58 files changed, 402 insertions, 234 deletions

diff --git a/src/core/ext/client_config/README.md b/src/core/ext/client_channel/README.md
index eda01e3e71..eda01e3e71 100644
--- a/src/core/ext/client_config/README.md
+++ b/src/core/ext/client_channel/README.md
diff --git a/src/core/ext/client_config/channel_connectivity.c b/src/core/ext/client_channel/channel_connectivity.c
index ce3c13a4ee..9797e66564 100644
--- a/src/core/ext/client_config/channel_connectivity.c
+++ b/src/core/ext/client_channel/channel_connectivity.c
@@ -36,7 +36,7 @@
 #include <grpc/support/alloc.h>
 #include <grpc/support/log.h>
 
-#include "src/core/ext/client_config/client_channel.h"
+#include "src/core/ext/client_channel/client_channel.h"
 #include "src/core/lib/iomgr/timer.h"
 #include "src/core/lib/surface/api_trace.h"
 #include "src/core/lib/surface/completion_queue.h"
diff --git a/src/core/ext/client_config/client_channel.c b/src/core/ext/client_channel/client_channel.c
index beaa9637c3..55bb877576 100644
--- a/src/core/ext/client_config/client_channel.c
+++ b/src/core/ext/client_channel/client_channel.c
@@ -31,7 +31,7 @@
  *
  */
 
-#include "src/core/ext/client_config/client_channel.h"
+#include "src/core/ext/client_channel/client_channel.h"
 
 #include <stdbool.h>
 #include <stdio.h>
@@ -42,9 +42,9 @@
 #include <grpc/support/sync.h>
 #include <grpc/support/useful.h>
 
-#include "src/core/ext/client_config/lb_policy_registry.h"
-#include "src/core/ext/client_config/method_config.h"
-#include "src/core/ext/client_config/subchannel.h"
+#include "src/core/ext/client_channel/lb_policy_registry.h"
+#include "src/core/ext/client_channel/method_config.h"
+#include "src/core/ext/client_channel/subchannel.h"
 #include "src/core/lib/channel/channel_args.h"
 #include "src/core/lib/channel/connected_channel.h"
 #include "src/core/lib/channel/deadline_filter.h"
@@ -61,6 +61,54 @@
 /* Client channel implementation */
 
 /*************************************************************************
+ * METHOD-CONFIG TABLE
+ */
+
+typedef enum {
+  WAIT_FOR_READY_UNSET,
+  WAIT_FOR_READY_FALSE,
+  WAIT_FOR_READY_TRUE
+} wait_for_ready_value;
+
+typedef struct method_parameters {
+  gpr_timespec timeout;
+  wait_for_ready_value wait_for_ready;
+} method_parameters;
+
+static void *method_parameters_copy(void *value) {
+  void *new_value = gpr_malloc(sizeof(method_parameters));
+  memcpy(new_value, value, sizeof(method_parameters));
+  return new_value;
+}
+
+static int method_parameters_cmp(void *value1, void *value2) {
+  const method_parameters *v1 = value1;
+  const method_parameters *v2 = value2;
+  const int retval = gpr_time_cmp(v1->timeout, v2->timeout);
+  if (retval != 0) return retval;
+  if (v1->wait_for_ready > v2->wait_for_ready) return 1;
+  if (v1->wait_for_ready < v2->wait_for_ready) return -1;
+  return 0;
+}
+
+static const grpc_mdstr_hash_table_vtable method_parameters_vtable = {
+    gpr_free, method_parameters_copy, method_parameters_cmp};
+
+static void *method_config_convert_value(
+    const grpc_method_config *method_config) {
+  method_parameters *value = gpr_malloc(sizeof(method_parameters));
+  const gpr_timespec *timeout = grpc_method_config_get_timeout(method_config);
+  value->timeout = timeout != NULL ? *timeout : gpr_time_0(GPR_TIMESPAN);
+  const bool *wait_for_ready =
+      grpc_method_config_get_wait_for_ready(method_config);
+  value->wait_for_ready =
+      wait_for_ready == NULL
+          ? WAIT_FOR_READY_UNSET
+          : (wait_for_ready ? WAIT_FOR_READY_TRUE : WAIT_FOR_READY_FALSE);
+  return value;
+}
+
+/*************************************************************************
  * CHANNEL-WIDE FUNCTIONS
  */
 
@@ -76,8 +124,8 @@ typedef struct client_channel_channel_data {
   gpr_mu mu;
   /** currently active load balancer */
   grpc_lb_policy *lb_policy;
-  /** method config table */
-  grpc_method_config_table *method_config_table;
+  /** maps method names to method_parameters structs */
+  grpc_mdstr_hash_table *method_params_table;
   /** incoming resolver result - set by resolver.next() */
   grpc_resolver_result *resolver_result;
   /** a list of closures that are all waiting for config to come in */
@@ -177,7 +225,7 @@ static void on_resolver_result_changed(grpc_exec_ctx *exec_ctx, void *arg,
   channel_data *chand = arg;
   grpc_lb_policy *lb_policy = NULL;
   grpc_lb_policy *old_lb_policy;
-  grpc_method_config_table *method_config_table = NULL;
+  grpc_mdstr_hash_table *method_params_table = NULL;
   grpc_connectivity_state state = GRPC_CHANNEL_TRANSIENT_FAILURE;
   bool exit_idle = false;
   grpc_error *state_error = GRPC_ERROR_CREATE("No load balancing policy");
@@ -230,8 +278,9 @@ static void on_resolver_result_changed(grpc_exec_ctx *exec_ctx, void *arg,
         lb_policy_args.additional_args, GRPC_ARG_SERVICE_CONFIG);
     if (channel_arg != NULL) {
       GPR_ASSERT(channel_arg->type == GRPC_ARG_POINTER);
-      method_config_table = grpc_method_config_table_ref(
-          (grpc_method_config_table *)channel_arg->value.pointer.p);
+      method_params_table = grpc_method_config_table_convert(
+          (grpc_method_config_table *)channel_arg->value.pointer.p,
+          method_config_convert_value, &method_parameters_vtable);
     }
     grpc_resolver_result_unref(exec_ctx, chand->resolver_result);
     chand->resolver_result = NULL;
@@ -245,10 +294,10 @@ static void on_resolver_result_changed(grpc_exec_ctx *exec_ctx, void *arg,
   gpr_mu_lock(&chand->mu);
   old_lb_policy = chand->lb_policy;
   chand->lb_policy = lb_policy;
-  if (chand->method_config_table != NULL) {
-    grpc_method_config_table_unref(chand->method_config_table);
+  if (chand->method_params_table != NULL) {
+    grpc_mdstr_hash_table_unref(chand->method_params_table);
   }
-  chand->method_config_table = method_config_table;
+  chand->method_params_table = method_params_table;
   if (lb_policy != NULL) {
     grpc_exec_ctx_enqueue_list(exec_ctx, &chand->waiting_for_config_closures,
                                NULL);
@@ -409,8 +458,8 @@ static void cc_destroy_channel_elem(grpc_exec_ctx *exec_ctx,
                                      chand->interested_parties);
     GRPC_LB_POLICY_UNREF(exec_ctx, chand->lb_policy, "channel");
   }
-  if (chand->method_config_table != NULL) {
-    grpc_method_config_table_unref(chand->method_config_table);
+  if (chand->method_params_table != NULL) {
+    grpc_mdstr_hash_table_unref(chand->method_params_table);
   }
   grpc_connectivity_state_destroy(exec_ctx, &chand->state_tracker);
   grpc_pollset_set_destroy(chand->interested_parties);
@@ -448,11 +497,7 @@ typedef struct client_channel_call_data {
   grpc_mdstr *path;  // Request path.
   gpr_timespec call_start_time;
   gpr_timespec deadline;
-  enum {
-    WAIT_FOR_READY_UNSET,
-    WAIT_FOR_READY_FALSE,
-    WAIT_FOR_READY_TRUE
-  } wait_for_ready_from_service_config;
+  wait_for_ready_value wait_for_ready_from_service_config;
   grpc_closure read_service_config;
 
   grpc_error *cancel_error;
@@ -846,41 +891,39 @@ static void read_service_config(grpc_exec_ctx *exec_ctx, void *arg,
   if (error == GRPC_ERROR_NONE) {
     // Get the method config table from channel data.
     gpr_mu_lock(&chand->mu);
-    grpc_method_config_table *method_config_table = NULL;
-    if (chand->method_config_table != NULL) {
-      method_config_table =
-          grpc_method_config_table_ref(chand->method_config_table);
+    grpc_mdstr_hash_table *method_params_table = NULL;
+    if (chand->method_params_table != NULL) {
+      method_params_table =
+          grpc_mdstr_hash_table_ref(chand->method_params_table);
     }
     gpr_mu_unlock(&chand->mu);
     // If the method config table was present, use it.
-    if (method_config_table != NULL) {
-      const grpc_method_config *method_config =
-          grpc_method_config_table_get_method_config(method_config_table,
-                                                     calld->path);
-      if (method_config != NULL) {
-        const gpr_timespec *per_method_timeout =
-            grpc_method_config_get_timeout(method_config);
-        const bool *wait_for_ready =
-            grpc_method_config_get_wait_for_ready(method_config);
-        if (per_method_timeout != NULL || wait_for_ready != NULL) {
+    if (method_params_table != NULL) {
+      const method_parameters *method_params =
+          grpc_method_config_table_get(method_params_table, calld->path);
+      if (method_params != NULL) {
+        const bool have_method_timeout =
+            gpr_time_cmp(method_params->timeout, gpr_time_0(GPR_TIMESPAN)) != 0;
+        if (have_method_timeout ||
+            method_params->wait_for_ready != WAIT_FOR_READY_UNSET) {
           gpr_mu_lock(&calld->mu);
-          if (per_method_timeout != NULL) {
-            gpr_timespec per_method_deadline =
-                gpr_time_add(calld->call_start_time, *per_method_timeout);
+          if (have_method_timeout) {
+            const gpr_timespec per_method_deadline =
+                gpr_time_add(calld->call_start_time, method_params->timeout);
             if (gpr_time_cmp(per_method_deadline, calld->deadline) < 0) {
               calld->deadline = per_method_deadline;
               // Reset deadline timer.
               grpc_deadline_state_reset(exec_ctx, elem, calld->deadline);
             }
           }
-          if (wait_for_ready != NULL) {
+          if (method_params->wait_for_ready != WAIT_FOR_READY_UNSET) {
             calld->wait_for_ready_from_service_config =
-                *wait_for_ready ? WAIT_FOR_READY_TRUE : WAIT_FOR_READY_FALSE;
+                method_params->wait_for_ready;
           }
           gpr_mu_unlock(&calld->mu);
         }
       }
-      grpc_method_config_table_unref(method_config_table);
+      grpc_mdstr_hash_table_unref(method_params_table);
     }
   }
   GRPC_CALL_STACK_UNREF(exec_ctx, calld->owning_call, "read_service_config");
@@ -917,29 +960,25 @@ static grpc_error *cc_init_call_elem(grpc_exec_ctx *exec_ctx,
   gpr_mu_lock(&chand->mu);
   if (chand->lb_policy != NULL) {
     // We already have a resolver result, so check for service config.
-    if (chand->method_config_table != NULL) {
-      grpc_method_config_table *method_config_table =
-          grpc_method_config_table_ref(chand->method_config_table);
+    if (chand->method_params_table != NULL) {
+      grpc_mdstr_hash_table *method_params_table =
+          grpc_mdstr_hash_table_ref(chand->method_params_table);
       gpr_mu_unlock(&chand->mu);
-      grpc_method_config *method_config =
-          grpc_method_config_table_get_method_config(method_config_table,
-                                                     args->path);
-      if (method_config != NULL) {
-        const gpr_timespec *per_method_timeout =
-            grpc_method_config_get_timeout(method_config);
-        if (per_method_timeout != NULL) {
+      method_parameters *method_params =
+          grpc_method_config_table_get(method_params_table, args->path);
+      if (method_params != NULL) {
+        if (gpr_time_cmp(method_params->timeout,
+                         gpr_time_0(GPR_CLOCK_MONOTONIC)) != 0) {
           gpr_timespec per_method_deadline =
-              gpr_time_add(calld->call_start_time, *per_method_timeout);
+              gpr_time_add(calld->call_start_time, method_params->timeout);
           calld->deadline = gpr_time_min(calld->deadline, per_method_deadline);
         }
-        const bool *wait_for_ready =
-            grpc_method_config_get_wait_for_ready(method_config);
-        if (wait_for_ready != NULL) {
+        if (method_params->wait_for_ready != WAIT_FOR_READY_UNSET) {
           calld->wait_for_ready_from_service_config =
-              *wait_for_ready ? WAIT_FOR_READY_TRUE : WAIT_FOR_READY_FALSE;
+              method_params->wait_for_ready;
         }
       }
-      grpc_method_config_table_unref(method_config_table);
+      grpc_mdstr_hash_table_unref(method_params_table);
     } else {
       gpr_mu_unlock(&chand->mu);
     }
diff --git a/src/core/ext/client_config/client_channel.h b/src/core/ext/client_channel/client_channel.h
index abb5ac4d87..ab5a84fdfb 100644
--- a/src/core/ext/client_config/client_channel.h
+++ b/src/core/ext/client_channel/client_channel.h
@@ -31,11 +31,11 @@
  *
  */
 
