55 files changed, 734 insertions, 393 deletions
diff --git a/src/core/lib/client_config/README.md b/src/core/ext/client_config/README.md
index fff7a5af5b..7024fd540d 100644
--- a/src/core/lib/client_config/README.md
+++ b/src/core/ext/client_config/README.md
@@ -40,7 +40,7 @@ decisions (for example, by avoiding disconnected backends).
 Configured sub-channels are fully setup to participate in the grpc data plane.
 Their behavior is specified by a set of grpc channel filters defined at their
 construction. To customize this behavior, resolvers build
-grpc_subchannel_factory objects, which use the decorator pattern to customize
+grpc_client_channel_factory objects, which use the decorator pattern to customize
 construction arguments for concrete grpc_subchannel instances.
 
 
diff --git a/src/core/lib/surface/channel_connectivity.c b/src/core/ext/client_config/channel_connectivity.c
index 9a9ee422c2..3ebc333608 100644
--- a/src/core/lib/surface/channel_connectivity.c
+++ b/src/core/ext/client_config/channel_connectivity.c
@@ -36,7 +36,7 @@
 #include <grpc/support/alloc.h>
 #include <grpc/support/log.h>
 
-#include "src/core/lib/channel/client_channel.h"
+#include "src/core/ext/client_config/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/lib/channel/client_channel.c b/src/core/ext/client_config/client_channel.c
index 3f7cf1cf97..93d54fdcfe 100644
--- a/src/core/lib/channel/client_channel.c
+++ b/src/core/ext/client_config/client_channel.c
@@ -31,7 +31,7 @@
  *
  */
 
-#include "src/core/lib/channel/client_channel.h"
+#include "src/core/ext/client_config/client_channel.h"
 
 #include <stdio.h>
 #include <string.h>
@@ -41,9 +41,9 @@
 #include <grpc/support/sync.h>
 #include <grpc/support/useful.h>
 
+#include "src/core/ext/client_config/subchannel_call_holder.h"
 #include "src/core/lib/channel/channel_args.h"
 #include "src/core/lib/channel/connected_channel.h"
-#include "src/core/lib/channel/subchannel_call_holder.h"
 #include "src/core/lib/iomgr/iomgr.h"
 #include "src/core/lib/profiling/timers.h"
 #include "src/core/lib/support/string.h"
@@ -114,6 +114,22 @@ static void watch_lb_policy(grpc_exec_ctx *exec_ctx, channel_data *chand,
                             grpc_lb_policy *lb_policy,
                             grpc_connectivity_state current_state);
 
+static void set_channel_connectivity_state_locked(grpc_exec_ctx *exec_ctx,
+                                                  channel_data *chand,
+                                                  grpc_connectivity_state state,
+                                                  const char *reason) {
+  if ((state == GRPC_CHANNEL_TRANSIENT_FAILURE ||
+       state == GRPC_CHANNEL_FATAL_FAILURE) &&
+      chand->lb_policy != NULL) {
+    /* cancel fail-fast picks */
+    grpc_lb_policy_cancel_picks(
+        exec_ctx, chand->lb_policy,
+        /* mask= */ GRPC_INITIAL_METADATA_IGNORE_CONNECTIVITY,
+        /* check= */ 0);
+  }
+  grpc_connectivity_state_set(exec_ctx, &chand->state_tracker, state, reason);
+}
+
 static void on_lb_policy_state_changed_locked(
     grpc_exec_ctx *exec_ctx, lb_policy_connectivity_watcher *w) {
   grpc_connectivity_state publish_state = w->state;
@@ -127,8 +143,8 @@ static void on_lb_policy_state_changed_locked(
     GRPC_LB_POLICY_UNREF(exec_ctx, w->chand->lb_policy, "channel");
     w->chand->lb_policy = NULL;
   }
-  grpc_connectivity_state_set(exec_ctx, &w->chand->state_tracker, publish_state,
-                              "lb_changed");
+  set_channel_connectivity_state_locked(exec_ctx, w->chand, publish_state,
+                                        "lb_changed");
   if (w->state != GRPC_CHANNEL_FATAL_FAILURE) {
     watch_lb_policy(exec_ctx, w->chand, w->lb_policy, w->state);
   }
@@ -200,8 +216,8 @@ static void cc_on_config_changed(grpc_exec_ctx *exec_ctx, void *arg,
   }
 
