Merge remote-tracking branch 'upstream/master' into fail_fast

22 files changed, 201 insertions, 95 deletions

diff --git a/src/compiler/python_generator.cc b/src/compiler/python_generator.cc
index 0f61b1fb6c..6830f49931 100644
--- a/src/compiler/python_generator.cc
+++ b/src/compiler/python_generator.cc
@@ -234,6 +234,13 @@ bool PrintBetaServicer(const ServiceDescriptor* service, Printer* out) {
              service->name());
   {
     IndentScope raii_class_indent(out);
+    out->Print(
+        "\"\"\"The Beta API is deprecated for 0.15.0 and later.\n"
+        "\nIt is recommended to use the GA API (classes and functions in this\n"
+        "file not marked beta) for all further purposes. This class was "
+        "generated\n"
+        "only to ease transition from grpcio<0.15.0 to "
+        "grpcio>=0.15.0.\"\"\"\n");
     PrintAllComments(service, out);
     for (int i = 0; i < service->method_count(); ++i) {
       auto meth = service->method(i);
@@ -256,6 +263,13 @@ bool PrintBetaStub(const ServiceDescriptor* service, Printer* out) {
   out->Print("class Beta$Service$Stub(object):\n", "Service", service->name());
   {
     IndentScope raii_class_indent(out);
+    out->Print(
+        "\"\"\"The Beta API is deprecated for 0.15.0 and later.\n"
+        "\nIt is recommended to use the GA API (classes and functions in this\n"
+        "file not marked beta) for all further purposes. This class was "
+        "generated\n"
+        "only to ease transition from grpcio<0.15.0 to "
+        "grpcio>=0.15.0.\"\"\"\n");
     PrintAllComments(service, out);
     for (int i = 0; i < service->method_count(); ++i) {
       const MethodDescriptor* meth = service->method(i);
@@ -287,6 +301,12 @@ bool PrintBetaServerFactory(const grpc::string& package_qualified_service_name,
       "Service", service->name());
   {
     IndentScope raii_create_server_indent(out);
+    out->Print(
+        "\"\"\"The Beta API is deprecated for 0.15.0 and later.\n"
+        "\nIt is recommended to use the GA API (classes and functions in this\n"
+        "file not marked beta) for all further purposes. This function was\n"
+        "generated only to ease transition from grpcio<0.15.0 to grpcio>=0.15.0"
+        "\"\"\"\n");
     map<grpc::string, grpc::string> method_implementation_constructors;
     map<grpc::string, grpc::string> input_message_modules_and_classes;
     map<grpc::string, grpc::string> output_message_modules_and_classes;
@@ -386,6 +406,12 @@ bool PrintBetaStubFactory(const grpc::string& package_qualified_service_name,
              " metadata_transformer=None, pool=None, pool_size=None):\n");
   {
     IndentScope raii_create_server_indent(out);
+    out->Print(
+        "\"\"\"The Beta API is deprecated for 0.15.0 and later.\n"
+        "\nIt is recommended to use the GA API (classes and functions in this\n"
+        "file not marked beta) for all further purposes. This function was\n"
+        "generated only to ease transition from grpcio<0.15.0 to grpcio>=0.15.0"
+        "\"\"\"\n");
     map<grpc::string, grpc::string> method_cardinalities;
     map<grpc::string, grpc::string> input_message_modules_and_classes;
     map<grpc::string, grpc::string> output_message_modules_and_classes;