-#ifndef GRPC_CORE_EXT_CLIENT_CONFIG_CLIENT_CHANNEL_H
-#define GRPC_CORE_EXT_CLIENT_CONFIG_CLIENT_CHANNEL_H
+#ifndef GRPC_CORE_EXT_CLIENT_CHANNEL_CLIENT_CHANNEL_H
+#define GRPC_CORE_EXT_CLIENT_CHANNEL_CLIENT_CHANNEL_H
 
-#include "src/core/ext/client_config/client_channel_factory.h"
-#include "src/core/ext/client_config/resolver.h"
+#include "src/core/ext/client_channel/client_channel_factory.h"
+#include "src/core/ext/client_channel/resolver.h"
 #include "src/core/lib/channel/channel_stack.h"
 
 /* A client channel is a channel that begins disconnected, and can connect
@@ -61,4 +61,4 @@ void grpc_client_channel_watch_connectivity_state(
     grpc_exec_ctx *exec_ctx, grpc_channel_element *elem, grpc_pollset *pollset,
     grpc_connectivity_state *state, grpc_closure *on_complete);
 
-#endif /* GRPC_CORE_EXT_CLIENT_CONFIG_CLIENT_CHANNEL_H */
+#endif /* GRPC_CORE_EXT_CLIENT_CHANNEL_CLIENT_CHANNEL_H */
diff --git a/src/core/ext/client_config/client_channel_factory.c b/src/core/ext/client_channel/client_channel_factory.c
index 71c64c0da1..db1cc9093c 100644
--- a/src/core/ext/client_config/client_channel_factory.c
+++ b/src/core/ext/client_channel/client_channel_factory.c
@@ -31,7 +31,7 @@
  *
  */
 
-#include "src/core/ext/client_config/client_channel_factory.h"
+#include "src/core/ext/client_channel/client_channel_factory.h"
 
 void grpc_client_channel_factory_ref(grpc_client_channel_factory* factory) {
   factory->vtable->ref(factory);
diff --git a/src/core/ext/client_config/client_channel_factory.h b/src/core/ext/client_channel/client_channel_factory.h
index 1241b9b781..28828c2eb6 100644
--- a/src/core/ext/client_config/client_channel_factory.h
+++ b/src/core/ext/client_channel/client_channel_factory.h
@@ -31,12 +31,12 @@
  *
  */
 
-#ifndef GRPC_CORE_EXT_CLIENT_CONFIG_CLIENT_CHANNEL_FACTORY_H
-#define GRPC_CORE_EXT_CLIENT_CONFIG_CLIENT_CHANNEL_FACTORY_H
+#ifndef GRPC_CORE_EXT_CLIENT_CHANNEL_CLIENT_CHANNEL_FACTORY_H
+#define GRPC_CORE_EXT_CLIENT_CHANNEL_CLIENT_CHANNEL_FACTORY_H
 
 #include <grpc/impl/codegen/grpc_types.h>
 
-#include "src/core/ext/client_config/subchannel.h"
+#include "src/core/ext/client_channel/subchannel.h"
 #include "src/core/lib/channel/channel_stack.h"
 
 typedef struct grpc_client_channel_factory grpc_client_channel_factory;
@@ -82,4 +82,4 @@ grpc_channel *grpc_client_channel_factory_create_channel(
     grpc_exec_ctx *exec_ctx, grpc_client_channel_factory *factory,
     const char *target, grpc_client_channel_type type, grpc_channel_args *args);
 
-#endif /* GRPC_CORE_EXT_CLIENT_CONFIG_CLIENT_CHANNEL_FACTORY_H */
+#endif /* GRPC_CORE_EXT_CLIENT_CHANNEL_CLIENT_CHANNEL_FACTORY_H */
diff --git a/src/core/ext/client_config/client_config_plugin.c b/src/core/ext/client_channel/client_channel_plugin.c
index dc3629d383..a3e5079843 100644
--- a/src/core/ext/client_config/client_config_plugin.c
+++ b/src/core/ext/client_channel/client_channel_plugin.c
@@ -37,10 +37,10 @@
 
 #include <grpc/support/alloc.h>
 
-#include "src/core/ext/client_config/client_channel.h"
-#include "src/core/ext/client_config/lb_policy_registry.h"
-#include "src/core/ext/client_config/resolver_registry.h"
-#include "src/core/ext/client_config/subchannel_index.h"
+#include "src/core/ext/client_channel/client_channel.h"
+#include "src/core/ext/client_channel/lb_policy_registry.h"
+#include "src/core/ext/client_channel/resolver_registry.h"
+#include "src/core/ext/client_channel/subchannel_index.h"
 #include "src/core/lib/surface/channel_init.h"
 
 static bool append_filter(grpc_channel_stack_builder *builder, void *arg) {
@@ -73,7 +73,7 @@ static bool set_default_host_if_unset(grpc_channel_stack_builder *builder,
   return true;
 }
 
-void grpc_client_config_init(void) {
+void grpc_client_channel_init(void) {
   grpc_lb_policy_registry_init();
   grpc_resolver_registry_init();
   grpc_subchannel_index_init();
@@ -83,7 +83,7 @@ void grpc_client_config_init(void) {
                                    (void *)&grpc_client_channel_filter);
 }
 
-void grpc_client_config_shutdown(void) {
+void grpc_client_channel_shutdown(void) {
   grpc_subchannel_index_shutdown();
   grpc_channel_init_shutdown();
   grpc_resolver_registry_shutdown();
diff --git a/src/core/ext/client_config/connector.c b/src/core/ext/client_channel/connector.c
index 5b629ed5fb..0582e5b372 100644
--- a/src/core/ext/client_config/connector.c
+++ b/src/core/ext/client_channel/connector.c
@@ -31,7 +31,7 @@
  *
  */
 
-#include "src/core/ext/client_config/connector.h"
+#include "src/core/ext/client_channel/connector.h"
 
 grpc_connector* grpc_connector_ref(grpc_connector* connector) {
   connector->vtable->ref(connector);
diff --git a/src/core/ext/client_config/connector.h b/src/core/ext/client_channel/connector.h
index ea9d23706e..e08244b2c0 100644
--- a/src/core/ext/client_config/connector.h
+++ b/src/core/ext/client_channel/connector.h
@@ -31,8 +31,8 @@
  *
  */
 
-#ifndef GRPC_CORE_EXT_CLIENT_CONFIG_CONNECTOR_H
-#define GRPC_CORE_EXT_CLIENT_CONFIG_CONNECTOR_H
+#ifndef GRPC_CORE_EXT_CLIENT_CHANNEL_CONNECTOR_H
+#define GRPC_CORE_EXT_CLIENT_CHANNEL_CONNECTOR_H
 
 #include "src/core/lib/channel/channel_stack.h"
 #include "src/core/lib/iomgr/sockaddr.h"
@@ -89,4 +89,4 @@ void grpc_connector_connect(grpc_exec_ctx *exec_ctx, grpc_connector *connector,
 void grpc_connector_shutdown(grpc_exec_ctx *exec_ctx,
                              grpc_connector *connector);
 
-#endif /* GRPC_CORE_EXT_CLIENT_CONFIG_CONNECTOR_H */
+#endif /* GRPC_CORE_EXT_CLIENT_CHANNEL_CONNECTOR_H */
diff --git a/src/core/ext/client_config/default_initial_connect_string.c b/src/core/ext/client_channel/default_initial_connect_string.c
index a70da4a84a..a70da4a84a 100644
--- a/src/core/ext/client_config/default_initial_connect_string.c
+++ b/src/core/ext/client_channel/default_initial_connect_string.c
diff --git a/src/core/ext/client_config/http_connect_handshaker.c b/src/core/ext/client_channel/http_connect_handshaker.c
index fda1df173e..ea2cbbdd97 100644
--- a/src/core/ext/client_config/http_connect_handshaker.c
+++ b/src/core/ext/client_channel/http_connect_handshaker.c
@@ -31,7 +31,7 @@
  *
  */
 
-#include "src/core/ext/client_config/http_connect_handshaker.h"
+#include "src/core/ext/client_channel/http_connect_handshaker.h"
 
 #include <string.h>
 
@@ -40,7 +40,7 @@
 #include <grpc/support/slice_buffer.h>
 #include <grpc/support/string_util.h>
 