   if (iomgr_success && chand->resolver) {
-    grpc_connectivity_state_set(exec_ctx, &chand->state_tracker, state,
-                                "new_lb+resolver");
+    set_channel_connectivity_state_locked(exec_ctx, chand, state,
+                                          "new_lb+resolver");
     if (lb_policy != NULL) {
       watch_lb_policy(exec_ctx, chand, lb_policy, state);
     }
@@ -216,8 +232,8 @@ static void cc_on_config_changed(grpc_exec_ctx *exec_ctx, void *arg,
       GRPC_RESOLVER_UNREF(exec_ctx, chand->resolver, "channel");
       chand->resolver = NULL;
     }
-    grpc_connectivity_state_set(exec_ctx, &chand->state_tracker,
-                                GRPC_CHANNEL_FATAL_FAILURE, "resolver_gone");
+    set_channel_connectivity_state_locked(
+        exec_ctx, chand, GRPC_CHANNEL_FATAL_FAILURE, "resolver_gone");
     gpr_mu_unlock(&chand->mu_config);
   }
 
@@ -272,8 +288,8 @@ static void cc_start_transport_op(grpc_exec_ctx *exec_ctx,
   }
 
   if (op->disconnect && chand->resolver != NULL) {
-    grpc_connectivity_state_set(exec_ctx, &chand->state_tracker,
-                                GRPC_CHANNEL_FATAL_FAILURE, "disconnect");
+    set_channel_connectivity_state_locked(
+        exec_ctx, chand, GRPC_CHANNEL_FATAL_FAILURE, "disconnect");
     grpc_resolver_shutdown(exec_ctx, chand->resolver);
     GRPC_RESOLVER_UNREF(exec_ctx, chand->resolver, "channel");
     chand->resolver = NULL;
@@ -290,6 +306,7 @@ static void cc_start_transport_op(grpc_exec_ctx *exec_ctx,
 
 typedef struct {
   grpc_metadata_batch *initial_metadata;
+  uint32_t initial_metadata_flags;
   grpc_connected_subchannel **connected_subchannel;
   grpc_closure *on_ready;
   grpc_call_element *elem;
@@ -298,6 +315,7 @@ typedef struct {
 
 static int cc_pick_subchannel(grpc_exec_ctx *exec_ctx, void *arg,
                               grpc_metadata_batch *initial_metadata,
+                              uint32_t initial_metadata_flags,
                               grpc_connected_subchannel **connected_subchannel,
                               grpc_closure *on_ready);
 
@@ -308,6 +326,7 @@ static void continue_picking(grpc_exec_ctx *exec_ctx, void *arg, bool success) {
   } else if (cpa->connected_subchannel == NULL) {
     /* cancelled, do nothing */
   } else if (cc_pick_subchannel(exec_ctx, cpa->elem, cpa->initial_metadata,
+                                cpa->initial_metadata_flags,
                                 cpa->connected_subchannel, cpa->on_ready)) {
     grpc_exec_ctx_enqueue(exec_ctx, cpa->on_ready, true, NULL);
   }
@@ -316,6 +335,7 @@ static void continue_picking(grpc_exec_ctx *exec_ctx, void *arg, bool success) {
 
 static int cc_pick_subchannel(grpc_exec_ctx *exec_ctx, void *elemp,
                               grpc_metadata_batch *initial_metadata,
+                              uint32_t initial_metadata_flags,
                               grpc_connected_subchannel **connected_subchannel,
                               grpc_closure *on_ready) {
   grpc_call_element *elem = elemp;
@@ -349,7 +369,8 @@ static int cc_pick_subchannel(grpc_exec_ctx *exec_ctx, void *elemp,
     GRPC_LB_POLICY_REF(lb_policy, "cc_pick_subchannel");
     gpr_mu_unlock(&chand->mu_config);
     r = grpc_lb_policy_pick(exec_ctx, lb_policy, calld->pollset,
-                            initial_metadata, connected_subchannel, on_ready);
+                            initial_metadata, initial_metadata_flags,
+                            connected_subchannel, on_ready);
     GRPC_LB_POLICY_UNREF(exec_ctx, lb_policy, "cc_pick_subchannel");
     return r;
   }
@@ -362,6 +383,7 @@ static int cc_pick_subchannel(grpc_exec_ctx *exec_ctx, void *elemp,
   }
   cpa = gpr_malloc(sizeof(*cpa));
   cpa->initial_metadata = initial_metadata;
+  cpa->initial_metadata_flags = initial_metadata_flags;
   cpa->connected_subchannel = connected_subchannel;
   cpa->on_ready = on_ready;
   cpa->elem = elem;
diff --git a/src/core/lib/channel/client_channel.h b/src/core/ext/client_config/client_channel.h
index ac418c8c51..1e47ad34ad 100644
--- a/src/core/lib/channel/client_channel.h
+++ b/src/core/ext/client_config/client_channel.h
@@ -31,11 +31,11 @@
  *
  */
 
