 #region Designer generated code
 
@@ -74,6 +76,7 @@ namespace Grpc.Reflection.V1Alpha {
   /// </summary>
   public sealed partial class ServerReflectionRequest : pb::IMessage<ServerReflectionRequest> {
     private static readonly pb::MessageParser<ServerReflectionRequest> _parser = new pb::MessageParser<ServerReflectionRequest>(() => new ServerReflectionRequest());
+    private pb::UnknownFieldSet _unknownFields;
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public static pb::MessageParser<ServerReflectionRequest> Parser { get { return _parser; } }
 
@@ -115,6 +118,7 @@ namespace Grpc.Reflection.V1Alpha {
           break;
       }
 
+      _unknownFields = pb::UnknownFieldSet.Clone(other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -256,7 +260,7 @@ namespace Grpc.Reflection.V1Alpha {
       if (AllExtensionNumbersOfType != other.AllExtensionNumbersOfType) return false;
       if (ListServices != other.ListServices) return false;
       if (MessageRequestCase != other.MessageRequestCase) return false;
-      return true;
+      return Equals(_unknownFields, other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -269,6 +273,9 @@ namespace Grpc.Reflection.V1Alpha {
       if (messageRequestCase_ == MessageRequestOneofCase.AllExtensionNumbersOfType) hash ^= AllExtensionNumbersOfType.GetHashCode();
       if (messageRequestCase_ == MessageRequestOneofCase.ListServices) hash ^= ListServices.GetHashCode();
       hash ^= (int) messageRequestCase_;
+      if (_unknownFields != null) {
+        hash ^= _unknownFields.GetHashCode();
+      }
       return hash;
     }
 
@@ -303,6 +310,9 @@ namespace Grpc.Reflection.V1Alpha {
         output.WriteRawTag(58);
         output.WriteString(ListServices);
       }
+      if (_unknownFields != null) {
+        _unknownFields.WriteTo(output);
+      }
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -326,6 +336,9 @@ namespace Grpc.Reflection.V1Alpha {
       if (messageRequestCase_ == MessageRequestOneofCase.ListServices) {
         size += 1 + pb::CodedOutputStream.ComputeStringSize(ListServices);
       }
+      if (_unknownFields != null) {
+        size += _unknownFields.CalculateSize();
+      }
       return size;
     }
 
@@ -358,6 +371,7 @@ namespace Grpc.Reflection.V1Alpha {
           break;
       }
 
+      _unknownFields = pb::UnknownFieldSet.MergeFrom(_unknownFields, other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -366,7 +380,7 @@ namespace Grpc.Reflection.V1Alpha {
       while ((tag = input.ReadTag()) != 0) {
         switch(tag) {
           default:
-            input.SkipLastField();
+            _unknownFields = pb::UnknownFieldSet.MergeFieldFrom(_unknownFields, input);
             break;
           case 10: {
             Host = input.ReadString();
@@ -409,6 +423,7 @@ namespace Grpc.Reflection.V1Alpha {
   /// </summary>
   public sealed partial class ExtensionRequest : pb::IMessage<ExtensionRequest> {
     private static readonly pb::MessageParser<ExtensionRequest> _parser = new pb::MessageParser<ExtensionRequest>(() => new ExtensionRequest());
+    private pb::UnknownFieldSet _unknownFields;
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public static pb::MessageParser<ExtensionRequest> Parser { get { return _parser; } }
 
@@ -433,6 +448,7 @@ namespace Grpc.Reflection.V1Alpha {
     public ExtensionRequest(ExtensionRequest other) : this() {
       containingType_ = other.containingType_;
       extensionNumber_ = other.extensionNumber_;
+      _unknownFields = pb::UnknownFieldSet.Clone(other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -480,7 +496,7 @@ namespace Grpc.Reflection.V1Alpha {
       }
       if (ContainingType != other.ContainingType) return false;
       if (ExtensionNumber != other.ExtensionNumber) return false;
-      return true;
+      return Equals(_unknownFields, other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -488,6 +504,9 @@ namespace Grpc.Reflection.V1Alpha {
       int hash = 1;
       if (ContainingType.Length != 0) hash ^= ContainingType.GetHashCode();
       if (ExtensionNumber != 0) hash ^= ExtensionNumber.GetHashCode();
+      if (_unknownFields != null) {
+        hash ^= _unknownFields.GetHashCode();
+      }
       return hash;
     }
 
@@ -506,6 +525,9 @@ namespace Grpc.Reflection.V1Alpha {
         output.WriteRawTag(16);
         output.WriteInt32(ExtensionNumber);
       }
+      if (_unknownFields != null) {
+        _unknownFields.WriteTo(output);
+      }
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -517,6 +539,9 @@ namespace Grpc.Reflection.V1Alpha {
       if (ExtensionNumber != 0) {
         size += 1 + pb::CodedOutputStream.ComputeInt32Size(ExtensionNumber);
       }
+      if (_unknownFields != null) {
+        size += _unknownFields.CalculateSize();
+      }
       return size;
     }
 
@@ -531,6 +556,7 @@ namespace Grpc.Reflection.V1Alpha {
       if (other.ExtensionNumber != 0) {
         ExtensionNumber = other.ExtensionNumber;
       }
+      _unknownFields = pb::UnknownFieldSet.MergeFrom(_unknownFields, other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -539,7 +565,7 @@ namespace Grpc.Reflection.V1Alpha {
       while ((tag = input.ReadTag()) != 0) {
         switch(tag) {
           default:
-            input.SkipLastField();
+            _unknownFields = pb::UnknownFieldSet.MergeFieldFrom(_unknownFields, input);
             break;
           case 10: {
             ContainingType = input.ReadString();
@@ -560,6 +586,7 @@ namespace Grpc.Reflection.V1Alpha {
   /// </summary>
   public sealed partial class ServerReflectionResponse : pb::IMessage<ServerReflectionResponse> {
     private static readonly pb::MessageParser<ServerReflectionResponse> _parser = new pb::MessageParser<ServerReflectionResponse>(() => new ServerReflectionResponse());
+    private pb::UnknownFieldSet _unknownFields;
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public static pb::MessageParser<ServerReflectionResponse> Parser { get { return _parser; } }
 
@@ -599,6 +626,7 @@ namespace Grpc.Reflection.V1Alpha {
           break;
       }
 
+      _unknownFields = pb::UnknownFieldSet.Clone(other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -730,7 +758,7 @@ namespace Grpc.Reflection.V1Alpha {
       if (!object.Equals(ListServicesResponse, other.ListServicesResponse)) return false;
       if (!object.Equals(ErrorResponse, other.ErrorResponse)) return false;
       if (MessageResponseCase != other.MessageResponseCase) return false;
-      return true;
+      return Equals(_unknownFields, other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -743,6 +771,9 @@ namespace Grpc.Reflection.V1Alpha {
       if (messageResponseCase_ == MessageResponseOneofCase.ListServicesResponse) hash ^= ListServicesResponse.GetHashCode();
       if (messageResponseCase_ == MessageResponseOneofCase.ErrorResponse) hash ^= ErrorResponse.GetHashCode();
       hash ^= (int) messageResponseCase_;
+      if (_unknownFields != null) {
+        hash ^= _unknownFields.GetHashCode();
+      }
       return hash;
     }
 
@@ -777,6 +808,9 @@ namespace Grpc.Reflection.V1Alpha {
         output.WriteRawTag(58);
         output.WriteMessage(ErrorResponse);
       }
+      if (_unknownFields != null) {
+        _unknownFields.WriteTo(output);
+      }
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -800,6 +834,9 @@ namespace Grpc.Reflection.V1Alpha {
       if (messageResponseCase_ == MessageResponseOneofCase.ErrorResponse) {
         size += 1 + pb::CodedOutputStream.ComputeMessageSize(ErrorResponse);
       }
+      if (_unknownFields != null) {
+        size += _unknownFields.CalculateSize();
+      }
       return size;
     }
 
@@ -844,6 +881,7 @@ namespace Grpc.Reflection.V1Alpha {
           break;
       }
 
+      _unknownFields = pb::UnknownFieldSet.MergeFrom(_unknownFields, other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -852,7 +890,7 @@ namespace Grpc.Reflection.V1Alpha {
       while ((tag = input.ReadTag()) != 0) {
         switch(tag) {
           default:
-            input.SkipLastField();
+            _unknownFields = pb::UnknownFieldSet.MergeFieldFrom(_unknownFields, input);
             break;
           case 10: {
             ValidHost = input.ReadString();
@@ -914,6 +952,7 @@ namespace Grpc.Reflection.V1Alpha {
   /// </summary>
   public sealed partial class FileDescriptorResponse : pb::IMessage<FileDescriptorResponse> {
     private static readonly pb::MessageParser<FileDescriptorResponse> _parser = new pb::MessageParser<FileDescriptorResponse>(() => new FileDescriptorResponse());
+    private pb::UnknownFieldSet _unknownFields;
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public static pb::MessageParser<FileDescriptorResponse> Parser { get { return _parser; } }
 
@@ -937,6 +976,7 @@ namespace Grpc.Reflection.V1Alpha {
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public FileDescriptorResponse(FileDescriptorResponse other) : this() {
       fileDescriptorProto_ = other.fileDescriptorProto_.Clone();
+      _unknownFields = pb::UnknownFieldSet.Clone(other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -973,13 +1013,16 @@ namespace Grpc.Reflection.V1Alpha {
         return true;
       }
       if(!fileDescriptorProto_.Equals(other.fileDescriptorProto_)) return false;
-      return true;
+      return Equals(_unknownFields, other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public override int GetHashCode() {
       int hash = 1;
       hash ^= fileDescriptorProto_.GetHashCode();
+      if (_unknownFields != null) {
+        hash ^= _unknownFields.GetHashCode();
+      }
       return hash;
     }
 
@@ -991,12 +1034,18 @@ namespace Grpc.Reflection.V1Alpha {
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public void WriteTo(pb::CodedOutputStream output) {
       fileDescriptorProto_.WriteTo(output, _repeated_fileDescriptorProto_codec);
+      if (_unknownFields != null) {
+        _unknownFields.WriteTo(output);
+      }
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public int CalculateSize() {
       int size = 0;
       size += fileDescriptorProto_.CalculateSize(_repeated_fileDescriptorProto_codec);
+      if (_unknownFields != null) {
+        size += _unknownFields.CalculateSize();
+      }
       return size;
     }
 
@@ -1006,6 +1055,7 @@ namespace Grpc.Reflection.V1Alpha {
         return;
       }
       fileDescriptorProto_.Add(other.fileDescriptorProto_);
+      _unknownFields = pb::UnknownFieldSet.MergeFrom(_unknownFields, other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -1014,7 +1064,7 @@ namespace Grpc.Reflection.V1Alpha {
       while ((tag = input.ReadTag()) != 0) {
         switch(tag) {
           default:
-            input.SkipLastField();
+            _unknownFields = pb::UnknownFieldSet.MergeFieldFrom(_unknownFields, input);
             break;
           case 10: {
             fileDescriptorProto_.AddEntriesFrom(input, _repeated_fileDescriptorProto_codec);
@@ -1032,6 +1082,7 @@ namespace Grpc.Reflection.V1Alpha {
   /// </summary>
   public sealed partial class ExtensionNumberResponse : pb::IMessage<ExtensionNumberResponse> {
     private static readonly pb::MessageParser<ExtensionNumberResponse> _parser = new pb::MessageParser<ExtensionNumberResponse>(() => new ExtensionNumberResponse());
+    private pb::UnknownFieldSet _unknownFields;
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public static pb::MessageParser<ExtensionNumberResponse> Parser { get { return _parser; } }
 
@@ -1056,6 +1107,7 @@ namespace Grpc.Reflection.V1Alpha {
     public ExtensionNumberResponse(ExtensionNumberResponse other) : this() {
       baseTypeName_ = other.baseTypeName_;
       extensionNumber_ = other.extensionNumber_.Clone();
+      _unknownFields = pb::UnknownFieldSet.Clone(other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -1103,7 +1155,7 @@ namespace Grpc.Reflection.V1Alpha {
       }
       if (BaseTypeName != other.BaseTypeName) return false;
       if(!extensionNumber_.Equals(other.extensionNumber_)) return false;
-      return true;
+      return Equals(_unknownFields, other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -1111,6 +1163,9 @@ namespace Grpc.Reflection.V1Alpha {
       int hash = 1;
       if (BaseTypeName.Length != 0) hash ^= BaseTypeName.GetHashCode();
       hash ^= extensionNumber_.GetHashCode();
+      if (_unknownFields != null) {
+        hash ^= _unknownFields.GetHashCode();
+      }
       return hash;
     }
 
@@ -1126,6 +1181,9 @@ namespace Grpc.Reflection.V1Alpha {
         output.WriteString(BaseTypeName);
       }
       extensionNumber_.WriteTo(output, _repeated_extensionNumber_codec);
+      if (_unknownFields != null) {
+        _unknownFields.WriteTo(output);
+      }
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -1135,6 +1193,9 @@ namespace Grpc.Reflection.V1Alpha {
         size += 1 + pb::CodedOutputStream.ComputeStringSize(BaseTypeName);
       }
       size += extensionNumber_.CalculateSize(_repeated_extensionNumber_codec);
+      if (_unknownFields != null) {
+        size += _unknownFields.CalculateSize();
+      }
       return size;
     }
 
@@ -1147,6 +1208,7 @@ namespace Grpc.Reflection.V1Alpha {
         BaseTypeName = other.BaseTypeName;
       }
       extensionNumber_.Add(other.extensionNumber_);
+      _unknownFields = pb::UnknownFieldSet.MergeFrom(_unknownFields, other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -1155,7 +1217,7 @@ namespace Grpc.Reflection.V1Alpha {
       while ((tag = input.ReadTag()) != 0) {
         switch(tag) {
           default:
-            input.SkipLastField();
+            _unknownFields = pb::UnknownFieldSet.MergeFieldFrom(_unknownFields, input);
             break;
           case 10: {
             BaseTypeName = input.ReadString();
@@ -1177,6 +1239,7 @@ namespace Grpc.Reflection.V1Alpha {
   /// </summary>
   public sealed partial class ListServiceResponse : pb::IMessage<ListServiceResponse> {
     private static readonly pb::MessageParser<ListServiceResponse> _parser = new pb::MessageParser<ListServiceResponse>(() => new ListServiceResponse());
+    private pb::UnknownFieldSet _unknownFields;
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public static pb::MessageParser<ListServiceResponse> Parser { get { return _parser; } }
 
@@ -1200,6 +1263,7 @@ namespace Grpc.Reflection.V1Alpha {
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public ListServiceResponse(ListServiceResponse other) : this() {
       service_ = other.service_.Clone();
+      _unknownFields = pb::UnknownFieldSet.Clone(other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -1235,13 +1299,16 @@ namespace Grpc.Reflection.V1Alpha {
         return true;
       }
       if(!service_.Equals(other.service_)) return false;
-      return true;
+      return Equals(_unknownFields, other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public override int GetHashCode() {
       int hash = 1;
       hash ^= service_.GetHashCode();
+      if (_unknownFields != null) {
+        hash ^= _unknownFields.GetHashCode();
+      }
       return hash;
     }
 
@@ -1253,12 +1320,18 @@ namespace Grpc.Reflection.V1Alpha {
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public void WriteTo(pb::CodedOutputStream output) {
       service_.WriteTo(output, _repeated_service_codec);
+      if (_unknownFields != null) {
+        _unknownFields.WriteTo(output);
+      }
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public int CalculateSize() {
       int size = 0;
       size += service_.CalculateSize(_repeated_service_codec);
+      if (_unknownFields != null) {
+        size += _unknownFields.CalculateSize();
+      }
       return size;
     }
 
@@ -1268,6 +1341,7 @@ namespace Grpc.Reflection.V1Alpha {
         return;
       }
       service_.Add(other.service_);
+      _unknownFields = pb::UnknownFieldSet.MergeFrom(_unknownFields, other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -1276,7 +1350,7 @@ namespace Grpc.Reflection.V1Alpha {
       while ((tag = input.ReadTag()) != 0) {
         switch(tag) {
           default:
-            input.SkipLastField();
+            _unknownFields = pb::UnknownFieldSet.MergeFieldFrom(_unknownFields, input);
             break;
           case 10: {
             service_.AddEntriesFrom(input, _repeated_service_codec);
@@ -1294,6 +1368,7 @@ namespace Grpc.Reflection.V1Alpha {
   /// </summary>
   public sealed partial class ServiceResponse : pb::IMessage<ServiceResponse> {
     private static readonly pb::MessageParser<ServiceResponse> _parser = new pb::MessageParser<ServiceResponse>(() => new ServiceResponse());
+    private pb::UnknownFieldSet _unknownFields;
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public static pb::MessageParser<ServiceResponse> Parser { get { return _parser; } }
 
@@ -1317,6 +1392,7 @@ namespace Grpc.Reflection.V1Alpha {
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public ServiceResponse(ServiceResponse other) : this() {
       name_ = other.name_;
+      _unknownFields = pb::UnknownFieldSet.Clone(other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -1353,13 +1429,16 @@ namespace Grpc.Reflection.V1Alpha {
         return true;
       }
       if (Name != other.Name) return false;
-      return true;
+      return Equals(_unknownFields, other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public override int GetHashCode() {
       int hash = 1;
       if (Name.Length != 0) hash ^= Name.GetHashCode();
+      if (_unknownFields != null) {
+        hash ^= _unknownFields.GetHashCode();
+      }
       return hash;
     }
 
@@ -1374,6 +1453,9 @@ namespace Grpc.Reflection.V1Alpha {
         output.WriteRawTag(10);
         output.WriteString(Name);
       }
+      if (_unknownFields != null) {
+        _unknownFields.WriteTo(output);
+      }
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -1382,6 +1464,9 @@ namespace Grpc.Reflection.V1Alpha {
       if (Name.Length != 0) {
         size += 1 + pb::CodedOutputStream.ComputeStringSize(Name);
       }
+      if (_unknownFields != null) {
+        size += _unknownFields.CalculateSize();
+      }
       return size;
     }
 
@@ -1393,6 +1478,7 @@ namespace Grpc.Reflection.V1Alpha {
       if (other.Name.Length != 0) {
         Name = other.Name;
       }
+      _unknownFields = pb::UnknownFieldSet.MergeFrom(_unknownFields, other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -1401,7 +1487,7 @@ namespace Grpc.Reflection.V1Alpha {
       while ((tag = input.ReadTag()) != 0) {
         switch(tag) {
           default:
-            input.SkipLastField();
+            _unknownFields = pb::UnknownFieldSet.MergeFieldFrom(_unknownFields, input);
             break;
           case 10: {
             Name = input.ReadString();
@@ -1418,6 +1504,7 @@ namespace Grpc.Reflection.V1Alpha {
   /// </summary>
   public sealed partial class ErrorResponse : pb::IMessage<ErrorResponse> {
     private static readonly pb::MessageParser<ErrorResponse> _parser = new pb::MessageParser<ErrorResponse>(() => new ErrorResponse());
+    private pb::UnknownFieldSet _unknownFields;
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public static pb::MessageParser<ErrorResponse> Parser { get { return _parser; } }
 
@@ -1442,6 +1529,7 @@ namespace Grpc.Reflection.V1Alpha {
     public ErrorResponse(ErrorResponse other) : this() {
       errorCode_ = other.errorCode_;
       errorMessage_ = other.errorMessage_;
+      _unknownFields = pb::UnknownFieldSet.Clone(other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -1489,7 +1577,7 @@ namespace Grpc.Reflection.V1Alpha {
       }
       if (ErrorCode != other.ErrorCode) return false;
       if (ErrorMessage != other.ErrorMessage) return false;
-      return true;
+      return Equals(_unknownFields, other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -1497,6 +1585,9 @@ namespace Grpc.Reflection.V1Alpha {
       int hash = 1;
       if (ErrorCode != 0) hash ^= ErrorCode.GetHashCode();
       if (ErrorMessage.Length != 0) hash ^= ErrorMessage.GetHashCode();
+      if (_unknownFields != null) {
+        hash ^= _unknownFields.GetHashCode();
+      }
       return hash;
     }
 
@@ -1515,6 +1606,9 @@ namespace Grpc.Reflection.V1Alpha {
         output.WriteRawTag(18);
         output.WriteString(ErrorMessage);
       }
+      if (_unknownFields != null) {
+        _unknownFields.WriteTo(output);
+      }
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -1526,6 +1620,9 @@ namespace Grpc.Reflection.V1Alpha {
       if (ErrorMessage.Length != 0) {
         size += 1 + pb::CodedOutputStream.ComputeStringSize(ErrorMessage);
       }
+      if (_unknownFields != null) {
+        size += _unknownFields.CalculateSize();
+      }
       return size;
     }
 
@@ -1540,6 +1637,7 @@ namespace Grpc.Reflection.V1Alpha {
       if (other.ErrorMessage.Length != 0) {
         ErrorMessage = other.ErrorMessage;
       }
+      _unknownFields = pb::UnknownFieldSet.MergeFrom(_unknownFields, other._unknownFields);
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -1548,7 +1646,7 @@ namespace Grpc.Reflection.V1Alpha {
       while ((tag = input.ReadTag()) != 0) {
         switch(tag) {
           default:
-            input.SkipLastField();
+            _unknownFields = pb::UnknownFieldSet.MergeFieldFrom(_unknownFields, input);
             break;
           case 8: {
             ErrorCode = input.ReadInt32();
diff --git a/src/csharp/README.md b/src/csharp/README.md
index 6821ad225e..e117e66afd 100644
--- a/src/csharp/README.md
+++ b/src/csharp/README.md
@@ -16,16 +16,17 @@ PREREQUISITES
 
 When using gRPC C# under .NET Core you only need to [install .NET Core](https://www.microsoft.com/net/core).
 
-- Windows: .NET Framework 4.5+, Visual Studio 2013, 2015, 2017
-- Linux: Mono 4+, MonoDevelop 5.9+ (with NuGet add-in installed)
-- Mac OS X: Xamarin Studio 5.9+
+In addition to that, you can also use gRPC C# with these runtimes / IDEs
+- Windows: .NET Framework 4.5+, Visual Studio 2013, 2015, 2017, Visual Studio Code
+- Linux: Mono 4+, Visual Studio Code, MonoDevelop 5.9+ 
+- Mac OS X: Mono 4+, Visual Studio Code, Xamarin Studio 5.9+
 
 HOW TO USE
 --------------
 
 **Windows, Linux, Mac OS X**
 
-- Open Visual Studio / MonoDevelop / Xamarin Studio and start a new project/solution.
+- Open Visual Studio / MonoDevelop / Xamarin Studio and start a new project/solution (alternatively, you can create a new project from command line with `dotnet` SDK)
 
 - Add the [Grpc](https://www.nuget.org/packages/Grpc/) NuGet package as a dependency (Project options -> Manage NuGet Packages). 
 
@@ -37,12 +38,23 @@ BUILD FROM SOURCE
 You only need to go through these steps if you are planning to develop gRPC C#.
 If you are a user of gRPC C#, go to Usage section above.
 
+**Prerequisites for contributors**
+
+- [dotnet SDK](https://www.microsoft.com/net/core)
+- [Mono 4+](https://www.mono-project.com/) (only needed for Linux and MacOS)
+- Prerequisites mentioned in [INSTALL.md](../../INSTALL.md#pre-requisites)
+  to be able to compile the native code.
+
 **Windows, Linux or Mac OS X**
 
-- The easiest way to build is using the `run_tests.py` script that will take care of building the `grpc_csharp_ext` native library:
+- The easiest way to build is using the `run_tests.py` script that will take care of building the `grpc_csharp_ext` native library.
+  
   ```
+  # NOTE: make sure all necessary git submodules with dependencies 
+  # are available by running "git submodule update --init"
+  
   # from the gRPC repository root
-  $ python tools/run_tests/run_tests.py -c dbg -l csharp --build_only
+  $ python tools/run_tests/run_tests.py -l csharp -c dbg --build_only
   ```
 
 - Use Visual Studio 2017 (on Windows) to open the solution `Grpc.sln` or use Visual Studio Code with C# extension (on Linux and Mac). gRPC C# code has been migrated to
@@ -57,11 +69,12 @@ gRPC C# is using NUnit as the testing framework.
 Under Visual Studio, make sure NUnit test adapter is installed (under "Extensions and Updates").
 Then you should be able to run all the tests using Test Explorer.
 
-gRPC team uses a Python script to simplify facilitate running tests for
+gRPC team uses a Python script to facilitate running tests for
 different languages.
 
 ```
-tools/run_tests/run_tests.py -l csharp
+# from the gRPC repository root
+$ python tools/run_tests/run_tests.py -l csharp -c dbg
 ```
 
 DOCUMENTATION
diff --git a/src/csharp/build_packages_dotnetcli.bat b/src/csharp/build_packages_dotnetcli.bat
index 0d65748697..924d7b1697 100755
--- a/src/csharp/build_packages_dotnetcli.bat
+++ b/src/csharp/build_packages_dotnetcli.bat
@@ -13,7 +13,7 @@
 @rem limitations under the License.
 
 @rem Current package versions
-set VERSION=1.12.0-dev
+set VERSION=1.13.0-dev
 
 @rem Adjust the location of nuget.exe
 set NUGET=C:\nuget\nuget.exe
diff --git a/src/csharp/build_packages_dotnetcli.sh b/src/csharp/build_packages_dotnetcli.sh
index 66aba36089..5c73a8f95f 100755
--- a/src/csharp/build_packages_dotnetcli.sh
+++ b/src/csharp/build_packages_dotnetcli.sh
@@ -45,7 +45,7 @@ dotnet pack --configuration Release Grpc.Auth --output ../../../artifacts
 dotnet pack --configuration Release Grpc.HealthCheck --output ../../../artifacts
 dotnet pack --configuration Release Grpc.Reflection --output ../../../artifacts
 
-nuget pack Grpc.nuspec -Version "1.12.0-dev" -OutputDirectory ../../artifacts
-nuget pack Grpc.Tools.nuspec -Version "1.12.0-dev" -OutputDirectory ../../artifacts
+nuget pack Grpc.nuspec -Version "1.13.0-dev" -OutputDirectory ../../artifacts
+nuget pack Grpc.Tools.nuspec -Version "1.13.0-dev" -OutputDirectory ../../artifacts
 
 (cd ../../artifacts && zip csharp_nugets_dotnetcli.zip *.nupkg)
diff --git a/src/csharp/generate_proto_csharp.sh b/src/csharp/generate_proto_csharp.sh
index 299dc3f816..1a38f860e8 100755
--- a/src/csharp/generate_proto_csharp.sh
+++ b/src/csharp/generate_proto_csharp.sh
@@ -42,4 +42,4 @@ $PROTOC --plugin=$PLUGIN --csharp_out=$TESTING_DIR/CoreStats --grpc_out=$TESTING
 # don't match the package names. Setting -I to the correct value src/proto
 # breaks the code generation.
 $PROTOC --plugin=$PLUGIN --csharp_out=$TESTING_DIR --grpc_out=$TESTING_DIR \
-    -I . src/proto/grpc/testing/{control,echo_messages,empty,messages,metrics,payloads,services,stats,test}.proto
+    -I . src/proto/grpc/testing/{control,echo_messages,empty,messages,metrics,payloads,benchmark_service,report_qps_scenario_service,worker_service,stats,test}.proto
diff --git a/src/csharp/global.json b/src/csharp/global.json
deleted file mode 100644
index 815be4bfb9..0000000000
--- a/src/csharp/global.json
+++ /dev/null
@@ -1,5 +0,0 @@
-{
-  "sdk": {
-    "version": "2.1.4"
-  }
-}
diff --git a/src/objective-c/!ProtoCompiler-gRPCPlugin.podspec b/src/objective-c/!ProtoCompiler-gRPCPlugin.podspec
index f06312bea9..515dc917d1 100644
--- a/src/objective-c/!ProtoCompiler-gRPCPlugin.podspec
+++ b/src/objective-c/!ProtoCompiler-gRPCPlugin.podspec
@@ -42,7 +42,7 @@ Pod::Spec.new do |s|
   # exclamation mark ensures that other "regular" pods will be able to find it as it'll be installed
   # before them.
   s.name     = '!ProtoCompiler-gRPCPlugin'
-  v = '1.12.0-dev'
+  v = '1.13.0-dev'
   s.version  = v
   s.summary  = 'The gRPC ProtoC plugin generates Objective-C files from .proto services.'
   s.description = <<-DESC
diff --git a/src/objective-c/BoringSSL.podspec b/src/objective-c/BoringSSL.podspec
index 8a32e9735d..ff55320d41 100644
--- a/src/objective-c/BoringSSL.podspec
+++ b/src/objective-c/BoringSSL.podspec
@@ -31,7 +31,7 @@
 
 Pod::Spec.new do |s|
   s.name     = 'BoringSSL'
-  version = '10.0'
+  version = '10.0.2'
   s.version  = version
   s.summary  = 'BoringSSL is a fork of OpenSSL that is designed to meet Google’s needs.'
   # Adapted from the homepage:
@@ -67,11 +67,9 @@ Pod::Spec.new do |s|
   # "The name and email addresses of the library maintainers, not the Podspec maintainer."
   s.authors  = 'Adam Langley', 'David Benjamin', 'Matt Braithwaite'
 
-  versions = version.split('.')
-  major_version = versions[0] + '.0'
   s.source = {
     :git => 'https://boringssl.googlesource.com/boringssl',
-    :tag => "version_for_cocoapods_#{major_version}",
+    :commit => "a20bb7ff8bb5057065a2e7941249773f9676cf45",
   }
 
   s.ios.deployment_target = '5.0'
@@ -123,7 +121,8 @@ Pod::Spec.new do |s|
                       'ssl/**/*.{h,cc}',
                       '*.{h,c}',
                       'crypto/*.{h,c}',
-                      'crypto/**/*.{h,c}'
+                      'crypto/**/*.{h,c}',
+                      'third_party/fiat/*.{h,c}'
     ss.private_header_files = 'ssl/*.h',
                               'ssl/**/*.h',
                               '*.h',
diff --git a/src/objective-c/GRPCClient/private/GRPCHost.m b/src/objective-c/GRPCClient/private/GRPCHost.m
index 283306262a..bfb1fd352c 100644
--- a/src/objective-c/GRPCClient/private/GRPCHost.m
+++ b/src/objective-c/GRPCClient/private/GRPCHost.m
@@ -108,7 +108,10 @@ static NSMutableDictionary *kHostCache;
                                    serverName:(NSString *)serverName
                                       timeout:(NSTimeInterval)timeout
                               completionQueue:(GRPCCompletionQueue *)queue {
-  GRPCChannel *channel;
+  // The __block attribute is to allow channel take refcount inside @synchronized block. Without
+  // this attribute, retain of channel object happens after objc_sync_exit in release builds, which
+  // may result in channel released before used. See grpc/#15033.
+  __block GRPCChannel *channel;
   // This is racing -[GRPCHost disconnect].
   @synchronized(self) {
     if (!_channel) {
diff --git a/src/objective-c/GRPCClient/private/version.h b/src/objective-c/GRPCClient/private/version.h
index 1298e7e191..6fe4a7d051 100644
--- a/src/objective-c/GRPCClient/private/version.h
+++ b/src/objective-c/GRPCClient/private/version.h
@@ -22,4 +22,4 @@
 // instead. This file can be regenerated from the template by running
 // `tools/buildgen/generate_projects.sh`.
 
-#define GRPC_OBJC_VERSION_STRING @"1.12.0-dev"
+#define GRPC_OBJC_VERSION_STRING @"1.13.0-dev"
diff --git a/src/objective-c/ProtoRPC/ProtoService.h b/src/objective-c/ProtoRPC/ProtoService.h
index 29c4e9be36..c411bed60f 100644
--- a/src/objective-c/ProtoRPC/ProtoService.h
+++ b/src/objective-c/ProtoRPC/ProtoService.h
@@ -22,6 +22,12 @@
 @protocol GRXWriteable;
 @class GRXWriter;
 
+@protocol GRPCProtoServiceInit
+
+- (instancetype)initWithHost:(NSString *)host;
+
+@end
+
 __attribute__((deprecated("Please use GRPCProtoService."))) @interface ProtoService
     : NSObject -
       (instancetype)initWithHost : (NSString *)host packageName
diff --git a/src/objective-c/examples/SwiftSample/SwiftSample.xcodeproj/project.pbxproj b/src/objective-c/examples/SwiftSample/SwiftSample.xcodeproj/project.pbxproj
index 6247d0b4e6..0113d9c5d6 100644
--- a/src/objective-c/examples/SwiftSample/SwiftSample.xcodeproj/project.pbxproj
+++ b/src/objective-c/examples/SwiftSample/SwiftSample.xcodeproj/project.pbxproj
@@ -168,13 +168,16 @@
 			files = (
 			);
 			inputPaths = (
+				"${PODS_PODFILE_DIR_PATH}/Podfile.lock",
+				"${PODS_ROOT}/Manifest.lock",
 			);
 			name = "[CP] Check Pods Manifest.lock";
 			outputPaths = (
+				"$(DERIVED_FILE_DIR)/Pods-SwiftSample-checkManifestLockResult.txt",
 			);
 			runOnlyForDeploymentPostprocessing = 0;
 			shellPath = /bin/sh;
-			shellScript = "diff \"${PODS_ROOT}/../Podfile.lock\" \"${PODS_ROOT}/Manifest.lock\" > /dev/null\nif [[ $? != 0 ]] ; then\n    cat << EOM\nerror: The sandbox is not in sync with the Podfile.lock. Run 'pod install' or update your CocoaPods installation.\nEOM\n    exit 1\nfi\n";
+			shellScript = "diff \"${PODS_PODFILE_DIR_PATH}/Podfile.lock\" \"${PODS_ROOT}/Manifest.lock\" > /dev/null\nif [ $? != 0 ] ; then\n    # print error to STDERR\n    echo \"error: The sandbox is not in sync with the Podfile.lock. Run 'pod install' or update your CocoaPods installation.\" >&2\n    exit 1\nfi\n# This output is used by Xcode 'outputs' to avoid re-running this script phase.\necho \"SUCCESS\" > \"${SCRIPT_OUTPUT_FILE_0}\"\n";
 			showEnvVarsInLog = 0;
 		};
 		A1738A987353B0BF2C64F0F7 /* [CP] Embed Pods Frameworks */ = {
@@ -183,9 +186,26 @@
 			files = (
 			);
 			inputPaths = (
+				"${SRCROOT}/Pods/Target Support Files/Pods-SwiftSample/Pods-SwiftSample-frameworks.sh",
+				"${BUILT_PRODUCTS_DIR}/BoringSSL/openssl.framework",
+				"${BUILT_PRODUCTS_DIR}/Protobuf/Protobuf.framework",
+				"${BUILT_PRODUCTS_DIR}/RemoteTest/RemoteTest.framework",
+				"${BUILT_PRODUCTS_DIR}/gRPC/GRPCClient.framework",
+				"${BUILT_PRODUCTS_DIR}/gRPC-Core/grpc.framework",
+				"${BUILT_PRODUCTS_DIR}/gRPC-ProtoRPC/ProtoRPC.framework",
+				"${BUILT_PRODUCTS_DIR}/gRPC-RxLibrary/RxLibrary.framework",
+				"${BUILT_PRODUCTS_DIR}/nanopb/nanopb.framework",
 			);
 			name = "[CP] Embed Pods Frameworks";
 			outputPaths = (
+				"${TARGET_BUILD_DIR}/${FRAMEWORKS_FOLDER_PATH}/openssl.framework",
+				"${TARGET_BUILD_DIR}/${FRAMEWORKS_FOLDER_PATH}/Protobuf.framework",
+				"${TARGET_BUILD_DIR}/${FRAMEWORKS_FOLDER_PATH}/RemoteTest.framework",
+				"${TARGET_BUILD_DIR}/${FRAMEWORKS_FOLDER_PATH}/GRPCClient.framework",
+				"${TARGET_BUILD_DIR}/${FRAMEWORKS_FOLDER_PATH}/grpc.framework",
+				"${TARGET_BUILD_DIR}/${FRAMEWORKS_FOLDER_PATH}/ProtoRPC.framework",
+				"${TARGET_BUILD_DIR}/${FRAMEWORKS_FOLDER_PATH}/RxLibrary.framework",
+				"${TARGET_BUILD_DIR}/${FRAMEWORKS_FOLDER_PATH}/nanopb.framework",
 			);
 			runOnlyForDeploymentPostprocessing = 0;
 			shellPath = /bin/sh;
@@ -329,7 +349,7 @@
 				PRODUCT_BUNDLE_IDENTIFIER = "io.grpc.$(PRODUCT_NAME:rfc1034identifier)";
 				PRODUCT_NAME = "$(TARGET_NAME)";
 				SWIFT_OBJC_BRIDGING_HEADER = "";
-				SWIFT_VERSION = 2.3;
+				SWIFT_VERSION = 4.0;
 				USER_HEADER_SEARCH_PATHS = "";
 			};
 			name = Debug;
@@ -344,7 +364,7 @@
 				PRODUCT_BUNDLE_IDENTIFIER = "io.grpc.$(PRODUCT_NAME:rfc1034identifier)";
 				PRODUCT_NAME = "$(TARGET_NAME)";
 				SWIFT_OBJC_BRIDGING_HEADER = "";
-				SWIFT_VERSION = 2.3;
+				SWIFT_VERSION = 4.0;
 				USER_HEADER_SEARCH_PATHS = "";
 			};
 			name = Release;
diff --git a/src/objective-c/examples/SwiftSample/ViewController.swift b/src/objective-c/examples/SwiftSample/ViewController.swift
index 5931914b7b..0ba6e21f02 100644
--- a/src/objective-c/examples/SwiftSample/ViewController.swift
+++ b/src/objective-c/examples/SwiftSample/ViewController.swift
@@ -36,7 +36,7 @@ class ViewController: UIViewController {
     // Example gRPC call using a generated proto client library:
 
     let service = RMTTestService(host: RemoteHost)
-    service.unaryCallWithRequest(request) { response, error in
+    service.unaryCall(with: request) { response, error in
       if let response = response {
         NSLog("1. Finished successfully with response:\n\(response)")
       } else {
@@ -48,7 +48,7 @@ class ViewController: UIViewController {
     // Same but manipulating headers:
 
     var RPC : GRPCProtoCall! // Needed to convince Swift to capture by reference (__block)
-    RPC = service.RPCToUnaryCallWithRequest(request) { response, error in
+    RPC = service.rpcToUnaryCall(with: request) { response, error in
       if let response = response {
         NSLog("2. Finished successfully with response:\n\(response)")
       } else {
@@ -59,23 +59,23 @@ class ViewController: UIViewController {
     }
 
     // TODO(jcanizales): Revert to using subscript syntax once XCode 8 is released.
-    RPC.requestHeaders.setObject("My value", forKey: "My-Header")
+    RPC.requestHeaders["My-Header"] = "My value"
 
     RPC.start()
 
 
     // Same example call using the generic gRPC client library:
 
-    let method = GRPCProtoMethod(package: "grpc.testing", service: "TestService", method: "UnaryCall")
+    let method = GRPCProtoMethod(package: "grpc.testing", service: "TestService", method: "UnaryCall")!
 
     let requestsWriter = GRXWriter(value: request.data())
 
-    let call = GRPCCall(host: RemoteHost, path: method.HTTPPath, requestsWriter: requestsWriter)
+    let call = GRPCCall(host: RemoteHost, path: method.httpPath, requestsWriter: requestsWriter)!
 
-    call.requestHeaders.setObject("My value", forKey: "My-Header")
+    call.requestHeaders["My-Header"] = "My value"
 
-    call.startWithWriteable(GRXWriteable { response, error in
-      if let response = response as? NSData {
+    call.start(with: GRXWriteable { response, error in
+      if let response = response as? Data {
         NSLog("3. Received response:\n\(try! RMTSimpleResponse(data: response))")
       } else {
         NSLog("3. Finished with error: \(error!)")
diff --git a/src/objective-c/tests/version.h b/src/objective-c/tests/version.h
index d36545fced..e9637099d9 100644
--- a/src/objective-c/tests/version.h
+++ b/src/objective-c/tests/version.h
@@ -22,5 +22,5 @@
 // instead. This file can be regenerated from the template by running
 // `tools/buildgen/generate_projects.sh`.
 