diff --git a/src/core/ext/client_config/subchannel.c b/src/core/ext/client_config/subchannel.c
index f2b860807f..0bbaa3e382 100644
--- a/src/core/ext/client_config/subchannel.c
+++ b/src/core/ext/client_config/subchannel.c
@@ -332,36 +332,40 @@ grpc_subchannel *grpc_subchannel_create(grpc_exec_ctx *exec_ctx,
   grpc_closure_init(&c->connected, subchannel_connected, c);
   grpc_connectivity_state_init(&c->state_tracker, GRPC_CHANNEL_IDLE,
                                "subchannel");
-  gpr_backoff_init(&c->backoff_state,
-                   GRPC_SUBCHANNEL_RECONNECT_BACKOFF_MULTIPLIER,
-                   GRPC_SUBCHANNEL_RECONNECT_JITTER,
-                   GRPC_SUBCHANNEL_INITIAL_CONNECT_BACKOFF_SECONDS * 1000,
-                   GRPC_SUBCHANNEL_RECONNECT_MAX_BACKOFF_SECONDS * 1000);
+  int initial_backoff_ms =
+      GRPC_SUBCHANNEL_INITIAL_CONNECT_BACKOFF_SECONDS * 1000;
+  int max_backoff_ms = GRPC_SUBCHANNEL_RECONNECT_MAX_BACKOFF_SECONDS * 1000;
+  bool fixed_reconnect_backoff = false;
   if (c->args) {
     for (size_t i = 0; i < c->args->num_args; i++) {
       if (0 == strcmp(c->args->args[i].key,
                       "grpc.testing.fixed_reconnect_backoff")) {
         GPR_ASSERT(c->args->args[i].type == GRPC_ARG_INTEGER);
-        gpr_backoff_init(&c->backoff_state, 1.0, 0.0,
-                         c->args->args[i].value.integer,
-                         c->args->args[i].value.integer);
-      }
-      if (0 ==
-          strcmp(c->args->args[i].key, GRPC_ARG_MAX_RECONNECT_BACKOFF_MS)) {
-        const grpc_integer_options options = {-1, 0, INT_MAX};
-        const int value =
-            grpc_channel_arg_get_integer(&c->args->args[i], options);
-        if (value >= 0) {
-          gpr_backoff_init(
-              &c->backoff_state, GRPC_SUBCHANNEL_RECONNECT_BACKOFF_MULTIPLIER,
-              GRPC_SUBCHANNEL_RECONNECT_JITTER,
-              GPR_MIN(value,
-                      GRPC_SUBCHANNEL_INITIAL_CONNECT_BACKOFF_SECONDS * 1000),
-              value);
-        }
+        fixed_reconnect_backoff = true;
+        initial_backoff_ms = max_backoff_ms = grpc_channel_arg_get_integer(
+            &c->args->args[i],
+            (grpc_integer_options){initial_backoff_ms, 100, INT_MAX});
+      } else if (0 == strcmp(c->args->args[i].key,
+                             GRPC_ARG_MAX_RECONNECT_BACKOFF_MS)) {
+        fixed_reconnect_backoff = false;
+        max_backoff_ms = grpc_channel_arg_get_integer(
+            &c->args->args[i],
+            (grpc_integer_options){max_backoff_ms, 100, INT_MAX});
+      } else if (0 == strcmp(c->args->args[i].key,
+                             GRPC_ARG_INITIAL_RECONNECT_BACKOFF_MS)) {
+        fixed_reconnect_backoff = false;
+        initial_backoff_ms = grpc_channel_arg_get_integer(
+            &c->args->args[i],
+            (grpc_integer_options){initial_backoff_ms, 100, INT_MAX});
       }
     }
   }
+  gpr_backoff_init(
+      &c->backoff_state,
+      fixed_reconnect_backoff ? 1.0
+                              : GRPC_SUBCHANNEL_RECONNECT_BACKOFF_MULTIPLIER,
+      fixed_reconnect_backoff ? 0.0 : GRPC_SUBCHANNEL_RECONNECT_JITTER,
+      initial_backoff_ms, max_backoff_ms);
   gpr_mu_init(&c->mu);
 