-#ifndef GRPC_CORE_LIB_CHANNEL_CLIENT_CHANNEL_H
-#define GRPC_CORE_LIB_CHANNEL_CLIENT_CHANNEL_H
+#ifndef GRPC_CORE_EXT_CLIENT_CONFIG_CLIENT_CHANNEL_H
+#define GRPC_CORE_EXT_CLIENT_CONFIG_CLIENT_CHANNEL_H
 
+#include "src/core/ext/client_config/resolver.h"
 #include "src/core/lib/channel/channel_stack.h"
-#include "src/core/lib/client_config/resolver.h"
 
 /* A client channel is a channel that begins disconnected, and can connect
    to some endpoint on demand. If that endpoint disconnects, it will be
@@ -60,4 +60,4 @@ 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_LIB_CHANNEL_CLIENT_CHANNEL_H */
+#endif /* GRPC_CORE_EXT_CLIENT_CONFIG_CLIENT_CHANNEL_H */
diff --git a/src/core/ext/client_config/client_channel_factory.c b/src/core/ext/client_config/client_channel_factory.c
new file mode 100644
index 0000000000..71c64c0da1
--- /dev/null
+++ b/src/core/ext/client_config/client_channel_factory.c
@@ -0,0 +1,57 @@
+/*
+ *
+ * Copyright 2015, Google Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ *     * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#include "src/core/ext/client_config/client_channel_factory.h"
+
+void grpc_client_channel_factory_ref(grpc_client_channel_factory* factory) {
+  factory->vtable->ref(factory);
+}
+
+void grpc_client_channel_factory_unref(grpc_exec_ctx* exec_ctx,
+                                       grpc_client_channel_factory* factory) {
+  factory->vtable->unref(exec_ctx, factory);
+}
+
+grpc_subchannel* grpc_client_channel_factory_create_subchannel(
+    grpc_exec_ctx* exec_ctx, grpc_client_channel_factory* factory,
+    grpc_subchannel_args* args) {
+  return factory->vtable->create_subchannel(exec_ctx, factory, args);
+}
+
+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) {
+  return factory->vtable->create_client_channel(exec_ctx, factory, target, type,
+                                                args);
+}
diff --git a/src/core/ext/client_config/client_channel_factory.h b/src/core/ext/client_config/client_channel_factory.h
new file mode 100644
index 0000000000..1241b9b781
--- /dev/null
+++ b/src/core/ext/client_config/client_channel_factory.h
@@ -0,0 +1,85 @@
+/*
+ *
+ * Copyright 2015, Google Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ *     * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#ifndef GRPC_CORE_EXT_CLIENT_CONFIG_CLIENT_CHANNEL_FACTORY_H
+#define GRPC_CORE_EXT_CLIENT_CONFIG_CLIENT_CHANNEL_FACTORY_H
+
+#include <grpc/impl/codegen/grpc_types.h>
+
+#include "src/core/ext/client_config/subchannel.h"
+#include "src/core/lib/channel/channel_stack.h"
+
+typedef struct grpc_client_channel_factory grpc_client_channel_factory;
+typedef struct grpc_client_channel_factory_vtable
+    grpc_client_channel_factory_vtable;
+
+typedef enum {
+  GRPC_CLIENT_CHANNEL_TYPE_REGULAR, /** for the user-level regular calls */
+  GRPC_CLIENT_CHANNEL_TYPE_LOAD_BALANCING, /** for communication with a load
+                                              balancing service */
+} grpc_client_channel_type;
+
+/** Constructor for new configured channels.
+    Creating decorators around this type is encouraged to adapt behavior. */
+struct grpc_client_channel_factory {
+  const grpc_client_channel_factory_vtable *vtable;
+};
+
+struct grpc_client_channel_factory_vtable {
+  void (*ref)(grpc_client_channel_factory *factory);
+  void (*unref)(grpc_exec_ctx *exec_ctx, grpc_client_channel_factory *factory);
+  grpc_subchannel *(*create_subchannel)(grpc_exec_ctx *exec_ctx,
+                                        grpc_client_channel_factory *factory,
+                                        grpc_subchannel_args *args);
+  grpc_channel *(*create_client_channel)(grpc_exec_ctx *exec_ctx,
+                                         grpc_client_channel_factory *factory,
+                                         const char *target,
+                                         grpc_client_channel_type type,
+                                         grpc_channel_args *args);
+};
+
+void grpc_client_channel_factory_ref(grpc_client_channel_factory *factory);
+void grpc_client_channel_factory_unref(grpc_exec_ctx *exec_ctx,
+                                       grpc_client_channel_factory *factory);
+
+/** Create a new grpc_subchannel */
+grpc_subchannel *grpc_client_channel_factory_create_subchannel(
+    grpc_exec_ctx *exec_ctx, grpc_client_channel_factory *factory,
+    grpc_subchannel_args *args);
+
+/** Create a new grpc_channel */
+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 */
diff --git a/src/core/lib/client_config/client_config.c b/src/core/ext/client_config/client_config.c
index 2521023364..f9b8e68698 100644
--- a/src/core/lib/client_config/client_config.c
+++ b/src/core/ext/client_config/client_config.c
@@ -31,7 +31,7 @@
  *
  */
 