-#define GRPC_OBJC_VERSION_STRING @"1.12.0-dev"
+#define GRPC_OBJC_VERSION_STRING @"1.13.0-dev"
 #define GRPC_C_VERSION_STRING @"6.0.0-dev"
diff --git a/src/php/composer.json b/src/php/composer.json
index 57d911db79..03dffb40ab 100644
--- a/src/php/composer.json
+++ b/src/php/composer.json
@@ -2,7 +2,7 @@
   "name": "grpc/grpc-dev",
   "description": "gRPC library for PHP - for Developement use only",
   "license": "Apache-2.0",
-  "version": "1.12.0",
+  "version": "1.13.0",
   "require": {
     "php": ">=5.5.0",
     "google/protobuf": "^v3.3.0"
diff --git a/src/php/ext/grpc/channel.c b/src/php/ext/grpc/channel.c
index f3a03ace09..35adf6b342 100644
--- a/src/php/ext/grpc/channel.c
+++ b/src/php/ext/grpc/channel.c
@@ -193,7 +193,6 @@ void create_and_add_channel_to_persistent_list(
   create_channel(channel, target, args, creds);
 
   le->channel = channel->wrapper;
-  le->ref_count = 1;
   new_rsrc.ptr = le;
   gpr_mu_lock(&global_persistent_list_mu);
   PHP_GRPC_PERSISTENT_LIST_UPDATE(&grpc_persistent_list, key, key_len,
@@ -342,7 +341,6 @@ PHP_METHOD(Channel, __construct) {
       free(channel->wrapper->target);
       free(channel->wrapper->args_hashstr);
       free(channel->wrapper);
-      le->ref_count += 1;
       channel->wrapper = le->channel;
       channel->wrapper->ref_count += 1;
     }
@@ -534,53 +532,6 @@ static void php_grpc_channel_plink_dtor(php_grpc_zend_resource *rsrc
   }
 }
 
-/**
- * Clean all channels in the persistent.
- * @return void
- */
-PHP_METHOD(Channel, cleanPersistentList) {
-  zend_hash_clean(&grpc_persistent_list);
-}
-
-/**
- * Return an array of persistent list.
- * @return array
- */
-PHP_METHOD(Channel, getPersistentList) {
-  array_init(return_value);
-  zval *data;
-  PHP_GRPC_HASH_FOREACH_VAL_START(&grpc_persistent_list, data)
-    php_grpc_zend_resource *rsrc  =
-                (php_grpc_zend_resource*) PHP_GRPC_HASH_VALPTR_TO_VAL(data)
-    if (rsrc == NULL) {
-      break;
-    }
-    channel_persistent_le_t* le = rsrc->ptr;
-    zval* ret_arr;
-    PHP_GRPC_MAKE_STD_ZVAL(ret_arr);
-    array_init(ret_arr);
-    // Info about the target
-    PHP_GRPC_ADD_STRING_TO_ARRAY(ret_arr, "target",
-                sizeof("target"), le->channel->target, true);
-    // Info about key
-    PHP_GRPC_ADD_STRING_TO_ARRAY(ret_arr, "key",
-                sizeof("key"), le->channel->key, true);
-    // Info about persistent channel ref_count
-    PHP_GRPC_ADD_LONG_TO_ARRAY(ret_arr, "ref_count",
-                sizeof("ref_count"), le->ref_count);
-    // Info about connectivity status
-    int state =
-        grpc_channel_check_connectivity_state(le->channel->wrapped, (int)0);
-    // It should be set to 'true' in PHP 5.6.33
-    PHP_GRPC_ADD_LONG_TO_ARRAY(ret_arr, "connectivity_status",
-                sizeof("connectivity_status"), state);
-    // Info about the channel is closed or not
-    PHP_GRPC_ADD_BOOL_TO_ARRAY(ret_arr, "is_valid",
-                sizeof("is_valid"), le->channel->is_valid);
-    add_assoc_zval(return_value, le->channel->target, ret_arr);
-  PHP_GRPC_HASH_FOREACH_END()
-}
-
 ZEND_BEGIN_ARG_INFO_EX(arginfo_construct, 0, 0, 2)
   ZEND_ARG_INFO(0, target)
   ZEND_ARG_INFO(0, args)
@@ -601,12 +552,6 @@ ZEND_END_ARG_INFO()
 ZEND_BEGIN_ARG_INFO_EX(arginfo_close, 0, 0, 0)
 ZEND_END_ARG_INFO()
 
-ZEND_BEGIN_ARG_INFO_EX(arginfo_cleanPersistentList, 0, 0, 0)
-ZEND_END_ARG_INFO()
-
-ZEND_BEGIN_ARG_INFO_EX(arginfo_getPersistentList, 0, 0, 0)
-ZEND_END_ARG_INFO()
-
 static zend_function_entry channel_methods[] = {
   PHP_ME(Channel, __construct, arginfo_construct,
          ZEND_ACC_PUBLIC | ZEND_ACC_CTOR)
@@ -618,10 +563,6 @@ static zend_function_entry channel_methods[] = {
          ZEND_ACC_PUBLIC)
   PHP_ME(Channel, close, arginfo_close,
          ZEND_ACC_PUBLIC)
-  PHP_ME(Channel, cleanPersistentList, arginfo_cleanPersistentList,
-         ZEND_ACC_PUBLIC)
-  PHP_ME(Channel, getPersistentList, arginfo_getPersistentList,
-         ZEND_ACC_PUBLIC)
   PHP_FE_END
 };
 
diff --git a/src/php/ext/grpc/channel.h b/src/php/ext/grpc/channel.h
index 807880534e..86bfdea51a 100644
--- a/src/php/ext/grpc/channel.h
+++ b/src/php/ext/grpc/channel.h
@@ -84,7 +84,6 @@ void php_grpc_delete_persistent_list_entry(char *key, php_grpc_int key_len
 
 typedef struct _channel_persistent_le {
   grpc_channel_wrapper *channel;
-  size_t ref_count;
 } channel_persistent_le_t;
 
 
diff --git a/src/php/ext/grpc/php7_wrapper.h b/src/php/ext/grpc/php7_wrapper.h
index d4fa859249..0239e04f76 100644
--- a/src/php/ext/grpc/php7_wrapper.h
+++ b/src/php/ext/grpc/php7_wrapper.h
@@ -30,6 +30,8 @@
   add_property_string(arg, name, context, b)
 #define php_grpc_add_property_stringl(res, name, str, len, b) \
   add_property_stringl(res, name, str, len, b)
+#define php_grpc_add_property_zval(res, name, val) \
+  add_property_zval(res, name, val)
 #define php_grpc_add_next_index_stringl(data, str, len, b) \
   add_next_index_stringl(data, str, len, b)
 
@@ -154,6 +156,11 @@ static inline int php_grpc_zend_hash_find(HashTable *ht, char *key, int len,
   add_property_string(arg, name, context)
 #define php_grpc_add_property_stringl(res, name, str, len, b) \
   add_property_stringl(res, name, str, len)
+#define php_grpc_add_property_zval(res, name, val) do { \
+  zval tmp; \
+  tmp = *val; \
+  add_property_zval(res, name, &tmp); \
+  } while(0)
 #define php_grpc_add_next_index_stringl(data, str, len, b) \
   add_next_index_stringl(data, str, len)
 
diff --git a/src/php/ext/grpc/server.c b/src/php/ext/grpc/server.c
index a65d233017..292d512e37 100644
--- a/src/php/ext/grpc/server.c
+++ b/src/php/ext/grpc/server.c
@@ -89,8 +89,6 @@ PHP_METHOD(Server, __construct) {
   if (args_array == NULL) {
     server->wrapped = grpc_server_create(NULL, NULL);
   } else {
-    //TODO(thinkerou): deal it if key of array is long, crash now on php7
-    // and update unit test case
     php_grpc_read_args_array(args_array, &args TSRMLS_CC);
     server->wrapped = grpc_server_create(&args, NULL);
     efree(args.args);
@@ -118,8 +116,8 @@ PHP_METHOD(Server, requestCall) {
   grpc_call_details_init(&details);
   grpc_metadata_array_init(&metadata);
   error_code =
-      grpc_server_request_call(server->wrapped, &call, &details, &metadata,
-                               completion_queue, completion_queue, NULL);
+    grpc_server_request_call(server->wrapped, &call, &details, &metadata,
+                             completion_queue, completion_queue, NULL);
   if (error_code != GRPC_CALL_OK) {
     zend_throw_exception(spl_ce_LogicException, "request_call failed",
                          (long)error_code TSRMLS_CC);
@@ -140,25 +138,12 @@ PHP_METHOD(Server, requestCall) {
   php_grpc_add_property_string(result, "host", host_text, true);
   gpr_free(method_text);
   gpr_free(host_text);
-#if PHP_MAJOR_VERSION < 7
-  add_property_zval(result, "call", grpc_php_wrap_call(call, true TSRMLS_CC));
-  add_property_zval(result, "absolute_deadline",
-                    grpc_php_wrap_timeval(details.deadline TSRMLS_CC));
-  add_property_zval(result, "metadata", grpc_parse_metadata_array(&metadata
-                                                                  TSRMLS_CC));
-#else
-  zval zv_call;
-  zval zv_timeval;
-  zval zv_md;
-  //TODO(thinkerou): why use zval* to unit test error?
-  zv_call = *grpc_php_wrap_call(call, true);
-  zv_timeval = *grpc_php_wrap_timeval(details.deadline);
-  zv_md = *grpc_parse_metadata_array(&metadata);
-
-  add_property_zval(result, "call", &zv_call);
-  add_property_zval(result, "absolute_deadline", &zv_timeval);
-  add_property_zval(result, "metadata", &zv_md);
-#endif
+  php_grpc_add_property_zval(result, "call",
+                             grpc_php_wrap_call(call, true TSRMLS_CC));
+  php_grpc_add_property_zval(result, "absolute_deadline",
+                             grpc_php_wrap_timeval(details.deadline TSRMLS_CC));
+  php_grpc_add_property_zval(result, "metadata",
+                             grpc_parse_metadata_array(&metadata TSRMLS_CC));
 
  cleanup:
   grpc_call_details_destroy(&details);
@@ -202,9 +187,9 @@ PHP_METHOD(Server, addSecureHttp2Port) {
   if (zend_parse_parameters(ZEND_NUM_ARGS() TSRMLS_CC, "sO", &addr, &addr_len,
                             &creds_obj, grpc_ce_server_credentials) ==
       FAILURE) {
-    zend_throw_exception(
-        spl_ce_InvalidArgumentException,
-        "add_http2_port expects a string and a ServerCredentials", 1 TSRMLS_CC);
+    zend_throw_exception(spl_ce_InvalidArgumentException,
+                         "add_http2_port expects a string and a "
+                         "ServerCredentials", 1 TSRMLS_CC);
     return;
   }
   wrapped_grpc_server_credentials *creds =
diff --git a/src/php/ext/grpc/version.h b/src/php/ext/grpc/version.h
index 37df2768bf..407d6347e6 100644
--- a/src/php/ext/grpc/version.h
+++ b/src/php/ext/grpc/version.h
@@ -20,6 +20,6 @@
 #ifndef VERSION_H
 #define VERSION_H
 
-#define PHP_GRPC_VERSION "1.12.0dev"
+#define PHP_GRPC_VERSION "1.13.0dev"
 
 #endif /* VERSION_H */
diff --git a/src/php/lib/Grpc/BaseStub.php b/src/php/lib/Grpc/BaseStub.php
index 5f3a96feaa..7860233ca2 100644
--- a/src/php/lib/Grpc/BaseStub.php
+++ b/src/php/lib/Grpc/BaseStub.php
@@ -38,12 +38,13 @@ class BaseStub
      *  - 'update_metadata': (optional) a callback function which takes in a
      * metadata array, and returns an updated metadata array
      *  - 'grpc.primary_user_agent': (optional) a user-agent string
-     * @param Channel $channel An already created Channel object (optional)
+     * @param Channel|InterceptorChannel $channel An already created Channel or InterceptorChannel object (optional)
      */
-    public function __construct($hostname, $opts, Channel $channel = null)
+    public function __construct($hostname, $opts, $channel = null)
     {
         $ssl_roots = file_get_contents(
-            dirname(__FILE__).'/../../../../etc/roots.pem');
+            dirname(__FILE__).'/../../../../etc/roots.pem'
+        );
         ChannelCredentials::setDefaultRootsPem($ssl_roots);
 
         $this->hostname = $hostname;
@@ -58,16 +59,20 @@ class BaseStub
             $this->hostname_override = $opts['grpc.ssl_target_name_override'];
         }
         if ($channel) {
-            if (!is_a($channel, 'Grpc\Channel')) {
-                throw new \Exception('The channel argument is not a'.
-                                     'Channel object');
+            if (!is_a($channel, 'Grpc\Channel') &&
+                !is_a($channel, 'Grpc\InterceptorChannel')) {
+                throw new \Exception('The channel argument is not a Channel object '.
+                    'or an InterceptorChannel object created by '.
+                    'Interceptor::intercept($channel, Interceptor|Interceptor[] $interceptors)');
             }
             $this->channel = $channel;
             return;
         }
 
         $package_config = json_decode(
-            file_get_contents(dirname(__FILE__).'/../../composer.json'), true);
+            file_get_contents(dirname(__FILE__).'/../../composer.json'),
+            true
+        );
         if (!empty($opts['grpc.primary_user_agent'])) {
             $opts['grpc.primary_user_agent'] .= ' ';
         } else {
@@ -77,8 +82,8 @@ class BaseStub
             'grpc-php/'.$package_config['version'];
         if (!array_key_exists('credentials', $opts)) {
             throw new \Exception("The opts['credentials'] key is now ".
-                                 'required. Please see one of the '.
-                                 'ChannelCredentials::create methods');
+                'required. Please see one of the '.
+                'ChannelCredentials::create methods');
         }
         $this->channel = new Channel($hostname, $opts);
     }
@@ -169,7 +174,8 @@ class BaseStub
         $last_slash_idx = strrpos($method, '/');
         if ($last_slash_idx === false) {
             throw new \InvalidArgumentException(
-                'service name must have a slash');
+                'service name must have a slash'
+            );
         }
         $service_name = substr($method, 0, $last_slash_idx);
 
@@ -197,7 +203,8 @@ class BaseStub
             if (!preg_match('/^[A-Za-z\d_-]+$/', $key)) {
                 throw new \InvalidArgumentException(
                     'Metadata keys must be nonempty strings containing only '.
-                    'alphanumeric characters, hyphens and underscores');
+                    'alphanumeric characters, hyphens and underscores'
+                );
             }
             $metadata_copy[strtolower($key)] = $value;
         }
@@ -205,9 +212,255 @@ class BaseStub
         return $metadata_copy;
     }
 
+    /**
+     * Create a function which can be used to create UnaryCall
+     *
+     * @param Channel|InterceptorChannel   $channel
+     * @param callable $deserialize A function that deserializes the response
+     *
+     * @return \Closure
+     */
+    private function _GrpcUnaryUnary($channel, $deserialize)
+    {
+        return function ($method,
+                         $argument,
+                         array $metadata = [],
+                         array $options = []) use ($channel, $deserialize) {
+            $call = new UnaryCall(
+                $channel,
+                $method,
+                $deserialize,
+                $options
+            );
+            $jwt_aud_uri = $this->_get_jwt_aud_uri($method);
+            if (is_callable($this->update_metadata)) {
+                $metadata = call_user_func(
+                    $this->update_metadata,
+                    $metadata,
+                    $jwt_aud_uri
+                );
+            }
+            $metadata = $this->_validate_and_normalize_metadata(
+                $metadata
+            );
+            $call->start($argument, $metadata, $options);
+            return $call;
+        };
+    }
+
+    /**
+     * Create a function which can be used to create ServerStreamingCall
+     *
+     * @param Channel|InterceptorChannel   $channel
+     * @param callable $deserialize A function that deserializes the response
+     *
+     * @return \Closure
+     */
+    private function _GrpcStreamUnary($channel, $deserialize)
+    {
+        return function ($method,
+                         array $metadata = [],
+                         array $options = []) use ($channel, $deserialize) {
+            $call = new ClientStreamingCall(
+                $channel,
+                $method,
+                $deserialize,
+                $options
+            );
+            $jwt_aud_uri = $this->_get_jwt_aud_uri($method);
+            if (is_callable($this->update_metadata)) {
+                $metadata = call_user_func(
+                    $this->update_metadata,
+                    $metadata,
+                    $jwt_aud_uri
+                );
+            }
+            $metadata = $this->_validate_and_normalize_metadata(
+                $metadata
+            );
+            $call->start($metadata);
+            return $call;
+        };
+    }
+
+    /**
+     * Create a function which can be used to create ClientStreamingCall
+     *
+     * @param Channel|InterceptorChannel   $channel
+     * @param callable $deserialize A function that deserializes the response
+     *
+     * @return \Closure
+     */
+    private function _GrpcUnaryStream($channel, $deserialize)
+    {
+        return function ($method,
+                         $argument,
+                         array $metadata = [],
+                         array $options = []) use ($channel, $deserialize) {
+            $call = new ServerStreamingCall(
+                $channel,
+                $method,
+                $deserialize,
+                $options
+            );
+            $jwt_aud_uri = $this->_get_jwt_aud_uri($method);
+            if (is_callable($this->update_metadata)) {
+                $metadata = call_user_func(
+                    $this->update_metadata,
+                    $metadata,
+                    $jwt_aud_uri
+                );
+            }
+            $metadata = $this->_validate_and_normalize_metadata(
+                $metadata
+            );
+            $call->start($argument, $metadata, $options);
+            return $call;
+        };
+    }
+
+    /**
+     * Create a function which can be used to create BidiStreamingCall
+     *
+     * @param Channel|InterceptorChannel   $channel
+     * @param callable $deserialize A function that deserializes the response
+     *
+     * @return \Closure
+     */
+    private function _GrpcStreamStream($channel, $deserialize)
+    {
+        return function ($method,
+                         array $metadata = [],
+                         array $options = []) use ($channel ,$deserialize) {
+            $call = new BidiStreamingCall(
+                $channel,
+                $method,
+                $deserialize,
+                $options
+            );
+            $jwt_aud_uri = $this->_get_jwt_aud_uri($method);
+            if (is_callable($this->update_metadata)) {
+                $metadata = call_user_func(
+                    $this->update_metadata,
+                    $metadata,
+                    $jwt_aud_uri
+                );
+            }
+            $metadata = $this->_validate_and_normalize_metadata(
+                $metadata
+            );
+            $call->start($metadata);
+
+            return $call;
+        };
+    }
+
+    /**
+     * Create a function which can be used to create UnaryCall
+     *
+     * @param Channel|InterceptorChannel   $channel
+     * @param callable $deserialize A function that deserializes the response
+     *
+     * @return \Closure
+     */
+    private function _UnaryUnaryCallFactory($channel, $deserialize)
+    {
+        if (is_a($channel, 'Grpc\InterceptorChannel')) {
+            return function ($method,
+                             $argument,
+                             array $metadata = [],
+                             array $options = []) use ($channel, $deserialize) {
+                return $channel->getInterceptor()->interceptUnaryUnary(
+                    $method,
+                    $argument,
+                    $metadata,
+                    $options,
+                    $this->_UnaryUnaryCallFactory($channel->getNext(), $deserialize)
+                );
+            };
+        }
+        return $this->_GrpcUnaryUnary($channel, $deserialize);
+    }
+
+    /**
+     * Create a function which can be used to create ServerStreamingCall
+     *
+     * @param Channel|InterceptorChannel   $channel
+     * @param callable $deserialize A function that deserializes the response
+     *
+     * @return \Closure
+     */
+    private function _UnaryStreamCallFactory($channel, $deserialize)
+    {
+        if (is_a($channel, 'Grpc\InterceptorChannel')) {
+            return function ($method,
+                             $argument,
+                             array $metadata = [],
+                             array $options = []) use ($channel, $deserialize) {
+                return $channel->getInterceptor()->interceptUnaryStream(
+                    $method,
+                    $argument,
+                    $metadata,
+                    $options,
+                    $this->_UnaryStreamCallFactory($channel->getNext(), $deserialize)
+                );
+            };
+        }
+        return $this->_GrpcUnaryStream($channel, $deserialize);
+    }
+
+    /**
+     * Create a function which can be used to create ClientStreamingCall
+     *
+     * @param Channel|InterceptorChannel   $channel
+     * @param callable $deserialize A function that deserializes the response
+     *
+     * @return \Closure
+     */
+    private function _StreamUnaryCallFactory($channel, $deserialize)
+    {
+        if (is_a($channel, 'Grpc\InterceptorChannel')) {
+            return function ($method,
+                             array $metadata = [],
+                             array $options = []) use ($channel, $deserialize) {
+                return $channel->getInterceptor()->interceptStreamUnary(
+                    $method,
+                    $metadata,
+                    $options,
+                    $this->_StreamUnaryCallFactory($channel->getNext(), $deserialize)
+                );
+            };
+        }
+        return $this->_GrpcStreamUnary($channel, $deserialize);
+    }
+
+    /**
+     * Create a function which can be used to create BidiStreamingCall
+     *
+     * @param Channel|InterceptorChannel   $channel
+     * @param callable $deserialize A function that deserializes the response
+     *
+     * @return \Closure
+     */
+    private function _StreamStreamCallFactory($channel, $deserialize)
+    {
+        if (is_a($channel, 'Grpc\InterceptorChannel')) {
+            return function ($method,
+                             array $metadata = [],
+                             array $options = []) use ($channel, $deserialize) {
+                return $channel->getInterceptor()->interceptStreamStream(
+                    $method,
+                    $metadata,
+                    $options,
+                    $this->_StreamStreamCallFactory($channel->getNext(), $deserialize)
+                );
+            };
+        }
+        return $this->_GrpcStreamStream($channel, $deserialize);
+    }
+
     /* This class is intended to be subclassed by generated code, so
      * all functions begin with "_" to avoid name collisions. */
-
     /**
      * Call a remote method that takes a single argument and has a
      * single output.
@@ -221,26 +474,15 @@ class BaseStub
      *
      * @return UnaryCall The active call object
      */
-    protected function _simpleRequest($method,
-                                   $argument,
-                                   $deserialize,
-                                   array $metadata = [],
-                                   array $options = [])
-    {
-        $call = new UnaryCall($this->channel,
-                              $method,
-                              $deserialize,
-                              $options);
-        $jwt_aud_uri = $this->_get_jwt_aud_uri($method);
-        if (is_callable($this->update_metadata)) {
-            $metadata = call_user_func($this->update_metadata,
-                                        $metadata,
-                                        $jwt_aud_uri);
-        }
-        $metadata = $this->_validate_and_normalize_metadata(
-            $metadata);
-        $call->start($argument, $metadata, $options);
-
+    protected function _simpleRequest(
+        $method,
+        $argument,
+        $deserialize,
+        array $metadata = [],
+        array $options = []
+    ) {
+        $call_factory = $this->_UnaryUnaryCallFactory($this->channel, $deserialize);
+        $call = $call_factory($method, $argument, $metadata, $options);
         return $call;
     }
 
@@ -256,25 +498,14 @@ class BaseStub
      *
      * @return ClientStreamingCall The active call object
      */
-    protected function _clientStreamRequest($method,
-                                         $deserialize,
-                                         array $metadata = [],
-                                         array $options = [])
-    {
-        $call = new ClientStreamingCall($this->channel,
-                                        $method,
-                                        $deserialize,
-                                        $options);
-        $jwt_aud_uri = $this->_get_jwt_aud_uri($method);
-        if (is_callable($this->update_metadata)) {
-            $metadata = call_user_func($this->update_metadata,
-                                        $metadata,
-                                        $jwt_aud_uri);
-        }
-        $metadata = $this->_validate_and_normalize_metadata(
-            $metadata);
-        $call->start($metadata);
-
+    protected function _clientStreamRequest(
+        $method,
+        $deserialize,
+        array $metadata = [],
+        array $options = []
+    ) {
+        $call_factory = $this->_StreamUnaryCallFactory($this->channel, $deserialize);
+        $call = $call_factory($method, $metadata, $options);
         return $call;
     }
 
@@ -291,26 +522,15 @@ class BaseStub
      *
      * @return ServerStreamingCall The active call object
      */
-    protected function _serverStreamRequest($method,
-                                         $argument,
-                                         $deserialize,
-                                         array $metadata = [],
-                                         array $options = [])
-    {
-        $call = new ServerStreamingCall($this->channel,
-                                        $method,
-                                        $deserialize,
-                                        $options);
-        $jwt_aud_uri = $this->_get_jwt_aud_uri($method);
-        if (is_callable($this->update_metadata)) {
-            $metadata = call_user_func($this->update_metadata,
-                                        $metadata,
-                                        $jwt_aud_uri);
-        }
-        $metadata = $this->_validate_and_normalize_metadata(
-            $metadata);
-        $call->start($argument, $metadata, $options);
-
+    protected function _serverStreamRequest(
+        $method,
+        $argument,
+        $deserialize,
+        array $metadata = [],
+        array $options = []
+    ) {
+        $call_factory = $this->_UnaryStreamCallFactory($this->channel, $deserialize);
+        $call = $call_factory($method, $argument, $metadata, $options);
         return $call;
     }
 
@@ -325,25 +545,14 @@ class BaseStub
      *
      * @return BidiStreamingCall The active call object
      */
-    protected function _bidiRequest($method,
-                                 $deserialize,
-                                 array $metadata = [],
-                                 array $options = [])
-    {
-        $call = new BidiStreamingCall($this->channel,
-                                      $method,
-                                      $deserialize,
-                                      $options);
-        $jwt_aud_uri = $this->_get_jwt_aud_uri($method);
-        if (is_callable($this->update_metadata)) {
-            $metadata = call_user_func($this->update_metadata,
-                                        $metadata,
-                                        $jwt_aud_uri);
-        }
-        $metadata = $this->_validate_and_normalize_metadata(
-            $metadata);
-        $call->start($metadata);
-
+    protected function _bidiRequest(
+        $method,
+        $deserialize,
+        array $metadata = [],
+        array $options = []
+    ) {
+        $call_factory = $this->_StreamStreamCallFactory($this->channel, $deserialize);
+        $call = $call_factory($method, $metadata, $options);
         return $call;
     }
 }
diff --git a/src/php/lib/Grpc/Interceptor.php b/src/php/lib/Grpc/Interceptor.php
new file mode 100644
index 0000000000..9c1b5616f2
--- /dev/null
+++ b/src/php/lib/Grpc/Interceptor.php
@@ -0,0 +1,86 @@
+<?php
+/*
+ *
+ * Copyright 2018 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+namespace Grpc;
+
+/**
+ * Represents an interceptor that intercept RPC invocations before call starts.
+ * This is an EXPERIMENTAL API.
+ */
+class Interceptor
+{
+    public function interceptUnaryUnary(
+        $method,
+        $argument,
+        array $metadata = [],
+        array $options = [],
+        $continuation
+    ) {
+        return $continuation($method, $argument, $metadata, $options);
+    }
+
+    public function interceptStreamUnary(
+        $method,
+        array $metadata = [],
+        array $options = [],
+        $continuation
+    ) {
+        return $continuation($method, $metadata, $options);
+    }
+
+    public function interceptUnaryStream(
+        $method,
+        $argument,
+        array $metadata = [],
+        array $options = [],
+        $continuation
+    ) {
+        return $continuation($method, $argument, $metadata, $options);
+    }
+
+    public function interceptStreamStream(
+        $method,
+        array $metadata = [],
+        array $options = [],
+        $continuation
+    ) {
+        return $continuation($method, $metadata, $options);
+    }
+
+    /**
+     * Intercept the methods with Channel
+     *
+     * @param Channel|InterceptorChannel $channel An already created Channel or InterceptorChannel object (optional)
+     * @param Interceptor|Interceptor[] $interceptors interceptors to be added
+     *
+     * @return InterceptorChannel
+     */
+    public static function intercept($channel, $interceptors)
+    {
+        if (is_array($interceptors)) {
+            for ($i = count($interceptors) - 1; $i >= 0; $i--) {
+                $channel = new InterceptorChannel($channel, $interceptors[$i]);
+            }
+        } else {
+            $channel =  new InterceptorChannel($channel, $interceptors);
+        }
+        return $channel;
+    }
+}
+
diff --git a/src/php/lib/Grpc/Internal/InterceptorChannel.php b/src/php/lib/Grpc/Internal/InterceptorChannel.php
new file mode 100644
index 0000000000..9ac05748f3
--- /dev/null
+++ b/src/php/lib/Grpc/Internal/InterceptorChannel.php
@@ -0,0 +1,76 @@
+<?php
+/*
+ *
+ * Copyright 2018 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+namespace Grpc;
+
+/**
+ * This is a PRIVATE API and can change without notice.
+ */
+class InterceptorChannel
+{
+    private $next = null;
+    private $interceptor;
+
+    /**
+     * @param Channel|InterceptorChannel $channel An already created Channel
+     * or InterceptorChannel object (optional)
+     * @param Interceptor  $interceptor
+     */
+    public function __construct($channel, $interceptor)
+    {
+        if (!is_a($channel, 'Grpc\Channel') &&
+            !is_a($channel, 'Grpc\InterceptorChannel')) {
+            throw new \Exception('The channel argument is not a Channel object '.
+                'or an InterceptorChannel object created by '.
+                'Interceptor::intercept($channel, Interceptor|Interceptor[] $interceptors)');
+        }
+        $this->interceptor = $interceptor;
+        $this->next = $channel;
+    }
+
+    public function getNext()
+    {
+        return $this->next;
+    }
+
+    public function getInterceptor()
+    {
+        return $this->interceptor;
+    }
+
+    public function getTarget()
+    {
+        return $this->getNext()->getTarget();
+    }
+
+    public function watchConnectivityState($new_state, $deadline)
+    {
+        return $this->getNext()->watchConnectivityState($new_state, $deadline);
+    }
+
+    public function getConnectivityState($try_to_connect = false)
+    {
+        return $this->getNext()->getConnectivityState($try_to_connect);
+    }
+
+    public function close()
+    {
+        return $this->getNext()->close();
+    }
+}
diff --git a/src/php/tests/qps/generated_code/GPBMetadata/Src/Proto/Grpc/Testing/BenchmarkService.php b/src/php/tests/qps/generated_code/GPBMetadata/Src/Proto/Grpc/Testing/BenchmarkService.php
new file mode 100644
index 0000000000..906f6a2d84
--- /dev/null
+++ b/src/php/tests/qps/generated_code/GPBMetadata/Src/Proto/Grpc/Testing/BenchmarkService.php
@@ -0,0 +1,41 @@
+<?php
+# Generated by the protocol buffer compiler.  DO NOT EDIT!
+# source: src/proto/grpc/testing/benchmark_service.proto
+
+namespace GPBMetadata\Src\Proto\Grpc\Testing;
+
+class BenchmarkService
+{
+    public static $is_initialized = false;
+
+    public static function initOnce() {
+        $pool = \Google\Protobuf\Internal\DescriptorPool::getGeneratedPool();
+
+        if (static::$is_initialized == true) {
+          return;
+        }
+        \GPBMetadata\Src\Proto\Grpc\Testing\Messages::initOnce();
+        $pool->internalAddGeneratedFile(hex2bin(
+            "0aef030a2e7372632f70726f746f2f677270632f74657374696e672f6265" .
+            "6e63686d61726b5f736572766963652e70726f746f120c677270632e7465" .
+            "7374696e6732a6030a1042656e63686d61726b5365727669636512460a09" .
+            "556e61727943616c6c121b2e677270632e74657374696e672e53696d706c" .
+            "65526571756573741a1c2e677270632e74657374696e672e53696d706c65" .
+            "526573706f6e7365124e0a0d53747265616d696e6743616c6c121b2e6772" .
+            "70632e74657374696e672e53696d706c65526571756573741a1c2e677270" .
+            "632e74657374696e672e53696d706c65526573706f6e7365280130011252" .
+            "0a1353747265616d696e6746726f6d436c69656e74121b2e677270632e74" .
+            "657374696e672e53696d706c65526571756573741a1c2e677270632e7465" .
+            "7374696e672e53696d706c65526573706f6e7365280112520a1353747265" .
+            "616d696e6746726f6d536572766572121b2e677270632e74657374696e67" .
+            "2e53696d706c65526571756573741a1c2e677270632e74657374696e672e" .
+            "53696d706c65526573706f6e7365300112520a1153747265616d696e6742" .
+            "6f746857617973121b2e677270632e74657374696e672e53696d706c6552" .
+            "6571756573741a1c2e677270632e74657374696e672e53696d706c655265" .
+            "73706f6e736528013001620670726f746f33"
+        ));
+
+        static::$is_initialized = true;
+    }
+}
+
diff --git a/src/php/tests/qps/generated_code/GPBMetadata/Src/Proto/Grpc/Testing/CompilerTest.php b/src/php/tests/qps/generated_code/GPBMetadata/Src/Proto/Grpc/Testing/CompilerTest.php
new file mode 100644
index 0000000000..2c4fe92f05
--- /dev/null
+++ b/src/php/tests/qps/generated_code/GPBMetadata/Src/Proto/Grpc/Testing/CompilerTest.php
@@ -0,0 +1,37 @@
+<?php
+# Generated by the protocol buffer compiler.  DO NOT EDIT!
+# source: src/proto/grpc/testing/compiler_test.proto
+
+namespace GPBMetadata\Src\Proto\Grpc\Testing;
+
+class CompilerTest
+{
+    public static $is_initialized = false;
+
+    public static function initOnce() {
+        $pool = \Google\Protobuf\Internal\DescriptorPool::getGeneratedPool();
+
+        if (static::$is_initialized == true) {
+          return;
+        }
+        $pool->internalAddGeneratedFile(hex2bin(
+            "0aa1030a2a7372632f70726f746f2f677270632f74657374696e672f636f" .
+            "6d70696c65725f746573742e70726f746f120c677270632e74657374696e" .
+            "6722090a0752657175657374220a0a08526573706f6e736532fe010a0853" .
+            "6572766963654112390a084d6574686f64413112152e677270632e746573" .
+            "74696e672e526571756573741a162e677270632e74657374696e672e5265" .
+            "73706f6e7365123b0a084d6574686f64413212152e677270632e74657374" .
+            "696e672e526571756573741a162e677270632e74657374696e672e526573" .
+            "706f6e73652801123b0a084d6574686f64413312152e677270632e746573" .
+            "74696e672e526571756573741a162e677270632e74657374696e672e5265" .
+            "73706f6e73653001123d0a084d6574686f64413412152e677270632e7465" .
+            "7374696e672e526571756573741a162e677270632e74657374696e672e52" .
+            "6573706f6e73652801300132450a08536572766963654212390a084d6574" .
+            "686f64423112152e677270632e74657374696e672e526571756573741a16" .
+            "2e677270632e74657374696e672e526573706f6e7365620670726f746f33"
+        ));
+
+        static::$is_initialized = true;
+    }
+}
+
diff --git a/src/php/tests/qps/generated_code/GPBMetadata/Src/Proto/Grpc/Testing/Control.php b/src/php/tests/qps/generated_code/GPBMetadata/Src/Proto/Grpc/Testing/Control.php
index 9b3a7529ec..2319bcd021 100644
--- a/src/php/tests/qps/generated_code/GPBMetadata/Src/Proto/Grpc/Testing/Control.php
+++ b/src/php/tests/qps/generated_code/GPBMetadata/Src/Proto/Grpc/Testing/Control.php
@@ -17,7 +17,7 @@ class Control
         \GPBMetadata\Src\Proto\Grpc\Testing\Payloads::initOnce();
         \GPBMetadata\Src\Proto\Grpc\Testing\Stats::initOnce();
         $pool->internalAddGeneratedFile(hex2bin(
-            "0aa21a0a247372632f70726f746f2f677270632f74657374696e672f636f" .
+            "0abc1a0a247372632f70726f746f2f677270632f74657374696e672f636f" .
             "6e74726f6c2e70726f746f120c677270632e74657374696e671a22737263" .
             "2f70726f746f2f677270632f74657374696e672f73746174732e70726f74" .
             "6f22250a0d506f6973736f6e506172616d7312140a0c6f6666657265645f" .
@@ -31,7 +31,7 @@ class Control
             "6f7665727269646518022001280912110a09637265645f74797065180320" .
             "012809224d0a0a4368616e6e656c417267120c0a046e616d651801200128" .
             "0912130a097374725f76616c7565180220012809480012130a09696e745f" .
-            "76616c7565180320012805480042070a0576616c756522d5040a0c436c69" .
+            "76616c7565180320012805480042070a0576616c756522ef040a0c436c69" .
             "656e74436f6e66696712160a0e7365727665725f74617267657473180120" .
             "032809122d0a0b636c69656e745f7479706518022001280e32182e677270" .
             "632e74657374696e672e436c69656e745479706512350a0f736563757269" .
@@ -51,85 +51,86 @@ class Control
             "745f617069180f20012809122e0a0c6368616e6e656c5f61726773181020" .
             "03280b32182e677270632e74657374696e672e4368616e6e656c41726712" .
             "160a0e746872656164735f7065725f6371181120012805121b0a136d6573" .
-            "73616765735f7065725f73747265616d18122001280522380a0c436c6965" .
-            "6e7453746174757312280a05737461747318012001280b32192e67727063" .
-            "2e74657374696e672e436c69656e74537461747322150a044d61726b120d" .
-            "0a05726573657418012001280822680a0a436c69656e7441726773122b0a" .
-            "05736574757018012001280b321a2e677270632e74657374696e672e436c" .
-            "69656e74436f6e666967480012220a046d61726b18022001280b32122e67" .
-            "7270632e74657374696e672e4d61726b480042090a076172677479706522" .
-            "fd020a0c536572766572436f6e666967122d0a0b7365727665725f747970" .
-            "6518012001280e32182e677270632e74657374696e672e53657276657254" .
-            "79706512350a0f73656375726974795f706172616d7318022001280b321c" .
-            "2e677270632e74657374696e672e5365637572697479506172616d73120c" .
-            "0a04706f7274180420012805121c0a146173796e635f7365727665725f74" .
-            "68726561647318072001280512120a0a636f72655f6c696d697418082001" .
-            "280512330a0e7061796c6f61645f636f6e66696718092001280b321b2e67" .
-            "7270632e74657374696e672e5061796c6f6164436f6e66696712110a0963" .
-            "6f72655f6c697374180a2003280512180a106f746865725f736572766572" .
-            "5f617069180b2001280912160a0e746872656164735f7065725f6371180c" .
-            "20012805121c0a137265736f757263655f71756f74615f73697a6518e907" .
-            "20012805122f0a0c6368616e6e656c5f6172677318ea072003280b32182e" .
-            "677270632e74657374696e672e4368616e6e656c41726722680a0a536572" .
-            "76657241726773122b0a05736574757018012001280b321a2e677270632e" .
-            "74657374696e672e536572766572436f6e666967480012220a046d61726b" .
-            "18022001280b32122e677270632e74657374696e672e4d61726b48004209" .
-            "0a076172677479706522550a0c53657276657253746174757312280a0573" .
-            "7461747318012001280b32192e677270632e74657374696e672e53657276" .
-            "65725374617473120c0a04706f7274180220012805120d0a05636f726573" .
-            "180320012805220d0a0b436f726552657175657374221d0a0c436f726552" .
-            "6573706f6e7365120d0a05636f72657318012001280522060a04566f6964" .
-            "22fd010a085363656e6172696f120c0a046e616d6518012001280912310a" .
-            "0d636c69656e745f636f6e66696718022001280b321a2e677270632e7465" .
-            "7374696e672e436c69656e74436f6e66696712130a0b6e756d5f636c6965" .
-            "6e747318032001280512310a0d7365727665725f636f6e66696718042001" .
-            "280b321a2e677270632e74657374696e672e536572766572436f6e666967" .
-            "12130a0b6e756d5f7365727665727318052001280512160a0e7761726d75" .
-            "705f7365636f6e647318062001280512190a1162656e63686d61726b5f73" .
-            "65636f6e647318072001280512200a18737061776e5f6c6f63616c5f776f" .
-            "726b65725f636f756e7418082001280522360a095363656e6172696f7312" .
-            "290a097363656e6172696f7318012003280b32162e677270632e74657374" .
-            "696e672e5363656e6172696f2284040a155363656e6172696f526573756c" .
-            "7453756d6d617279120b0a03717073180120012801121b0a137170735f70" .
-            "65725f7365727665725f636f7265180220012801121a0a12736572766572" .
-            "5f73797374656d5f74696d6518032001280112180a107365727665725f75" .
-            "7365725f74696d65180420012801121a0a12636c69656e745f7379737465" .
-            "6d5f74696d6518052001280112180a10636c69656e745f757365725f7469" .
-            "6d6518062001280112120a0a6c6174656e63795f35301807200128011212" .
-            "0a0a6c6174656e63795f393018082001280112120a0a6c6174656e63795f" .
-            "393518092001280112120a0a6c6174656e63795f3939180a200128011213" .
-            "0a0b6c6174656e63795f393939180b2001280112180a107365727665725f" .
-            "6370755f7573616765180c2001280112260a1e7375636365737366756c5f" .
-            "72657175657374735f7065725f7365636f6e64180d2001280112220a1a66" .
-            "61696c65645f72657175657374735f7065725f7365636f6e64180e200128" .
-            "0112200a18636c69656e745f706f6c6c735f7065725f7265717565737418" .
-            "0f2001280112200a187365727665725f706f6c6c735f7065725f72657175" .
-            "65737418102001280112220a1a7365727665725f717565726965735f7065" .
-            "725f6370755f73656318112001280112220a1a636c69656e745f71756572" .
-            "6965735f7065725f6370755f7365631812200128012283030a0e5363656e" .
-            "6172696f526573756c7412280a087363656e6172696f18012001280b3216" .
-            "2e677270632e74657374696e672e5363656e6172696f122e0a096c617465" .
-            "6e6369657318022001280b321b2e677270632e74657374696e672e486973" .
-            "746f6772616d44617461122f0a0c636c69656e745f737461747318032003" .
-            "280b32192e677270632e74657374696e672e436c69656e74537461747312" .
-            "2f0a0c7365727665725f737461747318042003280b32192e677270632e74" .
-            "657374696e672e536572766572537461747312140a0c7365727665725f63" .
-            "6f72657318052003280512340a0773756d6d61727918062001280b32232e" .
-            "677270632e74657374696e672e5363656e6172696f526573756c7453756d" .
-            "6d61727912160a0e636c69656e745f737563636573731807200328081216" .
-            "0a0e7365727665725f7375636365737318082003280812390a0f72657175" .
-            "6573745f726573756c747318092003280b32202e677270632e7465737469" .
-            "6e672e52657175657374526573756c74436f756e742a410a0a436c69656e" .
-            "7454797065120f0a0b53594e435f434c49454e54100012100a0c4153594e" .
-            "435f434c49454e54100112100a0c4f544845525f434c49454e5410022a5b" .
-            "0a0a53657276657254797065120f0a0b53594e435f534552564552100012" .
-            "100a0c4153594e435f534552564552100112180a144153594e435f47454e" .
-            "455249435f534552564552100212100a0c4f544845525f53455256455210" .
-            "032a720a075270635479706512090a05554e4152591000120d0a09535452" .
-            "45414d494e47100112190a1553545245414d494e475f46524f4d5f434c49" .
-            "454e54100212190a1553545245414d494e475f46524f4d5f534552564552" .
-            "100312170a1353545245414d494e475f424f54485f574159531004620670" .
-            "726f746f33"
+            "73616765735f7065725f73747265616d18122001280512180a107573655f" .
+            "636f616c657363655f61706918132001280822380a0c436c69656e745374" .
+            "6174757312280a05737461747318012001280b32192e677270632e746573" .
+            "74696e672e436c69656e74537461747322150a044d61726b120d0a057265" .
+            "73657418012001280822680a0a436c69656e7441726773122b0a05736574" .
+            "757018012001280b321a2e677270632e74657374696e672e436c69656e74" .
+            "436f6e666967480012220a046d61726b18022001280b32122e677270632e" .
+            "74657374696e672e4d61726b480042090a076172677479706522fd020a0c" .
+            "536572766572436f6e666967122d0a0b7365727665725f74797065180120" .
+            "01280e32182e677270632e74657374696e672e5365727665725479706512" .
+            "350a0f73656375726974795f706172616d7318022001280b321c2e677270" .
+            "632e74657374696e672e5365637572697479506172616d73120c0a04706f" .
+            "7274180420012805121c0a146173796e635f7365727665725f7468726561" .
+            "647318072001280512120a0a636f72655f6c696d69741808200128051233" .
+            "0a0e7061796c6f61645f636f6e66696718092001280b321b2e677270632e" .
+            "74657374696e672e5061796c6f6164436f6e66696712110a09636f72655f" .
+            "6c697374180a2003280512180a106f746865725f7365727665725f617069" .
+            "180b2001280912160a0e746872656164735f7065725f6371180c20012805" .
+            "121c0a137265736f757263655f71756f74615f73697a6518e90720012805" .
+            "122f0a0c6368616e6e656c5f6172677318ea072003280b32182e67727063" .
+            "2e74657374696e672e4368616e6e656c41726722680a0a53657276657241" .
+            "726773122b0a05736574757018012001280b321a2e677270632e74657374" .
+            "696e672e536572766572436f6e666967480012220a046d61726b18022001" .
+            "280b32122e677270632e74657374696e672e4d61726b480042090a076172" .
+            "677479706522550a0c53657276657253746174757312280a057374617473" .
+            "18012001280b32192e677270632e74657374696e672e5365727665725374" .
+            "617473120c0a04706f7274180220012805120d0a05636f72657318032001" .
+            "2805220d0a0b436f726552657175657374221d0a0c436f7265526573706f" .
+            "6e7365120d0a05636f72657318012001280522060a04566f696422fd010a" .
+            "085363656e6172696f120c0a046e616d6518012001280912310a0d636c69" .
+            "656e745f636f6e66696718022001280b321a2e677270632e74657374696e" .
+            "672e436c69656e74436f6e66696712130a0b6e756d5f636c69656e747318" .
+            "032001280512310a0d7365727665725f636f6e66696718042001280b321a" .
+            "2e677270632e74657374696e672e536572766572436f6e66696712130a0b" .
+            "6e756d5f7365727665727318052001280512160a0e7761726d75705f7365" .
+            "636f6e647318062001280512190a1162656e63686d61726b5f7365636f6e" .
+            "647318072001280512200a18737061776e5f6c6f63616c5f776f726b6572" .
+            "5f636f756e7418082001280522360a095363656e6172696f7312290a0973" .
+            "63656e6172696f7318012003280b32162e677270632e74657374696e672e" .
+            "5363656e6172696f2284040a155363656e6172696f526573756c7453756d" .
+            "6d617279120b0a03717073180120012801121b0a137170735f7065725f73" .
+            "65727665725f636f7265180220012801121a0a127365727665725f737973" .
+            "74656d5f74696d6518032001280112180a107365727665725f757365725f" .
+            "74696d65180420012801121a0a12636c69656e745f73797374656d5f7469" .
+            "6d6518052001280112180a10636c69656e745f757365725f74696d651806" .
+            "2001280112120a0a6c6174656e63795f353018072001280112120a0a6c61" .
+            "74656e63795f393018082001280112120a0a6c6174656e63795f39351809" .
+            "2001280112120a0a6c6174656e63795f3939180a2001280112130a0b6c61" .
+            "74656e63795f393939180b2001280112180a107365727665725f6370755f" .
+            "7573616765180c2001280112260a1e7375636365737366756c5f72657175" .
+            "657374735f7065725f7365636f6e64180d2001280112220a1a6661696c65" .
+            "645f72657175657374735f7065725f7365636f6e64180e2001280112200a" .
+            "18636c69656e745f706f6c6c735f7065725f72657175657374180f200128" .
+            "0112200a187365727665725f706f6c6c735f7065725f7265717565737418" .
+            "102001280112220a1a7365727665725f717565726965735f7065725f6370" .
+            "755f73656318112001280112220a1a636c69656e745f717565726965735f" .
+            "7065725f6370755f7365631812200128012283030a0e5363656e6172696f" .
+            "526573756c7412280a087363656e6172696f18012001280b32162e677270" .
+            "632e74657374696e672e5363656e6172696f122e0a096c6174656e636965" .
+            "7318022001280b321b2e677270632e74657374696e672e486973746f6772" .
+            "616d44617461122f0a0c636c69656e745f737461747318032003280b3219" .
+            "2e677270632e74657374696e672e436c69656e745374617473122f0a0c73" .
+            "65727665725f737461747318042003280b32192e677270632e7465737469" .
+            "6e672e536572766572537461747312140a0c7365727665725f636f726573" .
+            "18052003280512340a0773756d6d61727918062001280b32232e67727063" .
+            "2e74657374696e672e5363656e6172696f526573756c7453756d6d617279" .
+            "12160a0e636c69656e745f7375636365737318072003280812160a0e7365" .
+            "727665725f7375636365737318082003280812390a0f726571756573745f" .
+            "726573756c747318092003280b32202e677270632e74657374696e672e52" .
+            "657175657374526573756c74436f756e742a410a0a436c69656e74547970" .
+            "65120f0a0b53594e435f434c49454e54100012100a0c4153594e435f434c" .
+            "49454e54100112100a0c4f544845525f434c49454e5410022a5b0a0a5365" .
+            "7276657254797065120f0a0b53594e435f534552564552100012100a0c41" .
+            "53594e435f534552564552100112180a144153594e435f47454e45524943" .
+            "5f534552564552100212100a0c4f544845525f53455256455210032a720a" .
+            "075270635479706512090a05554e4152591000120d0a0953545245414d49" .
+            "4e47100112190a1553545245414d494e475f46524f4d5f434c49454e5410" .
+            "0212190a1553545245414d494e475f46524f4d5f53455256455210031217" .
+            "0a1353545245414d494e475f424f54485f574159531004620670726f746f" .
+            "33"
         ));
 