   return grpc_subchannel_index_register(exec_ctx, key, c);
diff --git a/src/core/ext/transport/chttp2/server/insecure/server_chttp2_posix.c b/src/core/ext/transport/chttp2/server/insecure/server_chttp2_posix.c
index 4350543c27..9af17fb5ae 100644
--- a/src/core/ext/transport/chttp2/server/insecure/server_chttp2_posix.c
+++ b/src/core/ext/transport/chttp2/server/insecure/server_chttp2_posix.c
@@ -50,10 +50,10 @@
 #include "src/core/lib/surface/server.h"
 
 void grpc_server_add_insecure_channel_from_fd(grpc_server *server,
-                                              grpc_completion_queue *cq,
-                                              int fd) {
-  grpc_exec_ctx exec_ctx = GRPC_EXEC_CTX_INIT;
+                                              void *reserved, int fd) {
+  GPR_ASSERT(reserved == NULL);
 
+  grpc_exec_ctx exec_ctx = GRPC_EXEC_CTX_INIT;
   char *name;
   gpr_asprintf(&name, "fd:%d", fd);
 
@@ -65,7 +65,15 @@ void grpc_server_add_insecure_channel_from_fd(grpc_server *server,
   const grpc_channel_args *server_args = grpc_server_get_channel_args(server);
   grpc_transport *transport = grpc_create_chttp2_transport(
       &exec_ctx, server_args, server_endpoint, 0 /* is_client */);
-  grpc_endpoint_add_to_pollset(&exec_ctx, server_endpoint, grpc_cq_pollset(cq));
+
+  grpc_pollset **pollsets;
+  size_t num_pollsets = 0;
+  grpc_server_get_pollsets(server, &pollsets, &num_pollsets);
+
+  for (size_t i = 0; i < num_pollsets; i++) {
+    grpc_endpoint_add_to_pollset(&exec_ctx, server_endpoint, pollsets[i]);
+  }
+
   grpc_server_setup_transport(&exec_ctx, server, transport, NULL, server_args);
   grpc_chttp2_transport_start_reading(&exec_ctx, transport, NULL);
   grpc_exec_ctx_finish(&exec_ctx);
@@ -74,8 +82,7 @@ void grpc_server_add_insecure_channel_from_fd(grpc_server *server,
 #else  // !GPR_SUPPORT_CHANNELS_FROM_FD
 
 void grpc_server_add_insecure_channel_from_fd(grpc_server *server,
-                                              grpc_completion_queue *cq,
-                                              int fd) {
+                                              void *reserved, int fd) {
   GPR_ASSERT(0);
 }
 
diff --git a/src/core/lib/iomgr/ev_epoll_linux.c b/src/core/lib/iomgr/ev_epoll_linux.c
index 740920d760..ab77ebc78b 100644
--- a/src/core/lib/iomgr/ev_epoll_linux.c
+++ b/src/core/lib/iomgr/ev_epoll_linux.c
@@ -1897,7 +1897,7 @@ const grpc_event_engine_vtable *grpc_init_epoll_linux(void) {
   }
 
   if (!is_grpc_wakeup_signal_initialized) {
-    grpc_use_signal(SIGRTMIN + 2);
+    grpc_use_signal(SIGRTMIN + 6);
   }
 
   fd_global_init();
diff --git a/src/core/lib/iomgr/tcp_windows.c b/src/core/lib/iomgr/tcp_windows.c
index 35054c42b5..448a72671c 100644
--- a/src/core/lib/iomgr/tcp_windows.c
+++ b/src/core/lib/iomgr/tcp_windows.c
@@ -319,6 +319,7 @@ static void win_write(grpc_exec_ctx *exec_ctx, grpc_endpoint *ep,
                             ? GRPC_ERROR_NONE
                             : GRPC_WSA_ERROR(info->wsa_error, "WSASend");
     grpc_exec_ctx_sched(exec_ctx, cb, error, NULL);
+    if (allocated) gpr_free(allocated);
     return;
   }
 
diff --git a/src/core/lib/surface/server.c b/src/core/lib/surface/server.c
index 56fb80e92e..7300d79b9f 100644
--- a/src/core/lib/surface/server.c
+++ b/src/core/lib/surface/server.c
@@ -1106,6 +1106,12 @@ void grpc_server_start(grpc_server *server) {
   grpc_exec_ctx_finish(&exec_ctx);
 }
 
+void grpc_server_get_pollsets(grpc_server *server, grpc_pollset ***pollsets,
+                              size_t *pollset_count) {
+  *pollset_count = server->cq_count;
+  *pollsets = server->pollsets;
+}
+
 void grpc_server_setup_transport(grpc_exec_ctx *exec_ctx, grpc_server *s,
                                  grpc_transport *transport,
                                  grpc_pollset *accepting_pollset,
diff --git a/src/core/lib/surface/server.h b/src/core/lib/surface/server.h
index fb6e4d60c5..551a40a4ff 100644
--- a/src/core/lib/surface/server.h
+++ b/src/core/lib/surface/server.h
@@ -60,4 +60,9 @@ const grpc_channel_args *grpc_server_get_channel_args(grpc_server *server);
 
 int grpc_server_has_open_connections(grpc_server *server);
 