-#include "src/core/lib/client_config/client_config.h"
+#include "src/core/ext/client_config/client_config.h"
 
 #include <string.h>
 
diff --git a/src/core/lib/client_config/client_config.h b/src/core/ext/client_config/client_config.h
index 8dc2f6b299..a6290cbcf0 100644
--- a/src/core/lib/client_config/client_config.h
+++ b/src/core/ext/client_config/client_config.h
@@ -31,10 +31,10 @@
  *
  */
 
-#ifndef GRPC_CORE_LIB_CLIENT_CONFIG_CLIENT_CONFIG_H
-#define GRPC_CORE_LIB_CLIENT_CONFIG_CLIENT_CONFIG_H
+#ifndef GRPC_CORE_EXT_CLIENT_CONFIG_CLIENT_CONFIG_H
+#define GRPC_CORE_EXT_CLIENT_CONFIG_CLIENT_CONFIG_H
 
-#include "src/core/lib/client_config/lb_policy.h"
+#include "src/core/ext/client_config/lb_policy.h"
 
 /** Total configuration for a client. Provided, and updated, by
     grpc_resolver */
@@ -50,4 +50,4 @@ void grpc_client_config_set_lb_policy(grpc_client_config *client_config,
 grpc_lb_policy *grpc_client_config_get_lb_policy(
     grpc_client_config *client_config);
 
-#endif /* GRPC_CORE_LIB_CLIENT_CONFIG_CLIENT_CONFIG_H */
+#endif /* GRPC_CORE_EXT_CLIENT_CONFIG_CLIENT_CONFIG_H */
diff --git a/src/core/lib/client_config/connector.c b/src/core/ext/client_config/connector.c
index 4c7b823dac..5b629ed5fb 100644
--- a/src/core/lib/client_config/connector.c
+++ b/src/core/ext/client_config/connector.c
@@ -31,7 +31,7 @@
  *
  */
 
-#include "src/core/lib/client_config/connector.h"
+#include "src/core/ext/client_config/connector.h"
 
 grpc_connector* grpc_connector_ref(grpc_connector* connector) {
   connector->vtable->ref(connector);
diff --git a/src/core/lib/client_config/connector.h b/src/core/ext/client_config/connector.h
index 39870a261c..dd85dfcb7d 100644
--- a/src/core/lib/client_config/connector.h
+++ b/src/core/ext/client_config/connector.h
@@ -31,8 +31,8 @@
  *
  */
 
-#ifndef GRPC_CORE_LIB_CLIENT_CONFIG_CONNECTOR_H
-#define GRPC_CORE_LIB_CLIENT_CONFIG_CONNECTOR_H
+#ifndef GRPC_CORE_EXT_CLIENT_CONFIG_CONNECTOR_H
+#define GRPC_CORE_EXT_CLIENT_CONFIG_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_LIB_CLIENT_CONFIG_CONNECTOR_H */
+#endif /* GRPC_CORE_EXT_CLIENT_CONFIG_CONNECTOR_H */
diff --git a/src/core/lib/client_config/default_initial_connect_string.c b/src/core/ext/client_config/default_initial_connect_string.c
index a70da4a84a..a70da4a84a 100644
--- a/src/core/lib/client_config/default_initial_connect_string.c
+++ b/src/core/ext/client_config/default_initial_connect_string.c
diff --git a/src/core/lib/client_config/initial_connect_string.c b/src/core/ext/client_config/initial_connect_string.c
index 4034ea2e87..41580d2106 100644
--- a/src/core/lib/client_config/initial_connect_string.c
+++ b/src/core/ext/client_config/initial_connect_string.c
@@ -31,7 +31,7 @@
  *
  */
 