         static::$is_initialized = true;
diff --git a/src/php/tests/qps/generated_code/GPBMetadata/Src/Proto/Grpc/Testing/Echo.php b/src/php/tests/qps/generated_code/GPBMetadata/Src/Proto/Grpc/Testing/Echo.php
new file mode 100644
index 0000000000..77c5230f45
--- /dev/null
+++ b/src/php/tests/qps/generated_code/GPBMetadata/Src/Proto/Grpc/Testing/Echo.php
@@ -0,0 +1,43 @@
+<?php
+# Generated by the protocol buffer compiler.  DO NOT EDIT!
+# source: src/proto/grpc/testing/echo.proto
+
+namespace GPBMetadata\Src\Proto\Grpc\Testing;
+
+class Echo
+{
+    public static $is_initialized = false;
+
+    public static function initOnce() {
+        $pool = \Google\Protobuf\Internal\DescriptorPool::getGeneratedPool();
+
+        if (static::$is_initialized == true) {
+          return;
+        }
+        \GPBMetadata\Src\Proto\Grpc\Testing\EchoMessages::initOnce();
+        $pool->internalAddGeneratedFile(hex2bin(
+            "0aa6040a217372632f70726f746f2f677270632f74657374696e672f6563" .
+            "686f2e70726f746f120c677270632e74657374696e6732f6020a0f456368" .
+            "6f5465737453657276696365123d0a044563686f12192e677270632e7465" .
+            "7374696e672e4563686f526571756573741a1a2e677270632e7465737469" .
+            "6e672e4563686f526573706f6e736512480a0d5265717565737453747265" .
+            "616d12192e677270632e74657374696e672e4563686f526571756573741a" .
+            "1a2e677270632e74657374696e672e4563686f526573706f6e7365280112" .
+            "490a0e526573706f6e736553747265616d12192e677270632e7465737469" .
+            "6e672e4563686f526571756573741a1a2e677270632e74657374696e672e" .
+            "4563686f526573706f6e7365300112470a0a4269646953747265616d1219" .
+            "2e677270632e74657374696e672e4563686f526571756573741a1a2e6772" .
+            "70632e74657374696e672e4563686f526573706f6e73652801300112460a" .
+            "0d556e696d706c656d656e74656412192e677270632e74657374696e672e" .
+            "4563686f526571756573741a1a2e677270632e74657374696e672e456368" .
+            "6f526573706f6e736532620a18556e696d706c656d656e7465644563686f" .
+            "5365727669636512460a0d556e696d706c656d656e74656412192e677270" .
+            "632e74657374696e672e4563686f526571756573741a1a2e677270632e74" .
+            "657374696e672e4563686f526573706f6e7365320e0a0c4e6f5270635365" .
+            "7276696365620670726f746f33"
+        ));
+
+        static::$is_initialized = true;
+    }
+}
+
diff --git a/src/php/tests/qps/generated_code/GPBMetadata/Src/Proto/Grpc/Testing/EchoMessages.php b/src/php/tests/qps/generated_code/GPBMetadata/Src/Proto/Grpc/Testing/EchoMessages.php
new file mode 100644
index 0000000000..4bac8a2906
--- /dev/null
+++ b/src/php/tests/qps/generated_code/GPBMetadata/Src/Proto/Grpc/Testing/EchoMessages.php
@@ -0,0 +1,54 @@
+<?php
+# Generated by the protocol buffer compiler.  DO NOT EDIT!
+# source: src/proto/grpc/testing/echo_messages.proto
+
+namespace GPBMetadata\Src\Proto\Grpc\Testing;
+
+class EchoMessages
+{
+    public static $is_initialized = false;
+
+    public static function initOnce() {
+        $pool = \Google\Protobuf\Internal\DescriptorPool::getGeneratedPool();
+
+        if (static::$is_initialized == true) {
+          return;
+        }
+        $pool->internalAddGeneratedFile(hex2bin(
+            "0a8f070a2a7372632f70726f746f2f677270632f74657374696e672f6563" .
+            "686f5f6d657373616765732e70726f746f120c677270632e74657374696e" .
+            "6722320a094465627567496e666f12150a0d737461636b5f656e74726965" .
+            "73180120032809120e0a0664657461696c18022001280922500a0b457272" .
+            "6f72537461747573120c0a04636f646518012001280512150a0d6572726f" .
+            "725f6d657373616765180220012809121c0a1462696e6172795f6572726f" .
+            "725f64657461696c7318032001280922e2030a0d52657175657374506172" .
+            "616d7312150a0d6563686f5f646561646c696e65180120012808121e0a16" .
+            "636c69656e745f63616e63656c5f61667465725f7573180220012805121e" .
+            "0a167365727665725f63616e63656c5f61667465725f7573180320012805" .
+            "12150a0d6563686f5f6d65746164617461180420012808121a0a12636865" .
+            "636b5f617574685f636f6e74657874180520012808121f0a17726573706f" .
+            "6e73655f6d6573736167655f6c656e67746818062001280512110a096563" .
+            "686f5f7065657218072001280812200a1865787065637465645f636c6965" .
+            "6e745f6964656e74697479180820012809121c0a14736b69705f63616e63" .
+            "656c6c65645f636865636b18092001280812280a2065787065637465645f" .
+            "7472616e73706f72745f73656375726974795f74797065180a2001280912" .
+            "2b0a0a64656275675f696e666f180b2001280b32172e677270632e746573" .
+            "74696e672e4465627567496e666f12120a0a7365727665725f646965180c" .
+            "20012808121c0a1462696e6172795f6572726f725f64657461696c73180d" .
+            "2001280912310a0e65787065637465645f6572726f72180e2001280b3219" .
+            "2e677270632e74657374696e672e4572726f7253746174757312170a0f73" .
+            "65727665725f736c6565705f7573180f20012805224a0a0b4563686f5265" .
+            "7175657374120f0a076d657373616765180120012809122a0a0570617261" .
+            "6d18022001280b321b2e677270632e74657374696e672e52657175657374" .
+            "506172616d7322460a0e526573706f6e7365506172616d7312180a107265" .
+            "71756573745f646561646c696e65180120012803120c0a04686f73741802" .
+            "20012809120c0a0470656572180320012809224c0a0c4563686f52657370" .
+            "6f6e7365120f0a076d657373616765180120012809122b0a05706172616d" .
+            "18022001280b321c2e677270632e74657374696e672e526573706f6e7365" .
+            "506172616d73620670726f746f33"
+        ));
+
+        static::$is_initialized = true;
+    }
+}
+
diff --git a/src/php/tests/qps/generated_code/GPBMetadata/Src/Proto/Grpc/Testing/GPBEmpty.php b/src/php/tests/qps/generated_code/GPBMetadata/Src/Proto/Grpc/Testing/GPBEmpty.php
new file mode 100644
index 0000000000..7198f7da0c
--- /dev/null
+++ b/src/php/tests/qps/generated_code/GPBMetadata/Src/Proto/Grpc/Testing/GPBEmpty.php
@@ -0,0 +1,26 @@
+<?php
+# Generated by the protocol buffer compiler.  DO NOT EDIT!
+# source: src/proto/grpc/testing/empty.proto
+
+namespace GPBMetadata\Src\Proto\Grpc\Testing;
+
+class GPBEmpty
+{
+    public static $is_initialized = false;
+
+    public static function initOnce() {
+        $pool = \Google\Protobuf\Internal\DescriptorPool::getGeneratedPool();
+
+        if (static::$is_initialized == true) {
+          return;
+        }
+        $pool->internalAddGeneratedFile(hex2bin(
+            "0a430a227372632f70726f746f2f677270632f74657374696e672f656d70" .
+            "74792e70726f746f120c677270632e74657374696e6722070a05456d7074" .
+            "79620670726f746f33"
+        ));
+
+        static::$is_initialized = true;
+    }
+}
+
diff --git a/src/php/tests/qps/generated_code/GPBMetadata/Src/Proto/Grpc/Testing/Metrics.php b/src/php/tests/qps/generated_code/GPBMetadata/Src/Proto/Grpc/Testing/Metrics.php
new file mode 100644
index 0000000000..7ac739fb54
--- /dev/null
+++ b/src/php/tests/qps/generated_code/GPBMetadata/Src/Proto/Grpc/Testing/Metrics.php
@@ -0,0 +1,36 @@
+<?php
+# Generated by the protocol buffer compiler.  DO NOT EDIT!
+# source: src/proto/grpc/testing/metrics.proto
+
+namespace GPBMetadata\Src\Proto\Grpc\Testing;
+
+class Metrics
+{
+    public static $is_initialized = false;
+
+    public static function initOnce() {
+        $pool = \Google\Protobuf\Internal\DescriptorPool::getGeneratedPool();
+
+        if (static::$is_initialized == true) {
+          return;
+        }
+        $pool->internalAddGeneratedFile(hex2bin(
+            "0afb020a247372632f70726f746f2f677270632f74657374696e672f6d65" .
+            "74726963732e70726f746f120c677270632e74657374696e67226c0a0d47" .
+            "61756765526573706f6e7365120c0a046e616d6518012001280912140a0a" .
+            "6c6f6e675f76616c7565180220012803480012160a0c646f75626c655f76" .
+            "616c7565180320012801480012160a0c737472696e675f76616c75651804" .
+            "20012809480042070a0576616c7565221c0a0c4761756765526571756573" .
+            "74120c0a046e616d65180120012809220e0a0c456d7074794d6573736167" .
+            "6532a0010a0e4d6574726963735365727669636512490a0c476574416c6c" .
+            "476175676573121a2e677270632e74657374696e672e456d7074794d6573" .
+            "736167651a1b2e677270632e74657374696e672e4761756765526573706f" .
+            "6e7365300112430a084765744761756765121a2e677270632e7465737469" .
+            "6e672e4761756765526571756573741a1b2e677270632e74657374696e67" .
+            "2e4761756765526573706f6e7365620670726f746f33"
+        ));
+
+        static::$is_initialized = true;
+    }
+}
+
diff --git a/src/php/tests/qps/generated_code/GPBMetadata/Src/Proto/Grpc/Testing/ReportQpsScenarioService.php b/src/php/tests/qps/generated_code/GPBMetadata/Src/Proto/Grpc/Testing/ReportQpsScenarioService.php
new file mode 100644
index 0000000000..35a1fb4acb
--- /dev/null
+++ b/src/php/tests/qps/generated_code/GPBMetadata/Src/Proto/Grpc/Testing/ReportQpsScenarioService.php
@@ -0,0 +1,30 @@
+<?php
+# Generated by the protocol buffer compiler.  DO NOT EDIT!
+# source: src/proto/grpc/testing/report_qps_scenario_service.proto
+
+namespace GPBMetadata\Src\Proto\Grpc\Testing;
+
+class ReportQpsScenarioService
+{
+    public static $is_initialized = false;
+
+    public static function initOnce() {
+        $pool = \Google\Protobuf\Internal\DescriptorPool::getGeneratedPool();
+
+        if (static::$is_initialized == true) {
+          return;
+        }
+        \GPBMetadata\Src\Proto\Grpc\Testing\Control::initOnce();
+        $pool->internalAddGeneratedFile(hex2bin(
+            "0ab0010a387372632f70726f746f2f677270632f74657374696e672f7265" .
+            "706f72745f7170735f7363656e6172696f5f736572766963652e70726f74" .
+            "6f120c677270632e74657374696e67325e0a185265706f72745170735363" .
+            "656e6172696f5365727669636512420a0e5265706f72745363656e617269" .
+            "6f121c2e677270632e74657374696e672e5363656e6172696f526573756c" .
+            "741a122e677270632e74657374696e672e566f6964620670726f746f33"
+        ));
+
+        static::$is_initialized = true;
+    }
+}
+
diff --git a/src/php/tests/qps/generated_code/GPBMetadata/Src/Proto/Grpc/Testing/Test.php b/src/php/tests/qps/generated_code/GPBMetadata/Src/Proto/Grpc/Testing/Test.php
new file mode 100644
index 0000000000..54628cfa37
--- /dev/null
+++ b/src/php/tests/qps/generated_code/GPBMetadata/Src/Proto/Grpc/Testing/Test.php
@@ -0,0 +1,60 @@
+<?php
+# Generated by the protocol buffer compiler.  DO NOT EDIT!
+# source: src/proto/grpc/testing/test.proto
+
+namespace GPBMetadata\Src\Proto\Grpc\Testing;
+
+class Test
+{
+    public static $is_initialized = false;
+
+    public static function initOnce() {
+        $pool = \Google\Protobuf\Internal\DescriptorPool::getGeneratedPool();
+
+        if (static::$is_initialized == true) {
+          return;
+        }
+        \GPBMetadata\Src\Proto\Grpc\Testing\GPBEmpty::initOnce();
+        \GPBMetadata\Src\Proto\Grpc\Testing\Messages::initOnce();
+        $pool->internalAddGeneratedFile(hex2bin(
+            "0a91080a217372632f70726f746f2f677270632f74657374696e672f7465" .
+            "73742e70726f746f120c677270632e74657374696e671a257372632f7072" .
+            "6f746f2f677270632f74657374696e672f6d657373616765732e70726f74" .
+            "6f32cb050a0b546573745365727669636512350a09456d70747943616c6c" .
+            "12132e677270632e74657374696e672e456d7074791a132e677270632e74" .
+            "657374696e672e456d70747912460a09556e61727943616c6c121b2e6772" .
+            "70632e74657374696e672e53696d706c65526571756573741a1c2e677270" .
+            "632e74657374696e672e53696d706c65526573706f6e7365124f0a124361" .
+            "63686561626c65556e61727943616c6c121b2e677270632e74657374696e" .
+            "672e53696d706c65526571756573741a1c2e677270632e74657374696e67" .
+            "2e53696d706c65526573706f6e7365126c0a1353747265616d696e674f75" .
+            "7470757443616c6c12282e677270632e74657374696e672e53747265616d" .
+            "696e674f757470757443616c6c526571756573741a292e677270632e7465" .
+            "7374696e672e53747265616d696e674f757470757443616c6c526573706f" .
+            "6e7365300112690a1253747265616d696e67496e70757443616c6c12272e" .
+            "677270632e74657374696e672e53747265616d696e67496e70757443616c" .
+            "6c526571756573741a282e677270632e74657374696e672e53747265616d" .
+            "696e67496e70757443616c6c526573706f6e7365280112690a0e46756c6c" .
+            "4475706c657843616c6c12282e677270632e74657374696e672e53747265" .
+            "616d696e674f757470757443616c6c526571756573741a292e677270632e" .
+            "74657374696e672e53747265616d696e674f757470757443616c6c526573" .
+            "706f6e73652801300112690a0e48616c664475706c657843616c6c12282e" .
+            "677270632e74657374696e672e53747265616d696e674f75747075744361" .
+            "6c6c526571756573741a292e677270632e74657374696e672e5374726561" .
+            "6d696e674f757470757443616c6c526573706f6e736528013001123d0a11" .
+            "556e696d706c656d656e74656443616c6c12132e677270632e7465737469" .
+            "6e672e456d7074791a132e677270632e74657374696e672e456d70747932" .
+            "550a14556e696d706c656d656e74656453657276696365123d0a11556e69" .
+            "6d706c656d656e74656443616c6c12132e677270632e74657374696e672e" .
+            "456d7074791a132e677270632e74657374696e672e456d7074793289010a" .
+            "105265636f6e6e65637453657276696365123b0a055374617274121d2e67" .
+            "7270632e74657374696e672e5265636f6e6e656374506172616d731a132e" .
+            "677270632e74657374696e672e456d70747912380a0453746f7012132e67" .
+            "7270632e74657374696e672e456d7074791a1b2e677270632e7465737469" .
+            "6e672e5265636f6e6e656374496e666f620670726f746f33"
+        ));
+
+        static::$is_initialized = true;
+    }
+}
+
diff --git a/src/php/tests/qps/generated_code/GPBMetadata/Src/Proto/Grpc/Testing/WorkerService.php b/src/php/tests/qps/generated_code/GPBMetadata/Src/Proto/Grpc/Testing/WorkerService.php
new file mode 100644
index 0000000000..a8a863df19
--- /dev/null
+++ b/src/php/tests/qps/generated_code/GPBMetadata/Src/Proto/Grpc/Testing/WorkerService.php
@@ -0,0 +1,36 @@
+<?php
+# Generated by the protocol buffer compiler.  DO NOT EDIT!
+# source: src/proto/grpc/testing/worker_service.proto
+
+namespace GPBMetadata\Src\Proto\Grpc\Testing;
+
+class WorkerService
+{
+    public static $is_initialized = false;
+
+    public static function initOnce() {
+        $pool = \Google\Protobuf\Internal\DescriptorPool::getGeneratedPool();
+
+        if (static::$is_initialized == true) {
+          return;
+        }
+        \GPBMetadata\Src\Proto\Grpc\Testing\Control::initOnce();
+        $pool->internalAddGeneratedFile(hex2bin(
+            "0add020a2b7372632f70726f746f2f677270632f74657374696e672f776f" .
+            "726b65725f736572766963652e70726f746f120c677270632e7465737469" .
+            "6e673297020a0d576f726b65725365727669636512450a0952756e536572" .
+            "76657212182e677270632e74657374696e672e536572766572417267731a" .
+            "1a2e677270632e74657374696e672e536572766572537461747573280130" .
+            "0112450a0952756e436c69656e7412182e677270632e74657374696e672e" .
+            "436c69656e74417267731a1a2e677270632e74657374696e672e436c6965" .
+            "6e745374617475732801300112420a09436f7265436f756e7412192e6772" .
+            "70632e74657374696e672e436f7265526571756573741a1a2e677270632e" .
+            "74657374696e672e436f7265526573706f6e736512340a0a51756974576f" .
+            "726b657212122e677270632e74657374696e672e566f69641a122e677270" .
+            "632e74657374696e672e566f6964620670726f746f33"
+        ));
+
+        static::$is_initialized = true;
+    }
+}
+
diff --git a/src/php/tests/qps/generated_code/Grpc/Testing/ClientConfig.php b/src/php/tests/qps/generated_code/Grpc/Testing/ClientConfig.php
index f7bc21587c..0dd3072f18 100644
--- a/src/php/tests/qps/generated_code/Grpc/Testing/ClientConfig.php
+++ b/src/php/tests/qps/generated_code/Grpc/Testing/ClientConfig.php
@@ -97,6 +97,12 @@ class ClientConfig extends \Google\Protobuf\Internal\Message
      * Generated from protobuf field <code>int32 messages_per_stream = 18;</code>
      */
     private $messages_per_stream = 0;
+    /**
+     * Use coalescing API when possible.
+     *
+     * Generated from protobuf field <code>bool use_coalesce_api = 19;</code>
+     */
+    private $use_coalesce_api = false;
 
     public function __construct() {
         \GPBMetadata\Src\Proto\Grpc\Testing\Control::initOnce();
@@ -495,5 +501,31 @@ class ClientConfig extends \Google\Protobuf\Internal\Message
         return $this;
     }
 
+    /**
+     * Use coalescing API when possible.
+     *
+     * Generated from protobuf field <code>bool use_coalesce_api = 19;</code>
+     * @return bool
+     */
+    public function getUseCoalesceApi()
+    {
+        return $this->use_coalesce_api;
+    }
+
+    /**
+     * Use coalescing API when possible.
+     *
+     * Generated from protobuf field <code>bool use_coalesce_api = 19;</code>
+     * @param bool $var
+     * @return $this
+     */
+    public function setUseCoalesceApi($var)
+    {
+        GPBUtil::checkBool($var);
+        $this->use_coalesce_api = $var;
+
+        return $this;
+    }
+
 }
 
diff --git a/src/php/tests/qps/generated_code/Grpc/Testing/DebugInfo.php b/src/php/tests/qps/generated_code/Grpc/Testing/DebugInfo.php
new file mode 100644
index 0000000000..805b629b0d
--- /dev/null
+++ b/src/php/tests/qps/generated_code/Grpc/Testing/DebugInfo.php
@@ -0,0 +1,77 @@
+<?php
+# Generated by the protocol buffer compiler.  DO NOT EDIT!
+# source: src/proto/grpc/testing/echo_messages.proto
+
+namespace Grpc\Testing;
+
+use Google\Protobuf\Internal\GPBType;
+use Google\Protobuf\Internal\RepeatedField;
+use Google\Protobuf\Internal\GPBUtil;
+
+/**
+ * Message to be echoed back serialized in trailer.
+ *
+ * Generated from protobuf message <code>grpc.testing.DebugInfo</code>
+ */
+class DebugInfo extends \Google\Protobuf\Internal\Message
+{
+    /**
+     * Generated from protobuf field <code>repeated string stack_entries = 1;</code>
+     */
+    private $stack_entries;
+    /**
+     * Generated from protobuf field <code>string detail = 2;</code>
+     */
+    private $detail = '';
+
+    public function __construct() {
+        \GPBMetadata\Src\Proto\Grpc\Testing\EchoMessages::initOnce();
+        parent::__construct();
+    }
+
+    /**
+     * Generated from protobuf field <code>repeated string stack_entries = 1;</code>
+     * @return \Google\Protobuf\Internal\RepeatedField
+     */
+    public function getStackEntries()
+    {
+        return $this->stack_entries;
+    }
+
+    /**
+     * Generated from protobuf field <code>repeated string stack_entries = 1;</code>
+     * @param string[]|\Google\Protobuf\Internal\RepeatedField $var
+     * @return $this
+     */
+    public function setStackEntries($var)
+    {
+        $arr = GPBUtil::checkRepeatedField($var, \Google\Protobuf\Internal\GPBType::STRING);
+        $this->stack_entries = $arr;
+
+        return $this;
+    }
+
+    /**
+     * Generated from protobuf field <code>string detail = 2;</code>
+     * @return string
+     */
+    public function getDetail()
+    {
+        return $this->detail;
+    }
+
+    /**
+     * Generated from protobuf field <code>string detail = 2;</code>
+     * @param string $var
+     * @return $this
+     */
+    public function setDetail($var)
+    {
+        GPBUtil::checkString($var, True);
+        $this->detail = $var;
+
+        return $this;
+    }
+
+}
+
diff --git a/src/php/tests/qps/generated_code/Grpc/Testing/EchoRequest.php b/src/php/tests/qps/generated_code/Grpc/Testing/EchoRequest.php
new file mode 100644
index 0000000000..9aadfc5dee
--- /dev/null
+++ b/src/php/tests/qps/generated_code/Grpc/Testing/EchoRequest.php
@@ -0,0 +1,75 @@
+<?php
+# Generated by the protocol buffer compiler.  DO NOT EDIT!
+# source: src/proto/grpc/testing/echo_messages.proto
+
+namespace Grpc\Testing;
+
+use Google\Protobuf\Internal\GPBType;
+use Google\Protobuf\Internal\RepeatedField;
+use Google\Protobuf\Internal\GPBUtil;
+
+/**
+ * Generated from protobuf message <code>grpc.testing.EchoRequest</code>
+ */
+class EchoRequest extends \Google\Protobuf\Internal\Message
+{
+    /**
+     * Generated from protobuf field <code>string message = 1;</code>
+     */
+    private $message = '';
+    /**
+     * Generated from protobuf field <code>.grpc.testing.RequestParams param = 2;</code>
+     */
+    private $param = null;
+
+    public function __construct() {
+        \GPBMetadata\Src\Proto\Grpc\Testing\EchoMessages::initOnce();
+        parent::__construct();
+    }
+
+    /**
+     * Generated from protobuf field <code>string message = 1;</code>
+     * @return string
+     */
+    public function getMessage()
+    {
+        return $this->message;
+    }
+
+    /**
+     * Generated from protobuf field <code>string message = 1;</code>
+     * @param string $var
+     * @return $this
+     */
+    public function setMessage($var)
+    {
+        GPBUtil::checkString($var, True);
+        $this->message = $var;
+
+        return $this;
+    }
+
+    /**
+     * Generated from protobuf field <code>.grpc.testing.RequestParams param = 2;</code>
+     * @return \Grpc\Testing\RequestParams
+     */
+    public function getParam()
+    {
+        return $this->param;
+    }
+
+    /**
+     * Generated from protobuf field <code>.grpc.testing.RequestParams param = 2;</code>
+     * @param \Grpc\Testing\RequestParams $var
+     * @return $this
+     */
+    public function setParam($var)
+    {
+        GPBUtil::checkMessage($var, \Grpc\Testing\RequestParams::class);
+        $this->param = $var;
+
+        return $this;
+    }
+
+}
+
diff --git a/src/php/tests/qps/generated_code/Grpc/Testing/EchoResponse.php b/src/php/tests/qps/generated_code/Grpc/Testing/EchoResponse.php
new file mode 100644
index 0000000000..c4a9db35ab
--- /dev/null
+++ b/src/php/tests/qps/generated_code/Grpc/Testing/EchoResponse.php
@@ -0,0 +1,75 @@
+<?php
+# Generated by the protocol buffer compiler.  DO NOT EDIT!
+# source: src/proto/grpc/testing/echo_messages.proto
+
+namespace Grpc\Testing;
+
+use Google\Protobuf\Internal\GPBType;
+use Google\Protobuf\Internal\RepeatedField;
+use Google\Protobuf\Internal\GPBUtil;
+
+/**
+ * Generated from protobuf message <code>grpc.testing.EchoResponse</code>
+ */
+class EchoResponse extends \Google\Protobuf\Internal\Message
+{
+    /**
+     * Generated from protobuf field <code>string message = 1;</code>
+     */
+    private $message = '';
+    /**
+     * Generated from protobuf field <code>.grpc.testing.ResponseParams param = 2;</code>
+     */
+    private $param = null;
+
+    public function __construct() {
+        \GPBMetadata\Src\Proto\Grpc\Testing\EchoMessages::initOnce();
+        parent::__construct();
+    }
+
+    /**
+     * Generated from protobuf field <code>string message = 1;</code>
+     * @return string
+     */
+    public function getMessage()
+    {
+        return $this->message;
+    }
+
+    /**
+     * Generated from protobuf field <code>string message = 1;</code>
+     * @param string $var
+     * @return $this
+     */
+    public function setMessage($var)
+    {
+        GPBUtil::checkString($var, True);
+        $this->message = $var;
+
+        return $this;
+    }
+
+    /**
+     * Generated from protobuf field <code>.grpc.testing.ResponseParams param = 2;</code>
+     * @return \Grpc\Testing\ResponseParams
+     */
+    public function getParam()
+    {
+        return $this->param;
+    }
+
+    /**
+     * Generated from protobuf field <code>.grpc.testing.ResponseParams param = 2;</code>
+     * @param \Grpc\Testing\ResponseParams $var
+     * @return $this
+     */
+    public function setParam($var)
+    {
+        GPBUtil::checkMessage($var, \Grpc\Testing\ResponseParams::class);
+        $this->param = $var;
+
+        return $this;
+    }
+
+}
+
diff --git a/src/php/tests/qps/generated_code/Grpc/Testing/EchoTestServiceClient.php b/src/php/tests/qps/generated_code/Grpc/Testing/EchoTestServiceClient.php
new file mode 100644
index 0000000000..b3dcf5b7af
--- /dev/null
+++ b/src/php/tests/qps/generated_code/Grpc/Testing/EchoTestServiceClient.php
@@ -0,0 +1,93 @@
+<?php
+// GENERATED CODE -- DO NOT EDIT!
+
+// Original file comments:
+// Copyright 2015 gRPC authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+namespace Grpc\Testing;
+
+/**
+ */
+class EchoTestServiceClient extends \Grpc\BaseStub {
+
+    /**
+     * @param string $hostname hostname
+     * @param array $opts channel options
+     * @param \Grpc\Channel $channel (optional) re-use channel object
+     */
+    public function __construct($hostname, $opts, $channel = null) {
+        parent::__construct($hostname, $opts, $channel);
+    }
+
+    /**
+     * @param \Grpc\Testing\EchoRequest $argument input argument
+     * @param array $metadata metadata
+     * @param array $options call options
+     */
+    public function Echo(\Grpc\Testing\EchoRequest $argument,
+      $metadata = [], $options = []) {
+        return $this->_simpleRequest('/grpc.testing.EchoTestService/Echo',
+        $argument,
+        ['\Grpc\Testing\EchoResponse', 'decode'],
+        $metadata, $options);
+    }
+
+    /**
+     * @param array $metadata metadata
+     * @param array $options call options
+     */
+    public function RequestStream($metadata = [], $options = []) {
+        return $this->_clientStreamRequest('/grpc.testing.EchoTestService/RequestStream',
+        ['\Grpc\Testing\EchoResponse','decode'],
+        $metadata, $options);
+    }
+
+    /**
+     * @param \Grpc\Testing\EchoRequest $argument input argument
+     * @param array $metadata metadata
+     * @param array $options call options
+     */
+    public function ResponseStream(\Grpc\Testing\EchoRequest $argument,
+      $metadata = [], $options = []) {
+        return $this->_serverStreamRequest('/grpc.testing.EchoTestService/ResponseStream',
+        $argument,
+        ['\Grpc\Testing\EchoResponse', 'decode'],
+        $metadata, $options);
+    }
+
+    /**
+     * @param array $metadata metadata
+     * @param array $options call options
+     */
+    public function BidiStream($metadata = [], $options = []) {
+        return $this->_bidiRequest('/grpc.testing.EchoTestService/BidiStream',
+        ['\Grpc\Testing\EchoResponse','decode'],
+        $metadata, $options);
+    }
+
+    /**
+     * @param \Grpc\Testing\EchoRequest $argument input argument
+     * @param array $metadata metadata
+     * @param array $options call options
+     */
+    public function Unimplemented(\Grpc\Testing\EchoRequest $argument,
+      $metadata = [], $options = []) {
+        return $this->_simpleRequest('/grpc.testing.EchoTestService/Unimplemented',
+        $argument,
+        ['\Grpc\Testing\EchoResponse', 'decode'],
+        $metadata, $options);
+    }
+
+}
diff --git a/src/php/tests/qps/generated_code/Grpc/Testing/EmptyMessage.php b/src/php/tests/qps/generated_code/Grpc/Testing/EmptyMessage.php
new file mode 100644
index 0000000000..3da163e7c0
--- /dev/null
+++ b/src/php/tests/qps/generated_code/Grpc/Testing/EmptyMessage.php
@@ -0,0 +1,23 @@
+<?php
+# Generated by the protocol buffer compiler.  DO NOT EDIT!
+# source: src/proto/grpc/testing/metrics.proto
+
+namespace Grpc\Testing;
+
+use Google\Protobuf\Internal\GPBType;
+use Google\Protobuf\Internal\RepeatedField;
+use Google\Protobuf\Internal\GPBUtil;
+
+/**
+ * Generated from protobuf message <code>grpc.testing.EmptyMessage</code>
+ */
+class EmptyMessage extends \Google\Protobuf\Internal\Message
+{
+
+    public function __construct() {
+        \GPBMetadata\Src\Proto\Grpc\Testing\Metrics::initOnce();
+        parent::__construct();
+    }
+
+}
+
diff --git a/src/php/tests/qps/generated_code/Grpc/Testing/ErrorStatus.php b/src/php/tests/qps/generated_code/Grpc/Testing/ErrorStatus.php
new file mode 100644
index 0000000000..cc378756c7
--- /dev/null
+++ b/src/php/tests/qps/generated_code/Grpc/Testing/ErrorStatus.php
@@ -0,0 +1,103 @@
+<?php
+# Generated by the protocol buffer compiler.  DO NOT EDIT!
+# source: src/proto/grpc/testing/echo_messages.proto
+
+namespace Grpc\Testing;
+
+use Google\Protobuf\Internal\GPBType;
+use Google\Protobuf\Internal\RepeatedField;
+use Google\Protobuf\Internal\GPBUtil;
+
+/**
+ * Error status client expects to see.
+ *
+ * Generated from protobuf message <code>grpc.testing.ErrorStatus</code>
+ */
+class ErrorStatus extends \Google\Protobuf\Internal\Message
+{
+    /**
+     * Generated from protobuf field <code>int32 code = 1;</code>
+     */
+    private $code = 0;
+    /**
+     * Generated from protobuf field <code>string error_message = 2;</code>
+     */
+    private $error_message = '';
+    /**
+     * Generated from protobuf field <code>string binary_error_details = 3;</code>
+     */
+    private $binary_error_details = '';
+
+    public function __construct() {
+        \GPBMetadata\Src\Proto\Grpc\Testing\EchoMessages::initOnce();
+        parent::__construct();
+    }
+
+    /**
+     * Generated from protobuf field <code>int32 code = 1;</code>
+     * @return int
+     */
+    public function getCode()
+    {
+        return $this->code;
+    }
+
+    /**
+     * Generated from protobuf field <code>int32 code = 1;</code>
+     * @param int $var
+     * @return $this
+     */
+    public function setCode($var)
+    {
+        GPBUtil::checkInt32($var);
+        $this->code = $var;
+
+        return $this;
+    }
+
+    /**
+     * Generated from protobuf field <code>string error_message = 2;</code>
+     * @return string
+     */
+    public function getErrorMessage()
+    {
+        return $this->error_message;
+    }
+
+    /**
+     * Generated from protobuf field <code>string error_message = 2;</code>
+     * @param string $var
+     * @return $this
+     */
+    public function setErrorMessage($var)
+    {
+        GPBUtil::checkString($var, True);
+        $this->error_message = $var;
+
+        return $this;
+    }
+
+    /**
+     * Generated from protobuf field <code>string binary_error_details = 3;</code>
+     * @return string
+     */
+    public function getBinaryErrorDetails()
+    {
+        return $this->binary_error_details;
+    }
+
+    /**
+     * Generated from protobuf field <code>string binary_error_details = 3;</code>
+     * @param string $var
+     * @return $this
+     */
+    public function setBinaryErrorDetails($var)
+    {
+        GPBUtil::checkString($var, True);
+        $this->binary_error_details = $var;
+
+        return $this;
+    }
+
+}
+
diff --git a/src/php/tests/qps/generated_code/Grpc/Testing/GaugeRequest.php b/src/php/tests/qps/generated_code/Grpc/Testing/GaugeRequest.php
new file mode 100644
index 0000000000..3c283693c9
--- /dev/null
+++ b/src/php/tests/qps/generated_code/Grpc/Testing/GaugeRequest.php
@@ -0,0 +1,51 @@
+<?php
+# Generated by the protocol buffer compiler.  DO NOT EDIT!
+# source: src/proto/grpc/testing/metrics.proto
+
+namespace Grpc\Testing;
+
+use Google\Protobuf\Internal\GPBType;
+use Google\Protobuf\Internal\RepeatedField;
+use Google\Protobuf\Internal\GPBUtil;
+
+/**
+ * Request message containing the gauge name
+ *
+ * Generated from protobuf message <code>grpc.testing.GaugeRequest</code>
+ */
+class GaugeRequest extends \Google\Protobuf\Internal\Message
+{
+    /**
+     * Generated from protobuf field <code>string name = 1;</code>
+     */
+    private $name = '';
+
+    public function __construct() {
+        \GPBMetadata\Src\Proto\Grpc\Testing\Metrics::initOnce();
+        parent::__construct();
+    }
+
+    /**
+     * Generated from protobuf field <code>string name = 1;</code>
+     * @return string
+     */
+    public function getName()
+    {
+        return $this->name;
+    }
+
+    /**
+     * Generated from protobuf field <code>string name = 1;</code>
+     * @param string $var
+     * @return $this
+     */
+    public function setName($var)
+    {
+        GPBUtil::checkString($var, True);
+        $this->name = $var;
+
+        return $this;
+    }
+
+}
+
diff --git a/src/php/tests/qps/generated_code/Grpc/Testing/GaugeResponse.php b/src/php/tests/qps/generated_code/Grpc/Testing/GaugeResponse.php
new file mode 100644
index 0000000000..da658ba198
--- /dev/null
+++ b/src/php/tests/qps/generated_code/Grpc/Testing/GaugeResponse.php
@@ -0,0 +1,126 @@
+<?php
+# Generated by the protocol buffer compiler.  DO NOT EDIT!
+# source: src/proto/grpc/testing/metrics.proto
+
+namespace Grpc\Testing;
+
+use Google\Protobuf\Internal\GPBType;
+use Google\Protobuf\Internal\RepeatedField;
+use Google\Protobuf\Internal\GPBUtil;
+
+/**
+ * Reponse message containing the gauge name and value
+ *
+ * Generated from protobuf message <code>grpc.testing.GaugeResponse</code>
+ */
+class GaugeResponse extends \Google\Protobuf\Internal\Message
+{
+    /**
+     * Generated from protobuf field <code>string name = 1;</code>
+     */
+    private $name = '';
+    protected $value;
+
+    public function __construct() {
+        \GPBMetadata\Src\Proto\Grpc\Testing\Metrics::initOnce();
+        parent::__construct();
+    }
+
+    /**
+     * Generated from protobuf field <code>string name = 1;</code>
+     * @return string
+     */
+    public function getName()
+    {
+        return $this->name;
+    }
+
+    /**
+     * Generated from protobuf field <code>string name = 1;</code>
+     * @param string $var
+     * @return $this
+     */
+    public function setName($var)
+    {
+        GPBUtil::checkString($var, True);
+        $this->name = $var;
+
+        return $this;
+    }
+
+    /**
+     * Generated from protobuf field <code>int64 long_value = 2;</code>
+     * @return int|string
+     */
+    public function getLongValue()
+    {
+        return $this->readOneof(2);
+    }
+
+    /**
+     * Generated from protobuf field <code>int64 long_value = 2;</code>
+     * @param int|string $var
+     * @return $this
+     */
+    public function setLongValue($var)
+    {
+        GPBUtil::checkInt64($var);
+        $this->writeOneof(2, $var);
+
+        return $this;
+    }
+
+    /**
+     * Generated from protobuf field <code>double double_value = 3;</code>
+     * @return float
+     */
+    public function getDoubleValue()
+    {
+        return $this->readOneof(3);
+    }
+
+    /**
+     * Generated from protobuf field <code>double double_value = 3;</code>
+     * @param float $var
+     * @return $this
+     */
+    public function setDoubleValue($var)
+    {
+        GPBUtil::checkDouble($var);
+        $this->writeOneof(3, $var);
+
+        return $this;
+    }
+
+    /**
+     * Generated from protobuf field <code>string string_value = 4;</code>
+     * @return string
+     */
+    public function getStringValue()
+    {
+        return $this->readOneof(4);
+    }
+
+    /**
+     * Generated from protobuf field <code>string string_value = 4;</code>
+     * @param string $var
+     * @return $this
+     */
+    public function setStringValue($var)
+    {
+        GPBUtil::checkString($var, True);
+        $this->writeOneof(4, $var);
+
+        return $this;
+    }
+
+    /**
+     * @return string
+     */
+    public function getValue()
+    {
+        return $this->whichOneof("value");
+    }
+
+}
+
diff --git a/src/php/tests/qps/generated_code/Grpc/Testing/MetricsServiceClient.php b/src/php/tests/qps/generated_code/Grpc/Testing/MetricsServiceClient.php
new file mode 100644
index 0000000000..491ccbce72
--- /dev/null
+++ b/src/php/tests/qps/generated_code/Grpc/Testing/MetricsServiceClient.php
@@ -0,0 +1,69 @@
+<?php
+// GENERATED CODE -- DO NOT EDIT!
+
+// Original file comments:
+// Copyright 2015-2016 gRPC authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+// Contains the definitions for a metrics service and the type of metrics
+// exposed by the service.
+//
+// Currently, 'Gauge' (i.e a metric that represents the measured value of
+// something at an instant of time) is the only metric type supported by the
+// service.
+namespace Grpc\Testing;
+
+/**
+ */
+class MetricsServiceClient extends \Grpc\BaseStub {
+
+    /**
+     * @param string $hostname hostname
+     * @param array $opts channel options
+     * @param \Grpc\Channel $channel (optional) re-use channel object
+     */
+    public function __construct($hostname, $opts, $channel = null) {
+        parent::__construct($hostname, $opts, $channel);
+    }
+
+    /**
+     * Returns the values of all the gauges that are currently being maintained by
+     * the service
+     * @param \Grpc\Testing\EmptyMessage $argument input argument
+     * @param array $metadata metadata
+     * @param array $options call options
+     */
+    public function GetAllGauges(\Grpc\Testing\EmptyMessage $argument,
+      $metadata = [], $options = []) {
+        return $this->_serverStreamRequest('/grpc.testing.MetricsService/GetAllGauges',
+        $argument,
+        ['\Grpc\Testing\GaugeResponse', 'decode'],
+        $metadata, $options);
+    }
+
+    /**
+     * Returns the value of one gauge
+     * @param \Grpc\Testing\GaugeRequest $argument input argument
+     * @param array $metadata metadata
+     * @param array $options call options
+     */
+    public function GetGauge(\Grpc\Testing\GaugeRequest $argument,
+      $metadata = [], $options = []) {
+        return $this->_simpleRequest('/grpc.testing.MetricsService/GetGauge',
+        $argument,
+        ['\Grpc\Testing\GaugeResponse', 'decode'],
+        $metadata, $options);
+    }
+
+}
diff --git a/src/php/tests/qps/generated_code/Grpc/Testing/NoRpcServiceClient.php b/src/php/tests/qps/generated_code/Grpc/Testing/NoRpcServiceClient.php
new file mode 100644
index 0000000000..1d58eaf88a
--- /dev/null
+++ b/src/php/tests/qps/generated_code/Grpc/Testing/NoRpcServiceClient.php
@@ -0,0 +1,35 @@
+<?php
+// GENERATED CODE -- DO NOT EDIT!
+
+// Original file comments:
+// Copyright 2015 gRPC authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+namespace Grpc\Testing;
+
+/**
+ * A service without any rpc defined to test coverage.
+ */
+class NoRpcServiceClient extends \Grpc\BaseStub {
+
+    /**
+     * @param string $hostname hostname
+     * @param array $opts channel options
+     * @param \Grpc\Channel $channel (optional) re-use channel object
+     */
+    public function __construct($hostname, $opts, $channel = null) {
+        parent::__construct($hostname, $opts, $channel);
+    }
+
+}
diff --git a/src/php/tests/qps/generated_code/Grpc/Testing/PBEmpty.php b/src/php/tests/qps/generated_code/Grpc/Testing/PBEmpty.php
new file mode 100644
index 0000000000..a1fe9df454
--- /dev/null
+++ b/src/php/tests/qps/generated_code/Grpc/Testing/PBEmpty.php
@@ -0,0 +1,30 @@
+<?php
+# Generated by the protocol buffer compiler.  DO NOT EDIT!
+# source: src/proto/grpc/testing/empty.proto
+
+namespace Grpc\Testing;
+
+use Google\Protobuf\Internal\GPBType;
+use Google\Protobuf\Internal\RepeatedField;
+use Google\Protobuf\Internal\GPBUtil;
+
+/**
+ * An empty message that you can re-use to avoid defining duplicated empty
+ * messages in your project. A typical example is to use it as argument or the
+ * return value of a service API. For instance:
+ *   service Foo {
+ *     rpc Bar (grpc.testing.Empty) returns (grpc.testing.Empty) { };
+ *   };
+ *
+ * Generated from protobuf message <code>grpc.testing.Empty</code>
+ */
+class PBEmpty extends \Google\Protobuf\Internal\Message
+{
+
+    public function __construct() {
+        \GPBMetadata\Src\Proto\Grpc\Testing\GPBEmpty::initOnce();
+        parent::__construct();
+    }
+
+}
+
diff --git a/src/php/tests/qps/generated_code/Grpc/Testing/PBVoid.php b/src/php/tests/qps/generated_code/Grpc/Testing/PBVoid.php
new file mode 100644
index 0000000000..94cb6c1ecf
--- /dev/null
+++ b/src/php/tests/qps/generated_code/Grpc/Testing/PBVoid.php
@@ -0,0 +1,23 @@
+<?php
+# Generated by the protocol buffer compiler.  DO NOT EDIT!
+# source: src/proto/grpc/testing/control.proto
+
+namespace Grpc\Testing;
+
+use Google\Protobuf\Internal\GPBType;
+use Google\Protobuf\Internal\RepeatedField;
+use Google\Protobuf\Internal\GPBUtil;
+
+/**
+ * Generated from protobuf message <code>grpc.testing.Void</code>
+ */
+class PBVoid extends \Google\Protobuf\Internal\Message
+{
+
+    public function __construct() {
+        \GPBMetadata\Src\Proto\Grpc\Testing\Control::initOnce();
+        parent::__construct();
+    }
+
+}
+
diff --git a/src/php/tests/qps/generated_code/Grpc/Testing/ProxyClientServiceClient.php b/src/php/tests/qps/generated_code/Grpc/Testing/ProxyClientServiceClient.php
index 5510b57064..c0e304929d 100644
--- a/src/php/tests/qps/generated_code/Grpc/Testing/ProxyClientServiceClient.php
+++ b/src/php/tests/qps/generated_code/Grpc/Testing/ProxyClientServiceClient.php
@@ -32,11 +32,11 @@ class ProxyClientServiceClient extends \Grpc\BaseStub {
     }
 