+/* Do not call this before grpc_server_start. Returns the pollsets and the
+ * number of pollsets via 'pollsets' and 'pollset_count'. */
+void grpc_server_get_pollsets(grpc_server *server, grpc_pollset ***pollsets,
+                              size_t *pollset_count);
+
 #endif /* GRPC_CORE_LIB_SURFACE_SERVER_H */
diff --git a/src/cpp/client/create_channel_posix.cc b/src/cpp/client/create_channel_posix.cc
index 60cfed3d62..eb323ac50b 100644
--- a/src/cpp/client/create_channel_posix.cc
+++ b/src/cpp/client/create_channel_posix.cc
@@ -51,6 +51,16 @@ std::shared_ptr<Channel> CreateInsecureChannelFromFd(const grpc::string& target,
       "", grpc_insecure_channel_create_from_fd(target.c_str(), fd, nullptr));
 }
 
+std::shared_ptr<Channel> CreateCustomInsecureChannelFromFd(
+    const grpc::string& target, int fd, const ChannelArguments& args) {
+  internal::GrpcLibrary init_lib;
+  init_lib.init();
+  grpc_channel_args channel_args;
+  args.SetChannelArgs(&channel_args);
+  return CreateChannelInternal("", grpc_insecure_channel_create_from_fd(
+                                       target.c_str(), fd, &channel_args));
+}
+
 #endif  // GPR_SUPPORT_CHANNELS_FROM_FD
 
 }  // namespace grpc
diff --git a/src/cpp/server/server_cc.cc b/src/cpp/server/server_cc.cc
index a693ce9b8e..3f89275370 100644
--- a/src/cpp/server/server_cc.cc
+++ b/src/cpp/server/server_cc.cc
@@ -332,8 +332,6 @@ void Server::SetGlobalCallbacks(GlobalCallbacks* callbacks) {
 
 grpc_server* Server::c_server() { return server_; }
 
-CompletionQueue* Server::completion_queue() { return &cq_; }
-
 static grpc_server_register_method_payload_handling PayloadHandlingForMethod(
     RpcServiceMethod* method) {
   switch (method->method_type()) {
diff --git a/src/cpp/server/server_posix.cc b/src/cpp/server/server_posix.cc
index c3aa2adc60..33d42a8dc7 100644
--- a/src/cpp/server/server_posix.cc
+++ b/src/cpp/server/server_posix.cc
@@ -40,8 +40,7 @@ namespace grpc {
 #ifdef GPR_SUPPORT_CHANNELS_FROM_FD
 
 void AddInsecureChannelFromFd(Server* server, int fd) {
-  grpc_server_add_insecure_channel_from_fd(
-      server->c_server(), server->completion_queue()->cq(), fd);
+  grpc_server_add_insecure_channel_from_fd(server->c_server(), NULL, fd);
 }
 
 #endif  // GPR_SUPPORT_CHANNELS_FROM_FD
diff --git a/src/csharp/Grpc.Core/Internal/PlatformApis.cs b/src/csharp/Grpc.Core/Internal/PlatformApis.cs
index 15391ddc64..406204e0a7 100644
--- a/src/csharp/Grpc.Core/Internal/PlatformApis.cs
+++ b/src/csharp/Grpc.Core/Internal/PlatformApis.cs
@@ -50,6 +50,7 @@ namespace Grpc.Core.Internal
         static readonly bool isMacOSX;
         static readonly bool isWindows;
         static readonly bool isMono;
+        static readonly bool isNetCore;
 
         static PlatformApis()
         {
@@ -57,6 +58,7 @@ namespace Grpc.Core.Internal
             isLinux = RuntimeInformation.IsOSPlatform(OSPlatform.Linux);
             isMacOSX = RuntimeInformation.IsOSPlatform(OSPlatform.OSX);
             isWindows = RuntimeInformation.IsOSPlatform(OSPlatform.Windows);
+            isNetCore = RuntimeInformation.FrameworkDescription.StartsWith(".NET Core");
 #else
             var platform = Environment.OSVersion.Platform;
 
@@ -64,6 +66,7 @@ namespace Grpc.Core.Internal
             isMacOSX = (platform == PlatformID.Unix && GetUname() == "Darwin");
             isLinux = (platform == PlatformID.Unix && !isMacOSX);
             isWindows = (platform == PlatformID.Win32NT || platform == PlatformID.Win32S || platform == PlatformID.Win32Windows);
+            isNetCore = false;
 #endif
             isMono = Type.GetType("Mono.Runtime") != null;
         }
@@ -88,6 +91,14 @@ namespace Grpc.Core.Internal
             get { return isMono; }
         }
 