-#include "src/core/ext/client_config/uri_parser.h"
+#include "src/core/ext/client_channel/uri_parser.h"
 #include "src/core/lib/http/format_request.h"
 #include "src/core/lib/http/parser.h"
 #include "src/core/lib/iomgr/timer.h"
diff --git a/src/core/ext/client_config/http_connect_handshaker.h b/src/core/ext/client_channel/http_connect_handshaker.h
index 1fc3948267..c689df2b2b 100644
--- a/src/core/ext/client_config/http_connect_handshaker.h
+++ b/src/core/ext/client_channel/http_connect_handshaker.h
@@ -31,8 +31,8 @@
  *
  */
 
-#ifndef GRPC_CORE_EXT_CLIENT_CONFIG_HTTP_CONNECT_HANDSHAKER_H
-#define GRPC_CORE_EXT_CLIENT_CONFIG_HTTP_CONNECT_HANDSHAKER_H
+#ifndef GRPC_CORE_EXT_CLIENT_CHANNEL_HTTP_CONNECT_HANDSHAKER_H
+#define GRPC_CORE_EXT_CLIENT_CHANNEL_HTTP_CONNECT_HANDSHAKER_H
 
 #include "src/core/lib/channel/handshaker.h"
 
@@ -44,4 +44,4 @@ grpc_handshaker* grpc_http_connect_handshaker_create(const char* proxy_server,
 /// Caller takes ownership of result.
 char* grpc_get_http_proxy_server();
 
-#endif /* GRPC_CORE_EXT_CLIENT_CONFIG_HTTP_CONNECT_HANDSHAKER_H */
+#endif /* GRPC_CORE_EXT_CLIENT_CHANNEL_HTTP_CONNECT_HANDSHAKER_H */
diff --git a/src/core/ext/client_config/initial_connect_string.c b/src/core/ext/client_channel/initial_connect_string.c
index 41580d2106..fd8ddb83a8 100644
--- a/src/core/ext/client_config/initial_connect_string.c
+++ b/src/core/ext/client_channel/initial_connect_string.c
@@ -31,7 +31,7 @@
  *
  */
 
-#include "src/core/ext/client_config/initial_connect_string.h"
+#include "src/core/ext/client_channel/initial_connect_string.h"
 
 #include <stddef.h>
 
diff --git a/src/core/ext/client_config/initial_connect_string.h b/src/core/ext/client_channel/initial_connect_string.h
index 06f0767832..39f6465fc9 100644
--- a/src/core/ext/client_config/initial_connect_string.h
+++ b/src/core/ext/client_channel/initial_connect_string.h
@@ -31,8 +31,8 @@
  *
  */
 
-#ifndef GRPC_CORE_EXT_CLIENT_CONFIG_INITIAL_CONNECT_STRING_H
-#define GRPC_CORE_EXT_CLIENT_CONFIG_INITIAL_CONNECT_STRING_H
+#ifndef GRPC_CORE_EXT_CLIENT_CHANNEL_INITIAL_CONNECT_STRING_H
+#define GRPC_CORE_EXT_CLIENT_CHANNEL_INITIAL_CONNECT_STRING_H
 
 #include <grpc/support/slice.h>
 #include "src/core/lib/iomgr/sockaddr.h"
@@ -47,4 +47,4 @@ void grpc_test_set_initial_connect_string_function(
 void grpc_set_initial_connect_string(struct sockaddr **addr, size_t *addr_len,
                                      gpr_slice *connect_string);
 
-#endif /* GRPC_CORE_EXT_CLIENT_CONFIG_INITIAL_CONNECT_STRING_H */
+#endif /* GRPC_CORE_EXT_CLIENT_CHANNEL_INITIAL_CONNECT_STRING_H */
diff --git a/src/core/ext/client_config/lb_policy.c b/src/core/ext/client_channel/lb_policy.c
index 46391272a6..45ee72e2f0 100644
--- a/src/core/ext/client_config/lb_policy.c
+++ b/src/core/ext/client_channel/lb_policy.c
@@ -31,7 +31,7 @@
  *
  */
 
-#include "src/core/ext/client_config/lb_policy.h"
+#include "src/core/ext/client_channel/lb_policy.h"
 
 #define WEAK_REF_BITS 16
 
diff --git a/src/core/ext/client_config/lb_policy.h b/src/core/ext/client_channel/lb_policy.h
index de424cd105..54ad779792 100644
--- a/src/core/ext/client_config/lb_policy.h
+++ b/src/core/ext/client_channel/lb_policy.h
@@ -31,10 +31,11 @@
  *
  */
 
-#ifndef GRPC_CORE_EXT_CLIENT_CONFIG_LB_POLICY_H
-#define GRPC_CORE_EXT_CLIENT_CONFIG_LB_POLICY_H
+#ifndef GRPC_CORE_EXT_CLIENT_CHANNEL_LB_POLICY_H
+#define GRPC_CORE_EXT_CLIENT_CHANNEL_LB_POLICY_H
 
-#include "src/core/ext/client_config/subchannel.h"
+#include "src/core/ext/client_channel/subchannel.h"
+#include "src/core/lib/iomgr/polling_entity.h"
 #include "src/core/lib/transport/connectivity_state.h"
 
 /** A load balancing policy: specified by a vtable and a struct (which
@@ -192,4 +193,4 @@ grpc_connectivity_state grpc_lb_policy_check_connectivity(
     grpc_exec_ctx *exec_ctx, grpc_lb_policy *policy,
     grpc_error **connectivity_error);
 
-#endif /* GRPC_CORE_EXT_CLIENT_CONFIG_LB_POLICY_H */
+#endif /* GRPC_CORE_EXT_CLIENT_CHANNEL_LB_POLICY_H */
diff --git a/src/core/ext/client_config/lb_policy_factory.c b/src/core/ext/client_channel/lb_policy_factory.c
index c17af91a09..45753e6942 100644
--- a/src/core/ext/client_config/lb_policy_factory.c
+++ b/src/core/ext/client_channel/lb_policy_factory.c
@@ -36,7 +36,7 @@
 #include <grpc/support/alloc.h>
 #include <grpc/support/string_util.h>
 
-#include "src/core/ext/client_config/lb_policy_factory.h"
+#include "src/core/ext/client_channel/lb_policy_factory.h"
 
 grpc_lb_addresses* grpc_lb_addresses_create(size_t num_addresses) {
   grpc_lb_addresses* addresses = gpr_malloc(sizeof(grpc_lb_addresses));
diff --git a/src/core/ext/client_config/lb_policy_factory.h b/src/core/ext/client_channel/lb_policy_factory.h
index ade55704f2..3e53972445 100644
--- a/src/core/ext/client_config/lb_policy_factory.h
+++ b/src/core/ext/client_channel/lb_policy_factory.h
@@ -31,11 +31,11 @@
  *
  */
 
-#ifndef GRPC_CORE_EXT_CLIENT_CONFIG_LB_POLICY_FACTORY_H
-#define GRPC_CORE_EXT_CLIENT_CONFIG_LB_POLICY_FACTORY_H
+#ifndef GRPC_CORE_EXT_CLIENT_CHANNEL_LB_POLICY_FACTORY_H
+#define GRPC_CORE_EXT_CLIENT_CHANNEL_LB_POLICY_FACTORY_H
 
-#include "src/core/ext/client_config/client_channel_factory.h"
-#include "src/core/ext/client_config/lb_policy.h"
+#include "src/core/ext/client_channel/client_channel_factory.h"
+#include "src/core/ext/client_channel/lb_policy.h"
 
 #include "src/core/lib/iomgr/exec_ctx.h"
 #include "src/core/lib/iomgr/resolve_address.h"
@@ -118,4 +118,4 @@ grpc_lb_policy *grpc_lb_policy_factory_create_lb_policy(
     grpc_exec_ctx *exec_ctx, grpc_lb_policy_factory *factory,
     grpc_lb_policy_args *args);
 
-#endif /* GRPC_CORE_EXT_CLIENT_CONFIG_LB_POLICY_FACTORY_H */
+#endif /* GRPC_CORE_EXT_CLIENT_CHANNEL_LB_POLICY_FACTORY_H */
diff --git a/src/core/ext/client_config/lb_policy_registry.c b/src/core/ext/client_channel/lb_policy_registry.c
index a23643ecc6..f46a721f9d 100644
--- a/src/core/ext/client_config/lb_policy_registry.c
+++ b/src/core/ext/client_channel/lb_policy_registry.c
@@ -31,7 +31,7 @@
  *
  */
 
-#include "src/core/ext/client_config/lb_policy_registry.h"
+#include "src/core/ext/client_channel/lb_policy_registry.h"
 
 #include <string.h>
 
diff --git a/src/core/ext/client_config/lb_policy_registry.h b/src/core/ext/client_channel/lb_policy_registry.h
index 92f38d6de6..21c468e021 100644
--- a/src/core/ext/client_config/lb_policy_registry.h
+++ b/src/core/ext/client_channel/lb_policy_registry.h
@@ -31,10 +31,10 @@
  *
  */
 
-#ifndef GRPC_CORE_EXT_CLIENT_CONFIG_LB_POLICY_REGISTRY_H
-#define GRPC_CORE_EXT_CLIENT_CONFIG_LB_POLICY_REGISTRY_H
+#ifndef GRPC_CORE_EXT_CLIENT_CHANNEL_LB_POLICY_REGISTRY_H
+#define GRPC_CORE_EXT_CLIENT_CHANNEL_LB_POLICY_REGISTRY_H
 
-#include "src/core/ext/client_config/lb_policy_factory.h"
+#include "src/core/ext/client_channel/lb_policy_factory.h"
 #include "src/core/lib/iomgr/exec_ctx.h"
 
 /** Initialize the registry and set \a default_factory as the factory to be
@@ -52,4 +52,4 @@ void grpc_register_lb_policy(grpc_lb_policy_factory *factory);
 grpc_lb_policy *grpc_lb_policy_create(grpc_exec_ctx *exec_ctx, const char *name,
                                       grpc_lb_policy_args *args);
 
-#endif /* GRPC_CORE_EXT_CLIENT_CONFIG_LB_POLICY_REGISTRY_H */
+#endif /* GRPC_CORE_EXT_CLIENT_CHANNEL_LB_POLICY_REGISTRY_H */
diff --git a/src/core/ext/client_config/method_config.c b/src/core/ext/client_channel/method_config.c
index f8a82323e7..4313ad5e0e 100644
--- a/src/core/ext/client_config/method_config.c
+++ b/src/core/ext/client_channel/method_config.c
@@ -29,7 +29,7 @@
 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 //
 
-#include "src/core/ext/client_config/method_config.h"
+#include "src/core/ext/client_channel/method_config.h"
 
 #include <string.h>
 
@@ -254,12 +254,12 @@ int grpc_method_config_table_cmp(const grpc_method_config_table* table1,
   return grpc_mdstr_hash_table_cmp(table1, table2);
 }
 