     /**
-     * @param \Grpc\Testing\Void $argument input argument
+     * @param \Grpc\Testing\PBVoid $argument input argument
      * @param array $metadata metadata
      * @param array $options call options
      */
-    public function GetConfig(\Grpc\Testing\Void $argument,
+    public function GetConfig(\Grpc\Testing\PBVoid $argument,
       $metadata = [], $options = []) {
         return $this->_simpleRequest('/grpc.testing.ProxyClientService/GetConfig',
         $argument,
@@ -50,7 +50,7 @@ class ProxyClientServiceClient extends \Grpc\BaseStub {
      */
     public function ReportTime($metadata = [], $options = []) {
         return $this->_clientStreamRequest('/grpc.testing.ProxyClientService/ReportTime',
-        ['\Grpc\Testing\Void','decode'],
+        ['\Grpc\Testing\PBVoid','decode'],
         $metadata, $options);
     }
 
@@ -60,7 +60,7 @@ class ProxyClientServiceClient extends \Grpc\BaseStub {
      */
     public function ReportHist($metadata = [], $options = []) {
         return $this->_clientStreamRequest('/grpc.testing.ProxyClientService/ReportHist',
-        ['\Grpc\Testing\Void','decode'],
+        ['\Grpc\Testing\PBVoid','decode'],
         $metadata, $options);
     }
 
diff --git a/src/php/tests/qps/generated_code/Grpc/Testing/ReconnectServiceClient.php b/src/php/tests/qps/generated_code/Grpc/Testing/ReconnectServiceClient.php
new file mode 100644
index 0000000000..a1802e97cd
--- /dev/null
+++ b/src/php/tests/qps/generated_code/Grpc/Testing/ReconnectServiceClient.php
@@ -0,0 +1,64 @@
+<?php
+// GENERATED CODE -- DO NOT EDIT!
+
+// Original file comments:
+// Copyright 2015-2016 gRPC authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+// An integration test service that covers all the method signature permutations
+// of unary/streaming requests/responses.
+//
+namespace Grpc\Testing;
+
+/**
+ * A service used to control reconnect server.
+ */
+class ReconnectServiceClient extends \Grpc\BaseStub {
+
+    /**
+     * @param string $hostname hostname
+     * @param array $opts channel options
+     * @param \Grpc\Channel $channel (optional) re-use channel object
+     */
+    public function __construct($hostname, $opts, $channel = null) {
+        parent::__construct($hostname, $opts, $channel);
+    }
+
+    /**
+     * @param \Grpc\Testing\ReconnectParams $argument input argument
+     * @param array $metadata metadata
+     * @param array $options call options
+     */
+    public function Start(\Grpc\Testing\ReconnectParams $argument,
+      $metadata = [], $options = []) {
+        return $this->_simpleRequest('/grpc.testing.ReconnectService/Start',
+        $argument,
+        ['\Grpc\Testing\PBEmpty', 'decode'],
+        $metadata, $options);
+    }
+
+    /**
+     * @param \Grpc\Testing\PBEmpty $argument input argument
+     * @param array $metadata metadata
+     * @param array $options call options
+     */
+    public function Stop(\Grpc\Testing\PBEmpty $argument,
+      $metadata = [], $options = []) {
+        return $this->_simpleRequest('/grpc.testing.ReconnectService/Stop',
+        $argument,
+        ['\Grpc\Testing\ReconnectInfo', 'decode'],
+        $metadata, $options);
+    }
+
+}
diff --git a/src/php/tests/qps/generated_code/Grpc/Testing/ReportQpsScenarioServiceClient.php b/src/php/tests/qps/generated_code/Grpc/Testing/ReportQpsScenarioServiceClient.php
index 72d44ffc66..3abb5abe6d 100644
--- a/src/php/tests/qps/generated_code/Grpc/Testing/ReportQpsScenarioServiceClient.php
+++ b/src/php/tests/qps/generated_code/Grpc/Testing/ReportQpsScenarioServiceClient.php
@@ -43,7 +43,7 @@ class ReportQpsScenarioServiceClient extends \Grpc\BaseStub {
       $metadata = [], $options = []) {
         return $this->_simpleRequest('/grpc.testing.ReportQpsScenarioService/ReportScenario',
         $argument,
-        ['\Grpc\Testing\Void', 'decode'],
+        ['\Grpc\Testing\PBVoid', 'decode'],
         $metadata, $options);
     }
 
diff --git a/src/php/tests/qps/generated_code/Grpc/Testing/Request.php b/src/php/tests/qps/generated_code/Grpc/Testing/Request.php
new file mode 100644
index 0000000000..6a20f6a897
--- /dev/null
+++ b/src/php/tests/qps/generated_code/Grpc/Testing/Request.php
@@ -0,0 +1,23 @@
+<?php
+# Generated by the protocol buffer compiler.  DO NOT EDIT!
+# source: src/proto/grpc/testing/compiler_test.proto
+
+namespace Grpc\Testing;
+
+use Google\Protobuf\Internal\GPBType;
+use Google\Protobuf\Internal\RepeatedField;
+use Google\Protobuf\Internal\GPBUtil;
+
+/**
+ * Generated from protobuf message <code>grpc.testing.Request</code>
+ */
+class Request extends \Google\Protobuf\Internal\Message
+{
+
+    public function __construct() {
+        \GPBMetadata\Src\Proto\Grpc\Testing\CompilerTest::initOnce();
+        parent::__construct();
+    }
+
+}
+
diff --git a/src/php/tests/qps/generated_code/Grpc/Testing/RequestParams.php b/src/php/tests/qps/generated_code/Grpc/Testing/RequestParams.php
new file mode 100644
index 0000000000..f01f50d5af
--- /dev/null
+++ b/src/php/tests/qps/generated_code/Grpc/Testing/RequestParams.php
@@ -0,0 +1,431 @@
+<?php
+# Generated by the protocol buffer compiler.  DO NOT EDIT!
+# source: src/proto/grpc/testing/echo_messages.proto
+
+namespace Grpc\Testing;
+
+use Google\Protobuf\Internal\GPBType;
+use Google\Protobuf\Internal\RepeatedField;
+use Google\Protobuf\Internal\GPBUtil;
+
+/**
+ * Generated from protobuf message <code>grpc.testing.RequestParams</code>
+ */
+class RequestParams extends \Google\Protobuf\Internal\Message
+{
+    /**
+     * Generated from protobuf field <code>bool echo_deadline = 1;</code>
+     */
+    private $echo_deadline = false;
+    /**
+     * Generated from protobuf field <code>int32 client_cancel_after_us = 2;</code>
+     */
+    private $client_cancel_after_us = 0;
+    /**
+     * Generated from protobuf field <code>int32 server_cancel_after_us = 3;</code>
+     */
+    private $server_cancel_after_us = 0;
+    /**
+     * Generated from protobuf field <code>bool echo_metadata = 4;</code>
+     */
+    private $echo_metadata = false;
+    /**
+     * Generated from protobuf field <code>bool check_auth_context = 5;</code>
+     */
+    private $check_auth_context = false;
+    /**
+     * Generated from protobuf field <code>int32 response_message_length = 6;</code>
+     */
+    private $response_message_length = 0;
+    /**
+     * Generated from protobuf field <code>bool echo_peer = 7;</code>
+     */
+    private $echo_peer = false;
+    /**
+     * will force check_auth_context.
+     *
+     * Generated from protobuf field <code>string expected_client_identity = 8;</code>
+     */
+    private $expected_client_identity = '';
+    /**
+     * Generated from protobuf field <code>bool skip_cancelled_check = 9;</code>
+     */
+    private $skip_cancelled_check = false;
+    /**
+     * Generated from protobuf field <code>string expected_transport_security_type = 10;</code>
+     */
+    private $expected_transport_security_type = '';
+    /**
+     * Generated from protobuf field <code>.grpc.testing.DebugInfo debug_info = 11;</code>
+     */
+    private $debug_info = null;
+    /**
+     * Server should not see a request with this set.
+     *
+     * Generated from protobuf field <code>bool server_die = 12;</code>
+     */
+    private $server_die = false;
+    /**
+     * Generated from protobuf field <code>string binary_error_details = 13;</code>
+     */
+    private $binary_error_details = '';
+    /**
+     * Generated from protobuf field <code>.grpc.testing.ErrorStatus expected_error = 14;</code>
+     */
+    private $expected_error = null;
+    /**
+     * Amount to sleep when invoking server
+     *
+     * Generated from protobuf field <code>int32 server_sleep_us = 15;</code>
+     */
+    private $server_sleep_us = 0;
+
+    public function __construct() {
+        \GPBMetadata\Src\Proto\Grpc\Testing\EchoMessages::initOnce();
+        parent::__construct();
+    }
+
+    /**
+     * Generated from protobuf field <code>bool echo_deadline = 1;</code>
+     * @return bool
+     */
+    public function getEchoDeadline()
+    {
+        return $this->echo_deadline;
+    }
+
+    /**
+     * Generated from protobuf field <code>bool echo_deadline = 1;</code>
+     * @param bool $var
+     * @return $this
+     */
+    public function setEchoDeadline($var)
+    {
+        GPBUtil::checkBool($var);
+        $this->echo_deadline = $var;
+
+        return $this;
+    }
+
+    /**
+     * Generated from protobuf field <code>int32 client_cancel_after_us = 2;</code>
+     * @return int
+     */
+    public function getClientCancelAfterUs()
+    {
+        return $this->client_cancel_after_us;
+    }
+
+    /**
+     * Generated from protobuf field <code>int32 client_cancel_after_us = 2;</code>
+     * @param int $var
+     * @return $this
+     */
+    public function setClientCancelAfterUs($var)
+    {
+        GPBUtil::checkInt32($var);
+        $this->client_cancel_after_us = $var;
+
+        return $this;
+    }
+
+    /**
+     * Generated from protobuf field <code>int32 server_cancel_after_us = 3;</code>
+     * @return int
+     */
+    public function getServerCancelAfterUs()
+    {
+        return $this->server_cancel_after_us;
+    }
+
+    /**
+     * Generated from protobuf field <code>int32 server_cancel_after_us = 3;</code>
+     * @param int $var
+     * @return $this
+     */
+    public function setServerCancelAfterUs($var)
+    {
+        GPBUtil::checkInt32($var);
+        $this->server_cancel_after_us = $var;
+
+        return $this;
+    }
+
+    /**
+     * Generated from protobuf field <code>bool echo_metadata = 4;</code>
+     * @return bool
+     */
+    public function getEchoMetadata()
+    {
+        return $this->echo_metadata;
+    }
+
+    /**
+     * Generated from protobuf field <code>bool echo_metadata = 4;</code>
+     * @param bool $var
+     * @return $this
+     */
+    public function setEchoMetadata($var)
+    {
+        GPBUtil::checkBool($var);
+        $this->echo_metadata = $var;
+
+        return $this;
+    }
+
+    /**
+     * Generated from protobuf field <code>bool check_auth_context = 5;</code>
+     * @return bool
+     */
+    public function getCheckAuthContext()
+    {
+        return $this->check_auth_context;
+    }
+
+    /**
+     * Generated from protobuf field <code>bool check_auth_context = 5;</code>
+     * @param bool $var
+     * @return $this
+     */
+    public function setCheckAuthContext($var)
+    {
+        GPBUtil::checkBool($var);
+        $this->check_auth_context = $var;
+
+        return $this;
+    }
+
+    /**
+     * Generated from protobuf field <code>int32 response_message_length = 6;</code>
+     * @return int
+     */
+    public function getResponseMessageLength()
+    {
+        return $this->response_message_length;
+    }
+
+    /**
+     * Generated from protobuf field <code>int32 response_message_length = 6;</code>
+     * @param int $var
+     * @return $this
+     */
+    public function setResponseMessageLength($var)
+    {
+        GPBUtil::checkInt32($var);
+        $this->response_message_length = $var;
+
+        return $this;
+    }
+
+    /**
+     * Generated from protobuf field <code>bool echo_peer = 7;</code>
+     * @return bool
+     */
+    public function getEchoPeer()
+    {
+        return $this->echo_peer;
+    }
+
+    /**
+     * Generated from protobuf field <code>bool echo_peer = 7;</code>
+     * @param bool $var
+     * @return $this
+     */
+    public function setEchoPeer($var)
+    {
+        GPBUtil::checkBool($var);
+        $this->echo_peer = $var;
+
+        return $this;
+    }
+
+    /**
+     * will force check_auth_context.
+     *
+     * Generated from protobuf field <code>string expected_client_identity = 8;</code>
+     * @return string
+     */
+    public function getExpectedClientIdentity()
+    {
+        return $this->expected_client_identity;
+    }
+
+    /**
+     * will force check_auth_context.
+     *
+     * Generated from protobuf field <code>string expected_client_identity = 8;</code>
+     * @param string $var
+     * @return $this
+     */
+    public function setExpectedClientIdentity($var)
+    {
+        GPBUtil::checkString($var, True);
+        $this->expected_client_identity = $var;
+
+        return $this;
+    }
+
+    /**
+     * Generated from protobuf field <code>bool skip_cancelled_check = 9;</code>
+     * @return bool
+     */
+    public function getSkipCancelledCheck()
+    {
+        return $this->skip_cancelled_check;
+    }
+
+    /**
+     * Generated from protobuf field <code>bool skip_cancelled_check = 9;</code>
+     * @param bool $var
+     * @return $this
+     */
+    public function setSkipCancelledCheck($var)
+    {
+        GPBUtil::checkBool($var);
+        $this->skip_cancelled_check = $var;
+
+        return $this;
+    }
+
+    /**
+     * Generated from protobuf field <code>string expected_transport_security_type = 10;</code>
+     * @return string
+     */
+    public function getExpectedTransportSecurityType()
+    {
+        return $this->expected_transport_security_type;
+    }
+
+    /**
+     * Generated from protobuf field <code>string expected_transport_security_type = 10;</code>
+     * @param string $var
+     * @return $this
+     */
+    public function setExpectedTransportSecurityType($var)
+    {
+        GPBUtil::checkString($var, True);
+        $this->expected_transport_security_type = $var;
+
+        return $this;
+    }
+
+    /**
+     * Generated from protobuf field <code>.grpc.testing.DebugInfo debug_info = 11;</code>
+     * @return \Grpc\Testing\DebugInfo
+     */
+    public function getDebugInfo()
+    {
+        return $this->debug_info;
+    }
+
+    /**
+     * Generated from protobuf field <code>.grpc.testing.DebugInfo debug_info = 11;</code>
+     * @param \Grpc\Testing\DebugInfo $var
+     * @return $this
+     */
+    public function setDebugInfo($var)
+    {
+        GPBUtil::checkMessage($var, \Grpc\Testing\DebugInfo::class);
+        $this->debug_info = $var;
+
+        return $this;
+    }
+
+    /**
+     * Server should not see a request with this set.
+     *
+     * Generated from protobuf field <code>bool server_die = 12;</code>
+     * @return bool
+     */
+    public function getServerDie()
+    {
+        return $this->server_die;
+    }
+
+    /**
+     * Server should not see a request with this set.
+     *
+     * Generated from protobuf field <code>bool server_die = 12;</code>
+     * @param bool $var
+     * @return $this
+     */
+    public function setServerDie($var)
+    {
+        GPBUtil::checkBool($var);
+        $this->server_die = $var;
+
+        return $this;
+    }
+
+    /**
+     * Generated from protobuf field <code>string binary_error_details = 13;</code>
+     * @return string
+     */
+    public function getBinaryErrorDetails()
+    {
+        return $this->binary_error_details;
+    }
+
+    /**
+     * Generated from protobuf field <code>string binary_error_details = 13;</code>
+     * @param string $var
+     * @return $this
+     */
+    public function setBinaryErrorDetails($var)
+    {
+        GPBUtil::checkString($var, True);
+        $this->binary_error_details = $var;
+
+        return $this;
+    }
+
+    /**
+     * Generated from protobuf field <code>.grpc.testing.ErrorStatus expected_error = 14;</code>
+     * @return \Grpc\Testing\ErrorStatus
+     */
+    public function getExpectedError()
+    {
+        return $this->expected_error;
+    }
+
+    /**
+     * Generated from protobuf field <code>.grpc.testing.ErrorStatus expected_error = 14;</code>
+     * @param \Grpc\Testing\ErrorStatus $var
+     * @return $this
+     */
+    public function setExpectedError($var)
+    {
+        GPBUtil::checkMessage($var, \Grpc\Testing\ErrorStatus::class);
+        $this->expected_error = $var;
+
+        return $this;
+    }
+
+    /**
+     * Amount to sleep when invoking server
+     *
+     * Generated from protobuf field <code>int32 server_sleep_us = 15;</code>
+     * @return int
+     */
+    public function getServerSleepUs()
+    {
+        return $this->server_sleep_us;
+    }
+
+    /**
+     * Amount to sleep when invoking server
+     *
+     * Generated from protobuf field <code>int32 server_sleep_us = 15;</code>
+     * @param int $var
+     * @return $this
+     */
+    public function setServerSleepUs($var)
+    {
+        GPBUtil::checkInt32($var);
+        $this->server_sleep_us = $var;
+
+        return $this;
+    }
+
+}
+
diff --git a/src/php/tests/qps/generated_code/Grpc/Testing/Response.php b/src/php/tests/qps/generated_code/Grpc/Testing/Response.php
new file mode 100644
index 0000000000..7925a7db3d
--- /dev/null
+++ b/src/php/tests/qps/generated_code/Grpc/Testing/Response.php
@@ -0,0 +1,23 @@
+<?php
+# Generated by the protocol buffer compiler.  DO NOT EDIT!
+# source: src/proto/grpc/testing/compiler_test.proto
+
+namespace Grpc\Testing;
+
+use Google\Protobuf\Internal\GPBType;
+use Google\Protobuf\Internal\RepeatedField;
+use Google\Protobuf\Internal\GPBUtil;
+
+/**
+ * Generated from protobuf message <code>grpc.testing.Response</code>
+ */
+class Response extends \Google\Protobuf\Internal\Message
+{
+
+    public function __construct() {
+        \GPBMetadata\Src\Proto\Grpc\Testing\CompilerTest::initOnce();
+        parent::__construct();
+    }
+
+}
+
diff --git a/src/php/tests/qps/generated_code/Grpc/Testing/ResponseParams.php b/src/php/tests/qps/generated_code/Grpc/Testing/ResponseParams.php
new file mode 100644
index 0000000000..d20f92289a
--- /dev/null
+++ b/src/php/tests/qps/generated_code/Grpc/Testing/ResponseParams.php
@@ -0,0 +1,101 @@
+<?php
+# Generated by the protocol buffer compiler.  DO NOT EDIT!
+# source: src/proto/grpc/testing/echo_messages.proto
+
+namespace Grpc\Testing;
+
+use Google\Protobuf\Internal\GPBType;
+use Google\Protobuf\Internal\RepeatedField;
+use Google\Protobuf\Internal\GPBUtil;
+
+/**
+ * Generated from protobuf message <code>grpc.testing.ResponseParams</code>
+ */
+class ResponseParams extends \Google\Protobuf\Internal\Message
+{
+    /**
+     * Generated from protobuf field <code>int64 request_deadline = 1;</code>
+     */
+    private $request_deadline = 0;
+    /**
+     * Generated from protobuf field <code>string host = 2;</code>
+     */
+    private $host = '';
+    /**
+     * Generated from protobuf field <code>string peer = 3;</code>
+     */
+    private $peer = '';
+
+    public function __construct() {
+        \GPBMetadata\Src\Proto\Grpc\Testing\EchoMessages::initOnce();
+        parent::__construct();
+    }
+
+    /**
+     * Generated from protobuf field <code>int64 request_deadline = 1;</code>
+     * @return int|string
+     */
+    public function getRequestDeadline()
+    {
+        return $this->request_deadline;
+    }
+
+    /**
+     * Generated from protobuf field <code>int64 request_deadline = 1;</code>
+     * @param int|string $var
+     * @return $this
+     */
+    public function setRequestDeadline($var)
+    {
+        GPBUtil::checkInt64($var);
+        $this->request_deadline = $var;
+
+        return $this;
+    }
+
+    /**
+     * Generated from protobuf field <code>string host = 2;</code>
+     * @return string
+     */
+    public function getHost()
+    {
+        return $this->host;
+    }
+
+    /**
+     * Generated from protobuf field <code>string host = 2;</code>
+     * @param string $var
+     * @return $this
+     */
+    public function setHost($var)
+    {
+        GPBUtil::checkString($var, True);
+        $this->host = $var;
+
+        return $this;
+    }
+
+    /**
+     * Generated from protobuf field <code>string peer = 3;</code>
+     * @return string
+     */
+    public function getPeer()
+    {
+        return $this->peer;
+    }
+
+    /**
+     * Generated from protobuf field <code>string peer = 3;</code>
+     * @param string $var
+     * @return $this
+     */
+    public function setPeer($var)
+    {
+        GPBUtil::checkString($var, True);
+        $this->peer = $var;
+
+        return $this;
+    }
+
+}
+
diff --git a/src/php/tests/qps/generated_code/Grpc/Testing/ServiceAClient.php b/src/php/tests/qps/generated_code/Grpc/Testing/ServiceAClient.php
new file mode 100644
index 0000000000..df469cbea3
--- /dev/null
+++ b/src/php/tests/qps/generated_code/Grpc/Testing/ServiceAClient.php
@@ -0,0 +1,97 @@
+<?php
+// GENERATED CODE -- DO NOT EDIT!
+
+// Original file comments:
+// Copyright 2016 gRPC authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+// File detached comment 1
+//
+// File detached comment 2
+//
+// File leading comment 1
+namespace Grpc\Testing;
+
+/**
+ * ServiceA detached comment 1
+ *
+ * ServiceA detached comment 2
+ *
+ * ServiceA leading comment 1
+ */
+class ServiceAClient extends \Grpc\BaseStub {
+
+    /**
+     * @param string $hostname hostname
+     * @param array $opts channel options
+     * @param \Grpc\Channel $channel (optional) re-use channel object
+     */
+    public function __construct($hostname, $opts, $channel = null) {
+        parent::__construct($hostname, $opts, $channel);
+    }
+
+    /**
+     * MethodA1 leading comment 1
+     * @param \Grpc\Testing\Request $argument input argument
+     * @param array $metadata metadata
+     * @param array $options call options
+     */
+    public function MethodA1(\Grpc\Testing\Request $argument,
+      $metadata = [], $options = []) {
+        return $this->_simpleRequest('/grpc.testing.ServiceA/MethodA1',
+        $argument,
+        ['\Grpc\Testing\Response', 'decode'],
+        $metadata, $options);
+    }
+
+    /**
+     * MethodA2 detached leading comment 1
+     *
+     * Method A2 leading comment 1
+     * Method A2 leading comment 2
+     * @param array $metadata metadata
+     * @param array $options call options
+     */
+    public function MethodA2($metadata = [], $options = []) {
+        return $this->_clientStreamRequest('/grpc.testing.ServiceA/MethodA2',
+        ['\Grpc\Testing\Response','decode'],
+        $metadata, $options);
+    }
+
+    /**
+     * Method A3 leading comment 1
+     * @param \Grpc\Testing\Request $argument input argument
+     * @param array $metadata metadata
+     * @param array $options call options
+     */
+    public function MethodA3(\Grpc\Testing\Request $argument,
+      $metadata = [], $options = []) {
+        return $this->_serverStreamRequest('/grpc.testing.ServiceA/MethodA3',
+        $argument,
+        ['\Grpc\Testing\Response', 'decode'],
+        $metadata, $options);
+    }
+
+    /**
+     * Method A4 leading comment 1
+     * @param array $metadata metadata
+     * @param array $options call options
+     */
+    public function MethodA4($metadata = [], $options = []) {
+        return $this->_bidiRequest('/grpc.testing.ServiceA/MethodA4',
+        ['\Grpc\Testing\Response','decode'],
+        $metadata, $options);
+    }
+
+}
diff --git a/src/php/tests/qps/generated_code/Grpc/Testing/ServiceBClient.php b/src/php/tests/qps/generated_code/Grpc/Testing/ServiceBClient.php
new file mode 100644
index 0000000000..54acf6364f
--- /dev/null
+++ b/src/php/tests/qps/generated_code/Grpc/Testing/ServiceBClient.php
@@ -0,0 +1,54 @@
+<?php
+// GENERATED CODE -- DO NOT EDIT!
+
+// Original file comments:
+// Copyright 2016 gRPC authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+// File detached comment 1
+//
+// File detached comment 2
+//
+// File leading comment 1
+namespace Grpc\Testing;
+
+/**
+ * ServiceB leading comment 1
+ */
+class ServiceBClient extends \Grpc\BaseStub {
+
+    /**
+     * @param string $hostname hostname
+     * @param array $opts channel options
+     * @param \Grpc\Channel $channel (optional) re-use channel object
+     */
+    public function __construct($hostname, $opts, $channel = null) {
+        parent::__construct($hostname, $opts, $channel);
+    }
+
+    /**
+     * MethodB1 leading comment 1
+     * @param \Grpc\Testing\Request $argument input argument
+     * @param array $metadata metadata
+     * @param array $options call options
+     */
+    public function MethodB1(\Grpc\Testing\Request $argument,
+      $metadata = [], $options = []) {
+        return $this->_simpleRequest('/grpc.testing.ServiceB/MethodB1',
+        $argument,
+        ['\Grpc\Testing\Response', 'decode'],
+        $metadata, $options);
+    }
+
+}
diff --git a/src/php/tests/qps/generated_code/Grpc/Testing/TestServiceClient.php b/src/php/tests/qps/generated_code/Grpc/Testing/TestServiceClient.php
new file mode 100644
index 0000000000..7da9713d65
--- /dev/null
+++ b/src/php/tests/qps/generated_code/Grpc/Testing/TestServiceClient.php
@@ -0,0 +1,152 @@
+<?php
+// GENERATED CODE -- DO NOT EDIT!
+
+// Original file comments:
+// Copyright 2015-2016 gRPC authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+// An integration test service that covers all the method signature permutations
+// of unary/streaming requests/responses.
+//
+namespace Grpc\Testing;
+
+/**
+ * A simple service to test the various types of RPCs and experiment with
+ * performance with various types of payload.
+ */
+class TestServiceClient extends \Grpc\BaseStub {
+
+    /**
+     * @param string $hostname hostname
+     * @param array $opts channel options
+     * @param \Grpc\Channel $channel (optional) re-use channel object
+     */
+    public function __construct($hostname, $opts, $channel = null) {
+        parent::__construct($hostname, $opts, $channel);
+    }
+
+    /**
+     * One empty request followed by one empty response.
+     * @param \Grpc\Testing\PBEmpty $argument input argument
+     * @param array $metadata metadata
+     * @param array $options call options
+     */
+    public function EmptyCall(\Grpc\Testing\PBEmpty $argument,
+      $metadata = [], $options = []) {
+        return $this->_simpleRequest('/grpc.testing.TestService/EmptyCall',
+        $argument,
+        ['\Grpc\Testing\PBEmpty', 'decode'],
+        $metadata, $options);
+    }
+
+    /**
+     * One request followed by one response.
+     * @param \Grpc\Testing\SimpleRequest $argument input argument
+     * @param array $metadata metadata
+     * @param array $options call options
+     */
+    public function UnaryCall(\Grpc\Testing\SimpleRequest $argument,
+      $metadata = [], $options = []) {
+        return $this->_simpleRequest('/grpc.testing.TestService/UnaryCall',
+        $argument,
+        ['\Grpc\Testing\SimpleResponse', 'decode'],
+        $metadata, $options);
+    }
+
+    /**
+     * One request followed by one response. Response has cache control
+     * headers set such that a caching HTTP proxy (such as GFE) can
+     * satisfy subsequent requests.
+     * @param \Grpc\Testing\SimpleRequest $argument input argument
+     * @param array $metadata metadata
+     * @param array $options call options
+     */
+    public function CacheableUnaryCall(\Grpc\Testing\SimpleRequest $argument,
+      $metadata = [], $options = []) {
+        return $this->_simpleRequest('/grpc.testing.TestService/CacheableUnaryCall',
+        $argument,
+        ['\Grpc\Testing\SimpleResponse', 'decode'],
+        $metadata, $options);
+    }
+
+    /**
+     * One request followed by a sequence of responses (streamed download).
+     * The server returns the payload with client desired type and sizes.
+     * @param \Grpc\Testing\StreamingOutputCallRequest $argument input argument
+     * @param array $metadata metadata
+     * @param array $options call options
+     */
+    public function StreamingOutputCall(\Grpc\Testing\StreamingOutputCallRequest $argument,
+      $metadata = [], $options = []) {
+        return $this->_serverStreamRequest('/grpc.testing.TestService/StreamingOutputCall',
+        $argument,
+        ['\Grpc\Testing\StreamingOutputCallResponse', 'decode'],
+        $metadata, $options);
+    }
+
+    /**
+     * A sequence of requests followed by one response (streamed upload).
+     * The server returns the aggregated size of client payload as the result.
+     * @param array $metadata metadata
+     * @param array $options call options
+     */
+    public function StreamingInputCall($metadata = [], $options = []) {
+        return $this->_clientStreamRequest('/grpc.testing.TestService/StreamingInputCall',
+        ['\Grpc\Testing\StreamingInputCallResponse','decode'],
+        $metadata, $options);
+    }
+
+    /**
+     * A sequence of requests with each request served by the server immediately.
+     * As one request could lead to multiple responses, this interface
+     * demonstrates the idea of full duplexing.
+     * @param array $metadata metadata
+     * @param array $options call options
+     */
+    public function FullDuplexCall($metadata = [], $options = []) {
+        return $this->_bidiRequest('/grpc.testing.TestService/FullDuplexCall',
+        ['\Grpc\Testing\StreamingOutputCallResponse','decode'],
+        $metadata, $options);
+    }
+
+    /**
+     * A sequence of requests followed by a sequence of responses.
+     * The server buffers all the client requests and then serves them in order. A
+     * stream of responses are returned to the client when the server starts with
+     * first request.
+     * @param array $metadata metadata
+     * @param array $options call options
+     */
+    public function HalfDuplexCall($metadata = [], $options = []) {
+        return $this->_bidiRequest('/grpc.testing.TestService/HalfDuplexCall',
+        ['\Grpc\Testing\StreamingOutputCallResponse','decode'],
+        $metadata, $options);
+    }
+
+    /**
+     * The test server will not implement this method. It will be used
+     * to test the behavior when clients call unimplemented methods.
+     * @param \Grpc\Testing\PBEmpty $argument input argument
+     * @param array $metadata metadata
+     * @param array $options call options
+     */
+    public function UnimplementedCall(\Grpc\Testing\PBEmpty $argument,
+      $metadata = [], $options = []) {
+        return $this->_simpleRequest('/grpc.testing.TestService/UnimplementedCall',
+        $argument,
+        ['\Grpc\Testing\PBEmpty', 'decode'],
+        $metadata, $options);
+    }
+
+}
diff --git a/src/php/tests/qps/generated_code/Grpc/Testing/UnimplementedEchoServiceClient.php b/src/php/tests/qps/generated_code/Grpc/Testing/UnimplementedEchoServiceClient.php
new file mode 100644
index 0000000000..fee0daa70c
--- /dev/null
+++ b/src/php/tests/qps/generated_code/Grpc/Testing/UnimplementedEchoServiceClient.php
@@ -0,0 +1,47 @@
+<?php
+// GENERATED CODE -- DO NOT EDIT!
+
+// Original file comments:
+// Copyright 2015 gRPC authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+namespace Grpc\Testing;
+
+/**
+ */
+class UnimplementedEchoServiceClient extends \Grpc\BaseStub {
+
+    /**
+     * @param string $hostname hostname
+     * @param array $opts channel options
+     * @param \Grpc\Channel $channel (optional) re-use channel object
+     */
+    public function __construct($hostname, $opts, $channel = null) {
+        parent::__construct($hostname, $opts, $channel);
+    }
+
+    /**
+     * @param \Grpc\Testing\EchoRequest $argument input argument
+     * @param array $metadata metadata
+     * @param array $options call options
+     */
+    public function Unimplemented(\Grpc\Testing\EchoRequest $argument,
+      $metadata = [], $options = []) {
+        return $this->_simpleRequest('/grpc.testing.UnimplementedEchoService/Unimplemented',
+        $argument,
+        ['\Grpc\Testing\EchoResponse', 'decode'],
+        $metadata, $options);
+    }
+
+}
diff --git a/src/php/tests/qps/generated_code/Grpc/Testing/UnimplementedServiceClient.php b/src/php/tests/qps/generated_code/Grpc/Testing/UnimplementedServiceClient.php
new file mode 100644
index 0000000000..53b2020f19
--- /dev/null
+++ b/src/php/tests/qps/generated_code/Grpc/Testing/UnimplementedServiceClient.php
@@ -0,0 +1,53 @@
+<?php
+// GENERATED CODE -- DO NOT EDIT!
+
+// Original file comments:
+// Copyright 2015-2016 gRPC authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+// An integration test service that covers all the method signature permutations
+// of unary/streaming requests/responses.
+//
+namespace Grpc\Testing;
+
+/**
+ * A simple service NOT implemented at servers so clients can test for
+ * that case.
+ */
+class UnimplementedServiceClient extends \Grpc\BaseStub {
+
+    /**
+     * @param string $hostname hostname
+     * @param array $opts channel options
+     * @param \Grpc\Channel $channel (optional) re-use channel object
+     */
+    public function __construct($hostname, $opts, $channel = null) {
+        parent::__construct($hostname, $opts, $channel);
+    }
+
+    /**
+     * A call that no server should implement
+     * @param \Grpc\Testing\PBEmpty $argument input argument
+     * @param array $metadata metadata
+     * @param array $options call options
+     */
+    public function UnimplementedCall(\Grpc\Testing\PBEmpty $argument,
+      $metadata = [], $options = []) {
+        return $this->_simpleRequest('/grpc.testing.UnimplementedService/UnimplementedCall',
+        $argument,
+        ['\Grpc\Testing\PBEmpty', 'decode'],
+        $metadata, $options);
+    }
+
+}
diff --git a/src/php/tests/qps/generated_code/Grpc/Testing/WorkerServiceClient.php b/src/php/tests/qps/generated_code/Grpc/Testing/WorkerServiceClient.php
index 98c244ff9d..366e36529e 100644
--- a/src/php/tests/qps/generated_code/Grpc/Testing/WorkerServiceClient.php
+++ b/src/php/tests/qps/generated_code/Grpc/Testing/WorkerServiceClient.php
@@ -81,15 +81,15 @@ class WorkerServiceClient extends \Grpc\BaseStub {
 
     /**
      * Quit this worker
-     * @param \Grpc\Testing\Void $argument input argument
+     * @param \Grpc\Testing\PBVoid $argument input argument
      * @param array $metadata metadata
      * @param array $options call options
      */
-    public function QuitWorker(\Grpc\Testing\Void $argument,
+    public function QuitWorker(\Grpc\Testing\PBVoid $argument,
       $metadata = [], $options = []) {
         return $this->_simpleRequest('/grpc.testing.WorkerService/QuitWorker',
         $argument,
-        ['\Grpc\Testing\Void', 'decode'],
+        ['\Grpc\Testing\PBVoid', 'decode'],
         $metadata, $options);
     }
 
diff --git a/src/php/tests/unit_tests/CallCredentials2Test.php b/src/php/tests/unit_tests/CallCredentials2Test.php
index a462bfff56..1c7e0c0ff6 100644
--- a/src/php/tests/unit_tests/CallCredentials2Test.php
+++ b/src/php/tests/unit_tests/CallCredentials2Test.php
@@ -46,9 +46,6 @@ class CallCredentials2Test extends PHPUnit_Framework_TestCase
     {
         unset($this->channel);
         unset($this->server);
-        $channel_clean_persistent =
-            new Grpc\Channel('localhost:50010', []);
-        $channel_clean_persistent->cleanPersistentList();
     }
 
     public function callbackFunc($context)
diff --git a/src/php/tests/unit_tests/CallCredentialsTest.php b/src/php/tests/unit_tests/CallCredentialsTest.php
index 31046e6395..4b5721d76a 100644
--- a/src/php/tests/unit_tests/CallCredentialsTest.php
+++ b/src/php/tests/unit_tests/CallCredentialsTest.php
@@ -52,9 +52,6 @@ class CallCredentialsTest extends PHPUnit_Framework_TestCase
     {
         unset($this->channel);
         unset($this->server);
-        $channel_clean_persistent =
-            new Grpc\Channel('localhost:50010', []);
-        $channel_clean_persistent->cleanPersistentList();
     }
 
     public function callbackFunc($context)
diff --git a/src/php/tests/unit_tests/CallTest.php b/src/php/tests/unit_tests/CallTest.php
index 38c36ed19a..c5e1890a98 100644
--- a/src/php/tests/unit_tests/CallTest.php
+++ b/src/php/tests/unit_tests/CallTest.php
@@ -38,9 +38,6 @@ class CallTest extends PHPUnit_Framework_TestCase
     public function tearDown()
     {
         $this->channel->close();
-        $channel_clean_persistent =
-            new Grpc\Channel('localhost:50010', []);
-        $channel_clean_persistent->cleanPersistentList();
     }
 
     public function testConstructor()
diff --git a/src/php/tests/unit_tests/ChannelTest.php b/src/php/tests/unit_tests/ChannelTest.php
index 63d4193a8b..5baff1fbd9 100644
--- a/src/php/tests/unit_tests/ChannelTest.php
+++ b/src/php/tests/unit_tests/ChannelTest.php
@@ -28,9 +28,6 @@ class ChannelTest extends PHPUnit_Framework_TestCase
         if (!empty($this->channel)) {
             $this->channel->close();
         }
-        $channel_clean_persistent =
-            new Grpc\Channel('localhost:50010', []);
-        $channel_clean_persistent->cleanPersistentList();
     }
 
     public function testInsecureCredentials()
@@ -383,11 +380,6 @@ class ChannelTest extends PHPUnit_Framework_TestCase
         // close channel1
         $this->channel1->close();
 