+        /// <summary>
+        /// true if running on .NET Core (CoreCLR), false otherwise.
+        /// </summary>
+        public static bool IsNetCore
+        {
+            get { return isNetCore; }
+        }
+
         public static bool Is64Bit
         {
             get { return IntPtr.Size == 8; }
diff --git a/src/csharp/Grpc.Core/Internal/UnmanagedLibrary.cs b/src/csharp/Grpc.Core/Internal/UnmanagedLibrary.cs
index dc629bd714..31e1402849 100644
--- a/src/csharp/Grpc.Core/Internal/UnmanagedLibrary.cs
+++ b/src/csharp/Grpc.Core/Internal/UnmanagedLibrary.cs
@@ -44,10 +44,9 @@ namespace Grpc.Core.Internal
 {
     /// <summary>
     /// Represents a dynamically loaded unmanaged library in a (partially) platform independent manner.
-    /// An important difference in library loading semantics is that on Windows, once we load a dynamic library using LoadLibrary,
-    /// that library becomes instantly available for <c>DllImport</c> P/Invoke calls referring to the same library name.
-    /// On Unix systems, dlopen has somewhat different semantics, so we need to use dlsym and <c>Marshal.GetDelegateForFunctionPointer</c>
-    /// to obtain delegates to native methods.
+    /// First, the native library is loaded using dlopen (on Unix systems) or using LoadLibrary (on Windows).
+    /// dlsym or GetProcAddress are then used to obtain symbol addresses. <c>Marshal.GetDelegateForFunctionPointer</c>
+    /// transforms the addresses into delegates to native methods.
     /// See http://stackoverflow.com/questions/13461989/p-invoke-to-dynamically-loaded-library-on-mono.
     /// </summary>
     internal class UnmanagedLibrary
@@ -114,6 +113,10 @@ namespace Grpc.Core.Internal
                 {
                     return Mono.dlsym(this.handle, symbolName);
                 }
+                if (PlatformApis.IsNetCore)
+                {
+                    return CoreCLR.dlsym(this.handle, symbolName);
+                }
                 return Linux.dlsym(this.handle, symbolName);
             }
             if (PlatformApis.IsMacOSX)
@@ -149,6 +152,10 @@ namespace Grpc.Core.Internal
                 {
                     return Mono.dlopen(libraryPath, RTLD_GLOBAL + RTLD_LAZY);
                 }
+                if (PlatformApis.IsNetCore)
+                {
+                    return CoreCLR.dlopen(libraryPath, RTLD_GLOBAL + RTLD_LAZY);
+                }
                 return Linux.dlopen(libraryPath, RTLD_GLOBAL + RTLD_LAZY);
             }
             if (PlatformApis.IsMacOSX)
@@ -215,5 +222,19 @@ namespace Grpc.Core.Internal
             [DllImport("__Internal")]
             internal static extern IntPtr dlsym(IntPtr handle, string symbol);
         }
+
+        /// <summary>
+        /// Similarly as for Mono on Linux, we load symbols for
+        /// dlopen and dlsym from the "libcoreclr.so",
+        /// to avoid the dependency on libc-dev Linux.
+        /// </summary>
+        private static class CoreCLR
+        {
+            [DllImport("libcoreclr.so")]
+            internal static extern IntPtr dlopen(string filename, int flags);
+
+            [DllImport("libcoreclr.so")]
+            internal static extern IntPtr dlsym(IntPtr handle, string symbol);
+        }
     }
 }
diff --git a/src/objective-c/GRPCClient/private/GRPCHost.m b/src/objective-c/GRPCClient/private/GRPCHost.m
index 1159aac7a7..f8634b448e 100644
--- a/src/objective-c/GRPCClient/private/GRPCHost.m
+++ b/src/objective-c/GRPCClient/private/GRPCHost.m
@@ -219,6 +219,8 @@ static NSMutableDictionary *kHostCache;
   if (_responseSizeLimitOverride) {
     args[@GRPC_ARG_MAX_RECEIVE_MESSAGE_LENGTH] = _responseSizeLimitOverride;
   }
+  // Use 10000ms initial backoff time for correct behavior on bad/slow networks  
+  args[@GRPC_ARG_INITIAL_RECONNECT_BACKOFF_MS] = @10000;
   return args;
 }
 
diff --git a/src/python/grpcio/grpc/__init__.py b/src/python/grpcio/grpc/__init__.py
index b9b662c032..526bd9e14f 100644
--- a/src/python/grpcio/grpc/__init__.py
+++ b/src/python/grpcio/grpc/__init__.py
@@ -649,6 +649,10 @@ class Channel(six.with_metaclass(abc.ABCMeta)):
 
     Args:
       method: The name of the RPC method.
+      request_serializer: Optional behaviour for serializing the request
+        message. Request goes unserialized in case None is passed.
+      response_deserializer: Optional behaviour for deserializing the response
+        message. Response goes undeserialized in case None is passed.
 