-grpc_method_config* grpc_method_config_table_get_method_config(
-    const grpc_method_config_table* table, const grpc_mdstr* path) {
-  grpc_method_config* method_config = grpc_mdstr_hash_table_get(table, path);
+void* grpc_method_config_table_get(const grpc_mdstr_hash_table* table,
+                                   const grpc_mdstr* path) {
+  void* value = grpc_mdstr_hash_table_get(table, path);
   // If we didn't find a match for the path, try looking for a wildcard
   // entry (i.e., change "/service/method" to "/service/*").
-  if (method_config == NULL) {
+  if (value == NULL) {
     const char* path_str = grpc_mdstr_as_c_string(path);
     const char* sep = strrchr(path_str, '/') + 1;
     const size_t len = (size_t)(sep - path_str);
@@ -269,10 +269,10 @@ grpc_method_config* grpc_method_config_table_get_method_config(
     buf[len + 1] = '\0';
     grpc_mdstr* wildcard_path = grpc_mdstr_from_string(buf);
     gpr_free(buf);
-    method_config = grpc_mdstr_hash_table_get(table, wildcard_path);
+    value = grpc_mdstr_hash_table_get(table, wildcard_path);
     GRPC_MDSTR_UNREF(wildcard_path);
   }
-  return method_config;
+  return value;
 }
 
 static void* copy_arg(void* p) { return grpc_method_config_table_ref(p); }
@@ -294,3 +294,47 @@ grpc_arg grpc_method_config_table_create_channel_arg(
   arg.value.pointer.vtable = &arg_vtable;
   return arg;
 }
+
+// State used by convert_entry() below.
+typedef struct conversion_state {
+  void* (*convert_value)(const grpc_method_config* method_config);
+  const grpc_mdstr_hash_table_vtable* vtable;
+  size_t num_entries;
+  grpc_mdstr_hash_table_entry* entries;
+} conversion_state;
+
+// A function to be passed to grpc_mdstr_hash_table_iterate() to create
+// a copy of the entries.
+static void convert_entry(const grpc_mdstr_hash_table_entry* entry,
+                          void* user_data) {
+  conversion_state* state = user_data;
+  state->entries[state->num_entries].key = GRPC_MDSTR_REF(entry->key);
+  state->entries[state->num_entries].value = state->convert_value(entry->value);
+  state->entries[state->num_entries].vtable = state->vtable;
+  ++state->num_entries;
+}
+
+grpc_mdstr_hash_table* grpc_method_config_table_convert(
+    const grpc_method_config_table* table,
+    void* (*convert_value)(const grpc_method_config* method_config),
+    const grpc_mdstr_hash_table_vtable* vtable) {
+  // Create an array of the entries in the table with converted values.
+  conversion_state state;
+  state.convert_value = convert_value;
+  state.vtable = vtable;
+  state.num_entries = 0;
+  state.entries = gpr_malloc(sizeof(grpc_mdstr_hash_table_entry) *
+                             grpc_mdstr_hash_table_num_entries(table));
+  grpc_mdstr_hash_table_iterate(table, convert_entry, &state);
+  // Create a new table based on the array we just constructed.
+  grpc_mdstr_hash_table* new_table =
+      grpc_mdstr_hash_table_create(state.num_entries, state.entries);
+  // Clean up the array.
+  for (size_t i = 0; i < state.num_entries; ++i) {
+    GRPC_MDSTR_UNREF(state.entries[i].key);
+    vtable->destroy_value(state.entries[i].value);
+  }
+  gpr_free(state.entries);
+  // Return the new table.
+  return new_table;
+}
diff --git a/src/core/ext/client_config/method_config.h b/src/core/ext/client_channel/method_config.h
index 1302ac425d..4cbeee5625 100644
--- a/src/core/ext/client_config/method_config.h
+++ b/src/core/ext/client_channel/method_config.h
@@ -29,8 +29,8 @@
 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 //
 
-#ifndef GRPC_CORE_EXT_CLIENT_CONFIG_METHOD_CONFIG_H
-#define GRPC_CORE_EXT_CLIENT_CONFIG_METHOD_CONFIG_H
+#ifndef GRPC_CORE_EXT_CLIENT_CHANNEL_METHOD_CONFIG_H
+#define GRPC_CORE_EXT_CLIENT_CHANNEL_METHOD_CONFIG_H
 
 #include <stdbool.h>
 
@@ -106,11 +106,31 @@ int grpc_method_config_table_cmp(const grpc_method_config_table* table1,
 /// the form "/service/method".
 /// Returns NULL if the method has no config.
 /// Caller does NOT own a reference to the result.
-grpc_method_config* grpc_method_config_table_get_method_config(
-    const grpc_method_config_table* table, const grpc_mdstr* path);
+///
+/// Note: This returns a void* instead of a grpc_method_config* so that
+/// it can also be used for tables constructed via
+/// grpc_method_config_table_convert().
+void* grpc_method_config_table_get(const grpc_mdstr_hash_table* table,
+                                   const grpc_mdstr* path);
 
 /// Returns a channel arg containing \a table.
 grpc_arg grpc_method_config_table_create_channel_arg(
     grpc_method_config_table* table);
 
-#endif /* GRPC_CORE_EXT_CLIENT_CONFIG_METHOD_CONFIG_H */
+/// Generates a new table from \a table whose values are converted to a
+/// new form via the \a convert_value function.  The new table will use
+/// \a vtable for its values.
+///
+/// This is generally used to convert the table's value type from
+/// grpc_method_config to a simple struct containing only the parameters
+/// relevant to a particular filter, thus avoiding the need for a hash
+/// table lookup on the fast path.  In that scenario, \a convert_value
+/// will return a new instance of the struct containing the values from
+/// the grpc_method_config, and \a vtable provides the methods for
+/// operating on the struct type.
+grpc_mdstr_hash_table* grpc_method_config_table_convert(
+    const grpc_method_config_table* table,
+    void* (*convert_value)(const grpc_method_config* method_config),
+    const grpc_mdstr_hash_table_vtable* vtable);
+
+#endif /* GRPC_CORE_EXT_CLIENT_CHANNEL_METHOD_CONFIG_H */
diff --git a/src/core/ext/client_config/parse_address.c b/src/core/ext/client_channel/parse_address.c
index 8b4abe24a6..31ca44299b 100644
--- a/src/core/ext/client_config/parse_address.c
+++ b/src/core/ext/client_channel/parse_address.c
@@ -31,7 +31,7 @@
  *
  */
 
-#include "src/core/ext/client_config/parse_address.h"
+#include "src/core/ext/client_channel/parse_address.h"
 
 #include <stdio.h>
 #include <string.h>
diff --git a/src/core/ext/client_config/parse_address.h b/src/core/ext/client_channel/parse_address.h
index 74c86f4d93..3aa6c41546 100644
--- a/src/core/ext/client_config/parse_address.h
+++ b/src/core/ext/client_channel/parse_address.h
@@ -31,12 +31,12 @@
  *
  */
 
-#ifndef GRPC_CORE_EXT_CLIENT_CONFIG_PARSE_ADDRESS_H
-#define GRPC_CORE_EXT_CLIENT_CONFIG_PARSE_ADDRESS_H
+#ifndef GRPC_CORE_EXT_CLIENT_CHANNEL_PARSE_ADDRESS_H
+#define GRPC_CORE_EXT_CLIENT_CHANNEL_PARSE_ADDRESS_H
 
 #include <stddef.h>
 
-#include "src/core/ext/client_config/uri_parser.h"
+#include "src/core/ext/client_channel/uri_parser.h"
 #include "src/core/lib/iomgr/sockaddr.h"
 
 #ifdef GPR_HAVE_UNIX_SOCKET
@@ -53,4 +53,4 @@ int parse_ipv4(grpc_uri *uri, struct sockaddr_storage *addr, size_t *len);
  * host:port pair. Returns true upon success. */
 int parse_ipv6(grpc_uri *uri, struct sockaddr_storage *addr, size_t *len);
 
-#endif /* GRPC_CORE_EXT_CLIENT_CONFIG_PARSE_ADDRESS_H */
+#endif /* GRPC_CORE_EXT_CLIENT_CHANNEL_PARSE_ADDRESS_H */
diff --git a/src/core/ext/client_config/resolver.c b/src/core/ext/client_channel/resolver.c
index 7534ea62af..0c26d95f2f 100644
--- a/src/core/ext/client_config/resolver.c
+++ b/src/core/ext/client_channel/resolver.c
@@ -31,7 +31,7 @@
  *
  */
 
-#include "src/core/ext/client_config/resolver.h"
+#include "src/core/ext/client_channel/resolver.h"
 
 void grpc_resolver_init(grpc_resolver *resolver,
                         const grpc_resolver_vtable *vtable) {
diff --git a/src/core/ext/client_config/resolver.h b/src/core/ext/client_channel/resolver.h
index 88ac262d51..0951613175 100644
--- a/src/core/ext/client_config/resolver.h
+++ b/src/core/ext/client_channel/resolver.h
@@ -31,11 +31,11 @@
  *
  */
 
-#ifndef GRPC_CORE_EXT_CLIENT_CONFIG_RESOLVER_H
-#define GRPC_CORE_EXT_CLIENT_CONFIG_RESOLVER_H
+#ifndef GRPC_CORE_EXT_CLIENT_CHANNEL_RESOLVER_H
+#define GRPC_CORE_EXT_CLIENT_CHANNEL_RESOLVER_H
 
-#include "src/core/ext/client_config/resolver_result.h"
-#include "src/core/ext/client_config/subchannel.h"
+#include "src/core/ext/client_channel/resolver_result.h"
+#include "src/core/ext/client_channel/subchannel.h"
 #include "src/core/lib/iomgr/iomgr.h"
 
 typedef struct grpc_resolver grpc_resolver;
@@ -91,4 +91,4 @@ void grpc_resolver_next(grpc_exec_ctx *exec_ctx, grpc_resolver *resolver,
                         grpc_resolver_result **result,
                         grpc_closure *on_complete);
 
-#endif /* GRPC_CORE_EXT_CLIENT_CONFIG_RESOLVER_H */
+#endif /* GRPC_CORE_EXT_CLIENT_CHANNEL_RESOLVER_H */
diff --git a/src/core/ext/client_config/resolver_factory.c b/src/core/ext/client_channel/resolver_factory.c
index 67832dcf59..7c3d644257 100644
--- a/src/core/ext/client_config/resolver_factory.c
+++ b/src/core/ext/client_channel/resolver_factory.c
@@ -31,7 +31,7 @@
  *
  */
 