-        // channel2 is now in SHUTDOWN state
-        $state = $this->channel2->getConnectivityState();
-        $this->assertEquals(GRPC\CHANNEL_FATAL_FAILURE, $state);
-
-        // calling it again will result in an exception because the
         // channel is already closed
         $state = $this->channel2->getConnectivityState();
     }
diff --git a/src/php/tests/unit_tests/EndToEndTest.php b/src/php/tests/unit_tests/EndToEndTest.php
index 71a56d2b6e..b54f1d87c9 100644
--- a/src/php/tests/unit_tests/EndToEndTest.php
+++ b/src/php/tests/unit_tests/EndToEndTest.php
@@ -29,9 +29,6 @@ class EndToEndTest extends PHPUnit_Framework_TestCase
     public function tearDown()
     {
         $this->channel->close();
-        $channel_clean_persistent =
-            new Grpc\Channel('localhost:50010', []);
-        $channel_clean_persistent->cleanPersistentList();
     }
 
     public function testSimpleRequestBody()
diff --git a/src/php/tests/unit_tests/InterceptorTest.php b/src/php/tests/unit_tests/InterceptorTest.php
new file mode 100644
index 0000000000..08f5abbb21
--- /dev/null
+++ b/src/php/tests/unit_tests/InterceptorTest.php
@@ -0,0 +1,427 @@
+<?php
+/*
+ *
+ * Copyright 2018 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+/**
+ * Interface exported by the server.
+ */
+require_once(dirname(__FILE__).'/../../lib/Grpc/BaseStub.php');
+require_once(dirname(__FILE__).'/../../lib/Grpc/AbstractCall.php');
+require_once(dirname(__FILE__).'/../../lib/Grpc/UnaryCall.php');
+require_once(dirname(__FILE__).'/../../lib/Grpc/ClientStreamingCall.php');
+require_once(dirname(__FILE__).'/../../lib/Grpc/Interceptor.php');
+require_once(dirname(__FILE__).'/../../lib/Grpc/Internal/InterceptorChannel.php');
+
+class SimpleRequest
+{
+    private $data;
+    public function __construct($data)
+    {
+        $this->data = $data;
+    }
+    public function setData($data)
+    {
+        $this->data = $data;
+    }
+    public function serializeToString()
+    {
+        return $this->data;
+    }
+}
+
+class InterceptorClient extends Grpc\BaseStub
+{
+
+    /**
+     * @param string $hostname hostname
+     * @param array $opts channel options
+     * @param Channel|InterceptorChannel $channel (optional) re-use channel object
+     */
+    public function __construct($hostname, $opts, $channel = null)
+    {
+        parent::__construct($hostname, $opts, $channel);
+    }
+
+    /**
+     * A simple RPC.
+     * @param \Routeguide\Point $argument input argument
+     * @param array $metadata metadata
+     * @param array $options call options
+     */
+    public function UnaryCall(
+        SimpleRequest $argument,
+        $metadata = [],
+        $options = []
+    ) {
+        return $this->_simpleRequest(
+            '/dummy_method',
+            $argument,
+            [],
+            $metadata,
+            $options
+        );
+    }
+
+    /**
+     * A client-to-server streaming RPC.
+     * @param array $metadata metadata
+     * @param array $options call options
+     */
+    public function StreamCall(
+        $metadata = [],
+        $options = []
+    ) {
+        return $this->_clientStreamRequest('/dummy_method', [], $metadata, $options);
+    }
+}
+
+
+class ChangeMetadataInterceptor extends Grpc\Interceptor
+{
+    public function interceptUnaryUnary($method,
+                                        $argument,
+                                        array $metadata = [],
+                                        array $options = [],
+                                        $continuation)
+    {
+        $metadata["foo"] = array('interceptor_from_unary_request');
+        return $continuation($method, $argument, $metadata, $options);
+    }
+    public function interceptStreamUnary($method, array $metadata = [], array $options = [], $continuation)
+    {
+        $metadata["foo"] = array('interceptor_from_stream_request');
+        return $continuation($method, $metadata, $options);
+    }
+}
+
+class ChangeMetadataInterceptor2 extends Grpc\Interceptor
+{
+    public function interceptUnaryUnary($method,
+                                        $argument,
+                                        array $metadata = [],
+                                        array $options = [],
+                                        $continuation)
+    {
+        if (array_key_exists('foo', $metadata)) {
+            $metadata['bar'] = array('ChangeMetadataInterceptor should be executed first');
+        } else {
+            $metadata["bar"] = array('interceptor_from_unary_request');
+        }
+        return $continuation($method, $argument, $metadata, $options);
+    }
+    public function interceptStreamUnary($method,
+                                         array $metadata = [],
+                                         array $options = [],
+                                         $continuation)
+    {
+        if (array_key_exists('foo', $metadata)) {
+            $metadata['bar'] = array('ChangeMetadataInterceptor should be executed first');
+        } else {
+            $metadata["bar"] = array('interceptor_from_stream_request');
+        }
+        return $continuation($method, $metadata, $options);
+    }
+}
+
+class ChangeRequestCall
+{
+    private $call;
+
+    public function __construct($call)
+    {
+        $this->call = $call;
+    }
+    public function getCall()
+    {
+        return $this->call;
+    }
+
+    public function write($request)
+    {
+        $request->setData('intercepted_stream_request');
+        $this->getCall()->write($request);
+    }
+
+    public function wait()
+    {
+        return $this->getCall()->wait();
+    }
+}
+
+class ChangeRequestInterceptor extends Grpc\Interceptor
+{
+    public function interceptUnaryUnary($method,
+                                        $argument,
+                                        array $metadata = [],
+                                        array $options = [],
+                                        $continuation)
+    {
+        $argument->setData('intercepted_unary_request');
+        return $continuation($method, $argument, $metadata, $options);
+    }
+    public function interceptStreamUnary($method, array $metadata = [], array $options = [], $continuation)
+    {
+        return new ChangeRequestCall(
+            $continuation($method, $metadata, $options)
+        );
+    }
+}
+
+class StopCallInterceptor extends Grpc\Interceptor
+{
+    public function interceptUnaryUnary($method,
+                                        $argument,
+                                        array $metadata = [],
+                                        array $options = [],
+                                        $continuation)
+    {
+        $metadata["foo"] = array('interceptor_from_request_response');
+    }
+    public function interceptStreamUnary($method,
+                                         array $metadata = [],
+                                         array $options = [],
+                                         $continuation)
+    {
+        $metadata["foo"] = array('interceptor_from_request_response');
+    }
+}
+
+class InterceptorTest extends PHPUnit_Framework_TestCase
+{
+    public function setUp()
+    {
+        $this->server = new Grpc\Server([]);
+        $this->port = $this->server->addHttp2Port('0.0.0.0:0');
+        $this->channel = new Grpc\Channel('localhost:'.$this->port, ['credentials' => Grpc\ChannelCredentials::createInsecure()]);
+        $this->server->start();
+    }
+
+    public function tearDown()
+    {
+        $this->channel->close();
+    }
+
+
+    public function testClientChangeMetadataOneInterceptor()
+    {
+        $req_text = 'client_request';
+        $channel_matadata_interceptor = new ChangeMetadataInterceptor();
+        $intercept_channel = Grpc\Interceptor::intercept($this->channel, $channel_matadata_interceptor);
+        echo "create Client\n";
+        $client = new InterceptorClient('localhost:'.$this->port, [
+            'credentials' => Grpc\ChannelCredentials::createInsecure(),
+        ], $intercept_channel);
+        echo "create Call\n";
+        $req = new SimpleRequest($req_text);
+        echo "Call created\n";
+        $unary_call = $client->UnaryCall($req);
+        echo "start call\n";
+        $event = $this->server->requestCall();
+        $this->assertSame('/dummy_method', $event->method);
+        $this->assertSame(['interceptor_from_unary_request'], $event->metadata['foo']);
+
+        $stream_call = $client->StreamCall();
+        $stream_call->write($req);
+        $event = $this->server->requestCall();
+        $this->assertSame('/dummy_method', $event->method);
+        $this->assertSame(['interceptor_from_stream_request'], $event->metadata['foo']);
+
+        unset($unary_call);
+        unset($stream_call);
+        unset($server_call);
+    }
+
+    public function testClientChangeMetadataTwoInterceptor()
+    {
+        $req_text = 'client_request';
+        $channel_matadata_interceptor = new ChangeMetadataInterceptor();
+        $channel_matadata_intercepto2 = new ChangeMetadataInterceptor2();
+        // test intercept separately.
+        $intercept_channel1 = Grpc\Interceptor::intercept($this->channel, $channel_matadata_interceptor);
+        $intercept_channel2 = Grpc\Interceptor::intercept($intercept_channel1, $channel_matadata_intercepto2);
+        $client = new InterceptorClient('localhost:'.$this->port, [
+            'credentials' => Grpc\ChannelCredentials::createInsecure(),
+        ], $intercept_channel2);
+
+        $req = new SimpleRequest($req_text);
+        $unary_call = $client->UnaryCall($req);
+        $event = $this->server->requestCall();
+        $this->assertSame('/dummy_method', $event->method);
+        $this->assertSame(['interceptor_from_unary_request'], $event->metadata['foo']);
+        $this->assertSame(['interceptor_from_unary_request'], $event->metadata['bar']);
+
+        $stream_call = $client->StreamCall();
+        $stream_call->write($req);
+        $event = $this->server->requestCall();
+        $this->assertSame('/dummy_method', $event->method);
+        $this->assertSame(['interceptor_from_stream_request'], $event->metadata['foo']);
+        $this->assertSame(['interceptor_from_stream_request'], $event->metadata['bar']);
+
+        unset($unary_call);
+        unset($stream_call);
+        unset($server_call);
+
+        // test intercept by array.
+        $intercept_channel3 = Grpc\Interceptor::intercept($this->channel,
+            [$channel_matadata_intercepto2, $channel_matadata_interceptor]);
+        $client = new InterceptorClient('localhost:'.$this->port, [
+            'credentials' => Grpc\ChannelCredentials::createInsecure(),
+        ], $intercept_channel3);
+
+        $req = new SimpleRequest($req_text);
+        $unary_call = $client->UnaryCall($req);
+        $event = $this->server->requestCall();
+        $this->assertSame('/dummy_method', $event->method);
+        $this->assertSame(['interceptor_from_unary_request'], $event->metadata['foo']);
+        $this->assertSame(['interceptor_from_unary_request'], $event->metadata['bar']);
+
+        $stream_call = $client->StreamCall();
+        $stream_call->write($req);
+        $event = $this->server->requestCall();
+        $this->assertSame('/dummy_method', $event->method);
+        $this->assertSame(['interceptor_from_stream_request'], $event->metadata['foo']);
+        $this->assertSame(['interceptor_from_stream_request'], $event->metadata['bar']);
+
+        unset($unary_call);
+        unset($stream_call);
+        unset($server_call);
+    }
+
+    public function testClientChangeRequestInterceptor()
+    {
+        $req_text = 'client_request';
+        $change_request_interceptor = new ChangeRequestInterceptor();
+        $intercept_channel = Grpc\Interceptor::intercept($this->channel,
+            $change_request_interceptor);
+        $client = new InterceptorClient('localhost:'.$this->port, [
+            'credentials' => Grpc\ChannelCredentials::createInsecure(),
+        ], $intercept_channel);
+
+        $req = new SimpleRequest($req_text);
+        $unary_call = $client->UnaryCall($req);
+
+        $event = $this->server->requestCall();
+        $this->assertSame('/dummy_method', $event->method);
+        $server_call = $event->call;
+        $event = $server_call->startBatch([
+            Grpc\OP_SEND_INITIAL_METADATA => [],
+            Grpc\OP_SEND_STATUS_FROM_SERVER => [
+                'metadata' => [],
+                'code' => Grpc\STATUS_OK,
+                'details' => '',
+            ],
+            Grpc\OP_RECV_MESSAGE => true,
+            Grpc\OP_RECV_CLOSE_ON_SERVER => true,
+        ]);
+        $this->assertSame('intercepted_unary_request', $event->message);
+
+        $stream_call = $client->StreamCall();
+        $stream_call->write($req);
+        $event = $this->server->requestCall();
+        $this->assertSame('/dummy_method', $event->method);
+        $server_call = $event->call;
+        $event = $server_call->startBatch([
+            Grpc\OP_SEND_INITIAL_METADATA => [],
+            Grpc\OP_SEND_STATUS_FROM_SERVER => [
+                'metadata' => [],
+                'code' => Grpc\STATUS_OK,
+                'details' => '',
+            ],
+            Grpc\OP_RECV_MESSAGE => true,
+            Grpc\OP_RECV_CLOSE_ON_SERVER => true,
+        ]);
+        $this->assertSame('intercepted_stream_request', $event->message);
+
+        unset($unary_call);
+        unset($stream_call);
+        unset($server_call);
+    }
+
+    public function testClientChangeStopCallInterceptor()
+    {
+        $req_text = 'client_request';
+        $channel_request_interceptor = new StopCallInterceptor();
+        $intercept_channel = Grpc\Interceptor::intercept($this->channel,
+            $channel_request_interceptor);
+        $client = new InterceptorClient('localhost:'.$this->port, [
+            'credentials' => Grpc\ChannelCredentials::createInsecure(),
+        ], $intercept_channel);
+
+        $req = new SimpleRequest($req_text);
+        $unary_call = $client->UnaryCall($req);
+        $this->assertNull($unary_call);
+
+
+        $stream_call = $client->StreamCall();
+        $this->assertNull($stream_call);
+
+        unset($unary_call);
+        unset($stream_call);
+        unset($server_call);
+    }
+
+    public function testGetInterceptorChannelConnectivityState()
+    {
+        $channel = new Grpc\Channel(
+            'localhost:0',
+            ['credentials' => Grpc\ChannelCredentials::createInsecure()]
+        );
+        $interceptor_channel = Grpc\Interceptor::intercept($channel, new Grpc\Interceptor());
+        $state = $interceptor_channel->getConnectivityState();
+        $this->assertEquals(0, $state);
+        $channel->close();
+    }
+
+    public function testInterceptorChannelWatchConnectivityState()
+    {
+        $channel = new Grpc\Channel(
+            'localhost:0',
+            ['credentials' => Grpc\ChannelCredentials::createInsecure()]
+        );
+        $interceptor_channel = Grpc\Interceptor::intercept($channel, new Grpc\Interceptor());
+        $now = Grpc\Timeval::now();
+        $deadline = $now->add(new Grpc\Timeval(100*1000));
+        $state = $interceptor_channel->watchConnectivityState(1, $deadline);
+        $this->assertTrue($state);
+        unset($time);
+        unset($deadline);
+        $channel->close();
+    }
+
+    public function testInterceptorChannelClose()
+    {
+        $channel = new Grpc\Channel(
+            'localhost:0',
+            ['credentials' => Grpc\ChannelCredentials::createInsecure()]
+        );
+        $interceptor_channel = Grpc\Interceptor::intercept($channel, new Grpc\Interceptor());
+        $this->assertNotNull($interceptor_channel);
+        $channel->close();
+    }
+
+    public function testInterceptorChannelGetTarget()
+    {
+        $channel = new Grpc\Channel(
+            'localhost:8888',
+            ['credentials' => Grpc\ChannelCredentials::createInsecure()]
+        );
+        $interceptor_channel = Grpc\Interceptor::intercept($channel, new Grpc\Interceptor());
+        $target = $interceptor_channel->getTarget();
+        $this->assertTrue(is_string($target));
+        $channel->close();
+    }
+}
diff --git a/src/php/tests/unit_tests/PersistentChannelTest.php b/src/php/tests/unit_tests/PersistentChannelTest.php
deleted file mode 100644
index 171780a137..0000000000
--- a/src/php/tests/unit_tests/PersistentChannelTest.php
+++ /dev/null
@@ -1,115 +0,0 @@
-<?php
-/*
- *
- * Copyright 2015 gRPC authors.
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- *
- */
-
-class PersistentListTest extends PHPUnit_Framework_TestCase
-{
-  public function setUp()
-  {
-  }
-
-  public function tearDown()
-  {
-      $channel_clean_persistent =
-          new Grpc\Channel('localhost:50010', []);
-      $channel_clean_persistent->cleanPersistentList();
-  }
-
-  public function waitUntilNotIdle($channel) {
-      for ($i = 0; $i < 10; $i++) {
-          $now = Grpc\Timeval::now();
-          $deadline = $now->add(new Grpc\Timeval(1000));
-          if ($channel->watchConnectivityState(GRPC\CHANNEL_IDLE,
-            $deadline)) {
-              return true;
-          }
-      }
-      $this->assertTrue(false);
-  }
-
-  public function assertConnecting($state) {
-      $this->assertTrue($state == GRPC\CHANNEL_CONNECTING ||
-      $state == GRPC\CHANNEL_TRANSIENT_FAILURE);
-  }
-
-  public function testPersistentChennelCreateOneChannel()
-  {
-      $this->channel1 = new Grpc\Channel('localhost:1', []);
-      $plist = $this->channel1->getPersistentList();
-      $this->assertEquals($plist['localhost:1']['target'], 'localhost:1');
-      $this->assertArrayHasKey('localhost:1', $plist);
-      $this->assertEquals($plist['localhost:1']['ref_count'], 1);
-      $this->assertEquals($plist['localhost:1']['connectivity_status'],
-                          GRPC\CHANNEL_IDLE);
-      $this->assertEquals($plist['localhost:1']['is_valid'], 1);
-      $this->channel1->close();
-  }
-
-  public function testPersistentChennelStatusChange()
-  {
-      $this->channel1 = new Grpc\Channel('localhost:1', []);
-      $plist = $this->channel1->getPersistentList();
-      $this->assertEquals($plist['localhost:1']['connectivity_status'],
-                          GRPC\CHANNEL_IDLE);
-      $this->assertEquals($plist['localhost:1']['is_valid'], 1);
-      $state = $this->channel1->getConnectivityState(true);
-
-      $this->waitUntilNotIdle($this->channel1);
-      $plist = $this->channel1->getPersistentList();
-      $this->assertConnecting($plist['localhost:1']['connectivity_status']);
-      $this->assertEquals($plist['localhost:1']['is_valid'], 1);
-
-      $this->channel1->close();
-  }
-
-  public function testPersistentChennelCloseChannel()
-  {
-      $this->channel1 = new Grpc\Channel('localhost:1', []);
-      $plist = $this->channel1->getPersistentList();
-      $this->assertEquals($plist['localhost:1']['ref_count'], 1);
-      $this->channel1->close();
-      $plist = $this->channel1->getPersistentList();
-      $this->assertArrayNotHasKey('localhost:1', $plist);
-  }
-
-  public function testPersistentChannelSameHost()
-  {
-      $this->channel1 = new Grpc\Channel('localhost:1', []);
-      $this->channel2 = new Grpc\Channel('localhost:1', []);
-      //ref_count should be 2
-      $plist = $this->channel1->getPersistentList();
-      $this->assertArrayHasKey('localhost:1', $plist);
-      $this->assertEquals($plist['localhost:1']['ref_count'], 2);
-      $this->channel1->close();
-      $this->channel2->close();
-  }
-
-  public function testPersistentChannelDifferentHost()
-  {
-      $this->channel1 = new Grpc\Channel('localhost:1', []);
-      $this->channel2 = new Grpc\Channel('localhost:2', []);
-      $plist = $this->channel1->getPersistentList();
-      $this->assertArrayHasKey('localhost:1', $plist);
-      $this->assertArrayHasKey('localhost:2', $plist);
-      $this->assertEquals($plist['localhost:1']['ref_count'], 1);
-      $this->assertEquals($plist['localhost:2']['ref_count'], 1);
-      $this->channel1->close();
-      $this->channel2->close();
-  }
-
-}
diff --git a/src/php/tests/unit_tests/SecureEndToEndTest.php b/src/php/tests/unit_tests/SecureEndToEndTest.php
index e358abe2d2..dff4e878ea 100644
--- a/src/php/tests/unit_tests/SecureEndToEndTest.php
+++ b/src/php/tests/unit_tests/SecureEndToEndTest.php
@@ -44,9 +44,6 @@ class SecureEndToEndTest extends PHPUnit_Framework_TestCase
     public function tearDown()
     {
         $this->channel->close();
-        $channel_clean_persistent =
-          new Grpc\Channel('localhost:50010', []);
-        $channel_clean_persistent->cleanPersistentList();
     }
 
     public function testSimpleRequestBody()
diff --git a/src/php/tests/unit_tests/ServerTest.php b/src/php/tests/unit_tests/ServerTest.php
index d18feecefe..ac6f2f0312 100644
--- a/src/php/tests/unit_tests/ServerTest.php
+++ b/src/php/tests/unit_tests/ServerTest.php
@@ -27,9 +27,6 @@ class ServerTest extends PHPUnit_Framework_TestCase
     public function tearDown()
     {
         unset($this->server);
-        $channel_clean_persistent =
-            new Grpc\Channel('localhost:50010', []);
-        $channel_clean_persistent->cleanPersistentList();
     }
 
     public function testConstructorWithNull()
@@ -102,6 +99,24 @@ class ServerTest extends PHPUnit_Framework_TestCase
     /**
      * @expectedException InvalidArgumentException
      */
+    public function testInvalidConstructorWithNumKeyOfArray()
+    {
+        $this->server = new Grpc\Server([10 => '127.0.0.1',
+                                         20 => '8080', ]);
+        $this->assertNull($this->server);
+    }
+
+    /**
+     * @expectedException InvalidArgumentException
+     */
+    public function testInvalidConstructorWithList()
+    {
+        $this->server = new Grpc\Server(['127.0.0.1', '8080']);
+        $this->assertNull($this->server);
+    }
+    /**
+     * @expectedException InvalidArgumentException
+     */
     public function testInvalidAddHttp2Port()
     {
         $this->server = new Grpc\Server([]);
diff --git a/src/php/tests/unit_tests/TimevalTest.php b/src/php/tests/unit_tests/TimevalTest.php
index be023adace..bc307ef7f1 100644
--- a/src/php/tests/unit_tests/TimevalTest.php
+++ b/src/php/tests/unit_tests/TimevalTest.php
@@ -25,9 +25,6 @@ class TimevalTest extends PHPUnit_Framework_TestCase
     public function tearDown()
     {
         unset($this->time);
-        $channel_clean_persistent =
-            new Grpc\Channel('localhost:50010', []);
-        $channel_clean_persistent->cleanPersistentList();
     }
 
     public function testConstructorWithInt()
diff --git a/src/proto/grpc/health/v1/health.proto b/src/proto/grpc/health/v1/health.proto
index 3fda02c2c3..4b4677b8a4 100644
--- a/src/proto/grpc/health/v1/health.proto
+++ b/src/proto/grpc/health/v1/health.proto
@@ -1,4 +1,4 @@
-// Copyright 2015 gRPC authors.
+// Copyright 2015 The gRPC Authors
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
@@ -12,10 +12,18 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
+// The canonical version of this proto can be found at
+// https://github.com/grpc/grpc-proto/blob/master/grpc/health/v1/health.proto
+
 syntax = "proto3";
 
 package grpc.health.v1;
+
 option csharp_namespace = "Grpc.Health.V1";
+option go_package = "google.golang.org/grpc/health/grpc_health_v1";
+option java_multiple_files = true;
+option java_outer_classname = "HealthProto";
+option java_package = "io.grpc.health.v1";
 
 message HealthCheckRequest {
   string service = 1;
diff --git a/src/proto/grpc/testing/BUILD b/src/proto/grpc/testing/BUILD
index 58412ed630..16721ff2ed 100644
--- a/src/proto/grpc/testing/BUILD
+++ b/src/proto/grpc/testing/BUILD
@@ -76,11 +76,26 @@ grpc_proto_library(
 )
 
 grpc_proto_library(
-    name = "services_proto",
-    srcs = ["services.proto"],
+    name = "benchmark_service_proto",
+    srcs = ["benchmark_service.proto"],
     deps = [
-        "control_proto",
-        "messages_proto",
+      "messages_proto",
+    ],
+)
+
+grpc_proto_library(
+    name = "report_qps_scenario_service_proto",
+    srcs = ["report_qps_scenario_service.proto"],
+    deps = [
+      "control_proto",
+    ],
+)
+
+grpc_proto_library(
+    name = "worker_service_proto",
+    srcs = ["worker_service.proto"],
+    deps = [
+      "control_proto",
     ],
 )
 
diff --git a/src/proto/grpc/testing/services.proto b/src/proto/grpc/testing/benchmark_service.proto
index 93c21f42d1..63167a8cee 100644
--- a/src/proto/grpc/testing/services.proto
+++ b/src/proto/grpc/testing/benchmark_service.proto
@@ -17,7 +17,6 @@
 syntax = "proto3";
 
 import "src/proto/grpc/testing/messages.proto";
-import "src/proto/grpc/testing/control.proto";
 
 package grpc.testing;
 
@@ -43,32 +42,3 @@ service BenchmarkService {
   // Both sides send the content of their own choice to the other
   rpc StreamingBothWays(stream SimpleRequest) returns (stream SimpleResponse);
 }
-
-service WorkerService {
-  // Start server with specified workload.
-  // First request sent specifies the ServerConfig followed by ServerStatus
-  // response. After that, a "Mark" can be sent anytime to request the latest
-  // stats. Closing the stream will initiate shutdown of the test server
-  // and once the shutdown has finished, the OK status is sent to terminate
-  // this RPC.
-  rpc RunServer(stream ServerArgs) returns (stream ServerStatus);
-
-  // Start client with specified workload.
-  // First request sent specifies the ClientConfig followed by ClientStatus
-  // response. After that, a "Mark" can be sent anytime to request the latest
-  // stats. Closing the stream will initiate shutdown of the test client
-  // and once the shutdown has finished, the OK status is sent to terminate
-  // this RPC.
-  rpc RunClient(stream ClientArgs) returns (stream ClientStatus);
-
-  // Just return the core count - unary call
-  rpc CoreCount(CoreRequest) returns (CoreResponse);
-
-  // Quit this worker
-  rpc QuitWorker(Void) returns (Void);
-}
-
-service ReportQpsScenarioService {
-  // Report results of a QPS test benchmark scenario.
-  rpc ReportScenario(ScenarioResult) returns (Void);
-}
diff --git a/src/proto/grpc/testing/report_qps_scenario_service.proto b/src/proto/grpc/testing/report_qps_scenario_service.proto
new file mode 100644
index 0000000000..f4e5c36254
--- /dev/null
+++ b/src/proto/grpc/testing/report_qps_scenario_service.proto
@@ -0,0 +1,26 @@
+// Copyright 2015 gRPC authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// An integration test service that covers all the method signature permutations
+// of unary/streaming requests/responses.
+syntax = "proto3";
+
+import "src/proto/grpc/testing/control.proto";
+
+package grpc.testing;
+
+service ReportQpsScenarioService {
+  // Report results of a QPS test benchmark scenario.
+  rpc ReportScenario(ScenarioResult) returns (Void);
+}
diff --git a/src/proto/grpc/testing/worker_service.proto b/src/proto/grpc/testing/worker_service.proto
new file mode 100644
index 0000000000..a4cde944b0
--- /dev/null
+++ b/src/proto/grpc/testing/worker_service.proto
@@ -0,0 +1,45 @@
+// Copyright 2015 gRPC authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// An integration test service that covers all the method signature permutations
+// of unary/streaming requests/responses.
+syntax = "proto3";
+
+import "src/proto/grpc/testing/control.proto";
+
+package grpc.testing;
+
+service WorkerService {
+  // Start server with specified workload.
+  // First request sent specifies the ServerConfig followed by ServerStatus
+  // response. After that, a "Mark" can be sent anytime to request the latest
+  // stats. Closing the stream will initiate shutdown of the test server
+  // and once the shutdown has finished, the OK status is sent to terminate
+  // this RPC.
+  rpc RunServer(stream ServerArgs) returns (stream ServerStatus);
+
+  // Start client with specified workload.
+  // First request sent specifies the ClientConfig followed by ClientStatus
+  // response. After that, a "Mark" can be sent anytime to request the latest
+  // stats. Closing the stream will initiate shutdown of the test client
+  // and once the shutdown has finished, the OK status is sent to terminate
+  // this RPC.
+  rpc RunClient(stream ClientArgs) returns (stream ClientStatus);
+
+  // Just return the core count - unary call
+  rpc CoreCount(CoreRequest) returns (CoreResponse);
+
+  // Quit this worker
+  rpc QuitWorker(Void) returns (Void);
+}
diff --git a/src/python/grpcio/grpc/__init__.py b/src/python/grpcio/grpc/__init__.py
index 7fa7303691..b7ed0c8563 100644
--- a/src/python/grpcio/grpc/__init__.py
+++ b/src/python/grpcio/grpc/__init__.py
@@ -813,7 +813,11 @@ class StreamStreamMultiCallable(six.with_metaclass(abc.ABCMeta)):
 
 
 class Channel(six.with_metaclass(abc.ABCMeta)):
-    """Affords RPC invocation via generic methods on client-side."""
+    """Affords RPC invocation via generic methods on client-side.
+
+    Channel objects implement the Context Manager type, although they need not
+    support being entered and exited multiple times.
+    """
 
     @abc.abstractmethod
     def subscribe(self, callback, try_to_connect=False):
@@ -926,6 +930,17 @@ class Channel(six.with_metaclass(abc.ABCMeta)):
         """
         raise NotImplementedError()
 
+    @abc.abstractmethod
+    def close(self):
+        """Closes this Channel and releases all resources held by it.
+
+        Closing the Channel will immediately terminate all RPCs active with the
+        Channel and it is not valid to invoke new RPCs with the Channel.
+
+        This method is idempotent.
+        """
+        raise NotImplementedError()
+
 
 ##########################  Service-Side Context  ##############################
 
diff --git a/src/python/grpcio/grpc/_channel.py b/src/python/grpcio/grpc/_channel.py
index 2eff08aa57..8cc0e981ef 100644
--- a/src/python/grpcio/grpc/_channel.py
+++ b/src/python/grpcio/grpc/_channel.py
@@ -79,27 +79,6 @@ def _wait_once_until(condition, until):
             condition.wait(timeout=remaining)
 
 
-_INTERNAL_CALL_ERROR_MESSAGE_FORMAT = (
-    'Internal gRPC call error %d. ' +
-    'Please report to https://github.com/grpc/grpc/issues')
-
-
-def _check_call_error(call_error, metadata):
-    if call_error == cygrpc.CallError.invalid_metadata:
-        raise ValueError('metadata was invalid: %s' % metadata)
-    elif call_error != cygrpc.CallError.ok:
-        raise ValueError(_INTERNAL_CALL_ERROR_MESSAGE_FORMAT % call_error)
-
-
-def _call_error_set_RPCstate(state, call_error, metadata):
-    if call_error == cygrpc.CallError.invalid_metadata:
-        _abort(state, grpc.StatusCode.INTERNAL,
-               'metadata was invalid: %s' % metadata)
-    else:
-        _abort(state, grpc.StatusCode.INTERNAL,
-               _INTERNAL_CALL_ERROR_MESSAGE_FORMAT % call_error)
-
-
 class _RPCState(object):
 
     def __init__(self, due, initial_metadata, trailing_metadata, code, details):
@@ -163,7 +142,7 @@ def _handle_event(event, state, response_deserializer):
     return callbacks
 
 
-def _event_handler(state, call, response_deserializer):
+def _event_handler(state, response_deserializer):
 
     def handle_event(event):
         with state.condition:
@@ -172,40 +151,47 @@ def _event_handler(state, call, response_deserializer):
             done = not state.due
         for callback in callbacks:
             callback()
-        return call if done else None
+        return done
 
     return handle_event
 
 
-def _consume_request_iterator(request_iterator, state, call,
-                              request_serializer):
-    event_handler = _event_handler(state, call, None)
+def _consume_request_iterator(request_iterator, state, call, request_serializer,
+                              event_handler):
 
-    def consume_request_iterator():
+    def consume_request_iterator():  # pylint: disable=too-many-branches
         while True:
             try:
                 request = next(request_iterator)
             except StopIteration:
                 break
             except Exception:  # pylint: disable=broad-except
-                logging.exception("Exception iterating requests!")
-                call.cancel()
-                _abort(state, grpc.StatusCode.UNKNOWN,
-                       "Exception iterating requests!")
+                code = grpc.StatusCode.UNKNOWN
+                details = 'Exception iterating requests!'
+                logging.exception(details)
+                call.cancel(_common.STATUS_CODE_TO_CYGRPC_STATUS_CODE[code],
+                            details)
+                _abort(state, code, details)
                 return
             serialized_request = _common.serialize(request, request_serializer)
             with state.condition:
                 if state.code is None and not state.cancelled:
                     if serialized_request is None:
-                        call.cancel()
+                        code = grpc.StatusCode.INTERNAL  # pylint: disable=redefined-variable-type
                         details = 'Exception serializing request!'
-                        _abort(state, grpc.StatusCode.INTERNAL, details)
+                        call.cancel(
+                            _common.STATUS_CODE_TO_CYGRPC_STATUS_CODE[code],
+                            details)
+                        _abort(state, code, details)
                         return
                     else:
                         operations = (cygrpc.SendMessageOperation(
                             serialized_request, _EMPTY_FLAGS),)
-                        call.start_client_batch(operations, event_handler)
-                        state.due.add(cygrpc.OperationType.send_message)
+                        operating = call.operate(operations, event_handler)
+                        if operating:
+                            state.due.add(cygrpc.OperationType.send_message)
+                        else:
+                            return
                         while True:
                             state.condition.wait()
                             if state.code is None:
@@ -219,19 +205,12 @@ def _consume_request_iterator(request_iterator, state, call,
             if state.code is None:
                 operations = (
                     cygrpc.SendCloseFromClientOperation(_EMPTY_FLAGS),)
-                call.start_client_batch(operations, event_handler)
-                state.due.add(cygrpc.OperationType.send_close_from_client)
+                operating = call.operate(operations, event_handler)
+                if operating:
+                    state.due.add(cygrpc.OperationType.send_close_from_client)
 
-    def stop_consumption_thread(timeout):  # pylint: disable=unused-argument
-        with state.condition:
-            if state.code is None:
-                call.cancel()
-                state.cancelled = True
-                _abort(state, grpc.StatusCode.CANCELLED, 'Cancelled!')
-                state.condition.notify_all()
-
-    consumption_thread = _common.CleanupThread(
-        stop_consumption_thread, target=consume_request_iterator)
+    consumption_thread = threading.Thread(target=consume_request_iterator)
+    consumption_thread.daemon = True
     consumption_thread.start()
 
 
@@ -247,9 +226,12 @@ class _Rendezvous(grpc.RpcError, grpc.Future, grpc.Call):
     def cancel(self):
         with self._state.condition:
             if self._state.code is None:
-                self._call.cancel()
+                code = grpc.StatusCode.CANCELLED
+                details = 'Locally cancelled by application!'
+                self._call.cancel(
+                    _common.STATUS_CODE_TO_CYGRPC_STATUS_CODE[code], details)
                 self._state.cancelled = True
-                _abort(self._state, grpc.StatusCode.CANCELLED, 'Cancelled!')
+                _abort(self._state, code, details)
                 self._state.condition.notify_all()
             return False
 
@@ -318,12 +300,13 @@ class _Rendezvous(grpc.RpcError, grpc.Future, grpc.Call):
     def _next(self):
         with self._state.condition:
             if self._state.code is None:
-                event_handler = _event_handler(self._state, self._call,
+                event_handler = _event_handler(self._state,
                                                self._response_deserializer)
-                self._call.start_client_batch(
+                operating = self._call.operate(
                     (cygrpc.ReceiveMessageOperation(_EMPTY_FLAGS),),
                     event_handler)
-                self._state.due.add(cygrpc.OperationType.receive_message)
+                if operating:
+                    self._state.due.add(cygrpc.OperationType.receive_message)
             elif self._state.code is grpc.StatusCode.OK:
                 raise StopIteration()
             else:
@@ -408,9 +391,12 @@ class _Rendezvous(grpc.RpcError, grpc.Future, grpc.Call):
     def __del__(self):
         with self._state.condition:
             if self._state.code is None:
-                self._call.cancel()
-                self._state.cancelled = True
                 self._state.code = grpc.StatusCode.CANCELLED
+                self._state.details = 'Cancelled upon garbage collection!'
+                self._state.cancelled = True
+                self._call.cancel(
+                    _common.STATUS_CODE_TO_CYGRPC_STATUS_CODE[self._state.code],
+                    self._state.details)
                 self._state.condition.notify_all()
 
 
@@ -437,6 +423,24 @@ def _end_unary_response_blocking(state, call, with_call, deadline):
         raise _Rendezvous(state, None, None, deadline)
 
 
+def _stream_unary_invocation_operationses(metadata):
+    return (
+        (
+            cygrpc.SendInitialMetadataOperation(metadata, _EMPTY_FLAGS),
+            cygrpc.ReceiveMessageOperation(_EMPTY_FLAGS),
+            cygrpc.ReceiveStatusOnClientOperation(_EMPTY_FLAGS),
+        ),
+        (cygrpc.ReceiveInitialMetadataOperation(_EMPTY_FLAGS),),
+    )
+
+
+def _stream_unary_invocation_operationses_and_tags(metadata):
+    return tuple((
+        operations,
+        None,
+    ) for operations in _stream_unary_invocation_operationses(metadata))
+
+
 class _UnaryUnaryMultiCallable(grpc.UnaryUnaryMultiCallable):
 
     def __init__(self, channel, managed_call, method, request_serializer,
@@ -448,8 +452,8 @@ class _UnaryUnaryMultiCallable(grpc.UnaryUnaryMultiCallable):
         self._response_deserializer = response_deserializer
 
     def _prepare(self, request, timeout, metadata):
-        deadline, serialized_request, rendezvous = (_start_unary_request(
-            request, timeout, self._request_serializer))
+        deadline, serialized_request, rendezvous = _start_unary_request(
+            request, timeout, self._request_serializer)
         if serialized_request is None:
             return None, None, None, rendezvous
         else:
@@ -467,48 +471,38 @@ class _UnaryUnaryMultiCallable(grpc.UnaryUnaryMultiCallable):
     def _blocking(self, request, timeout, metadata, credentials):
         state, operations, deadline, rendezvous = self._prepare(
             request, timeout, metadata)
-        if rendezvous:
+        if state is None:
             raise rendezvous
         else:
-            completion_queue = cygrpc.CompletionQueue()
-            call = self._channel.create_call(None, 0, completion_queue,
-                                             self._method, None, deadline)
-            if credentials is not None:
-                call.set_credentials(credentials._credentials)
-            call_error = call.start_client_batch(operations, None)
-            _check_call_error(call_error, metadata)
-            _handle_event(completion_queue.poll(), state,
-                          self._response_deserializer)
-            return state, call, deadline
+            call = self._channel.segregated_call(
+                0, self._method, None, deadline, metadata, None
+                if credentials is None else credentials._credentials, ((
+                    operations,
+                    None,
+                ),))
+            event = call.next_event()
+            _handle_event(event, state, self._response_deserializer)
+            return state, call,
 
     def __call__(self, request, timeout=None, metadata=None, credentials=None):
-        state, call, deadline = self._blocking(request, timeout, metadata,
-                                               credentials)
-        return _end_unary_response_blocking(state, call, False, deadline)
+        state, call, = self._blocking(request, timeout, metadata, credentials)
+        return _end_unary_response_blocking(state, call, False, None)
 
     def with_call(self, request, timeout=None, metadata=None, credentials=None):
-        state, call, deadline = self._blocking(request, timeout, metadata,
-                                               credentials)
-        return _end_unary_response_blocking(state, call, True, deadline)
+        state, call, = self._blocking(request, timeout, metadata, credentials)
+        return _end_unary_response_blocking(state, call, True, None)
 
     def future(self, request, timeout=None, metadata=None, credentials=None):
         state, operations, deadline, rendezvous = self._prepare(
             request, timeout, metadata)
-        if rendezvous:
-            return rendezvous
+        if state is None:
+            raise rendezvous
         else:
-            call, drive_call = self._managed_call(None, 0, self._method, None,
-                                                  deadline)
-            if credentials is not None:
-                call.set_credentials(credentials._credentials)
-            event_handler = _event_handler(state, call,
-                                           self._response_deserializer)
-            with state.condition:
-                call_error = call.start_client_batch(operations, event_handler)
-                if call_error != cygrpc.CallError.ok:
-                    _call_error_set_RPCstate(state, call_error, metadata)
-                    return _Rendezvous(state, None, None, deadline)
-                drive_call()
+            event_handler = _event_handler(state, self._response_deserializer)
+            call = self._managed_call(
+                0, self._method, None, deadline, metadata, None
+                if credentials is None else credentials._credentials,
+                (operations,), event_handler)
             return _Rendezvous(state, call, self._response_deserializer,
                                deadline)
 
@@ -524,34 +518,27 @@ class _UnaryStreamMultiCallable(grpc.UnaryStreamMultiCallable):
         self._response_deserializer = response_deserializer
 
     def __call__(self, request, timeout=None, metadata=None, credentials=None):
-        deadline, serialized_request, rendezvous = (_start_unary_request(
-            request, timeout, self._request_serializer))
+        deadline, serialized_request, rendezvous = _start_unary_request(
+            request, timeout, self._request_serializer)
         if serialized_request is None:
             raise rendezvous
         else:
             state = _RPCState(_UNARY_STREAM_INITIAL_DUE, None, None, None, None)
-            call, drive_call = self._managed_call(None, 0, self._method, None,
-                                                  deadline)
-            if credentials is not None:
-                call.set_credentials(credentials._credentials)
-            event_handler = _event_handler(state, call,
-                                           self._response_deserializer)
-            with state.condition:
-                call.start_client_batch(
-                    (cygrpc.ReceiveInitialMetadataOperation(_EMPTY_FLAGS),),
-                    event_handler)
-                operations = (
+            operationses = (
+                (
                     cygrpc.SendInitialMetadataOperation(metadata, _EMPTY_FLAGS),
                     cygrpc.SendMessageOperation(serialized_request,
                                                 _EMPTY_FLAGS),
                     cygrpc.SendCloseFromClientOperation(_EMPTY_FLAGS),
                     cygrpc.ReceiveStatusOnClientOperation(_EMPTY_FLAGS),
-                )
-                call_error = call.start_client_batch(operations, event_handler)
-                if call_error != cygrpc.CallError.ok:
-                    _call_error_set_RPCstate(state, call_error, metadata)
-                    return _Rendezvous(state, None, None, deadline)
-                drive_call()
+                ),
+                (cygrpc.ReceiveInitialMetadataOperation(_EMPTY_FLAGS),),
+            )
+            event_handler = _event_handler(state, self._response_deserializer)
+            call = self._managed_call(
+                0, self._method, None, deadline, metadata, None
+                if credentials is None else credentials._credentials,
+                operationses, event_handler)
             return _Rendezvous(state, call, self._response_deserializer,
                                deadline)
 
@@ -569,49 +556,38 @@ class _StreamUnaryMultiCallable(grpc.StreamUnaryMultiCallable):
     def _blocking(self, request_iterator, timeout, metadata, credentials):
         deadline = _deadline(timeout)
         state = _RPCState(_STREAM_UNARY_INITIAL_DUE, None, None, None, None)
-        completion_queue = cygrpc.CompletionQueue()
-        call = self._channel.create_call(None, 0, completion_queue,
-                                         self._method, None, deadline)
-        if credentials is not None:
-            call.set_credentials(credentials._credentials)
-        with state.condition:
-            call.start_client_batch(
-                (cygrpc.ReceiveInitialMetadataOperation(_EMPTY_FLAGS),), None)
-            operations = (
-                cygrpc.SendInitialMetadataOperation(metadata, _EMPTY_FLAGS),
-                cygrpc.ReceiveMessageOperation(_EMPTY_FLAGS),
-                cygrpc.ReceiveStatusOnClientOperation(_EMPTY_FLAGS),
-            )
-            call_error = call.start_client_batch(operations, None)
-            _check_call_error(call_error, metadata)
-            _consume_request_iterator(request_iterator, state, call,
-                                      self._request_serializer)
+        call = self._channel.segregated_call(
+            0, self._method, None, deadline, metadata, None
+            if credentials is None else credentials._credentials,
+            _stream_unary_invocation_operationses_and_tags(metadata))
+        _consume_request_iterator(request_iterator, state, call,
+                                  self._request_serializer, None)
         while True:
-            event = completion_queue.poll()
+            event = call.next_event()
             with state.condition:
                 _handle_event(event, state, self._response_deserializer)
                 state.condition.notify_all()
                 if not state.due:
                     break
-        return state, call, deadline
+        return state, call,
 
     def __call__(self,
                  request_iterator,
                  timeout=None,
                  metadata=None,
                  credentials=None):
-        state, call, deadline = self._blocking(request_iterator, timeout,
-                                               metadata, credentials)
-        return _end_unary_response_blocking(state, call, False, deadline)
+        state, call, = self._blocking(request_iterator, timeout, metadata,
+                                      credentials)
+        return _end_unary_response_blocking(state, call, False, None)
 
     def with_call(self,
                   request_iterator,
                   timeout=None,
                   metadata=None,
                   credentials=None):
-        state, call, deadline = self._blocking(request_iterator, timeout,
-                                               metadata, credentials)
-        return _end_unary_response_blocking(state, call, True, deadline)
+        state, call, = self._blocking(request_iterator, timeout, metadata,
+                                      credentials)
+        return _end_unary_response_blocking(state, call, True, None)
 
     def future(self,
                request_iterator,
@@ -620,27 +596,13 @@ class _StreamUnaryMultiCallable(grpc.StreamUnaryMultiCallable):
                credentials=None):
         deadline = _deadline(timeout)
         state = _RPCState(_STREAM_UNARY_INITIAL_DUE, None, None, None, None)
-        call, drive_call = self._managed_call(None, 0, self._method, None,
-                                              deadline)
-        if credentials is not None:
-            call.set_credentials(credentials._credentials)
-        event_handler = _event_handler(state, call, self._response_deserializer)
-        with state.condition:
-            call.start_client_batch(
-                (cygrpc.ReceiveInitialMetadataOperation(_EMPTY_FLAGS),),
-                event_handler)
-            operations = (
-                cygrpc.SendInitialMetadataOperation(metadata, _EMPTY_FLAGS),
-                cygrpc.ReceiveMessageOperation(_EMPTY_FLAGS),
-                cygrpc.ReceiveStatusOnClientOperation(_EMPTY_FLAGS),
-            )
-            call_error = call.start_client_batch(operations, event_handler)
-            if call_error != cygrpc.CallError.ok:
-                _call_error_set_RPCstate(state, call_error, metadata)
-                return _Rendezvous(state, None, None, deadline)
-            drive_call()
-            _consume_request_iterator(request_iterator, state, call,
-                                      self._request_serializer)
+        event_handler = _event_handler(state, self._response_deserializer)
+        call = self._managed_call(
+            0, self._method, None, deadline, metadata, None
+            if credentials is None else credentials._credentials,
+            _stream_unary_invocation_operationses(metadata), event_handler)
+        _consume_request_iterator(request_iterator, state, call,
+                                  self._request_serializer, event_handler)
         return _Rendezvous(state, call, self._response_deserializer, deadline)
 
 
@@ -661,26 +623,20 @@ class _StreamStreamMultiCallable(grpc.StreamStreamMultiCallable):
                  credentials=None):
         deadline = _deadline(timeout)
         state = _RPCState(_STREAM_STREAM_INITIAL_DUE, None, None, None, None)
-        call, drive_call = self._managed_call(None, 0, self._method, None,
-                                              deadline)
-        if credentials is not None:
-            call.set_credentials(credentials._credentials)
-        event_handler = _event_handler(state, call, self._response_deserializer)
-        with state.condition:
-            call.start_client_batch(
-                (cygrpc.ReceiveInitialMetadataOperation(_EMPTY_FLAGS),),
-                event_handler)
-            operations = (
+        operationses = (
+            (
                 cygrpc.SendInitialMetadataOperation(metadata, _EMPTY_FLAGS),
                 cygrpc.ReceiveStatusOnClientOperation(_EMPTY_FLAGS),
-            )
-            call_error = call.start_client_batch(operations, event_handler)
-            if call_error != cygrpc.CallError.ok:
-                _call_error_set_RPCstate(state, call_error, metadata)
-                return _Rendezvous(state, None, None, deadline)
-            drive_call()
-            _consume_request_iterator(request_iterator, state, call,
-                                      self._request_serializer)
+            ),
+            (cygrpc.ReceiveInitialMetadataOperation(_EMPTY_FLAGS),),
+        )
+        event_handler = _event_handler(state, self._response_deserializer)
+        call = self._managed_call(
+            0, self._method, None, deadline, metadata, None
+            if credentials is None else credentials._credentials, operationses,
+            event_handler)
+        _consume_request_iterator(request_iterator, state, call,
+                                  self._request_serializer, event_handler)
         return _Rendezvous(state, call, self._response_deserializer, deadline)
 
 
@@ -689,67 +645,63 @@ class _ChannelCallState(object):
     def __init__(self, channel):
         self.lock = threading.Lock()
         self.channel = channel
-        self.completion_queue = cygrpc.CompletionQueue()
-        self.managed_calls = None
+        self.managed_calls = 0
 
 
 def _run_channel_spin_thread(state):
 
     def channel_spin():
         while True:
-            event = state.completion_queue.poll()
-            completed_call = event.tag(event)
-            if completed_call is not None:
+            event = state.channel.next_call_event()
+            call_completed = event.tag(event)
+            if call_completed:
                 with state.lock:
-                    state.managed_calls.remove(completed_call)
-                    if not state.managed_calls:
-                        state.managed_calls = None
+                    state.managed_calls -= 1
+                    if state.managed_calls == 0:
                         return
 
-    def stop_channel_spin(timeout):  # pylint: disable=unused-argument
-        with state.lock:
-            if state.managed_calls is not None:
-                for call in state.managed_calls:
-                    call.cancel()
-
-    channel_spin_thread = _common.CleanupThread(
-        stop_channel_spin, target=channel_spin)
+    channel_spin_thread = threading.Thread(target=channel_spin)
+    channel_spin_thread.daemon = True
     channel_spin_thread.start()
 
 
 def _channel_managed_call_management(state):
 
-    def create(parent, flags, method, host, deadline):
-        """Creates a managed cygrpc.Call and a function to call to drive it.
-
-    If operations are successfully added to the returned cygrpc.Call, the
-    returned function must be called. If operations are not successfully added
-    to the returned cygrpc.Call, the returned function must not be called.
-
-    Args:
-      parent: A cygrpc.Call to be used as the parent of the created call.
-      flags: An integer bitfield of call flags.
-      method: The RPC method.
-      host: A host string for the created call.
-      deadline: A float to be the deadline of the created call or None if the
-        call is to have an infinite deadline.
-
-    Returns:
-      A cygrpc.Call with which to conduct an RPC and a function to call if
-        operations are successfully started on the call.
-    """
-        call = state.channel.create_call(parent, flags, state.completion_queue,
-                                         method, host, deadline)
-
-        def drive():
-            with state.lock:
-                if state.managed_calls is None:
-                    state.managed_calls = set((call,))
-                    _run_channel_spin_thread(state)
-                else:
-                    state.managed_calls.add(call)
+    # pylint: disable=too-many-arguments
+    def create(flags, method, host, deadline, metadata, credentials,
+               operationses, event_handler):
+        """Creates a cygrpc.IntegratedCall.
 