     Returns:
       A UnaryUnaryMultiCallable value for the named unary-unary method.
@@ -662,6 +666,10 @@ class Channel(six.with_metaclass(abc.ABCMeta)):
 
     Args:
       method: The name of the RPC method.
+      request_serializer: Optional behaviour for serializing the request
+        message. Request goes unserialized in case None is passed.
+      response_deserializer: Optional behaviour for deserializing the response
+        message. Response goes undeserialized in case None is passed.
 
     Returns:
       A UnaryStreamMultiCallable value for the name unary-stream method.
@@ -675,6 +683,10 @@ class Channel(six.with_metaclass(abc.ABCMeta)):
 
     Args:
       method: The name of the RPC method.
+      request_serializer: Optional behaviour for serializing the request
+        message. Request goes unserialized in case None is passed.
+      response_deserializer: Optional behaviour for deserializing the response
+        message. Response goes undeserialized in case None is passed.
 
     Returns:
       A StreamUnaryMultiCallable value for the named stream-unary method.
@@ -688,6 +700,10 @@ class Channel(six.with_metaclass(abc.ABCMeta)):
 
     Args:
       method: The name of the RPC method.
+      request_serializer: Optional behaviour for serializing the request
+        message. Request goes unserialized in case None is passed.
+      response_deserializer: Optional behaviour for deserializing the response
+        message. Response goes undeserialized in case None is passed.
 
     Returns:
       A StreamStreamMultiCallable value for the named stream-stream method.
diff --git a/src/ruby/ext/grpc/rb_grpc_imports.generated.h b/src/ruby/ext/grpc/rb_grpc_imports.generated.h
index b87abfd8ef..00a67b0b2c 100644
--- a/src/ruby/ext/grpc/rb_grpc_imports.generated.h
+++ b/src/ruby/ext/grpc/rb_grpc_imports.generated.h
@@ -350,7 +350,7 @@ extern grpc_call_error_to_string_type grpc_call_error_to_string_import;
 typedef grpc_channel *(*grpc_insecure_channel_create_from_fd_type)(const char *target, int fd, const grpc_channel_args *args);
 extern grpc_insecure_channel_create_from_fd_type grpc_insecure_channel_create_from_fd_import;
 #define grpc_insecure_channel_create_from_fd grpc_insecure_channel_create_from_fd_import
-typedef void(*grpc_server_add_insecure_channel_from_fd_type)(grpc_server *server, grpc_completion_queue *cq, int fd);
+typedef void(*grpc_server_add_insecure_channel_from_fd_type)(grpc_server *server, void *reserved, int fd);
 extern grpc_server_add_insecure_channel_from_fd_type grpc_server_add_insecure_channel_from_fd_import;
 #define grpc_server_add_insecure_channel_from_fd grpc_server_add_insecure_channel_from_fd_import
 typedef void(*grpc_use_signal_type)(int signum);
diff --git a/src/ruby/lib/grpc/generic/active_call.rb b/src/ruby/lib/grpc/generic/active_call.rb
index 23688dc924..dfc2644c46 100644
--- a/src/ruby/lib/grpc/generic/active_call.rb
+++ b/src/ruby/lib/grpc/generic/active_call.rb
@@ -240,11 +240,8 @@ module GRPC
         @call.metadata = batch_result.metadata
         @metadata_received = true
       end
-      GRPC.logger.debug("received req: #{batch_result}")
       unless batch_result.nil? || batch_result.message.nil?
-        GRPC.logger.debug("received req.to_s: #{batch_result.message}")
         res = @unmarshal.call(batch_result.message)
-        GRPC.logger.debug("received_req (unmarshalled): #{res.inspect}")
         return res
       end
       GRPC.logger.debug('found nil; the final response has been sent')
diff --git a/src/ruby/lib/grpc/generic/rpc_server.rb b/src/ruby/lib/grpc/generic/rpc_server.rb
index da0f6503db..7dbcb7d479 100644
--- a/src/ruby/lib/grpc/generic/rpc_server.rb
+++ b/src/ruby/lib/grpc/generic/rpc_server.rb
@@ -304,7 +304,6 @@ module GRPC
 