-#include "src/core/ext/client_config/resolver_factory.h"
+#include "src/core/ext/client_channel/resolver_factory.h"
 
 void grpc_resolver_factory_ref(grpc_resolver_factory* factory) {
   factory->vtable->ref(factory);
diff --git a/src/core/ext/client_config/resolver_factory.h b/src/core/ext/client_channel/resolver_factory.h
index 9ec5b9a70e..1ad018ce1f 100644
--- a/src/core/ext/client_config/resolver_factory.h
+++ b/src/core/ext/client_channel/resolver_factory.h
@@ -31,12 +31,12 @@
  *
  */
 
-#ifndef GRPC_CORE_EXT_CLIENT_CONFIG_RESOLVER_FACTORY_H
-#define GRPC_CORE_EXT_CLIENT_CONFIG_RESOLVER_FACTORY_H
+#ifndef GRPC_CORE_EXT_CLIENT_CHANNEL_RESOLVER_FACTORY_H
+#define GRPC_CORE_EXT_CLIENT_CHANNEL_RESOLVER_FACTORY_H
 
-#include "src/core/ext/client_config/client_channel_factory.h"
-#include "src/core/ext/client_config/resolver.h"
-#include "src/core/ext/client_config/uri_parser.h"
+#include "src/core/ext/client_channel/client_channel_factory.h"
+#include "src/core/ext/client_channel/resolver.h"
+#include "src/core/ext/client_channel/uri_parser.h"
 
 typedef struct grpc_resolver_factory grpc_resolver_factory;
 typedef struct grpc_resolver_factory_vtable grpc_resolver_factory_vtable;
@@ -76,4 +76,4 @@ grpc_resolver *grpc_resolver_factory_create_resolver(
 char *grpc_resolver_factory_get_default_authority(
     grpc_resolver_factory *factory, grpc_uri *uri);
 
-#endif /* GRPC_CORE_EXT_CLIENT_CONFIG_RESOLVER_FACTORY_H */
+#endif /* GRPC_CORE_EXT_CLIENT_CHANNEL_RESOLVER_FACTORY_H */
diff --git a/src/core/ext/client_config/resolver_registry.c b/src/core/ext/client_channel/resolver_registry.c
index bd5c683878..ee43329874 100644
--- a/src/core/ext/client_config/resolver_registry.c
+++ b/src/core/ext/client_channel/resolver_registry.c
@@ -31,7 +31,7 @@
  *
  */
 
-#include "src/core/ext/client_config/resolver_registry.h"
+#include "src/core/ext/client_channel/resolver_registry.h"
 
 #include <string.h>
 
@@ -55,7 +55,7 @@ void grpc_resolver_registry_shutdown(void) {
     grpc_resolver_factory_unref(g_all_of_the_resolvers[i]);
   }
   // FIXME(ctiller): this should live in grpc_resolver_registry_init,
-  // however that would have the client_config plugin call this AFTER we start
+  // however that would have the client_channel plugin call this AFTER we start
   // registering resolvers from third party plugins, and so they'd never show
   // up.
   // We likely need some kind of dependency system for plugins.... what form
diff --git a/src/core/ext/client_config/resolver_registry.h b/src/core/ext/client_channel/resolver_registry.h
index 4c6279b978..0a39d4a187 100644
--- a/src/core/ext/client_config/resolver_registry.h
+++ b/src/core/ext/client_channel/resolver_registry.h
@@ -31,10 +31,10 @@
  *
  */
 
-#ifndef GRPC_CORE_EXT_CLIENT_CONFIG_RESOLVER_REGISTRY_H
-#define GRPC_CORE_EXT_CLIENT_CONFIG_RESOLVER_REGISTRY_H
+#ifndef GRPC_CORE_EXT_CLIENT_CHANNEL_RESOLVER_REGISTRY_H
+#define GRPC_CORE_EXT_CLIENT_CHANNEL_RESOLVER_REGISTRY_H
 
-#include "src/core/ext/client_config/resolver_factory.h"
+#include "src/core/ext/client_channel/resolver_factory.h"
 
 void grpc_resolver_registry_init();
 void grpc_resolver_registry_shutdown(void);
@@ -68,4 +68,4 @@ grpc_resolver_factory *grpc_resolver_factory_lookup(const char *name);
     representing the default authority to pass from a client. */
 char *grpc_get_default_authority(const char *target);
 
-#endif /* GRPC_CORE_EXT_CLIENT_CONFIG_RESOLVER_REGISTRY_H */
+#endif /* GRPC_CORE_EXT_CLIENT_CHANNEL_RESOLVER_REGISTRY_H */
diff --git a/src/core/ext/client_config/resolver_result.c b/src/core/ext/client_channel/resolver_result.c
index 63480d152b..ab1c215955 100644
--- a/src/core/ext/client_config/resolver_result.c
+++ b/src/core/ext/client_channel/resolver_result.c
@@ -29,7 +29,7 @@
 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 //
 
-#include "src/core/ext/client_config/resolver_result.h"
+#include "src/core/ext/client_channel/resolver_result.h"
 
 #include <string.h>
 
diff --git a/src/core/ext/client_config/resolver_result.h b/src/core/ext/client_channel/resolver_result.h
index a7ea7c0f4b..5421fd9470 100644
--- a/src/core/ext/client_config/resolver_result.h
+++ b/src/core/ext/client_channel/resolver_result.h
@@ -29,11 +29,10 @@
 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 //
 
-#ifndef GRPC_CORE_EXT_CLIENT_CONFIG_RESOLVER_RESULT_H
-#define GRPC_CORE_EXT_CLIENT_CONFIG_RESOLVER_RESULT_H
+#ifndef GRPC_CORE_EXT_CLIENT_CHANNEL_RESOLVER_RESULT_H
+#define GRPC_CORE_EXT_CLIENT_CHANNEL_RESOLVER_RESULT_H
 
-#include "src/core/ext/client_config/lb_policy_factory.h"
-#include "src/core/lib/iomgr/resolve_address.h"
+#include "src/core/ext/client_channel/lb_policy_factory.h"
 
 // TODO(roth, ctiller): In the long term, we are considering replacing
 // the resolver_result data structure with grpc_channel_args.  The idea is
@@ -66,4 +65,4 @@ const char* grpc_resolver_result_get_lb_policy_name(
 grpc_channel_args* grpc_resolver_result_get_lb_policy_args(
     grpc_resolver_result* result);
 
-#endif /* GRPC_CORE_EXT_CLIENT_CONFIG_RESOLVER_RESULT_H */
+#endif /* GRPC_CORE_EXT_CLIENT_CHANNEL_RESOLVER_RESULT_H */
diff --git a/src/core/ext/client_config/subchannel.c b/src/core/ext/client_channel/subchannel.c
index c531b3b1a8..672e5c3a91 100644
--- a/src/core/ext/client_config/subchannel.c
+++ b/src/core/ext/client_channel/subchannel.c
@@ -31,7 +31,7 @@
  *
  */
 
-#include "src/core/ext/client_config/subchannel.h"
+#include "src/core/ext/client_channel/subchannel.h"
 
 #include <limits.h>
 #include <string.h>
@@ -39,9 +39,9 @@
 #include <grpc/support/alloc.h>
 #include <grpc/support/avl.h>
 
-#include "src/core/ext/client_config/client_channel.h"
-#include "src/core/ext/client_config/initial_connect_string.h"
-#include "src/core/ext/client_config/subchannel_index.h"
+#include "src/core/ext/client_channel/client_channel.h"
+#include "src/core/ext/client_channel/initial_connect_string.h"
+#include "src/core/ext/client_channel/subchannel_index.h"
 #include "src/core/lib/channel/channel_args.h"
 #include "src/core/lib/channel/connected_channel.h"
 #include "src/core/lib/iomgr/timer.h"
diff --git a/src/core/ext/client_config/subchannel.h b/src/core/ext/client_channel/subchannel.h
index f8de26dfd5..c4a7da0c24 100644
--- a/src/core/ext/client_config/subchannel.h
+++ b/src/core/ext/client_channel/subchannel.h
@@ -31,10 +31,10 @@
  *
  */
 
-#ifndef GRPC_CORE_EXT_CLIENT_CONFIG_SUBCHANNEL_H
-#define GRPC_CORE_EXT_CLIENT_CONFIG_SUBCHANNEL_H
+#ifndef GRPC_CORE_EXT_CLIENT_CHANNEL_SUBCHANNEL_H
+#define GRPC_CORE_EXT_CLIENT_CHANNEL_SUBCHANNEL_H
 
-#include "src/core/ext/client_config/connector.h"
+#include "src/core/ext/client_channel/connector.h"
 #include "src/core/lib/channel/channel_stack.h"
 #include "src/core/lib/iomgr/polling_entity.h"
 #include "src/core/lib/transport/connectivity_state.h"
@@ -176,4 +176,4 @@ grpc_subchannel *grpc_subchannel_create(grpc_exec_ctx *exec_ctx,
                                         grpc_connector *connector,
                                         grpc_subchannel_args *args);
 
-#endif /* GRPC_CORE_EXT_CLIENT_CONFIG_SUBCHANNEL_H */
+#endif /* GRPC_CORE_EXT_CLIENT_CHANNEL_SUBCHANNEL_H */
diff --git a/src/core/ext/client_config/subchannel_index.c b/src/core/ext/client_channel/subchannel_index.c
index 673f85b8cb..bf22975fba 100644
--- a/src/core/ext/client_config/subchannel_index.c
+++ b/src/core/ext/client_channel/subchannel_index.c
@@ -31,7 +31,7 @@
 //
 //
 
-#include "src/core/ext/client_config/subchannel_index.h"
+#include "src/core/ext/client_channel/subchannel_index.h"
 
 #include <stdbool.h>
 #include <string.h>
diff --git a/src/core/ext/client_config/subchannel_index.h b/src/core/ext/client_channel/subchannel_index.h
index 6b8d063855..5b3af6b054 100644
--- a/src/core/ext/client_config/subchannel_index.h
+++ b/src/core/ext/client_channel/subchannel_index.h
@@ -31,11 +31,11 @@
  *
  */
 
-#ifndef GRPC_CORE_EXT_CLIENT_CONFIG_SUBCHANNEL_INDEX_H
-#define GRPC_CORE_EXT_CLIENT_CONFIG_SUBCHANNEL_INDEX_H
+#ifndef GRPC_CORE_EXT_CLIENT_CHANNEL_SUBCHANNEL_INDEX_H
+#define GRPC_CORE_EXT_CLIENT_CHANNEL_SUBCHANNEL_INDEX_H
 
-#include "src/core/ext/client_config/connector.h"
-#include "src/core/ext/client_config/subchannel.h"
+#include "src/core/ext/client_channel/connector.h"
+#include "src/core/ext/client_channel/subchannel.h"
 
 /** \file Provides an index of active subchannels so that they can be
     shared amongst channels */
@@ -74,4 +74,4 @@ void grpc_subchannel_index_init(void);
 /** Shutdown the subchannel index (global) */
 void grpc_subchannel_index_shutdown(void);
 