-        return call, drive
+        Args:
+          flags: An integer bitfield of call flags.
+          method: The RPC method.
+          host: A host string for the created call.
+          deadline: A float to be the deadline of the created call or None if
+            the call is to have an infinite deadline.
+          metadata: The metadata for the call or None.
+          credentials: A cygrpc.CallCredentials or None.
+          operationses: An iterable of iterables of cygrpc.Operations to be
+            started on the call.
+          event_handler: A behavior to call to handle the events resultant from
+            the operations on the call.
+
+        Returns:
+          A cygrpc.IntegratedCall with which to conduct an RPC.
+        """
+        operationses_and_tags = tuple((
+            operations,
+            event_handler,
+        ) for operations in operationses)
+        with state.lock:
+            call = state.channel.integrated_call(flags, method, host, deadline,
+                                                 metadata, credentials,
+                                                 operationses_and_tags)
+            if state.managed_calls == 0:
+                state.managed_calls = 1
+                _run_channel_spin_thread(state)
+            else:
+                state.managed_calls += 1
+            return call
 
     return create
 
@@ -819,12 +771,9 @@ def _poll_connectivity(state, channel, initial_try_to_connect):
             callback_and_connectivity[1] = state.connectivity
         if callbacks:
             _spawn_delivery(state, callbacks)
-    completion_queue = cygrpc.CompletionQueue()
     while True:
-        channel.watch_connectivity_state(connectivity,
-                                         time.time() + 0.2, completion_queue,
-                                         None)
-        event = completion_queue.poll()
+        event = channel.watch_connectivity_state(connectivity,
+                                                 time.time() + 0.2)
         with state.lock:
             if not state.callbacks_and_connectivities and not state.try_to_connect:
                 state.polling = False
@@ -855,10 +804,10 @@ def _moot(state):
 def _subscribe(state, callback, try_to_connect):
     with state.lock:
         if not state.callbacks_and_connectivities and not state.polling:
-            polling_thread = _common.CleanupThread(
-                lambda timeout: _moot(state),
+            polling_thread = threading.Thread(
                 target=_poll_connectivity,
                 args=(state, state.channel, bool(try_to_connect)))
+            polling_thread.daemon = True
             polling_thread.start()
             state.polling = True
             state.callbacks_and_connectivities.append([callback, None])
@@ -944,5 +893,28 @@ class Channel(grpc.Channel):
             self._channel, _channel_managed_call_management(self._call_state),
             _common.encode(method), request_serializer, response_deserializer)
 
+    def _close(self):
+        self._channel.close(cygrpc.StatusCode.cancelled, 'Channel closed!')
+        _moot(self._connectivity_state)
+
+    def __enter__(self):
+        return self
+
+    def __exit__(self, exc_type, exc_val, exc_tb):
+        self._close()
+        return False
+
+    def close(self):
+        self._close()
+
     def __del__(self):
+        # TODO(https://github.com/grpc/grpc/issues/12531): Several releases
+        # after 1.12 (1.16 or thereabouts?) add a "self._channel.close" call
+        # here (or more likely, call self._close() here). We don't do this today
+        # because many valid use cases today allow the channel to be deleted
+        # immediately after stubs are created. After a sufficient period of time
+        # has passed for all users to be trusted to hang out to their channels
+        # for as long as they are in use and to close them after using them,
+        # then deletion of this grpc._channel.Channel instance can be made to
+        # effect closure of the underlying cygrpc.Channel instance.
         _moot(self._connectivity_state)
diff --git a/src/python/grpcio/grpc/_common.py b/src/python/grpcio/grpc/_common.py
index bbb69ad489..862987a0cd 100644
--- a/src/python/grpcio/grpc/_common.py
+++ b/src/python/grpcio/grpc/_common.py
@@ -14,8 +14,6 @@
 """Shared implementation."""
 
 import logging
-import threading
-import time
 
 import six
 
@@ -101,35 +99,3 @@ def deserialize(serialized_message, deserializer):
 
 def fully_qualified_method(group, method):
     return '/{}/{}'.format(group, method)
-
-
-class CleanupThread(threading.Thread):
-    """A threading.Thread subclass supporting custom behavior on join().
-
-    On Python Interpreter exit, Python will attempt to join outstanding threads
-    prior to garbage collection.  We may need to do additional cleanup, and
-    we accomplish this by overriding the join() method.
-    """
-
-    def __init__(self, behavior, *args, **kwargs):
-        """Constructor.
-
-        Args:
-            behavior (function): Function called on join() with a single
-                argument, timeout, indicating the maximum duration of
-                `behavior`, or None indicating `behavior` has no deadline.
-                `behavior` must be idempotent.
-            args: Positional arguments passed to threading.Thread constructor.
-            kwargs: Keyword arguments passed to threading.Thread constructor.
-        """
-        super(CleanupThread, self).__init__(*args, **kwargs)
-        self._behavior = behavior
-
-    def join(self, timeout=None):
-        start_time = time.time()
-        self._behavior(timeout)
-        end_time = time.time()
-        if timeout is not None:
-            timeout -= end_time - start_time
-            timeout = max(timeout, 0)
-        super(CleanupThread, self).join(timeout)
diff --git a/src/python/grpcio/grpc/_cython/_cygrpc/channel.pxd.pxi b/src/python/grpcio/grpc/_cython/_cygrpc/channel.pxd.pxi
index 1ba76b7f83..eefc685c0b 100644
--- a/src/python/grpcio/grpc/_cython/_cygrpc/channel.pxd.pxi
+++ b/src/python/grpcio/grpc/_cython/_cygrpc/channel.pxd.pxi
@@ -13,9 +13,59 @@
 # limitations under the License.
 
 
+cdef _check_call_error_no_metadata(c_call_error)
+
+
+cdef _check_and_raise_call_error_no_metadata(c_call_error)
+
+
+cdef _check_call_error(c_call_error, metadata)
+
+
+cdef class _CallState:
+
+  cdef grpc_call *c_call
+  cdef set due
+
+
+cdef class _ChannelState:
+
+  cdef object condition
+  cdef grpc_channel *c_channel
+  # A boolean field indicating that the channel is open (if True) or is being
+  # closed (i.e. a call to close is currently executing) or is closed (if
+  # False).
+  # TODO(https://github.com/grpc/grpc/issues/3064): Eliminate "is being closed"
+  # a state in which condition may be acquired by any thread, eliminate this
+  # field and just use the NULLness of c_channel as an indication that the
+  # channel is closed.
+  cdef object open
+
+  # A dict from _BatchOperationTag to _CallState
+  cdef dict integrated_call_states
+  cdef grpc_completion_queue *c_call_completion_queue
+
+  # A set of _CallState
+  cdef set segregated_call_states
+
+  cdef set connectivity_due
+  cdef grpc_completion_queue *c_connectivity_completion_queue
+
+
+cdef class IntegratedCall:
+
+  cdef _ChannelState _channel_state
+  cdef _CallState _call_state
+
+
+cdef class SegregatedCall:
+
+  cdef _ChannelState _channel_state
+  cdef _CallState _call_state
+  cdef grpc_completion_queue *_c_completion_queue
+
+
 cdef class Channel:
 
   cdef grpc_arg_pointer_vtable _vtable
-  cdef grpc_channel *c_channel
-  cdef list references
-  cdef readonly _ArgumentsProcessor _arguments_processor
+  cdef _ChannelState _state
diff --git a/src/python/grpcio/grpc/_cython/_cygrpc/channel.pyx.pxi b/src/python/grpcio/grpc/_cython/_cygrpc/channel.pyx.pxi
index a3966497bc..72e74e84ae 100644
--- a/src/python/grpcio/grpc/_cython/_cygrpc/channel.pyx.pxi
+++ b/src/python/grpcio/grpc/_cython/_cygrpc/channel.pyx.pxi
@@ -14,82 +14,439 @@
 
 cimport cpython
 
+import threading
+
+_INTERNAL_CALL_ERROR_MESSAGE_FORMAT = (
+    'Internal gRPC call error %d. ' +
+    'Please report to https://github.com/grpc/grpc/issues')
+
+
+cdef str _call_error_metadata(metadata):
+  return 'metadata was invalid: %s' % metadata
+
+
+cdef str _call_error_no_metadata(c_call_error):
+  return _INTERNAL_CALL_ERROR_MESSAGE_FORMAT % c_call_error
+
+
+cdef str _call_error(c_call_error, metadata):
+  if c_call_error == GRPC_CALL_ERROR_INVALID_METADATA:
+    return _call_error_metadata(metadata)
+  else:
+    return _call_error_no_metadata(c_call_error)
+
+
+cdef _check_call_error_no_metadata(c_call_error):
+  if c_call_error != GRPC_CALL_OK:
+    return _INTERNAL_CALL_ERROR_MESSAGE_FORMAT % c_call_error
+  else:
+    return None
+
+
+cdef _check_and_raise_call_error_no_metadata(c_call_error):
+  error = _check_call_error_no_metadata(c_call_error)
+  if error is not None:
+    raise ValueError(error)
+
+
+cdef _check_call_error(c_call_error, metadata):
+  if c_call_error == GRPC_CALL_ERROR_INVALID_METADATA:
+    return _call_error_metadata(metadata)
+  else:
+    return _check_call_error_no_metadata(c_call_error)
+
+
+cdef void _raise_call_error_no_metadata(c_call_error) except *:
+  raise ValueError(_call_error_no_metadata(c_call_error))
+
+
+cdef void _raise_call_error(c_call_error, metadata) except *:
+  raise ValueError(_call_error(c_call_error, metadata))
+
+
+cdef _destroy_c_completion_queue(grpc_completion_queue *c_completion_queue):
+  grpc_completion_queue_shutdown(c_completion_queue)
+  grpc_completion_queue_destroy(c_completion_queue)
+
+
+cdef class _CallState:
+
+  def __cinit__(self):
+    self.due = set()
+
+
+cdef class _ChannelState:
+
+  def __cinit__(self):
+    self.condition = threading.Condition()
+    self.open = True
+    self.integrated_call_states = {}
+    self.segregated_call_states = set()
+    self.connectivity_due = set()
+
+
+cdef tuple _operate(grpc_call *c_call, object operations, object user_tag):
+  cdef grpc_call_error c_call_error
+  cdef _BatchOperationTag tag = _BatchOperationTag(user_tag, operations, None)
+  tag.prepare()
+  cpython.Py_INCREF(tag)
+  with nogil:
+    c_call_error = grpc_call_start_batch(
+        c_call, tag.c_ops, tag.c_nops, <cpython.PyObject *>tag, NULL)
+  return c_call_error, tag
+
+
+cdef object _operate_from_integrated_call(
+    _ChannelState channel_state, _CallState call_state, object operations,
+    object user_tag):
+  cdef grpc_call_error c_call_error
+  cdef _BatchOperationTag tag
+  with channel_state.condition:
+    if call_state.due:
+      c_call_error, tag = _operate(call_state.c_call, operations, user_tag)
+      if c_call_error == GRPC_CALL_OK:
+        call_state.due.add(tag)
+        channel_state.integrated_call_states[tag] = call_state
+        return True
+      else:
+        _raise_call_error_no_metadata(c_call_error)
+    else:
+      return False
+
+
+cdef object _operate_from_segregated_call(
+    _ChannelState channel_state, _CallState call_state, object operations,
+    object user_tag):
+  cdef grpc_call_error c_call_error
+  cdef _BatchOperationTag tag
+  with channel_state.condition:
+    if call_state.due:
+      c_call_error, tag = _operate(call_state.c_call, operations, user_tag)
+      if c_call_error == GRPC_CALL_OK:
+        call_state.due.add(tag)
+        return True
+      else:
+        _raise_call_error_no_metadata(c_call_error)
+    else:
+      return False
+
+
+cdef _cancel(
+    _ChannelState channel_state, _CallState call_state, grpc_status_code code,
+    str details):
+  cdef grpc_call_error c_call_error
+  with channel_state.condition:
+    if call_state.due:
+      c_call_error = grpc_call_cancel_with_status(
+          call_state.c_call, code, _encode(details), NULL)
+      _check_and_raise_call_error_no_metadata(c_call_error)
+
+
+cdef BatchOperationEvent _next_call_event(
+    _ChannelState channel_state, grpc_completion_queue *c_completion_queue,
+    on_success):
+  tag, event = _latent_event(c_completion_queue, None)
+  with channel_state.condition:
+    on_success(tag)
+    channel_state.condition.notify_all()
+  return event
+
+
+# TODO(https://github.com/grpc/grpc/issues/14569): This could be a lot simpler.
+cdef void _call(
+    _ChannelState channel_state, _CallState call_state,
+    grpc_completion_queue *c_completion_queue, on_success, int flags, method,
+    host, object deadline, CallCredentials credentials,
+    object operationses_and_user_tags, object metadata) except *:
+  """Invokes an RPC.
+
+  Args:
+    channel_state: A _ChannelState with its "open" attribute set to True. RPCs
+      may not be invoked on a closed channel.
+    call_state: An empty _CallState to be altered (specifically assigned a
+      c_call and having its due set populated) if the RPC invocation is
+      successful.
+    c_completion_queue: A grpc_completion_queue to be used for the call's
+      operations.
+    on_success: A behavior to be called if attempting to start operations for
+      the call succeeds. If called the behavior will be called while holding the
+      channel_state condition and passed the tags associated with operations
+      that were successfully started for the call.
+    flags: Flags to be passed to gRPC Core as part of call creation.
+    method: The fully-qualified name of the RPC method being invoked.
+    host: A "host" string to be passed to gRPC Core as part of call creation.
+    deadline: A float for the deadline of the RPC, or None if the RPC is to have
+      no deadline.
+    credentials: A _CallCredentials for the RPC or None.
+    operationses_and_user_tags: A sequence of length-two sequences the first
+      element of which is a sequence of Operations and the second element of
+      which is an object to be used as a tag. A SendInitialMetadataOperation
+      must be present in the first element of this value.
+    metadata: The metadata for this call.
+  """
+  cdef grpc_slice method_slice
+  cdef grpc_slice host_slice
+  cdef grpc_slice *host_slice_ptr
+  cdef grpc_call_credentials *c_call_credentials
+  cdef grpc_call_error c_call_error
+  cdef tuple error_and_wrapper_tag
+  cdef _BatchOperationTag wrapper_tag
+  with channel_state.condition:
+    if channel_state.open:
+      method_slice = _slice_from_bytes(method)
+      if host is None:
+        host_slice_ptr = NULL
+      else:
+        host_slice = _slice_from_bytes(host)
+        host_slice_ptr = &host_slice
+      call_state.c_call = grpc_channel_create_call(
+          channel_state.c_channel, NULL, flags,
+          c_completion_queue, method_slice, host_slice_ptr,
+          _timespec_from_time(deadline), NULL)
+      grpc_slice_unref(method_slice)
+      if host_slice_ptr:
+        grpc_slice_unref(host_slice)
+      if credentials is not None:
+        c_call_credentials = credentials.c()
+        c_call_error = grpc_call_set_credentials(
+            call_state.c_call, c_call_credentials)
+        grpc_call_credentials_release(c_call_credentials)
+        if c_call_error != GRPC_CALL_OK:
+          grpc_call_unref(call_state.c_call)
+          call_state.c_call = NULL
+          _raise_call_error_no_metadata(c_call_error)
+      started_tags = set()
+      for operations, user_tag in operationses_and_user_tags:
+        c_call_error, tag = _operate(call_state.c_call, operations, user_tag)
+        if c_call_error == GRPC_CALL_OK:
+          started_tags.add(tag)
+        else:
+          grpc_call_cancel(call_state.c_call, NULL)
+          grpc_call_unref(call_state.c_call)
+          call_state.c_call = NULL
+          _raise_call_error(c_call_error, metadata)
+      else:
+        call_state.due.update(started_tags)
+        on_success(started_tags)
+    else:
+      raise ValueError('Cannot invoke RPC on closed channel!')
+
+cdef void _process_integrated_call_tag(
+    _ChannelState state, _BatchOperationTag tag) except *:
+  cdef _CallState call_state = state.integrated_call_states.pop(tag)
+  call_state.due.remove(tag)
+  if not call_state.due:
+    grpc_call_unref(call_state.c_call)
+    call_state.c_call = NULL
+
+
+cdef class IntegratedCall:
+
+  def __cinit__(self, _ChannelState channel_state, _CallState call_state):
+    self._channel_state = channel_state
+    self._call_state = call_state
+
+  def operate(self, operations, tag):
+    return _operate_from_integrated_call(
+        self._channel_state, self._call_state, operations, tag)
+
+  def cancel(self, code, details):
+    _cancel(self._channel_state, self._call_state, code, details)
+
+
+cdef IntegratedCall _integrated_call(
+    _ChannelState state, int flags, method, host, object deadline,
+    object metadata, CallCredentials credentials, operationses_and_user_tags):
+  call_state = _CallState()
+
+  def on_success(started_tags):
+    for started_tag in started_tags:
+      state.integrated_call_states[started_tag] = call_state
+
+  _call(
+      state, call_state, state.c_call_completion_queue, on_success, flags,
+      method, host, deadline, credentials, operationses_and_user_tags, metadata)
+
+  return IntegratedCall(state, call_state)
+
+
+cdef object _process_segregated_call_tag(
+    _ChannelState state, _CallState call_state,
+    grpc_completion_queue *c_completion_queue, _BatchOperationTag tag):
+  call_state.due.remove(tag)
+  if not call_state.due:
+    grpc_call_unref(call_state.c_call)
+    call_state.c_call = NULL
+    state.segregated_call_states.remove(call_state)
+    _destroy_c_completion_queue(c_completion_queue)
+    return True
+  else:
+    return False
+
+
+cdef class SegregatedCall:
+
+  def __cinit__(self, _ChannelState channel_state, _CallState call_state):
+    self._channel_state = channel_state
+    self._call_state = call_state
+
+  def operate(self, operations, tag):
+    return _operate_from_segregated_call(
+        self._channel_state, self._call_state, operations, tag)
+
+  def cancel(self, code, details):
+    _cancel(self._channel_state, self._call_state, code, details)
+
+  def next_event(self):
+    def on_success(tag):
+      _process_segregated_call_tag(
+          self._channel_state, self._call_state, self._c_completion_queue, tag)
+    return _next_call_event(
+        self._channel_state, self._c_completion_queue, on_success)
+
+
+cdef SegregatedCall _segregated_call(
+    _ChannelState state, int flags, method, host, object deadline,
+    object metadata, CallCredentials credentials, operationses_and_user_tags):
+  cdef _CallState call_state = _CallState()
+  cdef grpc_completion_queue *c_completion_queue = (
+      grpc_completion_queue_create_for_next(NULL))
+  cdef SegregatedCall segregated_call
+
+  def on_success(started_tags):
+    state.segregated_call_states.add(call_state)
+
+  try:
+    _call(
+        state, call_state, c_completion_queue, on_success, flags, method, host,
+        deadline, credentials, operationses_and_user_tags, metadata)
+  except:
+    _destroy_c_completion_queue(c_completion_queue)
+    raise
+
+  segregated_call = SegregatedCall(state, call_state)
+  segregated_call._c_completion_queue = c_completion_queue
+  return segregated_call
+
+
+cdef object _watch_connectivity_state(
+    _ChannelState state, grpc_connectivity_state last_observed_state,
+    object deadline):
+  cdef _ConnectivityTag tag = _ConnectivityTag(object())
+  with state.condition:
+    if state.open:
+      cpython.Py_INCREF(tag)
+      grpc_channel_watch_connectivity_state(
+          state.c_channel, last_observed_state, _timespec_from_time(deadline),
+          state.c_connectivity_completion_queue, <cpython.PyObject *>tag)
+      state.connectivity_due.add(tag)
+    else:
+      raise ValueError('Cannot invoke RPC on closed channel!')
+  completed_tag, event = _latent_event(
+      state.c_connectivity_completion_queue, None)
+  with state.condition:
+    state.connectivity_due.remove(completed_tag)
+    state.condition.notify_all()
+  return event
+
+
+cdef _close(_ChannelState state, grpc_status_code code, object details):
+  cdef _CallState call_state
+  encoded_details = _encode(details)
+  with state.condition:
+    if state.open:
+      state.open = False
+      for call_state in set(state.integrated_call_states.values()):
+        grpc_call_cancel_with_status(
+            call_state.c_call, code, encoded_details, NULL)
+      for call_state in state.segregated_call_states:
+        grpc_call_cancel_with_status(
+            call_state.c_call, code, encoded_details, NULL)
+      # TODO(https://github.com/grpc/grpc/issues/3064): Cancel connectivity
+      # watching.
+
+      while state.integrated_call_states:
+        state.condition.wait()
+      while state.segregated_call_states:
+        state.condition.wait()
+      while state.connectivity_due:
+        state.condition.wait()
+
+      _destroy_c_completion_queue(state.c_call_completion_queue)
+      _destroy_c_completion_queue(state.c_connectivity_completion_queue)
+      grpc_channel_destroy(state.c_channel)
+      state.c_channel = NULL
+      grpc_shutdown()
+      state.condition.notify_all()
+    else:
+      # Another call to close already completed in the past or is currently
+      # being executed in another thread.
+      while state.c_channel != NULL:
+        state.condition.wait()
+
 
 cdef class Channel:
 
-  def __cinit__(self, bytes target, object arguments,
-                ChannelCredentials channel_credentials=None):
+  def __cinit__(
+      self, bytes target, object arguments,
+      ChannelCredentials channel_credentials):
     grpc_init()
+    self._state = _ChannelState()
     self._vtable.copy = &_copy_pointer
     self._vtable.destroy = &_destroy_pointer
     self._vtable.cmp = &_compare_pointer
     cdef _ArgumentsProcessor arguments_processor = _ArgumentsProcessor(
         arguments)
     cdef grpc_channel_args *c_arguments = arguments_processor.c(&self._vtable)
-    self.references = []
-    c_target = target
     if channel_credentials is None:
-      self.c_channel = grpc_insecure_channel_create(c_target, c_arguments, NULL)
+      self._state.c_channel = grpc_insecure_channel_create(
+          <char *>target, c_arguments, NULL)
     else:
       c_channel_credentials = channel_credentials.c()
-      self.c_channel = grpc_secure_channel_create(
-          c_channel_credentials, c_target, c_arguments, NULL)
+      self._state.c_channel = grpc_secure_channel_create(
+          c_channel_credentials, <char *>target, c_arguments, NULL)
       grpc_channel_credentials_release(c_channel_credentials)
-    arguments_processor.un_c()
-    self.references.append(target)
-    self.references.append(arguments)
-
-  def create_call(self, Call parent, int flags,
-                  CompletionQueue queue not None,
-                  method, host, object deadline):
-    if queue.is_shutting_down:
-      raise ValueError("queue must not be shutting down or shutdown")
-    cdef grpc_slice method_slice = _slice_from_bytes(method)
-    cdef grpc_slice host_slice
-    cdef grpc_slice *host_slice_ptr = NULL
-    if host is not None:
-      host_slice = _slice_from_bytes(host)
-      host_slice_ptr = &host_slice
-    cdef Call operation_call = Call()
-    operation_call.references = [self, queue]
-    cdef grpc_call *parent_call = NULL
-    if parent is not None:
-      parent_call = parent.c_call
-    operation_call.c_call = grpc_channel_create_call(
-        self.c_channel, parent_call, flags,
-        queue.c_completion_queue, method_slice, host_slice_ptr,
-        _timespec_from_time(deadline), NULL)
-    grpc_slice_unref(method_slice)
-    if host_slice_ptr:
-      grpc_slice_unref(host_slice)
-    return operation_call
+    self._state.c_call_completion_queue = (
+        grpc_completion_queue_create_for_next(NULL))
+    self._state.c_connectivity_completion_queue = (
+        grpc_completion_queue_create_for_next(NULL))
+
+  def target(self):
+    cdef char *c_target
+    with self._state.condition:
+      c_target = grpc_channel_get_target(self._state.c_channel)
+      target = <bytes>c_target
+      gpr_free(c_target)
+      return target
+
+  def integrated_call(
+      self, int flags, method, host, object deadline, object metadata,
+      CallCredentials credentials, operationses_and_tags):
+    return _integrated_call(
+        self._state, flags, method, host, deadline, metadata, credentials,
+        operationses_and_tags)
+
+  def next_call_event(self):
+    def on_success(tag):
+      _process_integrated_call_tag(self._state, tag)
+    return _next_call_event(
+        self._state, self._state.c_call_completion_queue, on_success)
+
+  def segregated_call(
+      self, int flags, method, host, object deadline, object metadata,
+      CallCredentials credentials, operationses_and_tags):
+    return _segregated_call(
+        self._state, flags, method, host, deadline, metadata, credentials,
+        operationses_and_tags)
 
   def check_connectivity_state(self, bint try_to_connect):
-    cdef grpc_connectivity_state result
-    with nogil:
-      result = grpc_channel_check_connectivity_state(self.c_channel,
-                                                     try_to_connect)
-    return result
+    with self._state.condition:
+      return grpc_channel_check_connectivity_state(
+          self._state.c_channel, try_to_connect)
 
   def watch_connectivity_state(
-      self, grpc_connectivity_state last_observed_state,
-      object deadline, CompletionQueue queue not None, tag):
-    cdef _ConnectivityTag connectivity_tag = _ConnectivityTag(tag)
-    cpython.Py_INCREF(connectivity_tag)
-    grpc_channel_watch_connectivity_state(
-        self.c_channel, last_observed_state, _timespec_from_time(deadline),
-        queue.c_completion_queue, <cpython.PyObject *>connectivity_tag)
+      self, grpc_connectivity_state last_observed_state, object deadline):
+    return _watch_connectivity_state(self._state, last_observed_state, deadline)
 
-  def target(self):
-    cdef char *target = NULL
-    with nogil:
-      target = grpc_channel_get_target(self.c_channel)
-    result = <bytes>target
-    with nogil:
-      gpr_free(target)
-    return result
-
-  def __dealloc__(self):
-    if self.c_channel != NULL:
-      grpc_channel_destroy(self.c_channel)
-    grpc_shutdown()
+  def close(self, code, details):
+    _close(self._state, code, details)
diff --git a/src/python/grpcio/grpc/_cython/_cygrpc/completion_queue.pxd.pxi b/src/python/grpcio/grpc/_cython/_cygrpc/completion_queue.pxd.pxi
index 5ea0287b81..9f06ce086e 100644
--- a/src/python/grpcio/grpc/_cython/_cygrpc/completion_queue.pxd.pxi
+++ b/src/python/grpcio/grpc/_cython/_cygrpc/completion_queue.pxd.pxi
@@ -13,10 +13,16 @@
 # limitations under the License.
 
 
+cdef grpc_event _next(grpc_completion_queue *c_completion_queue, deadline)
+
+
+cdef _interpret_event(grpc_event c_event)
+
+
 cdef class CompletionQueue:
 
   cdef grpc_completion_queue *c_completion_queue
   cdef bint is_shutting_down
   cdef bint is_shutdown
 
-  cdef _interpret_event(self, grpc_event event)
+  cdef _interpret_event(self, grpc_event c_event)
diff --git a/src/python/grpcio/grpc/_cython/_cygrpc/completion_queue.pyx.pxi b/src/python/grpcio/grpc/_cython/_cygrpc/completion_queue.pyx.pxi
index 40496d1124..a2d765546a 100644
--- a/src/python/grpcio/grpc/_cython/_cygrpc/completion_queue.pyx.pxi
+++ b/src/python/grpcio/grpc/_cython/_cygrpc/completion_queue.pyx.pxi
@@ -20,6 +20,53 @@ import time
 cdef int _INTERRUPT_CHECK_PERIOD_MS = 200
 
 
+cdef grpc_event _next(grpc_completion_queue *c_completion_queue, deadline):
+  cdef gpr_timespec c_increment
+  cdef gpr_timespec c_timeout
+  cdef gpr_timespec c_deadline
+  c_increment = gpr_time_from_millis(_INTERRUPT_CHECK_PERIOD_MS, GPR_TIMESPAN)
+  if deadline is None:
+    c_deadline = gpr_inf_future(GPR_CLOCK_REALTIME)
+  else:
+    c_deadline = _timespec_from_time(deadline)
+
+  with nogil:
+    while True:
+      c_timeout = gpr_time_add(gpr_now(GPR_CLOCK_REALTIME), c_increment)
+      if gpr_time_cmp(c_timeout, c_deadline) > 0:
+        c_timeout = c_deadline
+      c_event = grpc_completion_queue_next(c_completion_queue, c_timeout, NULL)
+      if (c_event.type != GRPC_QUEUE_TIMEOUT or
+          gpr_time_cmp(c_timeout, c_deadline) == 0):
+        break
+
+      # Handle any signals
+      with gil:
+        cpython.PyErr_CheckSignals()
+  return c_event
+
+
+cdef _interpret_event(grpc_event c_event):
+  cdef _Tag tag
+  if c_event.type == GRPC_QUEUE_TIMEOUT:
+    # NOTE(nathaniel): For now we coopt ConnectivityEvent here.
+    return None, ConnectivityEvent(GRPC_QUEUE_TIMEOUT, False, None)
+  elif c_event.type == GRPC_QUEUE_SHUTDOWN:
+    # NOTE(nathaniel): For now we coopt ConnectivityEvent here.
+    return None, ConnectivityEvent(GRPC_QUEUE_SHUTDOWN, False, None)
+  else:
+    tag = <_Tag>c_event.tag
+    # We receive event tags only after they've been inc-ref'd elsewhere in
+    # the code.
+    cpython.Py_DECREF(tag)
+    return tag, tag.event(c_event)
+
+
+cdef _latent_event(grpc_completion_queue *c_completion_queue, object deadline):
+  cdef grpc_event c_event = _next(c_completion_queue, deadline)
+  return _interpret_event(c_event)
+
+
 cdef class CompletionQueue:
 
   def __cinit__(self, shutdown_cq=False):
@@ -36,48 +83,16 @@ cdef class CompletionQueue:
     self.is_shutting_down = False
     self.is_shutdown = False
 
-  cdef _interpret_event(self, grpc_event event):
-    cdef _Tag tag = None
-    if event.type == GRPC_QUEUE_TIMEOUT:
-      # NOTE(nathaniel): For now we coopt ConnectivityEvent here.
-      return ConnectivityEvent(GRPC_QUEUE_TIMEOUT, False, None)
-    elif event.type == GRPC_QUEUE_SHUTDOWN:
+  cdef _interpret_event(self, grpc_event c_event):
+    unused_tag, event = _interpret_event(c_event)
+    if event.completion_type == GRPC_QUEUE_SHUTDOWN:
       self.is_shutdown = True
-      # NOTE(nathaniel): For now we coopt ConnectivityEvent here.
-      return ConnectivityEvent(GRPC_QUEUE_TIMEOUT, True, None)
-    else:
-      tag = <_Tag>event.tag
-      # We receive event tags only after they've been inc-ref'd elsewhere in
-      # the code.
-      cpython.Py_DECREF(tag)
-      return tag.event(event)
+    return event
 
+  # We name this 'poll' to avoid problems with CPython's expectations for
+  # 'special' methods (like next and __next__).
   def poll(self, deadline=None):
-    # We name this 'poll' to avoid problems with CPython's expectations for
-    # 'special' methods (like next and __next__).
-    cdef gpr_timespec c_increment
-    cdef gpr_timespec c_timeout
-    cdef gpr_timespec c_deadline
-    if deadline is None:
-      c_deadline = gpr_inf_future(GPR_CLOCK_REALTIME)
-    else:
-      c_deadline = _timespec_from_time(deadline)
-    with nogil:
-      c_increment = gpr_time_from_millis(_INTERRUPT_CHECK_PERIOD_MS, GPR_TIMESPAN)
-
-      while True:
-        c_timeout = gpr_time_add(gpr_now(GPR_CLOCK_REALTIME), c_increment)
-        if gpr_time_cmp(c_timeout, c_deadline) > 0:
-          c_timeout = c_deadline
-        event = grpc_completion_queue_next(
-          self.c_completion_queue, c_timeout, NULL)
-        if event.type != GRPC_QUEUE_TIMEOUT or gpr_time_cmp(c_timeout, c_deadline) == 0:
-          break;
-
-        # Handle any signals
-        with gil:
-          cpython.PyErr_CheckSignals()
-    return self._interpret_event(event)
+    return self._interpret_event(_next(self.c_completion_queue, deadline))
 
   def shutdown(self):
     with nogil:
diff --git a/src/python/grpcio/grpc/_grpcio_metadata.py b/src/python/grpcio/grpc/_grpcio_metadata.py
index cb5da72f1f..ad53f60ad3 100644
--- a/src/python/grpcio/grpc/_grpcio_metadata.py
+++ b/src/python/grpcio/grpc/_grpcio_metadata.py
@@ -14,4 +14,4 @@
 
 # AUTO-GENERATED FROM `$REPO_ROOT/templates/src/python/grpcio/grpc/_grpcio_metadata.py.template`!!!
 
-__version__ = """1.12.0.dev0"""
+__version__ = """1.13.0.dev0"""
diff --git a/src/python/grpcio/grpc/_interceptor.py b/src/python/grpcio/grpc/_interceptor.py
index d029472c68..f465e35a9c 100644
--- a/src/python/grpcio/grpc/_interceptor.py
+++ b/src/python/grpcio/grpc/_interceptor.py
@@ -334,6 +334,19 @@ class _Channel(grpc.Channel):
         else:
             return thunk(method)
 
+    def _close(self):
+        self._channel.close()
+
+    def __enter__(self):
+        return self
+
+    def __exit__(self, exc_type, exc_val, exc_tb):
+        self._close()
+        return False
+
+    def close(self):
+        self._channel.close()
+
 
 def intercept_channel(channel, *interceptors):
     for interceptor in reversed(list(interceptors)):
diff --git a/src/python/grpcio/grpc/_server.py b/src/python/grpcio/grpc/_server.py
index c988e0c87c..d849cadbee 100644
--- a/src/python/grpcio/grpc/_server.py
+++ b/src/python/grpcio/grpc/_server.py
@@ -780,14 +780,8 @@ def _start(state):
         state.stage = _ServerStage.STARTED
         _request_call(state)
 
-        def cleanup_server(timeout):
-            if timeout is None:
-                _stop(state, _UNEXPECTED_EXIT_SERVER_GRACE).wait()
-            else:
-                _stop(state, timeout).wait()
-
-        thread = _common.CleanupThread(
-            cleanup_server, target=_serve, args=(state,))
+        thread = threading.Thread(target=_serve, args=(state,))
+        thread.daemon = True
         thread.start()
 
 
diff --git a/src/python/grpcio/grpc/beta/_server_adaptations.py b/src/python/grpcio/grpc/beta/_server_adaptations.py
index 3c04fd7639..ccafec8951 100644
--- a/src/python/grpcio/grpc/beta/_server_adaptations.py
+++ b/src/python/grpcio/grpc/beta/_server_adaptations.py
@@ -168,11 +168,8 @@ def _run_request_pipe_thread(request_iterator, request_consumer,
                 return
         request_consumer.terminate()
 
-    def stop_request_pipe(timeout):  # pylint: disable=unused-argument
-        thread_joined.set()
-
-    request_pipe_thread = _common.CleanupThread(
-        stop_request_pipe, target=pipe_requests)
+    request_pipe_thread = threading.Thread(target=pipe_requests)
+    request_pipe_thread.daemon = True
     request_pipe_thread.start()
 
 
diff --git a/src/python/grpcio/grpc_core_dependencies.py b/src/python/grpcio/grpc_core_dependencies.py
index b1f9d2018e..234f7634e2 100644
--- a/src/python/grpcio/grpc_core_dependencies.py
+++ b/src/python/grpcio/grpc_core_dependencies.py
@@ -344,7 +344,6 @@ CORE_SOURCE_FILES = [
     'src/core/ext/filters/client_channel/lb_policy/grpclb/proto/grpc/lb/v1/load_balancer.pb.c',
     'src/core/ext/filters/client_channel/resolver/fake/fake_resolver.cc',
     'src/core/ext/filters/client_channel/lb_policy/pick_first/pick_first.cc',
-    'src/core/ext/filters/client_channel/lb_policy/subchannel_list.cc',
     'src/core/ext/filters/client_channel/lb_policy/round_robin/round_robin.cc',
     'src/core/ext/filters/client_channel/resolver/dns/c_ares/dns_resolver_ares.cc',
     'src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver_posix.cc',
diff --git a/src/python/grpcio/grpc_version.py b/src/python/grpcio/grpc_version.py
index de5a780abd..57dc26dbeb 100644
--- a/src/python/grpcio/grpc_version.py
+++ b/src/python/grpcio/grpc_version.py
@@ -14,4 +14,4 @@
 
 # AUTO-GENERATED FROM `$REPO_ROOT/templates/src/python/grpcio/grpc_version.py.template`!!!
 
-VERSION = '1.12.0.dev0'
+VERSION = '1.13.0.dev0'
diff --git a/src/python/grpcio_health_checking/grpc_version.py b/src/python/grpcio_health_checking/grpc_version.py
index afcd316e5c..ba0d4a3b6d 100644
--- a/src/python/grpcio_health_checking/grpc_version.py
+++ b/src/python/grpcio_health_checking/grpc_version.py
@@ -14,4 +14,4 @@
 
 # AUTO-GENERATED FROM `$REPO_ROOT/templates/src/python/grpcio_health_checking/grpc_version.py.template`!!!
 
-VERSION = '1.12.0.dev0'
+VERSION = '1.13.0.dev0'
diff --git a/src/python/grpcio_health_checking/setup.py b/src/python/grpcio_health_checking/setup.py
index 60d309ec65..35c09827ba 100644
--- a/src/python/grpcio_health_checking/setup.py
+++ b/src/python/grpcio_health_checking/setup.py
@@ -57,7 +57,7 @@ PACKAGE_DIRECTORIES = {
 }
 
 INSTALL_REQUIRES = (
-    'protobuf>=3.5.0.post1',
+    'protobuf>=3.5.2.post1',
     'grpcio>={version}'.format(version=grpc_version.VERSION),
 )
 
diff --git a/src/python/grpcio_reflection/grpc_version.py b/src/python/grpcio_reflection/grpc_version.py
index 824b73201d..ea2878d9ee 100644
--- a/src/python/grpcio_reflection/grpc_version.py
+++ b/src/python/grpcio_reflection/grpc_version.py
@@ -14,4 +14,4 @@
 
 # AUTO-GENERATED FROM `$REPO_ROOT/templates/src/python/grpcio_reflection/grpc_version.py.template`!!!
 
-VERSION = '1.12.0.dev0'
+VERSION = '1.13.0.dev0'
diff --git a/src/python/grpcio_reflection/setup.py b/src/python/grpcio_reflection/setup.py
index 10c4c38f19..589d0ff556 100644
--- a/src/python/grpcio_reflection/setup.py
+++ b/src/python/grpcio_reflection/setup.py
@@ -58,7 +58,7 @@ PACKAGE_DIRECTORIES = {
 }
 
 INSTALL_REQUIRES = (
-    'protobuf>=3.5.0.post1',
+    'protobuf>=3.5.2.post1',
     'grpcio>={version}'.format(version=grpc_version.VERSION),
 )
 
diff --git a/src/python/grpcio_testing/grpc_testing/_channel/_channel.py b/src/python/grpcio_testing/grpc_testing/_channel/_channel.py
index b015b8d738..0c1941e6be 100644
--- a/src/python/grpcio_testing/grpc_testing/_channel/_channel.py
+++ b/src/python/grpcio_testing/grpc_testing/_channel/_channel.py
@@ -56,6 +56,21 @@ class TestingChannel(grpc_testing.Channel):
                       response_deserializer=None):
         return _multi_callable.StreamStream(method, self._state)
 