       # allow the metadata to be accessed from the call
       an_rpc.call.metadata = an_rpc.metadata  # attaches md to call for handlers
-      GRPC.logger.debug("call md is #{an_rpc.metadata}")
       connect_md = nil
       unless @connect_md_proc.nil?
         connect_md = @connect_md_proc.call(an_rpc.method, an_rpc.metadata)
diff --git a/src/ruby/pb/test/server.rb b/src/ruby/pb/test/server.rb
index 0808121661..3f1e0a1ccf 100755
--- a/src/ruby/pb/test/server.rb
+++ b/src/ruby/pb/test/server.rb
@@ -129,27 +129,36 @@ def nulls(l)
   [].pack('x' * l).force_encoding('ascii-8bit')
 end
 
-# A EnumeratorQueue wraps a Queue yielding the items added to it via each_item.
-class EnumeratorQueue
-  extend Forwardable
-  def_delegators :@q, :push
-
-  def initialize(sentinel)
-    @q = Queue.new
-    @sentinel = sentinel
-  end
+# A FullDuplexEnumerator passes requests to a block and yields generated responses
+class FullDuplexEnumerator
+  include Grpc::Testing
+  include Grpc::Testing::PayloadType
 
+  def initialize(requests)
+    @requests = requests
+  end
   def each_item
     return enum_for(:each_item) unless block_given?
-    loop do
-      r = @q.pop
-      break if r.equal?(@sentinel)
-      fail r if r.is_a? Exception
-      yield r
+    GRPC.logger.info('interop-server: started receiving')
+    begin
+      cls = StreamingOutputCallResponse
+      @requests.each do |req|
+        req.response_parameters.each do |params|
+          resp_size = params.size
+          GRPC.logger.info("read a req, response size is #{resp_size}")
+          yield cls.new(payload: Payload.new(type: req.response_type,
+                                              body: nulls(resp_size)))
+        end
+      end
+      GRPC.logger.info('interop-server: finished receiving')
+    rescue StandardError => e
+      GRPC.logger.info('interop-server: failed')
+      GRPC.logger.warn(e)
+      fail e
     end
   end
 end
-
+    
 # A runnable implementation of the schema-specified testing service, with each
 # service method implemented as required by the interop testing spec.
 class TestTarget < Grpc::Testing::TestService::Service
@@ -182,31 +191,9 @@ class TestTarget < Grpc::Testing::TestService::Service
 
   def full_duplex_call(reqs)
     # reqs is a lazy Enumerator of the requests sent by the client.
-    q = EnumeratorQueue.new(self)
-    cls = StreamingOutputCallResponse
-    Thread.new do
-      begin
-        GRPC.logger.info('interop-server: started receiving')
-        reqs.each do |req|
-          req.response_parameters.each do |params|
-            resp_size = params.size
-            GRPC.logger.info("read a req, response size is #{resp_size}")
-            resp = cls.new(payload: Payload.new(type: req.response_type,
-                                                body: nulls(resp_size)))
-            q.push(resp)
-          end
-        end
-        GRPC.logger.info('interop-server: finished receiving')
-        q.push(self)
-      rescue StandardError => e
-        GRPC.logger.info('interop-server: failed')
-        GRPC.logger.warn(e)
-        q.push(e)  # share the exception with the enumerator
-      end
-    end
-    q.each_item
+    FullDuplexEnumerator.new(reqs).each_item
   end
-
+        
   def half_duplex_call(reqs)
     # TODO: update with unique behaviour of the half_duplex_call if that's
     # ever required by any of the tests.
diff --git a/src/ruby/qps/client.rb b/src/ruby/qps/client.rb
index 7ed648acef..8aed866da5 100644
--- a/src/ruby/qps/client.rb
+++ b/src/ruby/qps/client.rb
@@ -89,12 +89,14 @@ class BenchmarkClient
                    payload: gtp.new(type: gtpt::COMPRESSABLE,
                                     body: nulls(simple_params.req_size)))
 