-#endif /* GRPC_CORE_EXT_CLIENT_CONFIG_SUBCHANNEL_INDEX_H */
+#endif /* GRPC_CORE_EXT_CLIENT_CHANNEL_SUBCHANNEL_INDEX_H */
diff --git a/src/core/ext/client_config/uri_parser.c b/src/core/ext/client_channel/uri_parser.c
index 3ca1a58e69..bcb6a1dee4 100644
--- a/src/core/ext/client_config/uri_parser.c
+++ b/src/core/ext/client_channel/uri_parser.c
@@ -31,7 +31,7 @@
  *
  */
 
-#include "src/core/ext/client_config/uri_parser.h"
+#include "src/core/ext/client_channel/uri_parser.h"
 
 #include <string.h>
 
diff --git a/src/core/ext/client_config/uri_parser.h b/src/core/ext/client_channel/uri_parser.h
index 875a7cb07c..5fe0e8f35e 100644
--- a/src/core/ext/client_config/uri_parser.h
+++ b/src/core/ext/client_channel/uri_parser.h
@@ -31,8 +31,8 @@
  *
  */
 
-#ifndef GRPC_CORE_EXT_CLIENT_CONFIG_URI_PARSER_H
-#define GRPC_CORE_EXT_CLIENT_CONFIG_URI_PARSER_H
+#ifndef GRPC_CORE_EXT_CLIENT_CHANNEL_URI_PARSER_H
+#define GRPC_CORE_EXT_CLIENT_CHANNEL_URI_PARSER_H
 
 #include <stddef.h>
 
@@ -60,4 +60,4 @@ const char *grpc_uri_get_query_arg(const grpc_uri *uri, const char *key);
 /** destroy a uri */
 void grpc_uri_destroy(grpc_uri *uri);
 
-#endif /* GRPC_CORE_EXT_CLIENT_CONFIG_URI_PARSER_H */
+#endif /* GRPC_CORE_EXT_CLIENT_CHANNEL_URI_PARSER_H */
diff --git a/src/core/ext/lb_policy/grpclb/grpclb.c b/src/core/ext/lb_policy/grpclb/grpclb.c
index b24b522449..412090158a 100644
--- a/src/core/ext/lb_policy/grpclb/grpclb.c
+++ b/src/core/ext/lb_policy/grpclb/grpclb.c
@@ -107,10 +107,10 @@
 #include <grpc/support/string_util.h>
 #include <grpc/support/time.h>
 
-#include "src/core/ext/client_config/client_channel_factory.h"
-#include "src/core/ext/client_config/lb_policy_factory.h"
-#include "src/core/ext/client_config/lb_policy_registry.h"
-#include "src/core/ext/client_config/parse_address.h"
+#include "src/core/ext/client_channel/client_channel_factory.h"
+#include "src/core/ext/client_channel/lb_policy_factory.h"
+#include "src/core/ext/client_channel/lb_policy_registry.h"
+#include "src/core/ext/client_channel/parse_address.h"
 #include "src/core/ext/lb_policy/grpclb/grpclb.h"
 #include "src/core/ext/lb_policy/grpclb/load_balancer_api.h"
 #include "src/core/lib/channel/channel_args.h"
diff --git a/src/core/ext/lb_policy/grpclb/grpclb.h b/src/core/ext/lb_policy/grpclb/grpclb.h
index 83552b4fa0..ff23f3a545 100644
--- a/src/core/ext/lb_policy/grpclb/grpclb.h
+++ b/src/core/ext/lb_policy/grpclb/grpclb.h
@@ -34,7 +34,7 @@
 #ifndef GRPC_CORE_EXT_LB_POLICY_GRPCLB_GRPCLB_H
 #define GRPC_CORE_EXT_LB_POLICY_GRPCLB_GRPCLB_H
 
-#include "src/core/ext/client_config/lb_policy_factory.h"
+#include "src/core/ext/client_channel/lb_policy_factory.h"
 
 /** Returns a load balancing factory for the glb policy, which tries to connect
  * to a load balancing server to decide the next successfully connected
diff --git a/src/core/ext/lb_policy/grpclb/load_balancer_api.h b/src/core/ext/lb_policy/grpclb/load_balancer_api.h
index c1e73d08ef..079a64a3f3 100644
--- a/src/core/ext/lb_policy/grpclb/load_balancer_api.h
+++ b/src/core/ext/lb_policy/grpclb/load_balancer_api.h
@@ -36,7 +36,7 @@
 
 #include <grpc/support/slice_buffer.h>
 
-#include "src/core/ext/client_config/lb_policy_factory.h"
+#include "src/core/ext/client_channel/lb_policy_factory.h"
 #include "src/core/ext/lb_policy/grpclb/proto/grpc/lb/v1/load_balancer.pb.h"
 
 #ifdef __cplusplus
diff --git a/src/core/ext/lb_policy/pick_first/pick_first.c b/src/core/ext/lb_policy/pick_first/pick_first.c
index da20b9281b..270fe3fe70 100644
--- a/src/core/ext/lb_policy/pick_first/pick_first.c
+++ b/src/core/ext/lb_policy/pick_first/pick_first.c
@@ -34,7 +34,7 @@
 #include <string.h>
 
 #include <grpc/support/alloc.h>
-#include "src/core/ext/client_config/lb_policy_registry.h"
+#include "src/core/ext/client_channel/lb_policy_registry.h"
 #include "src/core/lib/transport/connectivity_state.h"
 
 typedef struct pending_pick {
diff --git a/src/core/ext/lb_policy/round_robin/round_robin.c b/src/core/ext/lb_policy/round_robin/round_robin.c
index b8f4f67aeb..b32f6be99e 100644
--- a/src/core/ext/lb_policy/round_robin/round_robin.c
+++ b/src/core/ext/lb_policy/round_robin/round_robin.c
@@ -63,7 +63,7 @@
 
 #include <grpc/support/alloc.h>
 
-#include "src/core/ext/client_config/lb_policy_registry.h"
+#include "src/core/ext/client_channel/lb_policy_registry.h"
 #include "src/core/lib/debug/trace.h"
 #include "src/core/lib/transport/connectivity_state.h"
 #include "src/core/lib/transport/static_metadata.h"
diff --git a/src/core/ext/load_reporting/load_reporting.h b/src/core/ext/load_reporting/load_reporting.h
index e13097654d..a157844734 100644
--- a/src/core/ext/load_reporting/load_reporting.h
+++ b/src/core/ext/load_reporting/load_reporting.h
@@ -51,7 +51,7 @@
  * The value corresponding to this key is an opaque binary blob reported by the
  * backend as part of its trailing metadata containing cost information for the
  * call. */
-#define GRPC_LB_COST_MD_KEY "lb-cost"
+#define GRPC_LB_COST_MD_KEY "lb-cost-bin"
 
 /** Identifiers for the invocation point of the users LR callback */
 typedef enum grpc_load_reporting_source {
diff --git a/src/core/ext/load_reporting/load_reporting_filter.c b/src/core/ext/load_reporting/load_reporting_filter.c
index 22bf36367f..eeae2400fb 100644
--- a/src/core/ext/load_reporting/load_reporting_filter.c
+++ b/src/core/ext/load_reporting/load_reporting_filter.c
@@ -193,7 +193,7 @@ static grpc_mdelem *lr_trailing_md_filter(void *user_data, grpc_mdelem *md) {
   grpc_call_element *elem = user_data;
   call_data *calld = elem->call_data;
 
-  if (md->key == GRPC_MDSTR_LB_COST) {
+  if (md->key == GRPC_MDSTR_LB_COST_BIN) {
     calld->trailing_md_string = gpr_strdup(grpc_mdstr_as_c_string(md->value));
     return NULL;
   }
diff --git a/src/core/ext/resolver/dns/native/dns_resolver.c b/src/core/ext/resolver/dns/native/dns_resolver.c
index fa33ffd7bd..b4ceee340e 100644
--- a/src/core/ext/resolver/dns/native/dns_resolver.c
+++ b/src/core/ext/resolver/dns/native/dns_resolver.c
@@ -37,9 +37,9 @@
 #include <grpc/support/host_port.h>
 #include <grpc/support/string_util.h>
 
-#include "src/core/ext/client_config/http_connect_handshaker.h"
-#include "src/core/ext/client_config/lb_policy_registry.h"
-#include "src/core/ext/client_config/resolver_registry.h"
+#include "src/core/ext/client_channel/http_connect_handshaker.h"
+#include "src/core/ext/client_channel/lb_policy_registry.h"
+#include "src/core/ext/client_channel/resolver_registry.h"
 #include "src/core/lib/iomgr/resolve_address.h"
 #include "src/core/lib/iomgr/timer.h"
 #include "src/core/lib/support/backoff.h"
diff --git a/src/core/ext/resolver/sockaddr/sockaddr_resolver.c b/src/core/ext/resolver/sockaddr/sockaddr_resolver.c
index 28dd2569e8..9924fc6fec 100644
--- a/src/core/ext/resolver/sockaddr/sockaddr_resolver.c
+++ b/src/core/ext/resolver/sockaddr/sockaddr_resolver.c
@@ -41,9 +41,8 @@
 #include <grpc/support/port_platform.h>
 #include <grpc/support/string_util.h>
 
-#include "src/core/ext/client_config/parse_address.h"
-#include "src/core/ext/client_config/resolver_registry.h"
-#include "src/core/lib/channel/channel_args.h"
+#include "src/core/ext/client_channel/parse_address.h"
+#include "src/core/ext/client_channel/resolver_registry.h"
 #include "src/core/lib/iomgr/resolve_address.h"
 #include "src/core/lib/iomgr/unix_sockets_posix.h"
 #include "src/core/lib/support/string.h"
diff --git a/src/core/ext/transport/chttp2/client/insecure/channel_create.c b/src/core/ext/transport/chttp2/client/insecure/channel_create.c
index f2ba62c218..41432b54a9 100644
--- a/src/core/ext/transport/chttp2/client/insecure/channel_create.c
+++ b/src/core/ext/transport/chttp2/client/insecure/channel_create.c
@@ -40,9 +40,9 @@
 #include <grpc/support/slice.h>
 #include <grpc/support/slice_buffer.h>
 
-#include "src/core/ext/client_config/client_channel.h"
-#include "src/core/ext/client_config/http_connect_handshaker.h"
-#include "src/core/ext/client_config/resolver_registry.h"
+#include "src/core/ext/client_channel/client_channel.h"
+#include "src/core/ext/client_channel/http_connect_handshaker.h"
+#include "src/core/ext/client_channel/resolver_registry.h"
 #include "src/core/ext/transport/chttp2/transport/chttp2_transport.h"
 #include "src/core/lib/channel/channel_args.h"
 #include "src/core/lib/channel/compress_filter.h"
diff --git a/src/core/ext/transport/chttp2/client/secure/secure_channel_create.c b/src/core/ext/transport/chttp2/client/secure/secure_channel_create.c
index 94516f7f6f..2e6b3f2fc8 100644
--- a/src/core/ext/transport/chttp2/client/secure/secure_channel_create.c
+++ b/src/core/ext/transport/chttp2/client/secure/secure_channel_create.c
@@ -40,9 +40,9 @@
 #include <grpc/support/slice.h>
 #include <grpc/support/slice_buffer.h>
 