+    def _close(self):
+        # TODO(https://github.com/grpc/grpc/issues/12531): Decide what
+        # action to take here, if any?
+        pass
+
+    def __enter__(self):
+        return self
+
+    def __exit__(self, exc_type, exc_val, exc_tb):
+        self._close()
+        return False
+
+    def close(self):
+        self._close()
+
     def take_unary_unary(self, method_descriptor):
         return _channel_rpc.unary_unary(self._state, method_descriptor)
 
diff --git a/src/python/grpcio_testing/grpc_version.py b/src/python/grpcio_testing/grpc_version.py
index 5b1f4c4cc0..02f19f2283 100644
--- a/src/python/grpcio_testing/grpc_version.py
+++ b/src/python/grpcio_testing/grpc_version.py
@@ -14,4 +14,4 @@
 
 # AUTO-GENERATED FROM `$REPO_ROOT/templates/src/python/grpcio_testing/grpc_version.py.template`!!!
 
-VERSION = '1.12.0.dev0'
+VERSION = '1.13.0.dev0'
diff --git a/src/python/grpcio_testing/setup.py b/src/python/grpcio_testing/setup.py
index 5a9d593ec1..eb480a5464 100644
--- a/src/python/grpcio_testing/setup.py
+++ b/src/python/grpcio_testing/setup.py
@@ -29,7 +29,7 @@ PACKAGE_DIRECTORIES = {
 }
 
 INSTALL_REQUIRES = (
-    'protobuf>=3.5.0.post1',
+    'protobuf>=3.5.2.post1',
     'grpcio>={version}'.format(version=grpc_version.VERSION),
 )
 
diff --git a/src/python/grpcio_tests/grpc_version.py b/src/python/grpcio_tests/grpc_version.py
index 382f95018e..9d2e41644e 100644
--- a/src/python/grpcio_tests/grpc_version.py
+++ b/src/python/grpcio_tests/grpc_version.py
@@ -14,4 +14,4 @@
 
 # AUTO-GENERATED FROM `$REPO_ROOT/templates/src/python/grpcio_tests/grpc_version.py.template`!!!
 
-VERSION = '1.12.0.dev0'
+VERSION = '1.13.0.dev0'
diff --git a/src/python/grpcio_tests/setup.py b/src/python/grpcio_tests/setup.py
index 4e0f6726fa..98ac19d188 100644
--- a/src/python/grpcio_tests/setup.py
+++ b/src/python/grpcio_tests/setup.py
@@ -41,7 +41,7 @@ INSTALL_REQUIRES = (
     'grpcio>={version}'.format(version=grpc_version.VERSION),
     'grpcio-tools>={version}'.format(version=grpc_version.VERSION),
     'grpcio-health-checking>={version}'.format(version=grpc_version.VERSION),
-    'oauth2client>=1.4.7', 'protobuf>=3.5.0.post1', 'six>=1.10',
+    'oauth2client>=1.4.7', 'protobuf>=3.5.2.post1', 'six>=1.10',
     'google-auth>=1.0.0', 'requests>=2.14.2')
 
 COMMAND_CLASS = {
diff --git a/src/python/grpcio_tests/tests/_loader.py b/src/python/grpcio_tests/tests/_loader.py
index 31680916b4..be0af64646 100644
--- a/src/python/grpcio_tests/tests/_loader.py
+++ b/src/python/grpcio_tests/tests/_loader.py
@@ -54,7 +54,7 @@ class Loader(object):
         for module in modules:
             try:
                 package_paths = module.__path__
-            except:
+            except AttributeError:
                 continue
             self.walk_packages(package_paths)
         coverage_context.stop()
diff --git a/src/python/grpcio_tests/tests/_result.py b/src/python/grpcio_tests/tests/_result.py
index 9907c4e1f9..b105f18e78 100644
--- a/src/python/grpcio_tests/tests/_result.py
+++ b/src/python/grpcio_tests/tests/_result.py
@@ -46,7 +46,7 @@ class CaseResult(
       None.
   """
 
-    class Kind:
+    class Kind(object):
         UNTESTED = 'untested'
         RUNNING = 'running'
         ERROR = 'error'
@@ -257,7 +257,7 @@ class CoverageResult(AugmentedResult):
         #coverage.Coverage().combine()
 
 
-class _Colors:
+class _Colors(object):
     """Namespaced constants for terminal color magic numbers."""
     HEADER = '\033[95m'
     INFO = '\033[94m'
diff --git a/src/python/grpcio_tests/tests/interop/client.py b/src/python/grpcio_tests/tests/interop/client.py
index 3780ed9020..698c37017f 100644
--- a/src/python/grpcio_tests/tests/interop/client.py
+++ b/src/python/grpcio_tests/tests/interop/client.py
@@ -66,10 +66,6 @@ def _args():
     return parser.parse_args()
 
 
-def _application_default_credentials():
-    return oauth2client_client.GoogleCredentials.get_application_default()
-
-
 def _stub(args):
     target = '{}:{}'.format(args.server_host, args.server_port)
     if args.test_case == 'oauth2_auth_token':
diff --git a/src/python/grpcio_tests/tests/protoc_plugin/beta_python_plugin_test.py b/src/python/grpcio_tests/tests/protoc_plugin/beta_python_plugin_test.py
index ad0ecf0079..b46e53315e 100644
--- a/src/python/grpcio_tests/tests/protoc_plugin/beta_python_plugin_test.py
+++ b/src/python/grpcio_tests/tests/protoc_plugin/beta_python_plugin_test.py
@@ -329,9 +329,7 @@ class PythonPluginTest(unittest.TestCase):
 
         _packagify(self._python_out)
 
-        with _system_path([
-                self._python_out,
-        ]):
+        with _system_path([self._python_out]):
             self._payload_pb2 = importlib.import_module(_PAYLOAD_PB2)
             self._requests_pb2 = importlib.import_module(_REQUESTS_PB2)
             self._responses_pb2 = importlib.import_module(_RESPONSES_PB2)
diff --git a/src/python/grpcio_tests/tests/qps/benchmark_client.py b/src/python/grpcio_tests/tests/qps/benchmark_client.py
index e6392a8b8c..0488450740 100644
--- a/src/python/grpcio_tests/tests/qps/benchmark_client.py
+++ b/src/python/grpcio_tests/tests/qps/benchmark_client.py
@@ -22,7 +22,7 @@ from six.moves import queue
 
 import grpc
 from src.proto.grpc.testing import messages_pb2
-from src.proto.grpc.testing import services_pb2_grpc
+from src.proto.grpc.testing import benchmark_service_pb2_grpc
 from tests.unit import resources
 from tests.unit import test_common
 
@@ -58,7 +58,8 @@ class BenchmarkClient:
 
         if config.payload_config.WhichOneof('payload') == 'simple_params':
             self._generic = False
-            self._stub = services_pb2_grpc.BenchmarkServiceStub(channel)
+            self._stub = benchmark_service_pb2_grpc.BenchmarkServiceStub(
+                channel)
             payload = messages_pb2.Payload(
                 body='\0' * config.payload_config.simple_params.req_size)
             self._request = messages_pb2.SimpleRequest(
diff --git a/src/python/grpcio_tests/tests/qps/benchmark_server.py b/src/python/grpcio_tests/tests/qps/benchmark_server.py
index bb07844491..2bd89cbbdf 100644
--- a/src/python/grpcio_tests/tests/qps/benchmark_server.py
+++ b/src/python/grpcio_tests/tests/qps/benchmark_server.py
@@ -13,10 +13,10 @@
 # limitations under the License.
 
 from src.proto.grpc.testing import messages_pb2
-from src.proto.grpc.testing import services_pb2_grpc
+from src.proto.grpc.testing import benchmark_service_pb2_grpc
 
 
-class BenchmarkServer(services_pb2_grpc.BenchmarkServiceServicer):
+class BenchmarkServer(benchmark_service_pb2_grpc.BenchmarkServiceServicer):
     """Synchronous Server implementation for the Benchmark service."""
 
     def UnaryCall(self, request, context):
@@ -29,7 +29,8 @@ class BenchmarkServer(services_pb2_grpc.BenchmarkServiceServicer):
             yield messages_pb2.SimpleResponse(payload=payload)
 
 
-class GenericBenchmarkServer(services_pb2_grpc.BenchmarkServiceServicer):
+class GenericBenchmarkServer(
+        benchmark_service_pb2_grpc.BenchmarkServiceServicer):
     """Generic Server implementation for the Benchmark service."""
 
     def __init__(self, resp_size):
diff --git a/src/python/grpcio_tests/tests/qps/qps_worker.py b/src/python/grpcio_tests/tests/qps/qps_worker.py
index 54f69db109..c33d013882 100644
--- a/src/python/grpcio_tests/tests/qps/qps_worker.py
+++ b/src/python/grpcio_tests/tests/qps/qps_worker.py
@@ -17,7 +17,7 @@ import argparse
 import time
 
 import grpc
-from src.proto.grpc.testing import services_pb2_grpc
+from src.proto.grpc.testing import worker_service_pb2_grpc
 
 from tests.qps import worker_server
 from tests.unit import test_common
@@ -26,7 +26,8 @@ from tests.unit import test_common
 def run_worker_server(port):
     server = test_common.test_server()
     servicer = worker_server.WorkerServer()
-    services_pb2_grpc.add_WorkerServiceServicer_to_server(servicer, server)
+    worker_service_pb2_grpc.add_WorkerServiceServicer_to_server(
+        servicer, server)
     server.add_insecure_port('[::]:{}'.format(port))
     server.start()
     servicer.wait_for_quit()
diff --git a/src/python/grpcio_tests/tests/qps/worker_server.py b/src/python/grpcio_tests/tests/qps/worker_server.py
index 41e2403c8f..db145fbf64 100644
--- a/src/python/grpcio_tests/tests/qps/worker_server.py
+++ b/src/python/grpcio_tests/tests/qps/worker_server.py
@@ -20,7 +20,7 @@ import time
 from concurrent import futures
 import grpc
 from src.proto.grpc.testing import control_pb2
-from src.proto.grpc.testing import services_pb2_grpc
+from src.proto.grpc.testing import worker_service_pb2_grpc
 from src.proto.grpc.testing import stats_pb2
 
 from tests.qps import benchmark_client
@@ -31,7 +31,7 @@ from tests.unit import resources
 from tests.unit import test_common
 
 
-class WorkerServer(services_pb2_grpc.WorkerServiceServicer):
+class WorkerServer(worker_service_pb2_grpc.WorkerServiceServicer):
     """Python Worker Server implementation."""
 
     def __init__(self):
@@ -72,7 +72,7 @@ class WorkerServer(services_pb2_grpc.WorkerServiceServicer):
         server = test_common.test_server(max_workers=server_threads)
         if config.server_type == control_pb2.ASYNC_SERVER:
             servicer = benchmark_server.BenchmarkServer()
-            services_pb2_grpc.add_BenchmarkServiceServicer_to_server(
+            worker_service_pb2_grpc.add_BenchmarkServiceServicer_to_server(
                 servicer, server)
         elif config.server_type == control_pb2.ASYNC_GENERIC_SERVER:
             resp_size = config.payload_config.bytebuf_params.resp_size
diff --git a/src/python/grpcio_tests/tests/stress/test_runner.py b/src/python/grpcio_tests/tests/stress/test_runner.py
index d5038e3ba2..764cda17fb 100644
--- a/src/python/grpcio_tests/tests/stress/test_runner.py
+++ b/src/python/grpcio_tests/tests/stress/test_runner.py
@@ -50,7 +50,7 @@ class TestRunner(threading.Thread):
                 test_case.test_interoperability(self._stub, None)
                 end_time = time.time()
                 self._histogram.add((end_time - start_time) * 1e9)
-            except Exception as e:
+            except Exception as e:  # pylint: disable=broad-except
                 traceback.print_exc()
                 self._exception_queue.put(
                     Exception("An exception occured during test {}"
diff --git a/src/python/grpcio_tests/tests/testing/_client_application.py b/src/python/grpcio_tests/tests/testing/_client_application.py
index 7d0d74c8c4..3ddeba2373 100644
--- a/src/python/grpcio_tests/tests/testing/_client_application.py
+++ b/src/python/grpcio_tests/tests/testing/_client_application.py
@@ -215,30 +215,6 @@ def _run_infinite_request_stream(stub):
         return _UNSATISFACTORY_OUTCOME
 
 
-def run(scenario, channel):
-    stub = services_pb2_grpc.FirstServiceStub(channel)
-    try:
-        if scenario is Scenario.UNARY_UNARY:
-            return _run_unary_unary(stub)
-        elif scenario is Scenario.UNARY_STREAM:
-            return _run_unary_stream(stub)
-        elif scenario is Scenario.STREAM_UNARY:
-            return _run_stream_unary(stub)
-        elif scenario is Scenario.STREAM_STREAM:
-            return _run_stream_stream(stub)
-        elif scenario is Scenario.CONCURRENT_STREAM_UNARY:
-            return _run_concurrent_stream_unary(stub)
-        elif scenario is Scenario.CONCURRENT_STREAM_STREAM:
-            return _run_concurrent_stream_stream(stub)
-        elif scenario is Scenario.CANCEL_UNARY_UNARY:
-            return _run_cancel_unary_unary(stub)
-        elif scenario is Scenario.INFINITE_REQUEST_STREAM:
-            return _run_infinite_request_stream(stub)
-    except grpc.RpcError as rpc_error:
-        return Outcome(Outcome.Kind.RPC_ERROR, rpc_error.code(),
-                       rpc_error.details())
-
-
 _IMPLEMENTATIONS = {
     Scenario.UNARY_UNARY: _run_unary_unary,
     Scenario.UNARY_STREAM: _run_unary_stream,
diff --git a/src/python/grpcio_tests/tests/testing/_server_application.py b/src/python/grpcio_tests/tests/testing/_server_application.py
index 02769ca68d..243c385daf 100644
--- a/src/python/grpcio_tests/tests/testing/_server_application.py
+++ b/src/python/grpcio_tests/tests/testing/_server_application.py
@@ -38,7 +38,7 @@ class FirstServiceServicer(services_pb2_grpc.FirstServiceServicer):
             context.set_code(grpc.StatusCode.INVALID_ARGUMENT)
             context.set_details('Something is wrong with your request!')
         return
-        yield services_pb2.Strange()
+        yield services_pb2.Strange()  # pylint: disable=unreachable
 
     def StreUn(self, request_iterator, context):
         context.send_initial_metadata(((
diff --git a/src/python/grpcio_tests/tests/testing/_server_test.py b/src/python/grpcio_tests/tests/testing/_server_test.py
index 4f4abd7708..88e3a79ae5 100644
--- a/src/python/grpcio_tests/tests/testing/_server_test.py
+++ b/src/python/grpcio_tests/tests/testing/_server_test.py
@@ -21,13 +21,8 @@ import grpc_testing
 from tests.testing import _application_common
 from tests.testing import _application_testing_common
 from tests.testing import _server_application
-from tests.testing.proto import services_pb2
 
 
-# TODO(https://github.com/google/protobuf/issues/3452): Drop this skip.
-@unittest.skipIf(
-    services_pb2.DESCRIPTOR.services_by_name.get('FirstService') is None,
-    'Fix protobuf issue 3452!')
 class FirstServiceServicerTest(unittest.TestCase):
 
     def setUp(self):
diff --git a/src/python/grpcio_tests/tests/tests.json b/src/python/grpcio_tests/tests/tests.json
index d38ee517f0..0d94426413 100644
--- a/src/python/grpcio_tests/tests/tests.json
+++ b/src/python/grpcio_tests/tests/tests.json
@@ -25,6 +25,7 @@
   "unit._auth_test.AccessTokenAuthMetadataPluginTest",
   "unit._auth_test.GoogleCallCredentialsTest",
   "unit._channel_args_test.ChannelArgsTest",
+  "unit._channel_close_test.ChannelCloseTest",
   "unit._channel_connectivity_test.ChannelConnectivityTest",
   "unit._channel_ready_future_test.ChannelReadyFutureTest",
   "unit._compression_test.CompressionTest",
@@ -52,7 +53,6 @@
   "unit._server_ssl_cert_config_test.ServerSSLCertReloadTestCertConfigReuse",
   "unit._server_ssl_cert_config_test.ServerSSLCertReloadTestWithClientAuth",
   "unit._server_ssl_cert_config_test.ServerSSLCertReloadTestWithoutClientAuth",
-  "unit._thread_cleanup_test.CleanupThreadTest",
   "unit.beta._beta_features_test.BetaFeaturesTest",
   "unit.beta._beta_features_test.ContextManagementAndLifecycleTest",
   "unit.beta._connectivity_channel_test.ConnectivityStatesTest",
diff --git a/src/python/grpcio_tests/tests/unit/_channel_close_test.py b/src/python/grpcio_tests/tests/unit/_channel_close_test.py
new file mode 100644
index 0000000000..af3a9ee1ee
--- /dev/null
+++ b/src/python/grpcio_tests/tests/unit/_channel_close_test.py
@@ -0,0 +1,185 @@
+# Copyright 2018 gRPC authors.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+"""Tests server and client side compression."""
+
+import threading
+import time
+import unittest
+
+import grpc
+
+from tests.unit import test_common
+from tests.unit.framework.common import test_constants
+
+_BEAT = 0.5
+_SOME_TIME = 5
+_MORE_TIME = 10
+
+
+class _MethodHandler(grpc.RpcMethodHandler):
+
+    request_streaming = True
+    response_streaming = True
+    request_deserializer = None
+    response_serializer = None
+
+    def stream_stream(self, request_iterator, servicer_context):
+        for request in request_iterator:
+            yield request * 2
+
+
+_METHOD_HANDLER = _MethodHandler()
+
+
+class _GenericHandler(grpc.GenericRpcHandler):
+
+    def service(self, handler_call_details):
+        return _METHOD_HANDLER
+
+
+_GENERIC_HANDLER = _GenericHandler()
+
+
+class _Pipe(object):
+
+    def __init__(self, values):
+        self._condition = threading.Condition()
+        self._values = list(values)
+        self._open = True
+
+    def __iter__(self):
+        return self
+
+    def _next(self):
+        with self._condition:
+            while not self._values and self._open:
+                self._condition.wait()
+            if self._values:
+                return self._values.pop(0)
+            else:
+                raise StopIteration()
+
+    def next(self):
+        return self._next()
+
+    def __next__(self):
+        return self._next()
+
+    def add(self, value):
+        with self._condition:
+            self._values.append(value)
+            self._condition.notify()
+
+    def close(self):
+        with self._condition:
+            self._open = False
+            self._condition.notify()
+
+    def __enter__(self):
+        return self
+
+    def __exit__(self, type, value, traceback):
+        self.close()
+
+
+class ChannelCloseTest(unittest.TestCase):
+
+    def setUp(self):
+        self._server = test_common.test_server(
+            max_workers=test_constants.THREAD_CONCURRENCY)
+        self._server.add_generic_rpc_handlers((_GENERIC_HANDLER,))
+        self._port = self._server.add_insecure_port('[::]:0')
+        self._server.start()
+
+    def tearDown(self):
+        self._server.stop(None)
+
+    def test_close_immediately_after_call_invocation(self):
+        channel = grpc.insecure_channel('localhost:{}'.format(self._port))
+        multi_callable = channel.stream_stream('Meffod')
+        request_iterator = _Pipe(())
+        response_iterator = multi_callable(request_iterator)
+        channel.close()
+        request_iterator.close()
+
+        self.assertIs(response_iterator.code(), grpc.StatusCode.CANCELLED)
+
+    def test_close_while_call_active(self):
+        channel = grpc.insecure_channel('localhost:{}'.format(self._port))
+        multi_callable = channel.stream_stream('Meffod')
+        request_iterator = _Pipe((b'abc',))
+        response_iterator = multi_callable(request_iterator)
+        next(response_iterator)
+        channel.close()
+        request_iterator.close()
+
+        self.assertIs(response_iterator.code(), grpc.StatusCode.CANCELLED)
+
+    def test_context_manager_close_while_call_active(self):
+        with grpc.insecure_channel('localhost:{}'.format(
+                self._port)) as channel:  # pylint: disable=bad-continuation
+            multi_callable = channel.stream_stream('Meffod')
+            request_iterator = _Pipe((b'abc',))
+            response_iterator = multi_callable(request_iterator)
+            next(response_iterator)
+        request_iterator.close()
+
+        self.assertIs(response_iterator.code(), grpc.StatusCode.CANCELLED)
+
+    def test_context_manager_close_while_many_calls_active(self):
+        with grpc.insecure_channel('localhost:{}'.format(
+                self._port)) as channel:  # pylint: disable=bad-continuation
+            multi_callable = channel.stream_stream('Meffod')
+            request_iterators = tuple(
+                _Pipe((b'abc',))
+                for _ in range(test_constants.THREAD_CONCURRENCY))
+            response_iterators = []
+            for request_iterator in request_iterators:
+                response_iterator = multi_callable(request_iterator)
+                next(response_iterator)
+                response_iterators.append(response_iterator)
+        for request_iterator in request_iterators:
+            request_iterator.close()
+
+        for response_iterator in response_iterators:
+            self.assertIs(response_iterator.code(), grpc.StatusCode.CANCELLED)
+
+    def test_many_concurrent_closes(self):
+        channel = grpc.insecure_channel('localhost:{}'.format(self._port))
+        multi_callable = channel.stream_stream('Meffod')
+        request_iterator = _Pipe((b'abc',))
+        response_iterator = multi_callable(request_iterator)
+        next(response_iterator)
+        start = time.time()
+        end = start + _MORE_TIME
+
+        def sleep_some_time_then_close():
+            time.sleep(_SOME_TIME)
+            channel.close()
+
+        for _ in range(test_constants.THREAD_CONCURRENCY):
+            close_thread = threading.Thread(target=sleep_some_time_then_close)
+            close_thread.start()
+        while True:
+            request_iterator.add(b'def')
+            time.sleep(_BEAT)
+            if end < time.time():
+                break
+        request_iterator.close()
+
+        self.assertIs(response_iterator.code(), grpc.StatusCode.CANCELLED)
+
+
+if __name__ == '__main__':
+    unittest.main(verbosity=2)
diff --git a/src/python/grpcio_tests/tests/unit/_compression_test.py b/src/python/grpcio_tests/tests/unit/_compression_test.py
index 7550cd39ba..0b11f03adf 100644
--- a/src/python/grpcio_tests/tests/unit/_compression_test.py
+++ b/src/python/grpcio_tests/tests/unit/_compression_test.py
@@ -52,9 +52,9 @@ class _MethodHandler(grpc.RpcMethodHandler):
         self.stream_unary = None
         self.stream_stream = None
         if self.request_streaming and self.response_streaming:
-            self.stream_stream = lambda x, y: handle_stream(x, y)
+            self.stream_stream = handle_stream
         elif not self.request_streaming and not self.response_streaming:
-            self.unary_unary = lambda x, y: handle_unary(x, y)
+            self.unary_unary = handle_unary
 
 
 class _GenericHandler(grpc.GenericRpcHandler):
diff --git a/src/python/grpcio_tests/tests/unit/_cython/_cancel_many_calls_test.py b/src/python/grpcio_tests/tests/unit/_cython/_cancel_many_calls_test.py
index 4f8868d346..578a3d79ad 100644
--- a/src/python/grpcio_tests/tests/unit/_cython/_cancel_many_calls_test.py
+++ b/src/python/grpcio_tests/tests/unit/_cython/_cancel_many_calls_test.py
@@ -19,6 +19,7 @@ import unittest
 from grpc._cython import cygrpc
 from grpc.framework.foundation import logging_pool
 from tests.unit.framework.common import test_constants
+from tests.unit._cython import test_utilities
 
 _EMPTY_FLAGS = 0
 _EMPTY_METADATA = ()
@@ -30,6 +31,8 @@ _RECEIVE_MESSAGE_TAG = 'receive_message'
 _SERVER_COMPLETE_CALL_TAG = 'server_complete_call'
 
 _SUCCESS_CALL_FRACTION = 1.0 / 8.0
+_SUCCESSFUL_CALLS = int(test_constants.RPC_CONCURRENCY * _SUCCESS_CALL_FRACTION)
+_UNSUCCESSFUL_CALLS = test_constants.RPC_CONCURRENCY - _SUCCESSFUL_CALLS
 
 
 class _State(object):
@@ -150,7 +153,8 @@ class CancelManyCallsTest(unittest.TestCase):
         server.register_completion_queue(server_completion_queue)
         port = server.add_http2_port(b'[::]:0')
         server.start()
-        channel = cygrpc.Channel('localhost:{}'.format(port).encode(), None)
+        channel = cygrpc.Channel('localhost:{}'.format(port).encode(), None,
+                                 None)
 
         state = _State()
 
@@ -165,31 +169,33 @@ class CancelManyCallsTest(unittest.TestCase):
 
         client_condition = threading.Condition()
         client_due = set()
-        client_completion_queue = cygrpc.CompletionQueue()
-        client_driver = _QueueDriver(client_condition, client_completion_queue,
-                                     client_due)
-        client_driver.start()
 
         with client_condition:
             client_calls = []
             for index in range(test_constants.RPC_CONCURRENCY):
-                client_call = channel.create_call(None, _EMPTY_FLAGS,
-                                                  client_completion_queue,
-                                                  b'/twinkies', None, None)
-                operations = (
-                    cygrpc.SendInitialMetadataOperation(_EMPTY_METADATA,
-                                                        _EMPTY_FLAGS),
-                    cygrpc.SendMessageOperation(b'\x45\x56', _EMPTY_FLAGS),
-                    cygrpc.SendCloseFromClientOperation(_EMPTY_FLAGS),
-                    cygrpc.ReceiveInitialMetadataOperation(_EMPTY_FLAGS),
-                    cygrpc.ReceiveMessageOperation(_EMPTY_FLAGS),
-                    cygrpc.ReceiveStatusOnClientOperation(_EMPTY_FLAGS),
-                )
                 tag = 'client_complete_call_{0:04d}_tag'.format(index)
-                client_call.start_client_batch(operations, tag)
+                client_call = channel.integrated_call(
+                    _EMPTY_FLAGS, b'/twinkies', None, None, _EMPTY_METADATA,
+                    None, ((
+                        (
+                            cygrpc.SendInitialMetadataOperation(
+                                _EMPTY_METADATA, _EMPTY_FLAGS),
+                            cygrpc.SendMessageOperation(b'\x45\x56',
+                                                        _EMPTY_FLAGS),
+                            cygrpc.SendCloseFromClientOperation(_EMPTY_FLAGS),
+                            cygrpc.ReceiveInitialMetadataOperation(
+                                _EMPTY_FLAGS),
+                            cygrpc.ReceiveMessageOperation(_EMPTY_FLAGS),
+                            cygrpc.ReceiveStatusOnClientOperation(_EMPTY_FLAGS),
+                        ),
+                        tag,
+                    ),))
                 client_due.add(tag)
                 client_calls.append(client_call)
 
+        client_events_future = test_utilities.SimpleFuture(
+            lambda: tuple(channel.next_call_event() for _ in range(_SUCCESSFUL_CALLS)))
+
         with state.condition:
             while True:
                 if state.parked_handlers < test_constants.THREAD_CONCURRENCY:
@@ -201,12 +207,14 @@ class CancelManyCallsTest(unittest.TestCase):
                     state.condition.notify_all()
                     break
 
-        client_driver.events(
-            test_constants.RPC_CONCURRENCY * _SUCCESS_CALL_FRACTION)
+        client_events_future.result()
         with client_condition:
             for client_call in client_calls:
-                client_call.cancel()
+                client_call.cancel(cygrpc.StatusCode.cancelled, 'Cancelled!')
+        for _ in range(_UNSUCCESSFUL_CALLS):
+            channel.next_call_event()
 
+        channel.close(cygrpc.StatusCode.unknown, 'Cancelled on channel close!')
         with state.condition:
             server.shutdown(server_completion_queue, _SERVER_SHUTDOWN_TAG)
 
diff --git a/src/python/grpcio_tests/tests/unit/_cython/_channel_test.py b/src/python/grpcio_tests/tests/unit/_cython/_channel_test.py
index 7305d0fa3f..d95286071d 100644
--- a/src/python/grpcio_tests/tests/unit/_cython/_channel_test.py
+++ b/src/python/grpcio_tests/tests/unit/_cython/_channel_test.py
@@ -21,25 +21,20 @@ from grpc._cython import cygrpc
 from tests.unit.framework.common import test_constants
 
 
-def _channel_and_completion_queue():
-    channel = cygrpc.Channel(b'localhost:54321', ())
-    completion_queue = cygrpc.CompletionQueue()
-    return channel, completion_queue
+def _channel():
+    return cygrpc.Channel(b'localhost:54321', (), None)
 
 
-def _connectivity_loop(channel, completion_queue):
+def _connectivity_loop(channel):
     for _ in range(100):
         connectivity = channel.check_connectivity_state(True)
-        channel.watch_connectivity_state(connectivity,
-                                         time.time() + 0.2, completion_queue,
-                                         None)
-        completion_queue.poll()
+        channel.watch_connectivity_state(connectivity, time.time() + 0.2)
 
 
 def _create_loop_destroy():
-    channel, completion_queue = _channel_and_completion_queue()
-    _connectivity_loop(channel, completion_queue)
-    completion_queue.shutdown()
+    channel = _channel()
+    _connectivity_loop(channel)
+    channel.close(cygrpc.StatusCode.ok, 'Channel close!')
 
 
 def _in_parallel(behavior, arguments):
@@ -55,12 +50,9 @@ def _in_parallel(behavior, arguments):
 class ChannelTest(unittest.TestCase):
 
     def test_single_channel_lonely_connectivity(self):
-        channel, completion_queue = _channel_and_completion_queue()
-        _in_parallel(_connectivity_loop, (
-            channel,
-            completion_queue,
-        ))
-        completion_queue.shutdown()
+        channel = _channel()
+        _connectivity_loop(channel)
+        channel.close(cygrpc.StatusCode.ok, 'Channel close!')
 
     def test_multiple_channels_lonely_connectivity(self):
         _in_parallel(_create_loop_destroy, ())
diff --git a/src/python/grpcio_tests/tests/unit/_cython/_common.py b/src/python/grpcio_tests/tests/unit/_cython/_common.py
index 7fd3d19b4e..d8210f36f8 100644
--- a/src/python/grpcio_tests/tests/unit/_cython/_common.py
+++ b/src/python/grpcio_tests/tests/unit/_cython/_common.py
@@ -100,7 +100,8 @@ class RpcTest(object):
         self.server.register_completion_queue(self.server_completion_queue)
         port = self.server.add_http2_port(b'[::]:0')
         self.server.start()
-        self.channel = cygrpc.Channel('localhost:{}'.format(port).encode(), [])
+        self.channel = cygrpc.Channel('localhost:{}'.format(port).encode(), [],
+                                      None)
 
         self._server_shutdown_tag = 'server_shutdown_tag'
         self.server_condition = threading.Condition()
diff --git a/src/python/grpcio_tests/tests/unit/_cython/_no_messages_server_completion_queue_per_call_test.py b/src/python/grpcio_tests/tests/unit/_cython/_no_messages_server_completion_queue_per_call_test.py
index 7caa98f72d..8a721788f4 100644
--- a/src/python/grpcio_tests/tests/unit/_cython/_no_messages_server_completion_queue_per_call_test.py
+++ b/src/python/grpcio_tests/tests/unit/_cython/_no_messages_server_completion_queue_per_call_test.py
@@ -19,6 +19,7 @@ import unittest
 from grpc._cython import cygrpc
 
 from tests.unit._cython import _common
+from tests.unit._cython import test_utilities
 
 
 class Test(_common.RpcTest, unittest.TestCase):
@@ -41,31 +42,27 @@ class Test(_common.RpcTest, unittest.TestCase):
                 server_request_call_tag,
             })
 
-        client_call = self.channel.create_call(None, _common.EMPTY_FLAGS,
-                                               self.client_completion_queue,
-                                               b'/twinkies', None, None)
         client_receive_initial_metadata_tag = 'client_receive_initial_metadata_tag'
         client_complete_rpc_tag = 'client_complete_rpc_tag'
-        with self.client_condition:
-            client_receive_initial_metadata_start_batch_result = (
-                client_call.start_client_batch([
-                    cygrpc.ReceiveInitialMetadataOperation(_common.EMPTY_FLAGS),
-                ], client_receive_initial_metadata_tag))
-            self.assertEqual(cygrpc.CallError.ok,
-                             client_receive_initial_metadata_start_batch_result)
-            client_complete_rpc_start_batch_result = client_call.start_client_batch(
+        client_call = self.channel.integrated_call(
+            _common.EMPTY_FLAGS, b'/twinkies', None, None,
+            _common.INVOCATION_METADATA, None, [(
                 [
-                    cygrpc.SendInitialMetadataOperation(
-                        _common.INVOCATION_METADATA, _common.EMPTY_FLAGS),
-                    cygrpc.SendCloseFromClientOperation(_common.EMPTY_FLAGS),
-                    cygrpc.ReceiveStatusOnClientOperation(_common.EMPTY_FLAGS),
-                ], client_complete_rpc_tag)
-            self.assertEqual(cygrpc.CallError.ok,
-                             client_complete_rpc_start_batch_result)
-            self.client_driver.add_due({
+                    cygrpc.ReceiveInitialMetadataOperation(_common.EMPTY_FLAGS),
+                ],
                 client_receive_initial_metadata_tag,
-                client_complete_rpc_tag,
-            })
+            )])
+        client_call.operate([
+            cygrpc.SendInitialMetadataOperation(_common.INVOCATION_METADATA,
+                                                _common.EMPTY_FLAGS),
+            cygrpc.SendCloseFromClientOperation(_common.EMPTY_FLAGS),
+            cygrpc.ReceiveStatusOnClientOperation(_common.EMPTY_FLAGS),
+        ], client_complete_rpc_tag)
+
+        client_events_future = test_utilities.SimpleFuture(
+            lambda: [
+                self.channel.next_call_event(),
+                self.channel.next_call_event(),])
 
         server_request_call_event = self.server_driver.event_with_tag(
             server_request_call_tag)
@@ -96,20 +93,23 @@ class Test(_common.RpcTest, unittest.TestCase):
         server_complete_rpc_event = server_call_driver.event_with_tag(
             server_complete_rpc_tag)
 
-        client_receive_initial_metadata_event = self.client_driver.event_with_tag(
-            client_receive_initial_metadata_tag)
-        client_complete_rpc_event = self.client_driver.event_with_tag(
-            client_complete_rpc_tag)
+        client_events = client_events_future.result()
+        if client_events[0].tag is client_receive_initial_metadata_tag:
+            client_receive_initial_metadata_event = client_events[0]
+            client_complete_rpc_event = client_events[1]
+        else:
+            client_complete_rpc_event = client_events[0]
+            client_receive_initial_metadata_event = client_events[1]
 
         return (
             _common.OperationResult(server_request_call_start_batch_result,
                                     server_request_call_event.completion_type,
                                     server_request_call_event.success),
             _common.OperationResult(
-                client_receive_initial_metadata_start_batch_result,
+                cygrpc.CallError.ok,
                 client_receive_initial_metadata_event.completion_type,
                 client_receive_initial_metadata_event.success),
-            _common.OperationResult(client_complete_rpc_start_batch_result,
+            _common.OperationResult(cygrpc.CallError.ok,
                                     client_complete_rpc_event.completion_type,
                                     client_complete_rpc_event.success),
             _common.OperationResult(
diff --git a/src/python/grpcio_tests/tests/unit/_cython/_no_messages_single_server_completion_queue_test.py b/src/python/grpcio_tests/tests/unit/_cython/_no_messages_single_server_completion_queue_test.py
index 8582a39c01..47f39ebce2 100644
--- a/src/python/grpcio_tests/tests/unit/_cython/_no_messages_single_server_completion_queue_test.py
+++ b/src/python/grpcio_tests/tests/unit/_cython/_no_messages_single_server_completion_queue_test.py
@@ -19,6 +19,7 @@ import unittest
 from grpc._cython import cygrpc
 
 from tests.unit._cython import _common
+from tests.unit._cython import test_utilities
 
 
 class Test(_common.RpcTest, unittest.TestCase):
@@ -36,28 +37,31 @@ class Test(_common.RpcTest, unittest.TestCase):
                 server_request_call_tag,
             })
 
-        client_call = self.channel.create_call(None, _common.EMPTY_FLAGS,
-                                               self.client_completion_queue,
-                                               b'/twinkies', None, None)
         client_receive_initial_metadata_tag = 'client_receive_initial_metadata_tag'
         client_complete_rpc_tag = 'client_complete_rpc_tag'
-        with self.client_condition:
-            client_receive_initial_metadata_start_batch_result = (
-                client_call.start_client_batch([
-                    cygrpc.ReceiveInitialMetadataOperation(_common.EMPTY_FLAGS),
-                ], client_receive_initial_metadata_tag))
-            client_complete_rpc_start_batch_result = client_call.start_client_batch(
-                [
-                    cygrpc.SendInitialMetadataOperation(
-                        _common.INVOCATION_METADATA, _common.EMPTY_FLAGS),
-                    cygrpc.SendCloseFromClientOperation(_common.EMPTY_FLAGS),
-                    cygrpc.ReceiveStatusOnClientOperation(_common.EMPTY_FLAGS),
-                ], client_complete_rpc_tag)
-            self.client_driver.add_due({
-                client_receive_initial_metadata_tag,
-                client_complete_rpc_tag,
-            })
-
+        client_call = self.channel.integrated_call(
+            _common.EMPTY_FLAGS, b'/twinkies', None, None,
+            _common.INVOCATION_METADATA, None, [
+                (
+                    [
+                        cygrpc.SendInitialMetadataOperation(
+                            _common.INVOCATION_METADATA, _common.EMPTY_FLAGS),
+                        cygrpc.SendCloseFromClientOperation(
+                            _common.EMPTY_FLAGS),
+                        cygrpc.ReceiveStatusOnClientOperation(
+                            _common.EMPTY_FLAGS),
+                    ],
+                    client_complete_rpc_tag,
+                ),
+            ])
+        client_call.operate([
+            cygrpc.ReceiveInitialMetadataOperation(_common.EMPTY_FLAGS),
+        ], client_receive_initial_metadata_tag)
+
+        client_events_future = test_utilities.SimpleFuture(
+            lambda: [
+                self.channel.next_call_event(),
+                self.channel.next_call_event(),])
         server_request_call_event = self.server_driver.event_with_tag(
             server_request_call_tag)
 
@@ -87,20 +91,19 @@ class Test(_common.RpcTest, unittest.TestCase):
         server_complete_rpc_event = self.server_driver.event_with_tag(
             server_complete_rpc_tag)
 
-        client_receive_initial_metadata_event = self.client_driver.event_with_tag(
-            client_receive_initial_metadata_tag)
-        client_complete_rpc_event = self.client_driver.event_with_tag(
-            client_complete_rpc_tag)
+        client_events = client_events_future.result()
+        client_receive_initial_metadata_event = client_events[0]
+        client_complete_rpc_event = client_events[1]
 
         return (
             _common.OperationResult(server_request_call_start_batch_result,
                                     server_request_call_event.completion_type,
                                     server_request_call_event.success),
             _common.OperationResult(
-                client_receive_initial_metadata_start_batch_result,
+                cygrpc.CallError.ok,
                 client_receive_initial_metadata_event.completion_type,
                 client_receive_initial_metadata_event.success),
-            _common.OperationResult(client_complete_rpc_start_batch_result,
+            _common.OperationResult(cygrpc.CallError.ok,
                                     client_complete_rpc_event.completion_type,
                                     client_complete_rpc_event.success),
             _common.OperationResult(
diff --git a/src/python/grpcio_tests/tests/unit/_cython/_read_some_but_not_all_responses_test.py b/src/python/grpcio_tests/tests/unit/_cython/_read_some_but_not_all_responses_test.py
index bc63b54879..8a903bfaf9 100644
--- a/src/python/grpcio_tests/tests/unit/_cython/_read_some_but_not_all_responses_test.py
+++ b/src/python/grpcio_tests/tests/unit/_cython/_read_some_but_not_all_responses_test.py
@@ -17,6 +17,7 @@ import threading
 import unittest
 
 from grpc._cython import cygrpc
+from tests.unit._cython import test_utilities
 
 _EMPTY_FLAGS = 0
 _EMPTY_METADATA = ()
@@ -118,7 +119,8 @@ class ReadSomeButNotAllResponsesTest(unittest.TestCase):
         server.register_completion_queue(server_completion_queue)
         port = server.add_http2_port(b'[::]:0')
         server.start()
-        channel = cygrpc.Channel('localhost:{}'.format(port).encode(), set())
+        channel = cygrpc.Channel('localhost:{}'.format(port).encode(), set(),
+                                 None)
 
         server_shutdown_tag = 'server_shutdown_tag'
         server_driver = _ServerDriver(server_completion_queue,
@@ -127,10 +129,6 @@ class ReadSomeButNotAllResponsesTest(unittest.TestCase):
 
         client_condition = threading.Condition()
         client_due = set()
-        client_completion_queue = cygrpc.CompletionQueue()
-        client_driver = _QueueDriver(client_condition, client_completion_queue,
-                                     client_due)
-        client_driver.start()
 
         server_call_condition = threading.Condition()
         server_send_initial_metadata_tag = 'server_send_initial_metadata_tag'
@@ -154,25 +152,28 @@ class ReadSomeButNotAllResponsesTest(unittest.TestCase):
                                                   server_completion_queue,
                                                   server_rpc_tag)
 
-        client_call = channel.create_call(None, _EMPTY_FLAGS,
-                                          client_completion_queue, b'/twinkies',
-                                          None, None)
         client_receive_initial_metadata_tag = 'client_receive_initial_metadata_tag'
         client_complete_rpc_tag = 'client_complete_rpc_tag'
-        with client_condition:
-            client_receive_initial_metadata_start_batch_result = (
-                client_call.start_client_batch([
-                    cygrpc.ReceiveInitialMetadataOperation(_EMPTY_FLAGS),
-                ], client_receive_initial_metadata_tag))
-            client_due.add(client_receive_initial_metadata_tag)
-            client_complete_rpc_start_batch_result = (
-                client_call.start_client_batch([
-                    cygrpc.SendInitialMetadataOperation(_EMPTY_METADATA,
-                                                        _EMPTY_FLAGS),
-                    cygrpc.SendCloseFromClientOperation(_EMPTY_FLAGS),
-                    cygrpc.ReceiveStatusOnClientOperation(_EMPTY_FLAGS),
-                ], client_complete_rpc_tag))
-            client_due.add(client_complete_rpc_tag)
+        client_call = channel.segregated_call(
+            _EMPTY_FLAGS, b'/twinkies', None, None, _EMPTY_METADATA, None, (
+                (
+                    [
+                        cygrpc.ReceiveInitialMetadataOperation(_EMPTY_FLAGS),
+                    ],
+                    client_receive_initial_metadata_tag,
+                ),
+                (
+                    [
+                        cygrpc.SendInitialMetadataOperation(
+                            _EMPTY_METADATA, _EMPTY_FLAGS),
+                        cygrpc.SendCloseFromClientOperation(_EMPTY_FLAGS),
+                        cygrpc.ReceiveStatusOnClientOperation(_EMPTY_FLAGS),
+                    ],
+                    client_complete_rpc_tag,
+                ),
+            ))
+        client_receive_initial_metadata_event_future = test_utilities.SimpleFuture(
+            client_call.next_event)
 
         server_rpc_event = server_driver.first_event()
 
@@ -208,19 +209,20 @@ class ReadSomeButNotAllResponsesTest(unittest.TestCase):
             server_complete_rpc_tag)
         server_call_driver.events()
 
-        with client_condition:
-            client_receive_first_message_tag = 'client_receive_first_message_tag'
-            client_receive_first_message_start_batch_result = (
-                client_call.start_client_batch([
-                    cygrpc.ReceiveMessageOperation(_EMPTY_FLAGS),
-                ], client_receive_first_message_tag))
-            client_due.add(client_receive_first_message_tag)
-        client_receive_first_message_event = client_driver.event_with_tag(
-            client_receive_first_message_tag)
+        client_recieve_initial_metadata_event = client_receive_initial_metadata_event_future.result(
+        )
+
+        client_receive_first_message_tag = 'client_receive_first_message_tag'
+        client_call.operate([
+            cygrpc.ReceiveMessageOperation(_EMPTY_FLAGS),
+        ], client_receive_first_message_tag)
+        client_receive_first_message_event = client_call.next_event()
 
-        client_call_cancel_result = client_call.cancel()
-        client_driver.events()
+        client_call_cancel_result = client_call.cancel(
+            cygrpc.StatusCode.cancelled, 'Cancelled during test!')
+        client_complete_rpc_event = client_call.next_event()
 
+        channel.close(cygrpc.StatusCode.unknown, 'Channel closed!')
         server.shutdown(server_completion_queue, server_shutdown_tag)
         server.cancel_all_calls()
         server_driver.events()
@@ -228,11 +230,6 @@ class ReadSomeButNotAllResponsesTest(unittest.TestCase):
         self.assertEqual(cygrpc.CallError.ok, request_call_result)
         self.assertEqual(cygrpc.CallError.ok,
                          server_send_initial_metadata_start_batch_result)
-        self.assertEqual(cygrpc.CallError.ok,
-                         client_receive_initial_metadata_start_batch_result)
-        self.assertEqual(cygrpc.CallError.ok,
-                         client_complete_rpc_start_batch_result)
-        self.assertEqual(cygrpc.CallError.ok, client_call_cancel_result)
         self.assertIs(server_rpc_tag, server_rpc_event.tag)
         self.assertEqual(cygrpc.CompletionType.operation_complete,
                          server_rpc_event.completion_type)
diff --git a/src/python/grpcio_tests/tests/unit/_cython/cygrpc_test.py b/src/python/grpcio_tests/tests/unit/_cython/cygrpc_test.py
index 9045ff58a0..724a690746 100644
--- a/src/python/grpcio_tests/tests/unit/_cython/cygrpc_test.py
+++ b/src/python/grpcio_tests/tests/unit/_cython/cygrpc_test.py
@@ -51,8 +51,8 @@ class TypeSmokeTest(unittest.TestCase):
         del server
 
     def testChannelUpDown(self):
-        channel = cygrpc.Channel(b'[::]:0', None)
-        del channel
+        channel = cygrpc.Channel(b'[::]:0', None, None)
+        channel.close(cygrpc.StatusCode.cancelled, 'Test method anyway!')
 
     def test_metadata_plugin_call_credentials_up_down(self):
         cygrpc.MetadataPluginCallCredentials(_metadata_plugin,
@@ -121,7 +121,7 @@ class ServerClientMixin(object):
                                                  client_credentials)
         else:
             self.client_channel = cygrpc.Channel('localhost:{}'.format(
-                self.port).encode(), set())
+                self.port).encode(), set(), None)
         if host_override:
             self.host_argument = None  # default host
             self.expected_host = host_override
@@ -131,17 +131,20 @@ class ServerClientMixin(object):
             self.expected_host = self.host_argument
 
     def tearDownMixin(self):
+        self.client_channel.close(cygrpc.StatusCode.ok, 'test being torn down!')
+        del self.client_channel
         del self.server
         del self.client_completion_queue
         del self.server_completion_queue
 
-    def _perform_operations(self, operations, call, queue, deadline,
-                            description):
-        """Perform the list of operations with given call, queue, and deadline.
+    def _perform_queue_operations(self, operations, call, queue, deadline,
+                                  description):
+        """Perform the operations with given call, queue, and deadline.
 