+    @child_threads = []
+
     (0..config.client_channels-1).each do |chan|
       gtbss = Grpc::Testing::BenchmarkService::Stub
       st = config.server_targets
       stub = gtbss.new(st[chan % st.length], cred, **opts)
       (0..config.outstanding_rpcs_per_channel-1).each do |r|
-        Thread.new {
+        @child_threads << Thread.new {
           case config.load_params.load.to_s
           when 'closed_loop'
             waiter = nil
@@ -162,5 +164,8 @@ class BenchmarkClient
   end
   def shutdown
     @done = true
+    @child_threads.each do |thread|
+      thread.join
+    end
   end
 end
diff --git a/src/ruby/qps/qps-common.rb b/src/ruby/qps/qps-common.rb
index 4119d600b1..4714ccfdb7 100644
--- a/src/ruby/qps/qps-common.rb
+++ b/src/ruby/qps/qps-common.rb
@@ -52,6 +52,7 @@ def load_test_certs
   files.map { |f| File.open(File.join(data_dir, f)).read }
 end
 
+
 # A EnumeratorQueue wraps a Queue yielding the items added to it via each_item.
 class EnumeratorQueue
   extend Forwardable
@@ -73,4 +74,19 @@ class EnumeratorQueue
   end
 end
 
+# A PingPongEnumerator reads requests and responds one-by-one when enumerated
+# via #each_item
+class PingPongEnumerator
+  def initialize(reqs)
+    @reqs = reqs
+  end
 
+  def each_item
+    return enum_for(:each_item) unless block_given?
+    sr = Grpc::Testing::SimpleResponse
+    pl = Grpc::Testing::Payload
+    @reqs.each do |req|
+      yield sr.new(payload: pl.new(body: nulls(req.response_size)))
+    end
+  end
+end
diff --git a/src/ruby/qps/server.rb b/src/ruby/qps/server.rb
index cd98ee1fd9..d0c2073dd1 100644
--- a/src/ruby/qps/server.rb
+++ b/src/ruby/qps/server.rb
@@ -49,16 +49,7 @@ class BenchmarkServiceImpl < Grpc::Testing::BenchmarkService::Service
     sr.new(payload: pl.new(body: nulls(req.response_size)))
   end
   def streaming_call(reqs)
-    q = EnumeratorQueue.new(self)
-    Thread.new {
-      sr = Grpc::Testing::SimpleResponse
-      pl = Grpc::Testing::Payload
-      reqs.each do |req|
-        q.push(sr.new(payload: pl.new(body: nulls(req.response_size))))
-      end
-      q.push(self)
-    }
-    q.each_item
+    PingPongEnumerator.new(reqs).each_item
   end
 end
 
@@ -71,7 +62,8 @@ class BenchmarkServer
     else
       cred = :this_port_is_insecure
     end
-    @server = GRPC::RpcServer.new
+    # Make sure server can handle the large number of calls in benchmarks
+    @server = GRPC::RpcServer.new(pool_size: 100, max_waiting_requests: 100)
     @port = @server.add_http2_port("0.0.0.0:" + port.to_s, cred)
     @server.handle(BenchmarkServiceImpl.new)
     @start_time = Time.now
diff --git a/src/ruby/qps/worker.rb b/src/ruby/qps/worker.rb
index 12b8087ca0..61a0b723a3 100755
--- a/src/ruby/qps/worker.rb
+++ b/src/ruby/qps/worker.rb
@@ -64,8 +64,8 @@ class WorkerServiceImpl < Grpc::Testing::WorkerService::Service
           q.push(gtss.new(stats: bms.mark(req.mark.reset), cores: cpu_cores))
         end
       end
-      q.push(self)
       bms.stop
+      q.push(self)
     }
     q.each_item
   end
@@ -83,8 +83,8 @@ class WorkerServiceImpl < Grpc::Testing::WorkerService::Service
                                                    client.mark(req.mark.reset)))
         end
       end
-      q.push(self)
       client.shutdown
+      q.push(self)
     }
     q.each_item
   end
@@ -118,6 +118,10 @@ def main
       options['server_port'] = v
     end
   end.parse!
+
+  # Configure any errors with client or server child threads to surface
+  Thread.abort_on_exception = true
+  
   s = GRPC::RpcServer.new
   s.add_http2_port("0.0.0.0:" + options['driver_port'].to_s,
                    :this_port_is_insecure)