-#include "src/core/ext/client_config/client_channel.h"
-#include "src/core/ext/client_config/http_connect_handshaker.h"
-#include "src/core/ext/client_config/resolver_registry.h"
+#include "src/core/ext/client_channel/client_channel.h"
+#include "src/core/ext/client_channel/http_connect_handshaker.h"
+#include "src/core/ext/client_channel/resolver_registry.h"
 #include "src/core/ext/transport/chttp2/transport/chttp2_transport.h"
 #include "src/core/lib/channel/channel_args.h"
 #include "src/core/lib/channel/handshaker.h"
@@ -291,8 +291,6 @@ static grpc_channel *client_channel_factory_create_channel(
     channel = NULL;
   }
 
-  GRPC_SECURITY_CONNECTOR_UNREF(&f->security_connector->base,
-                                "client_channel_factory_create_channel");
   return channel;
 }
 
@@ -361,6 +359,9 @@ grpc_channel *grpc_secure_channel_create(grpc_channel_credentials *creds,
   grpc_channel *channel = client_channel_factory_create_channel(
       &exec_ctx, &f->base, target, GRPC_CLIENT_CHANNEL_TYPE_REGULAR, NULL);
 
+  GRPC_SECURITY_CONNECTOR_UNREF(&f->security_connector->base,
+                                "client_channel_factory_create_channel");
+
   grpc_client_channel_factory_unref(&exec_ctx, &f->base);
   grpc_exec_ctx_finish(&exec_ctx);
 
diff --git a/src/core/lib/channel/http_server_filter.c b/src/core/lib/channel/http_server_filter.c
index 0f2bf97824..f2221fb0fb 100644
--- a/src/core/lib/channel/http_server_filter.c
+++ b/src/core/lib/channel/http_server_filter.c
@@ -42,6 +42,8 @@
 #define EXPECTED_CONTENT_TYPE "application/grpc"
 #define EXPECTED_CONTENT_TYPE_LENGTH sizeof(EXPECTED_CONTENT_TYPE) - 1
 
+extern int grpc_http_trace;
+
 typedef struct call_data {
   uint8_t seen_path;
   uint8_t seen_method;
@@ -209,6 +211,11 @@ static void hs_on_recv(grpc_exec_ctx *exec_ctx, void *user_data,
             err, GRPC_ERROR_CREATE("Missing te: trailers header"));
       }
       /* Error this call out */
+      if (grpc_http_trace) {
+        const char *error_str = grpc_error_string(err);
+        gpr_log(GPR_ERROR, "Invalid http2 headers: %s", error_str);
+        grpc_error_free_string(error_str);
+      }
       grpc_call_element_send_cancel(exec_ctx, elem);
     }
   } else {
diff --git a/src/core/lib/channel/message_size_filter.c b/src/core/lib/channel/message_size_filter.c
index 1382f19945..b8b2546035 100644
--- a/src/core/lib/channel/message_size_filter.c
+++ b/src/core/lib/channel/message_size_filter.c
@@ -38,13 +38,51 @@
 #include <grpc/support/log.h>
 #include <grpc/support/string_util.h>
 
-#include "src/core/ext/client_config/method_config.h"
+#include "src/core/ext/client_channel/method_config.h"
 #include "src/core/lib/channel/channel_args.h"
 
 #define DEFAULT_MAX_SEND_MESSAGE_LENGTH -1  // Unlimited.
 // The protobuf library will (by default) start warning at 100 megs.
 #define DEFAULT_MAX_RECV_MESSAGE_LENGTH (4 * 1024 * 1024)
 
+typedef struct message_size_limits {
+  int max_send_size;
+  int max_recv_size;
+} message_size_limits;
+
+static void* message_size_limits_copy(void* value) {
+  void* new_value = gpr_malloc(sizeof(message_size_limits));
+  memcpy(new_value, value, sizeof(message_size_limits));
+  return new_value;
+}
+
+static int message_size_limits_cmp(void* value1, void* value2) {
+  const message_size_limits* v1 = value1;
+  const message_size_limits* v2 = value2;
+  if (v1->max_send_size > v2->max_send_size) return 1;
+  if (v1->max_send_size < v2->max_send_size) return -1;
+  if (v1->max_recv_size > v2->max_recv_size) return 1;
+  if (v1->max_recv_size < v2->max_recv_size) return -1;
+  return 0;
+}
+
+static const grpc_mdstr_hash_table_vtable message_size_limits_vtable = {
+    gpr_free, message_size_limits_copy, message_size_limits_cmp};
+
+static void* method_config_convert_value(
+    const grpc_method_config* method_config) {
+  message_size_limits* value = gpr_malloc(sizeof(message_size_limits));
+  const int32_t* max_request_message_bytes =
+      grpc_method_config_get_max_request_message_bytes(method_config);
+  value->max_send_size =
+      max_request_message_bytes != NULL ? *max_request_message_bytes : -1;
+  const int32_t* max_response_message_bytes =
+      grpc_method_config_get_max_response_message_bytes(method_config);
+  value->max_recv_size =
+      max_response_message_bytes != NULL ? *max_response_message_bytes : -1;
+  return value;
+}
+
 typedef struct call_data {
   int max_send_size;
   int max_recv_size;
@@ -61,8 +99,8 @@ typedef struct call_data {
 typedef struct channel_data {
   int max_send_size;
   int max_recv_size;
-  // Method config table.
-  grpc_method_config_table* method_config_table;
+  // Maps path names to message_size_limits structs.
+  grpc_mdstr_hash_table* method_limit_table;
 } channel_data;
 
 // Callback invoked when we receive a message.  Here we check the max
@@ -132,24 +170,19 @@ static grpc_error* init_call_elem(grpc_exec_ctx* exec_ctx,
   // size to the receive limit.
   calld->max_send_size = chand->max_send_size;
   calld->max_recv_size = chand->max_recv_size;
-  if (chand->method_config_table != NULL) {
-    grpc_method_config* method_config =
-        grpc_method_config_table_get_method_config(chand->method_config_table,
-                                                   args->path);
-    if (method_config != NULL) {
-      const int32_t* max_request_message_bytes =
-          grpc_method_config_get_max_request_message_bytes(method_config);
-      if (max_request_message_bytes != NULL &&
-          (*max_request_message_bytes < calld->max_send_size ||
+  if (chand->method_limit_table != NULL) {
+    message_size_limits* limits =
+        grpc_method_config_table_get(chand->method_limit_table, args->path);
+    if (limits != NULL) {
+      if (limits->max_send_size >= 0 &&
+          (limits->max_send_size < calld->max_send_size ||
            calld->max_send_size < 0)) {
-        calld->max_send_size = *max_request_message_bytes;
+        calld->max_send_size = limits->max_send_size;
       }
-      const int32_t* max_response_message_bytes =
-          grpc_method_config_get_max_response_message_bytes(method_config);
-      if (max_response_message_bytes != NULL &&
-          (*max_response_message_bytes < calld->max_recv_size ||
+      if (limits->max_recv_size >= 0 &&
+          (limits->max_recv_size < calld->max_recv_size ||
            calld->max_recv_size < 0)) {
-        calld->max_recv_size = *max_response_message_bytes;
+        calld->max_recv_size = limits->max_recv_size;
       }
     }
   }
@@ -191,8 +224,9 @@ static void init_channel_elem(grpc_exec_ctx* exec_ctx,
       grpc_channel_args_find(args->channel_args, GRPC_ARG_SERVICE_CONFIG);
   if (channel_arg != NULL) {
     GPR_ASSERT(channel_arg->type == GRPC_ARG_POINTER);
-    chand->method_config_table = grpc_method_config_table_ref(
-        (grpc_method_config_table*)channel_arg->value.pointer.p);
+    chand->method_limit_table = grpc_method_config_table_convert(
+        (grpc_method_config_table*)channel_arg->value.pointer.p,
+        method_config_convert_value, &message_size_limits_vtable);
   }
 }
 
@@ -200,7 +234,7 @@ static void init_channel_elem(grpc_exec_ctx* exec_ctx,
 static void destroy_channel_elem(grpc_exec_ctx* exec_ctx,
                                  grpc_channel_element* elem) {
   channel_data* chand = elem->channel_data;
-  grpc_method_config_table_unref(chand->method_config_table);
+  grpc_mdstr_hash_table_unref(chand->method_limit_table);
 }
 
 const grpc_channel_filter grpc_message_size_filter = {
diff --git a/src/core/lib/transport/mdstr_hash_table.c b/src/core/lib/transport/mdstr_hash_table.c
index 4be0536dd7..8e914c420b 100644
--- a/src/core/lib/transport/mdstr_hash_table.c
+++ b/src/core/lib/transport/mdstr_hash_table.c
@@ -42,6 +42,7 @@
 struct grpc_mdstr_hash_table {
   gpr_refcount refs;
   size_t num_entries;
+  size_t size;
   grpc_mdstr_hash_table_entry* entries;
 };
 
@@ -50,13 +51,12 @@ struct grpc_mdstr_hash_table {
 static size_t grpc_mdstr_hash_table_find_index(
     const grpc_mdstr_hash_table* table, const grpc_mdstr* key,
     bool find_empty) {
-  for (size_t i = 0; i < table->num_entries; ++i) {
-    const size_t idx = (key->hash + i * i) % table->num_entries;
-    if (table->entries[idx].key == NULL)
-      return find_empty ? idx : table->num_entries;
+  for (size_t i = 0; i < table->size; ++i) {
+    const size_t idx = (key->hash + i * i) % table->size;
+    if (table->entries[idx].key == NULL) return find_empty ? idx : table->size;
     if (table->entries[idx].key == key) return idx;
   }
-  return table->num_entries;  // Not found.
+  return table->size;  // Not found.
 }
 
 static void grpc_mdstr_hash_table_add(
@@ -65,7 +65,7 @@ static void grpc_mdstr_hash_table_add(
   GPR_ASSERT(value != NULL);
   const size_t idx =
       grpc_mdstr_hash_table_find_index(table, key, true /* find_empty */);
-  GPR_ASSERT(idx != table->num_entries);  // Table should never be full.
+  GPR_ASSERT(idx != table->size);  // Table should never be full.
   grpc_mdstr_hash_table_entry* entry = &table->entries[idx];
   entry->key = GRPC_MDSTR_REF(key);
   entry->value = vtable->copy_value(value);
@@ -77,11 +77,11 @@ grpc_mdstr_hash_table* grpc_mdstr_hash_table_create(
   grpc_mdstr_hash_table* table = gpr_malloc(sizeof(*table));
   memset(table, 0, sizeof(*table));
   gpr_ref_init(&table->refs, 1);
+  table->num_entries = num_entries;
   // Quadratic probing gets best performance when the table is no more
   // than half full.
-  table->num_entries = num_entries * 2;
-  const size_t entry_size =
-      sizeof(grpc_mdstr_hash_table_entry) * table->num_entries;
+  table->size = num_entries * 2;
+  const size_t entry_size = sizeof(grpc_mdstr_hash_table_entry) * table->size;
   table->entries = gpr_malloc(entry_size);
   memset(table->entries, 0, entry_size);
   for (size_t i = 0; i < num_entries; ++i) {
@@ -98,7 +98,7 @@ grpc_mdstr_hash_table* grpc_mdstr_hash_table_ref(grpc_mdstr_hash_table* table) {
 
 int grpc_mdstr_hash_table_unref(grpc_mdstr_hash_table* table) {
   if (table != NULL && gpr_unref(&table->refs)) {
-    for (size_t i = 0; i < table->num_entries; ++i) {
+    for (size_t i = 0; i < table->size; ++i) {
       grpc_mdstr_hash_table_entry* entry = &table->entries[i];
       if (entry->key != NULL) {
         GRPC_MDSTR_UNREF(entry->key);
@@ -112,11 +112,15 @@ int grpc_mdstr_hash_table_unref(grpc_mdstr_hash_table* table) {
   return 0;
 }
 