-    Invocation errors are reported with as an exception with `description` in
-    the message. Performs the operations asynchronously, returning a future.
-    """
+        Invocation errors are reported with as an exception with `description`
+        in the message. Performs the operations asynchronously, returning a
+        future.
+        """
 
         def performer():
             tag = object()
@@ -185,9 +188,6 @@ class ServerClientMixin(object):
         self.assertEqual(cygrpc.CallError.ok, request_call_result)
 
         client_call_tag = object()
-        client_call = self.client_channel.create_call(
-            None, 0, self.client_completion_queue, METHOD, self.host_argument,
-            DEADLINE)
         client_initial_metadata = (
             (
                 CLIENT_METADATA_ASCII_KEY,
@@ -198,18 +198,24 @@ class ServerClientMixin(object):
                 CLIENT_METADATA_BIN_VALUE,
             ),
         )
-        client_start_batch_result = client_call.start_client_batch([
-            cygrpc.SendInitialMetadataOperation(client_initial_metadata,
-                                                _EMPTY_FLAGS),
-            cygrpc.SendMessageOperation(REQUEST, _EMPTY_FLAGS),
-            cygrpc.SendCloseFromClientOperation(_EMPTY_FLAGS),
-            cygrpc.ReceiveInitialMetadataOperation(_EMPTY_FLAGS),
-            cygrpc.ReceiveMessageOperation(_EMPTY_FLAGS),
-            cygrpc.ReceiveStatusOnClientOperation(_EMPTY_FLAGS),
-        ], client_call_tag)
-        self.assertEqual(cygrpc.CallError.ok, client_start_batch_result)
-        client_event_future = test_utilities.CompletionQueuePollFuture(
-            self.client_completion_queue, DEADLINE)
+        client_call = self.client_channel.integrated_call(
+            0, METHOD, self.host_argument, DEADLINE, client_initial_metadata,
+            None, [
+                (
+                    [
+                        cygrpc.SendInitialMetadataOperation(
+                            client_initial_metadata, _EMPTY_FLAGS),
+                        cygrpc.SendMessageOperation(REQUEST, _EMPTY_FLAGS),
+                        cygrpc.SendCloseFromClientOperation(_EMPTY_FLAGS),
+                        cygrpc.ReceiveInitialMetadataOperation(_EMPTY_FLAGS),
+                        cygrpc.ReceiveMessageOperation(_EMPTY_FLAGS),
+                        cygrpc.ReceiveStatusOnClientOperation(_EMPTY_FLAGS),
+                    ],
+                    client_call_tag,
+                ),
+            ])
+        client_event_future = test_utilities.SimpleFuture(
+            self.client_channel.next_call_event)
 
         request_event = self.server_completion_queue.poll(deadline=DEADLINE)
         self.assertEqual(cygrpc.CompletionType.operation_complete,
@@ -285,7 +291,7 @@ class ServerClientMixin(object):
         self.assertEqual(5, len(server_event.batch_operations))
         found_server_op_types = set()
         for server_result in server_event.batch_operations:
-            self.assertNotIn(client_result.type(), found_server_op_types)
+            self.assertNotIn(server_result.type(), found_server_op_types)
             found_server_op_types.add(server_result.type())
             if server_result.type() == cygrpc.OperationType.receive_message:
                 self.assertEqual(REQUEST, server_result.message())
@@ -304,66 +310,76 @@ class ServerClientMixin(object):
         del client_call
         del server_call
 
-    def test6522(self):
+    def test_6522(self):
         DEADLINE = time.time() + 5
         DEADLINE_TOLERANCE = 0.25
         METHOD = b'twinkies'
 
         empty_metadata = ()
 
+        # Prologue
         server_request_tag = object()
         self.server.request_call(self.server_completion_queue,
                                  self.server_completion_queue,
                                  server_request_tag)
-        client_call = self.client_channel.create_call(
-            None, 0, self.client_completion_queue, METHOD, self.host_argument,
-            DEADLINE)
-
-        # Prologue
-        def perform_client_operations(operations, description):
-            return self._perform_operations(operations, client_call,
-                                            self.client_completion_queue,
-                                            DEADLINE, description)
-
-        client_event_future = perform_client_operations([
-            cygrpc.SendInitialMetadataOperation(empty_metadata, _EMPTY_FLAGS),
-            cygrpc.ReceiveInitialMetadataOperation(_EMPTY_FLAGS),
-        ], "Client prologue")
+        client_call = self.client_channel.segregated_call(
+            0, METHOD, self.host_argument, DEADLINE, None, None, ([(
+                [
+                    cygrpc.SendInitialMetadataOperation(empty_metadata,
+                                                        _EMPTY_FLAGS),
+                    cygrpc.ReceiveInitialMetadataOperation(_EMPTY_FLAGS),
+                ],
+                object(),
+            ), (
+                [
+                    cygrpc.ReceiveStatusOnClientOperation(_EMPTY_FLAGS),
+                ],
+                object(),
+            )]))
+
+        client_initial_metadata_event_future = test_utilities.SimpleFuture(
+            client_call.next_event)
 
         request_event = self.server_completion_queue.poll(deadline=DEADLINE)
         server_call = request_event.call
 
         def perform_server_operations(operations, description):
-            return self._perform_operations(operations, server_call,
-                                            self.server_completion_queue,
-                                            DEADLINE, description)
+            return self._perform_queue_operations(operations, server_call,
+                                                  self.server_completion_queue,
+                                                  DEADLINE, description)
 
         server_event_future = perform_server_operations([
             cygrpc.SendInitialMetadataOperation(empty_metadata, _EMPTY_FLAGS),
         ], "Server prologue")
 
-        client_event_future.result()  # force completion
+        client_initial_metadata_event_future.result()  # force completion
         server_event_future.result()
 
         # Messaging
         for _ in range(10):
-            client_event_future = perform_client_operations([
+            client_call.operate([
                 cygrpc.SendMessageOperation(b'', _EMPTY_FLAGS),
                 cygrpc.ReceiveMessageOperation(_EMPTY_FLAGS),
             ], "Client message")
+            client_message_event_future = test_utilities.SimpleFuture(
+                client_call.next_event)
             server_event_future = perform_server_operations([
                 cygrpc.SendMessageOperation(b'', _EMPTY_FLAGS),
                 cygrpc.ReceiveMessageOperation(_EMPTY_FLAGS),
             ], "Server receive")
 
-            client_event_future.result()  # force completion
+            client_message_event_future.result()  # force completion
             server_event_future.result()
 
         # Epilogue
-        client_event_future = perform_client_operations([
+        client_call.operate([
             cygrpc.SendCloseFromClientOperation(_EMPTY_FLAGS),
-            cygrpc.ReceiveStatusOnClientOperation(_EMPTY_FLAGS)
         ], "Client epilogue")
+        # One for ReceiveStatusOnClient, one for SendCloseFromClient.
+        client_events_future = test_utilities.SimpleFuture(
+            lambda: {
+                client_call.next_event(),
+                client_call.next_event(),})
 
         server_event_future = perform_server_operations([
             cygrpc.ReceiveCloseOnServerOperation(_EMPTY_FLAGS),
@@ -371,7 +387,7 @@ class ServerClientMixin(object):
                 empty_metadata, cygrpc.StatusCode.ok, b'', _EMPTY_FLAGS)
         ], "Server epilogue")
 
-        client_event_future.result()  # force completion
+        client_events_future.result()  # force completion
         server_event_future.result()
 
 
diff --git a/src/python/grpcio_tests/tests/unit/_cython/test_utilities.py b/src/python/grpcio_tests/tests/unit/_cython/test_utilities.py
index 4a00b9ef2f..7d5eaaaa84 100644
--- a/src/python/grpcio_tests/tests/unit/_cython/test_utilities.py
+++ b/src/python/grpcio_tests/tests/unit/_cython/test_utilities.py
@@ -25,7 +25,7 @@ class SimpleFuture(object):
         def wrapped_function():
             try:
                 self._result = function(*args, **kwargs)
-            except Exception as error:
+            except Exception as error:  # pylint: disable=broad-except
                 self._error = error
 
         self._result = None
@@ -41,7 +41,7 @@ class SimpleFuture(object):
         self._thread.join()
         if self._error:
             # TODO(atash): re-raise exceptions in a way that preserves tracebacks
-            raise self._error
+            raise self._error  # pylint: disable=raising-bad-type
         return self._result
 
 
diff --git a/src/python/grpcio_tests/tests/unit/_exit_test.py b/src/python/grpcio_tests/tests/unit/_exit_test.py
index 6e6d9de0fb..f40f3ae07c 100644
--- a/src/python/grpcio_tests/tests/unit/_exit_test.py
+++ b/src/python/grpcio_tests/tests/unit/_exit_test.py
@@ -49,7 +49,7 @@ def cleanup_processes():
         for process in processes:
             try:
                 process.kill()
-            except Exception:
+            except Exception:  # pylint: disable=broad-except
                 pass
 
 
diff --git a/src/python/grpcio_tests/tests/unit/_from_grpc_import_star.py b/src/python/grpcio_tests/tests/unit/_from_grpc_import_star.py
index e683131722..ad847ae03e 100644
--- a/src/python/grpcio_tests/tests/unit/_from_grpc_import_star.py
+++ b/src/python/grpcio_tests/tests/unit/_from_grpc_import_star.py
@@ -14,7 +14,7 @@
 
 _BEFORE_IMPORT = tuple(globals())
 
-from grpc import *
+from grpc import *  # pylint: disable=wildcard-import
 
 _AFTER_IMPORT = tuple(globals())
 
diff --git a/src/python/grpcio_tests/tests/unit/_invalid_metadata_test.py b/src/python/grpcio_tests/tests/unit/_invalid_metadata_test.py
index 4edf0fc4ad..f153089a24 100644
--- a/src/python/grpcio_tests/tests/unit/_invalid_metadata_test.py
+++ b/src/python/grpcio_tests/tests/unit/_invalid_metadata_test.py
@@ -81,29 +81,16 @@ class InvalidMetadataTest(unittest.TestCase):
         request = b'\x07\x08'
         metadata = (('InVaLiD', 'UnaryRequestFutureUnaryResponse'),)
         expected_error_details = "metadata was invalid: %s" % metadata
-        response_future = self._unary_unary.future(request, metadata=metadata)
-        with self.assertRaises(grpc.RpcError) as exception_context:
-            response_future.result()
-        self.assertEqual(exception_context.exception.details(),
-                         expected_error_details)
-        self.assertEqual(exception_context.exception.code(),
-                         grpc.StatusCode.INTERNAL)
-        self.assertEqual(response_future.details(), expected_error_details)
-        self.assertEqual(response_future.code(), grpc.StatusCode.INTERNAL)
+        with self.assertRaises(ValueError) as exception_context:
+            self._unary_unary.future(request, metadata=metadata)
 
     def testUnaryRequestStreamResponse(self):
         request = b'\x37\x58'
         metadata = (('InVaLiD', 'UnaryRequestStreamResponse'),)
         expected_error_details = "metadata was invalid: %s" % metadata
-        response_iterator = self._unary_stream(request, metadata=metadata)
-        with self.assertRaises(grpc.RpcError) as exception_context:
-            next(response_iterator)
-        self.assertEqual(exception_context.exception.details(),
-                         expected_error_details)
-        self.assertEqual(exception_context.exception.code(),
-                         grpc.StatusCode.INTERNAL)
-        self.assertEqual(response_iterator.details(), expected_error_details)
-        self.assertEqual(response_iterator.code(), grpc.StatusCode.INTERNAL)
+        with self.assertRaises(ValueError) as exception_context:
+            self._unary_stream(request, metadata=metadata)
+        self.assertIn(expected_error_details, str(exception_context.exception))
 
     def testStreamRequestBlockingUnaryResponse(self):
         request_iterator = (
@@ -129,32 +116,18 @@ class InvalidMetadataTest(unittest.TestCase):
             b'\x07\x08' for _ in range(test_constants.STREAM_LENGTH))
         metadata = (('InVaLiD', 'StreamRequestFutureUnaryResponse'),)
         expected_error_details = "metadata was invalid: %s" % metadata
-        response_future = self._stream_unary.future(
-            request_iterator, metadata=metadata)
-        with self.assertRaises(grpc.RpcError) as exception_context:
-            response_future.result()
-        self.assertEqual(exception_context.exception.details(),
-                         expected_error_details)
-        self.assertEqual(exception_context.exception.code(),
-                         grpc.StatusCode.INTERNAL)
-        self.assertEqual(response_future.details(), expected_error_details)
-        self.assertEqual(response_future.code(), grpc.StatusCode.INTERNAL)
+        with self.assertRaises(ValueError) as exception_context:
+            self._stream_unary.future(request_iterator, metadata=metadata)
+        self.assertIn(expected_error_details, str(exception_context.exception))
 
     def testStreamRequestStreamResponse(self):
         request_iterator = (
             b'\x07\x08' for _ in range(test_constants.STREAM_LENGTH))
         metadata = (('InVaLiD', 'StreamRequestStreamResponse'),)
         expected_error_details = "metadata was invalid: %s" % metadata
-        response_iterator = self._stream_stream(
-            request_iterator, metadata=metadata)
-        with self.assertRaises(grpc.RpcError) as exception_context:
-            next(response_iterator)
-        self.assertEqual(exception_context.exception.details(),
-                         expected_error_details)
-        self.assertEqual(exception_context.exception.code(),
-                         grpc.StatusCode.INTERNAL)
-        self.assertEqual(response_iterator.details(), expected_error_details)
-        self.assertEqual(response_iterator.code(), grpc.StatusCode.INTERNAL)
+        with self.assertRaises(ValueError) as exception_context:
+            self._stream_stream(request_iterator, metadata=metadata)
+        self.assertIn(expected_error_details, str(exception_context.exception))
 
 
 if __name__ == '__main__':
diff --git a/src/python/grpcio_tests/tests/unit/_invocation_defects_test.py b/src/python/grpcio_tests/tests/unit/_invocation_defects_test.py
index e40cca8b24..93a5fdf9ff 100644
--- a/src/python/grpcio_tests/tests/unit/_invocation_defects_test.py
+++ b/src/python/grpcio_tests/tests/unit/_invocation_defects_test.py
@@ -165,11 +165,13 @@ class FailAfterFewIterationsCounter(object):
 
     def __next__(self):
         if self._current >= self._high:
-            raise Exception("This is a deliberate failure in a unit test.")
+            raise test_control.Defect()
         else:
             self._current += 1
             return self._bytestring
 
+    next = __next__
+
 
 def _unary_unary_multi_callable(channel):
     return channel.unary_unary(_UNARY_UNARY)
diff --git a/src/python/grpcio_tests/tests/unit/_thread_cleanup_test.py b/src/python/grpcio_tests/tests/unit/_thread_cleanup_test.py
deleted file mode 100644
index 18f5af058a..0000000000
--- a/src/python/grpcio_tests/tests/unit/_thread_cleanup_test.py
+++ /dev/null
@@ -1,115 +0,0 @@
-# Copyright 2016 gRPC authors.
-#
-# Licensed under the Apache License, Version 2.0 (the "License");
-# you may not use this file except in compliance with the License.
-# You may obtain a copy of the License at
-#
-#     http://www.apache.org/licenses/LICENSE-2.0
-#
-# Unless required by applicable law or agreed to in writing, software
-# distributed under the License is distributed on an "AS IS" BASIS,
-# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-# See the License for the specific language governing permissions and
-# limitations under the License.
-"""Tests for CleanupThread."""
-
-import threading
-import time
-import unittest
-
-from grpc import _common
-
-_SHORT_TIME = 0.5
-_LONG_TIME = 5.0
-_EPSILON = 0.5
-
-
-def cleanup(timeout):
-    if timeout is not None:
-        time.sleep(timeout)
-    else:
-        time.sleep(_LONG_TIME)
-
-
-def slow_cleanup(timeout):
-    # Don't respect timeout
-    time.sleep(_LONG_TIME)
-
-
-class CleanupThreadTest(unittest.TestCase):
-
-    def testTargetInvocation(self):
-        event = threading.Event()
-
-        def target(arg1, arg2, arg3=None):
-            self.assertEqual('arg1', arg1)
-            self.assertEqual('arg2', arg2)
-            self.assertEqual('arg3', arg3)
-            event.set()
-
-        cleanup_thread = _common.CleanupThread(
-            behavior=lambda x: None,
-            target=target,
-            name='test-name',
-            args=('arg1', 'arg2'),
-            kwargs={
-                'arg3': 'arg3'
-            })
-        cleanup_thread.start()
-        cleanup_thread.join()
-        self.assertEqual(cleanup_thread.name, 'test-name')
-        self.assertTrue(event.is_set())
-
-    def testJoinNoTimeout(self):
-        cleanup_thread = _common.CleanupThread(behavior=cleanup)
-        cleanup_thread.start()
-        start_time = time.time()
-        cleanup_thread.join()
-        end_time = time.time()
-        self.assertAlmostEqual(
-            _LONG_TIME, end_time - start_time, delta=_EPSILON)
-
-    def testJoinTimeout(self):
-        cleanup_thread = _common.CleanupThread(behavior=cleanup)
-        cleanup_thread.start()
-        start_time = time.time()
-        cleanup_thread.join(_SHORT_TIME)
-        end_time = time.time()
-        self.assertAlmostEqual(
-            _SHORT_TIME, end_time - start_time, delta=_EPSILON)
-
-    def testJoinTimeoutSlowBehavior(self):
-        cleanup_thread = _common.CleanupThread(behavior=slow_cleanup)
-        cleanup_thread.start()
-        start_time = time.time()
-        cleanup_thread.join(_SHORT_TIME)
-        end_time = time.time()
-        self.assertAlmostEqual(
-            _LONG_TIME, end_time - start_time, delta=_EPSILON)
-
-    def testJoinTimeoutSlowTarget(self):
-        event = threading.Event()
-
-        def target():
-            event.wait(_LONG_TIME)
-
-        cleanup_thread = _common.CleanupThread(behavior=cleanup, target=target)
-        cleanup_thread.start()
-        start_time = time.time()
-        cleanup_thread.join(_SHORT_TIME)
-        end_time = time.time()
-        self.assertAlmostEqual(
-            _SHORT_TIME, end_time - start_time, delta=_EPSILON)
-        event.set()
-
-    def testJoinZeroTimeout(self):
-        cleanup_thread = _common.CleanupThread(behavior=cleanup)
-        cleanup_thread.start()
-        start_time = time.time()
-        cleanup_thread.join(0)
-        end_time = time.time()
-        self.assertAlmostEqual(0, end_time - start_time, delta=_EPSILON)
-
-
-if __name__ == '__main__':
-    unittest.main(verbosity=2)
diff --git a/src/python/grpcio_tests/tests/unit/beta/_beta_features_test.py b/src/python/grpcio_tests/tests/unit/beta/_beta_features_test.py
index 61c03f64ba..b43c647fc9 100644
--- a/src/python/grpcio_tests/tests/unit/beta/_beta_features_test.py
+++ b/src/python/grpcio_tests/tests/unit/beta/_beta_features_test.py
@@ -65,7 +65,7 @@ class _Servicer(object):
             self._serviced = True
             self._condition.notify_all()
             return
-            yield
+            yield  # pylint: disable=unreachable
 
     def stream_unary(self, request_iterator, context):
         for request in request_iterator:
diff --git a/src/ruby/lib/grpc/version.rb b/src/ruby/lib/grpc/version.rb
index 2cb7c4be53..15f375100a 100644
--- a/src/ruby/lib/grpc/version.rb
+++ b/src/ruby/lib/grpc/version.rb
@@ -14,5 +14,5 @@
 
 # GRPC contains the General RPC module.
 module GRPC
-  VERSION = '1.12.0.dev'
+  VERSION = '1.13.0.dev'
 end
diff --git a/src/ruby/pb/generate_proto_ruby.sh b/src/ruby/pb/generate_proto_ruby.sh
index d25eff5819..ec6e2eedd1 100755
--- a/src/ruby/pb/generate_proto_ruby.sh
+++ b/src/ruby/pb/generate_proto_ruby.sh
@@ -32,7 +32,13 @@ $PROTOC -I . \
     --plugin=$PLUGIN
 
 $PROTOC -I . \
-    src/proto/grpc/testing/{messages,payloads,stats,services,control}.proto \
+    src/proto/grpc/core/stats.proto \
+    --grpc_out=src/ruby/qps \
+    --ruby_out=src/ruby/qps \
+    --plugin=$PLUGIN
+
+$PROTOC -I . \
+    src/proto/grpc/testing/{messages,payloads,stats,benchmark_service,report_qps_scenario_service,worker_service,control}.proto \
     --grpc_out=src/ruby/qps \
     --ruby_out=src/ruby/qps \
     --plugin=$PLUGIN
diff --git a/src/ruby/pb/grpc/health/v1/health_services_pb.rb b/src/ruby/pb/grpc/health/v1/health_services_pb.rb
index 520f8e7ec5..169e160f90 100644
--- a/src/ruby/pb/grpc/health/v1/health_services_pb.rb
+++ b/src/ruby/pb/grpc/health/v1/health_services_pb.rb
@@ -1,7 +1,7 @@
 # Generated by the protocol buffer compiler.  DO NOT EDIT!
 # Source: grpc/health/v1/health.proto for package 'grpc.health.v1'
 # Original file comments:
-# Copyright 2015 gRPC authors.
+# Copyright 2015 The gRPC Authors
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
 # you may not use this file except in compliance with the License.
@@ -15,6 +15,9 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 #
+# The canonical version of this proto can be found at
+# https://github.com/grpc/grpc-proto/blob/master/grpc/health/v1/health.proto
+#
 
 require 'grpc'
 require 'grpc/health/v1/health_pb'
diff --git a/src/ruby/qps/client.rb b/src/ruby/qps/client.rb
index 0426aee7c8..d573d827b9 100644
--- a/src/ruby/qps/client.rb
+++ b/src/ruby/qps/client.rb
@@ -23,7 +23,7 @@ $LOAD_PATH.unshift(this_dir) unless $LOAD_PATH.include?(this_dir)
 
 require 'grpc'
 require 'histogram'
-require 'src/proto/grpc/testing/services_services_pb'
+require 'src/proto/grpc/testing/benchmark_service_services_pb'
 
 class Poisson
   def interarrival
diff --git a/src/ruby/qps/proxy-worker.rb b/src/ruby/qps/proxy-worker.rb
index 4c7c510fdb..5f23d896cc 100755
--- a/src/ruby/qps/proxy-worker.rb
+++ b/src/ruby/qps/proxy-worker.rb
@@ -27,7 +27,7 @@ require 'histogram'
 require 'etc'
 require 'facter'
 require 'qps-common'
-require 'src/proto/grpc/testing/services_services_pb'
+require 'src/proto/grpc/testing/worker_service_services_pb'
 require 'src/proto/grpc/testing/proxy-service_services_pb'
 
 class ProxyBenchmarkClientServiceImpl < Grpc::Testing::ProxyClientService::Service
diff --git a/src/ruby/qps/server.rb b/src/ruby/qps/server.rb
index 90218ea5d2..dccc64e300 100644
--- a/src/ruby/qps/server.rb
+++ b/src/ruby/qps/server.rb
@@ -24,7 +24,7 @@ $LOAD_PATH.unshift(this_dir) unless $LOAD_PATH.include?(this_dir)
 require 'grpc'
 require 'qps-common'
 require 'src/proto/grpc/testing/messages_pb'
-require 'src/proto/grpc/testing/services_services_pb'
+require 'src/proto/grpc/testing/benchmark_service_services_pb'
 require 'src/proto/grpc/testing/stats_pb'
 
 class BenchmarkServiceImpl < Grpc::Testing::BenchmarkService::Service
diff --git a/src/ruby/qps/src/proto/grpc/core/stats_pb.rb b/src/ruby/qps/src/proto/grpc/core/stats_pb.rb
new file mode 100644
index 0000000000..59c057820b
--- /dev/null
+++ b/src/ruby/qps/src/proto/grpc/core/stats_pb.rb
@@ -0,0 +1,33 @@
+# Generated by the protocol buffer compiler.  DO NOT EDIT!
+# source: src/proto/grpc/core/stats.proto
+
+require 'google/protobuf'
+
+Google::Protobuf::DescriptorPool.generated_pool.build do
+  add_message "grpc.core.Bucket" do
+    optional :start, :double, 1
+    optional :count, :uint64, 2
+  end
+  add_message "grpc.core.Histogram" do
+    repeated :buckets, :message, 1, "grpc.core.Bucket"
+  end
+  add_message "grpc.core.Metric" do
+    optional :name, :string, 1
+    oneof :value do
+      optional :count, :uint64, 10
+      optional :histogram, :message, 11, "grpc.core.Histogram"
+    end
+  end
+  add_message "grpc.core.Stats" do
+    repeated :metrics, :message, 1, "grpc.core.Metric"
+  end
+end
+
+module Grpc
+  module Core
+    Bucket = Google::Protobuf::DescriptorPool.generated_pool.lookup("grpc.core.Bucket").msgclass
+    Histogram = Google::Protobuf::DescriptorPool.generated_pool.lookup("grpc.core.Histogram").msgclass
+    Metric = Google::Protobuf::DescriptorPool.generated_pool.lookup("grpc.core.Metric").msgclass
+    Stats = Google::Protobuf::DescriptorPool.generated_pool.lookup("grpc.core.Stats").msgclass
+  end
+end
diff --git a/src/ruby/qps/src/proto/grpc/testing/services_pb.rb b/src/ruby/qps/src/proto/grpc/testing/benchmark_service_pb.rb
index 5ce13bf8b0..0bd3625f3d 100644
--- a/src/ruby/qps/src/proto/grpc/testing/services_pb.rb
+++ b/src/ruby/qps/src/proto/grpc/testing/benchmark_service_pb.rb
@@ -1,10 +1,9 @@
 # Generated by the protocol buffer compiler.  DO NOT EDIT!
-# source: src/proto/grpc/testing/services.proto
+# source: src/proto/grpc/testing/benchmark_service.proto
 
 require 'google/protobuf'
 
 require 'src/proto/grpc/testing/messages_pb'
-require 'src/proto/grpc/testing/control_pb'
 Google::Protobuf::DescriptorPool.generated_pool.build do
 end
 
diff --git a/src/ruby/qps/src/proto/grpc/testing/benchmark_service_services_pb.rb b/src/ruby/qps/src/proto/grpc/testing/benchmark_service_services_pb.rb
new file mode 100644
index 0000000000..65e5a75c4d
--- /dev/null
+++ b/src/ruby/qps/src/proto/grpc/testing/benchmark_service_services_pb.rb
@@ -0,0 +1,56 @@
+# Generated by the protocol buffer compiler.  DO NOT EDIT!
+# Source: src/proto/grpc/testing/benchmark_service.proto for package 'grpc.testing'
+# Original file comments:
+# Copyright 2015 gRPC authors.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+# An integration test service that covers all the method signature permutations
+# of unary/streaming requests/responses.
+
+require 'grpc'
+require 'src/proto/grpc/testing/benchmark_service_pb'
+
+module Grpc
+  module Testing
+    module BenchmarkService
+      class Service
+
+        include GRPC::GenericService
+
+        self.marshal_class_method = :encode
+        self.unmarshal_class_method = :decode
+        self.service_name = 'grpc.testing.BenchmarkService'
+
+        # One request followed by one response.
+        # The server returns the client payload as-is.
+        rpc :UnaryCall, SimpleRequest, SimpleResponse
+        # Repeated sequence of one request followed by one response.
+        # Should be called streaming ping-pong
+        # The server returns the client payload as-is on each response
+        rpc :StreamingCall, stream(SimpleRequest), stream(SimpleResponse)
+        # Single-sided unbounded streaming from client to server
+        # The server returns the client payload as-is once the client does WritesDone
+        rpc :StreamingFromClient, stream(SimpleRequest), SimpleResponse
+        # Single-sided unbounded streaming from server to client
+        # The server repeatedly returns the client payload as-is
+        rpc :StreamingFromServer, SimpleRequest, stream(SimpleResponse)
+        # Two-sided unbounded streaming between server to client
+        # Both sides send the content of their own choice to the other
+        rpc :StreamingBothWays, stream(SimpleRequest), stream(SimpleResponse)
+      end
+
+      Stub = Service.rpc_stub_class
+    end
+  end
+end
diff --git a/src/ruby/qps/src/proto/grpc/testing/control_pb.rb b/src/ruby/qps/src/proto/grpc/testing/control_pb.rb
index 02207a2b5d..5acc7fc0c6 100644
--- a/src/ruby/qps/src/proto/grpc/testing/control_pb.rb
+++ b/src/ruby/qps/src/proto/grpc/testing/control_pb.rb
@@ -20,6 +20,14 @@ Google::Protobuf::DescriptorPool.generated_pool.build do
   add_message "grpc.testing.SecurityParams" do
     optional :use_test_ca, :bool, 1
     optional :server_host_override, :string, 2
+    optional :cred_type, :string, 3
+  end
+  add_message "grpc.testing.ChannelArg" do
+    optional :name, :string, 1
+    oneof :value do
+      optional :str_value, :string, 2
+      optional :int_value, :int32, 3
+    end
   end
   add_message "grpc.testing.ClientConfig" do
     repeated :server_targets, :string, 1
@@ -35,6 +43,10 @@ Google::Protobuf::DescriptorPool.generated_pool.build do
     repeated :core_list, :int32, 13
     optional :core_limit, :int32, 14
     optional :other_client_api, :string, 15
+    repeated :channel_args, :message, 16, "grpc.testing.ChannelArg"
+    optional :threads_per_cq, :int32, 17
+    optional :messages_per_stream, :int32, 18
+    optional :use_coalesce_api, :bool, 19
   end
   add_message "grpc.testing.ClientStatus" do
     optional :stats, :message, 1, "grpc.testing.ClientStats"
@@ -57,6 +69,9 @@ Google::Protobuf::DescriptorPool.generated_pool.build do
     optional :payload_config, :message, 9, "grpc.testing.PayloadConfig"
     repeated :core_list, :int32, 10
     optional :other_server_api, :string, 11
+    optional :threads_per_cq, :int32, 12
+    optional :resource_quota_size, :int32, 1001
+    repeated :channel_args, :message, 1002, "grpc.testing.ChannelArg"
   end
   add_message "grpc.testing.ServerArgs" do
     oneof :argtype do
@@ -101,6 +116,13 @@ Google::Protobuf::DescriptorPool.generated_pool.build do
     optional :latency_95, :double, 9
     optional :latency_99, :double, 10
     optional :latency_999, :double, 11
+    optional :server_cpu_usage, :double, 12
+    optional :successful_requests_per_second, :double, 13
+    optional :failed_requests_per_second, :double, 14
+    optional :client_polls_per_request, :double, 15
+    optional :server_polls_per_request, :double, 16
+    optional :server_queries_per_cpu_sec, :double, 17
+    optional :client_queries_per_cpu_sec, :double, 18
   end
   add_message "grpc.testing.ScenarioResult" do
     optional :scenario, :message, 1, "grpc.testing.Scenario"
@@ -111,6 +133,7 @@ Google::Protobuf::DescriptorPool.generated_pool.build do
     optional :summary, :message, 6, "grpc.testing.ScenarioResultSummary"
     repeated :client_success, :bool, 7
     repeated :server_success, :bool, 8
+    repeated :request_results, :message, 9, "grpc.testing.RequestResultCount"
   end
   add_enum "grpc.testing.ClientType" do
     value :SYNC_CLIENT, 0
@@ -126,6 +149,9 @@ Google::Protobuf::DescriptorPool.generated_pool.build do
   add_enum "grpc.testing.RpcType" do
     value :UNARY, 0
     value :STREAMING, 1
+    value :STREAMING_FROM_CLIENT, 2
+    value :STREAMING_FROM_SERVER, 3
+    value :STREAMING_BOTH_WAYS, 4
   end
 end
 
@@ -135,6 +161,7 @@ module Grpc
     ClosedLoopParams = Google::Protobuf::DescriptorPool.generated_pool.lookup("grpc.testing.ClosedLoopParams").msgclass
     LoadParams = Google::Protobuf::DescriptorPool.generated_pool.lookup("grpc.testing.LoadParams").msgclass
     SecurityParams = Google::Protobuf::DescriptorPool.generated_pool.lookup("grpc.testing.SecurityParams").msgclass
+    ChannelArg = Google::Protobuf::DescriptorPool.generated_pool.lookup("grpc.testing.ChannelArg").msgclass
     ClientConfig = Google::Protobuf::DescriptorPool.generated_pool.lookup("grpc.testing.ClientConfig").msgclass
     ClientStatus = Google::Protobuf::DescriptorPool.generated_pool.lookup("grpc.testing.ClientStatus").msgclass
     Mark = Google::Protobuf::DescriptorPool.generated_pool.lookup("grpc.testing.Mark").msgclass
diff --git a/src/ruby/qps/src/proto/grpc/testing/report_qps_scenario_service_pb.rb b/src/ruby/qps/src/proto/grpc/testing/report_qps_scenario_service_pb.rb
new file mode 100644
index 0000000000..1b43e37299
--- /dev/null
+++ b/src/ruby/qps/src/proto/grpc/testing/report_qps_scenario_service_pb.rb
@@ -0,0 +1,13 @@
+# Generated by the protocol buffer compiler.  DO NOT EDIT!
+# source: src/proto/grpc/testing/report_qps_scenario_service.proto
+
+require 'google/protobuf'
+
+require 'src/proto/grpc/testing/control_pb'
+Google::Protobuf::DescriptorPool.generated_pool.build do
+end
+
+module Grpc
+  module Testing
+  end
+end
diff --git a/src/ruby/qps/src/proto/grpc/testing/report_qps_scenario_service_services_pb.rb b/src/ruby/qps/src/proto/grpc/testing/report_qps_scenario_service_services_pb.rb
new file mode 100644
index 0000000000..ddc81bed3d
--- /dev/null
+++ b/src/ruby/qps/src/proto/grpc/testing/report_qps_scenario_service_services_pb.rb
@@ -0,0 +1,42 @@
+# Generated by the protocol buffer compiler.  DO NOT EDIT!
+# Source: src/proto/grpc/testing/report_qps_scenario_service.proto for package 'grpc.testing'
+# Original file comments:
+# Copyright 2015 gRPC authors.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+# An integration test service that covers all the method signature permutations
+# of unary/streaming requests/responses.
+
+require 'grpc'
+require 'src/proto/grpc/testing/report_qps_scenario_service_pb'
+
+module Grpc
+  module Testing
+    module ReportQpsScenarioService
+      class Service
+
+        include GRPC::GenericService
+
+        self.marshal_class_method = :encode
+        self.unmarshal_class_method = :decode
+        self.service_name = 'grpc.testing.ReportQpsScenarioService'
+
+        # Report results of a QPS test benchmark scenario.
+        rpc :ReportScenario, ScenarioResult, Void
+      end
+
+      Stub = Service.rpc_stub_class
+    end
+  end
+end
diff --git a/src/ruby/qps/src/proto/grpc/testing/stats_pb.rb b/src/ruby/qps/src/proto/grpc/testing/stats_pb.rb
index 41f75bedf0..2069840168 100644
--- a/src/ruby/qps/src/proto/grpc/testing/stats_pb.rb
+++ b/src/ruby/qps/src/proto/grpc/testing/stats_pb.rb
@@ -3,11 +3,16 @@
 
 require 'google/protobuf'
 
+require 'src/proto/grpc/core/stats_pb'
 Google::Protobuf::DescriptorPool.generated_pool.build do
   add_message "grpc.testing.ServerStats" do
     optional :time_elapsed, :double, 1
     optional :time_user, :double, 2
     optional :time_system, :double, 3
+    optional :total_cpu_time, :uint64, 4
+    optional :idle_cpu_time, :uint64, 5
+    optional :cq_poll_count, :uint64, 6
+    optional :core_stats, :message, 7, "grpc.core.Stats"
   end
   add_message "grpc.testing.HistogramParams" do
     optional :resolution, :double, 1
@@ -21,11 +26,18 @@ Google::Protobuf::DescriptorPool.generated_pool.build do
     optional :sum_of_squares, :double, 5
     optional :count, :double, 6
   end
+  add_message "grpc.testing.RequestResultCount" do
+    optional :status_code, :int32, 1
+    optional :count, :int64, 2
+  end
   add_message "grpc.testing.ClientStats" do
     optional :latencies, :message, 1, "grpc.testing.HistogramData"
     optional :time_elapsed, :double, 2
     optional :time_user, :double, 3
     optional :time_system, :double, 4
+    repeated :request_results, :message, 5, "grpc.testing.RequestResultCount"
+    optional :cq_poll_count, :uint64, 6
+    optional :core_stats, :message, 7, "grpc.core.Stats"
   end
 end
 
@@ -34,6 +46,7 @@ module Grpc
     ServerStats = Google::Protobuf::DescriptorPool.generated_pool.lookup("grpc.testing.ServerStats").msgclass
     HistogramParams = Google::Protobuf::DescriptorPool.generated_pool.lookup("grpc.testing.HistogramParams").msgclass
     HistogramData = Google::Protobuf::DescriptorPool.generated_pool.lookup("grpc.testing.HistogramData").msgclass
+    RequestResultCount = Google::Protobuf::DescriptorPool.generated_pool.lookup("grpc.testing.RequestResultCount").msgclass
     ClientStats = Google::Protobuf::DescriptorPool.generated_pool.lookup("grpc.testing.ClientStats").msgclass
   end
 end
diff --git a/src/ruby/qps/src/proto/grpc/testing/worker_service_pb.rb b/src/ruby/qps/src/proto/grpc/testing/worker_service_pb.rb
new file mode 100644
index 0000000000..18b63452b6
--- /dev/null
+++ b/src/ruby/qps/src/proto/grpc/testing/worker_service_pb.rb
@@ -0,0 +1,13 @@
+# Generated by the protocol buffer compiler.  DO NOT EDIT!
+# source: src/proto/grpc/testing/worker_service.proto
+
+require 'google/protobuf'
+
+require 'src/proto/grpc/testing/control_pb'
+Google::Protobuf::DescriptorPool.generated_pool.build do
+end
+
+module Grpc
+  module Testing
+  end
+end
diff --git a/src/ruby/qps/src/proto/grpc/testing/services_services_pb.rb b/src/ruby/qps/src/proto/grpc/testing/worker_service_services_pb.rb
index 1d8b619d30..a7ecc95757 100644
--- a/src/ruby/qps/src/proto/grpc/testing/services_services_pb.rb
+++ b/src/ruby/qps/src/proto/grpc/testing/worker_service_services_pb.rb
@@ -1,5 +1,5 @@
 # Generated by the protocol buffer compiler.  DO NOT EDIT!
-# Source: src/proto/grpc/testing/services.proto for package 'grpc.testing'
+# Source: src/proto/grpc/testing/worker_service.proto for package 'grpc.testing'
 # Original file comments:
 # Copyright 2015 gRPC authors.
 #
@@ -19,29 +19,10 @@
 # of unary/streaming requests/responses.
 
 require 'grpc'
-require 'src/proto/grpc/testing/services_pb'
+require 'src/proto/grpc/testing/worker_service_pb'
 
 module Grpc
   module Testing
-    module BenchmarkService
-      class Service
-
-        include GRPC::GenericService
-
-        self.marshal_class_method = :encode
-        self.unmarshal_class_method = :decode
-        self.service_name = 'grpc.testing.BenchmarkService'
-
-        # One request followed by one response.
-        # The server returns the client payload as-is.
-        rpc :UnaryCall, SimpleRequest, SimpleResponse
-        # One request followed by one response.
-        # The server returns the client payload as-is.
-        rpc :StreamingCall, stream(SimpleRequest), stream(SimpleResponse)
-      end
-
-      Stub = Service.rpc_stub_class
-    end
     module WorkerService
       class Service
 
diff --git a/src/ruby/qps/worker.rb b/src/ruby/qps/worker.rb
index 8258487418..633ff13c35 100755
--- a/src/ruby/qps/worker.rb
+++ b/src/ruby/qps/worker.rb
@@ -29,7 +29,7 @@ require 'facter'
 require 'client'
 require 'qps-common'
 require 'server'
-require 'src/proto/grpc/testing/services_services_pb'
+require 'src/proto/grpc/testing/worker_service_services_pb'
 
 class WorkerServiceImpl < Grpc::Testing::WorkerService::Service
   def cpu_cores
diff --git a/src/ruby/tools/version.rb b/src/ruby/tools/version.rb
index 822f70eb0a..09d5c82674 100644
--- a/src/ruby/tools/version.rb
+++ b/src/ruby/tools/version.rb
@@ -14,6 +14,6 @@
 
 module GRPC
   module Tools
-    VERSION = '1.12.0.dev'
+    VERSION = '1.13.0.dev'
   end
 end