+size_t grpc_mdstr_hash_table_num_entries(const grpc_mdstr_hash_table* table) {
+  return table->num_entries;
+}
+
 void* grpc_mdstr_hash_table_get(const grpc_mdstr_hash_table* table,
                                 const grpc_mdstr* key) {
   const size_t idx =
       grpc_mdstr_hash_table_find_index(table, key, false /* find_empty */);
-  if (idx == table->num_entries) return NULL;  // Not found.
+  if (idx == table->size) return NULL;  // Not found.
   return table->entries[idx].value;
 }
 
@@ -140,3 +144,14 @@ int grpc_mdstr_hash_table_cmp(const grpc_mdstr_hash_table* table1,
   }
   return 0;
 }
+
+void grpc_mdstr_hash_table_iterate(
+    const grpc_mdstr_hash_table* table,
+    void (*func)(const grpc_mdstr_hash_table_entry* entry, void* user_data),
+    void* user_data) {
+  for (size_t i = 0; i < table->size; ++i) {
+    if (table->entries[i].key != NULL) {
+      func(&table->entries[i], user_data);
+    }
+  }
+}
diff --git a/src/core/lib/transport/mdstr_hash_table.h b/src/core/lib/transport/mdstr_hash_table.h
index 52e5b023db..bceb4df93d 100644
--- a/src/core/lib/transport/mdstr_hash_table.h
+++ b/src/core/lib/transport/mdstr_hash_table.h
@@ -70,6 +70,9 @@ grpc_mdstr_hash_table* grpc_mdstr_hash_table_ref(grpc_mdstr_hash_table* table);
 /** Returns 1 when \a table is destroyed. */
 int grpc_mdstr_hash_table_unref(grpc_mdstr_hash_table* table);
 
+/** Returns the number of entries in \a table. */
+size_t grpc_mdstr_hash_table_num_entries(const grpc_mdstr_hash_table* table);
+
 /** Returns the value from \a table associated with \a key.
     Returns NULL if \a key is not found. */
 void* grpc_mdstr_hash_table_get(const grpc_mdstr_hash_table* table,
@@ -80,4 +83,10 @@ void* grpc_mdstr_hash_table_get(const grpc_mdstr_hash_table* table,
 int grpc_mdstr_hash_table_cmp(const grpc_mdstr_hash_table* table1,
                               const grpc_mdstr_hash_table* table2);
 
+/** Iterates over the entries in \a table, calling \a func for each entry. */
+void grpc_mdstr_hash_table_iterate(
+    const grpc_mdstr_hash_table* table,
+    void (*func)(const grpc_mdstr_hash_table_entry* entry, void* user_data),
+    void* user_data);
+
 #endif /* GRPC_CORE_LIB_TRANSPORT_MDSTR_HASH_TABLE_H */
diff --git a/src/core/lib/transport/static_metadata.c b/src/core/lib/transport/static_metadata.c
index f019ef156a..8b22592b45 100644
--- a/src/core/lib/transport/static_metadata.c
+++ b/src/core/lib/transport/static_metadata.c
@@ -126,7 +126,7 @@ const char *const grpc_static_metadata_strings[GRPC_STATIC_MDSTR_COUNT] = {
     "if-range",
     "if-unmodified-since",
     "last-modified",
-    "lb-cost",
+    "lb-cost-bin",
     "lb-token",
     "link",
     "location",
diff --git a/src/core/lib/transport/static_metadata.h b/src/core/lib/transport/static_metadata.h
index e0a8196419..28ad6f2961 100644
--- a/src/core/lib/transport/static_metadata.h
+++ b/src/core/lib/transport/static_metadata.h
@@ -175,8 +175,8 @@ extern grpc_mdstr grpc_static_mdstr_table[GRPC_STATIC_MDSTR_COUNT];
 #define GRPC_MDSTR_IF_UNMODIFIED_SINCE (&grpc_static_mdstr_table[62])
 /* "last-modified" */
 #define GRPC_MDSTR_LAST_MODIFIED (&grpc_static_mdstr_table[63])
-/* "lb-cost" */
-#define GRPC_MDSTR_LB_COST (&grpc_static_mdstr_table[64])
+/* "lb-cost-bin" */
+#define GRPC_MDSTR_LB_COST_BIN (&grpc_static_mdstr_table[64])
 /* "lb-token" */
 #define GRPC_MDSTR_LB_TOKEN (&grpc_static_mdstr_table[65])
 /* "link" */
@@ -337,8 +337,8 @@ extern uintptr_t grpc_static_mdelem_user_data[GRPC_STATIC_MDELEM_COUNT];
 #define GRPC_MDELEM_IF_UNMODIFIED_SINCE_EMPTY (&grpc_static_mdelem_table[44])
 /* "last-modified": "" */
 #define GRPC_MDELEM_LAST_MODIFIED_EMPTY (&grpc_static_mdelem_table[45])
-/* "lb-cost": "" */
-#define GRPC_MDELEM_LB_COST_EMPTY (&grpc_static_mdelem_table[46])
+/* "lb-cost-bin": "" */
+#define GRPC_MDELEM_LB_COST_BIN_EMPTY (&grpc_static_mdelem_table[46])
 /* "lb-token": "" */
 #define GRPC_MDELEM_LB_TOKEN_EMPTY (&grpc_static_mdelem_table[47])
 /* "link": "" */
diff --git a/src/core/plugin_registry/grpc_cronet_plugin_registry.c b/src/core/plugin_registry/grpc_cronet_plugin_registry.c
index d0b5f5c702..d339ed327f 100644
--- a/src/core/plugin_registry/grpc_cronet_plugin_registry.c
+++ b/src/core/plugin_registry/grpc_cronet_plugin_registry.c
@@ -35,12 +35,12 @@
 
 extern void grpc_chttp2_plugin_init(void);
 extern void grpc_chttp2_plugin_shutdown(void);
-extern void grpc_client_config_init(void);
-extern void grpc_client_config_shutdown(void);
+extern void grpc_client_channel_init(void);
+extern void grpc_client_channel_shutdown(void);
 
 void grpc_register_built_in_plugins(void) {
   grpc_register_plugin(grpc_chttp2_plugin_init,
                        grpc_chttp2_plugin_shutdown);
-  grpc_register_plugin(grpc_client_config_init,
-                       grpc_client_config_shutdown);
+  grpc_register_plugin(grpc_client_channel_init,
+                       grpc_client_channel_shutdown);
 }
diff --git a/src/core/plugin_registry/grpc_plugin_registry.c b/src/core/plugin_registry/grpc_plugin_registry.c
index 7a7a9ce477..2efd9cd1ad 100644
--- a/src/core/plugin_registry/grpc_plugin_registry.c
+++ b/src/core/plugin_registry/grpc_plugin_registry.c
@@ -35,8 +35,8 @@
 
 extern void grpc_chttp2_plugin_init(void);
 extern void grpc_chttp2_plugin_shutdown(void);
-extern void grpc_client_config_init(void);
-extern void grpc_client_config_shutdown(void);
+extern void grpc_client_channel_init(void);
+extern void grpc_client_channel_shutdown(void);
 extern void grpc_lb_policy_grpclb_init(void);
 extern void grpc_lb_policy_grpclb_shutdown(void);
 extern void grpc_lb_policy_pick_first_init(void);
@@ -55,8 +55,8 @@ extern void census_grpc_plugin_shutdown(void);
 void grpc_register_built_in_plugins(void) {
   grpc_register_plugin(grpc_chttp2_plugin_init,
                        grpc_chttp2_plugin_shutdown);
-  grpc_register_plugin(grpc_client_config_init,
-                       grpc_client_config_shutdown);
+  grpc_register_plugin(grpc_client_channel_init,
+                       grpc_client_channel_shutdown);
   grpc_register_plugin(grpc_lb_policy_grpclb_init,
                        grpc_lb_policy_grpclb_shutdown);
   grpc_register_plugin(grpc_lb_policy_pick_first_init,
diff --git a/src/core/plugin_registry/grpc_unsecure_plugin_registry.c b/src/core/plugin_registry/grpc_unsecure_plugin_registry.c
index ad4ddf0ff4..8b18af699d 100644
--- a/src/core/plugin_registry/grpc_unsecure_plugin_registry.c
+++ b/src/core/plugin_registry/grpc_unsecure_plugin_registry.c
@@ -35,8 +35,8 @@
 
 extern void grpc_chttp2_plugin_init(void);
 extern void grpc_chttp2_plugin_shutdown(void);
-extern void grpc_client_config_init(void);
-extern void grpc_client_config_shutdown(void);
+extern void grpc_client_channel_init(void);
+extern void grpc_client_channel_shutdown(void);
 extern void grpc_resolver_dns_native_init(void);
 extern void grpc_resolver_dns_native_shutdown(void);
 extern void grpc_resolver_sockaddr_init(void);
@@ -55,8 +55,8 @@ extern void census_grpc_plugin_shutdown(void);
 void grpc_register_built_in_plugins(void) {
   grpc_register_plugin(grpc_chttp2_plugin_init,
                        grpc_chttp2_plugin_shutdown);
-  grpc_register_plugin(grpc_client_config_init,
-                       grpc_client_config_shutdown);
+  grpc_register_plugin(grpc_client_channel_init,
+                       grpc_client_channel_shutdown);
   grpc_register_plugin(grpc_resolver_dns_native_init,
                        grpc_resolver_dns_native_shutdown);
   grpc_register_plugin(grpc_resolver_sockaddr_init,