-#include "src/core/lib/client_config/initial_connect_string.h"
+#include "src/core/ext/client_config/initial_connect_string.h"
 
 #include <stddef.h>
 
diff --git a/src/core/lib/client_config/initial_connect_string.h b/src/core/ext/client_config/initial_connect_string.h
index 51302768c6..06f0767832 100644
--- a/src/core/lib/client_config/initial_connect_string.h
+++ b/src/core/ext/client_config/initial_connect_string.h
@@ -31,8 +31,8 @@
  *
  */
 
-#ifndef GRPC_CORE_LIB_CLIENT_CONFIG_INITIAL_CONNECT_STRING_H
-#define GRPC_CORE_LIB_CLIENT_CONFIG_INITIAL_CONNECT_STRING_H
+#ifndef GRPC_CORE_EXT_CLIENT_CONFIG_INITIAL_CONNECT_STRING_H
+#define GRPC_CORE_EXT_CLIENT_CONFIG_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_LIB_CLIENT_CONFIG_INITIAL_CONNECT_STRING_H */
+#endif /* GRPC_CORE_EXT_CLIENT_CONFIG_INITIAL_CONNECT_STRING_H */
diff --git a/src/core/lib/client_config/lb_policy.c b/src/core/ext/client_config/lb_policy.c
index 3d23669ec2..a7ad9842dc 100644
--- a/src/core/lib/client_config/lb_policy.c
+++ b/src/core/ext/client_config/lb_policy.c
@@ -31,7 +31,7 @@
  *
  */
 
-#include "src/core/lib/client_config/lb_policy.h"
+#include "src/core/ext/client_config/lb_policy.h"
 
 #define WEAK_REF_BITS 16
 
@@ -101,10 +101,11 @@ void grpc_lb_policy_weak_unref(grpc_exec_ctx *exec_ctx,
 int grpc_lb_policy_pick(grpc_exec_ctx *exec_ctx, grpc_lb_policy *policy,
                         grpc_pollset *pollset,
                         grpc_metadata_batch *initial_metadata,
+                        uint32_t initial_metadata_flags,
                         grpc_connected_subchannel **target,
                         grpc_closure *on_complete) {
   return policy->vtable->pick(exec_ctx, policy, pollset, initial_metadata,
-                              target, on_complete);
+                              initial_metadata_flags, target, on_complete);
 }
 
 void grpc_lb_policy_cancel_pick(grpc_exec_ctx *exec_ctx, grpc_lb_policy *policy,
@@ -112,6 +113,14 @@ void grpc_lb_policy_cancel_pick(grpc_exec_ctx *exec_ctx, grpc_lb_policy *policy,
   policy->vtable->cancel_pick(exec_ctx, policy, target);
 }
 
+void grpc_lb_policy_cancel_picks(grpc_exec_ctx *exec_ctx,
+                                 grpc_lb_policy *policy,
+                                 uint32_t initial_metadata_flags_mask,
+                                 uint32_t initial_metadata_flags_eq) {
+  policy->vtable->cancel_picks(exec_ctx, policy, initial_metadata_flags_mask,
+                               initial_metadata_flags_eq);
+}
+
 void grpc_lb_policy_exit_idle(grpc_exec_ctx *exec_ctx, grpc_lb_policy *policy) {
   policy->vtable->exit_idle(exec_ctx, policy);
 }
diff --git a/src/core/lib/client_config/lb_policy.h b/src/core/ext/client_config/lb_policy.h
index a63e8e68df..0384e0b2eb 100644
--- a/src/core/lib/client_config/lb_policy.h
+++ b/src/core/ext/client_config/lb_policy.h
@@ -31,10 +31,10 @@
  *
  */
 
-#ifndef GRPC_CORE_LIB_CLIENT_CONFIG_LB_POLICY_H
-#define GRPC_CORE_LIB_CLIENT_CONFIG_LB_POLICY_H
+#ifndef GRPC_CORE_EXT_CLIENT_CONFIG_LB_POLICY_H
+#define GRPC_CORE_EXT_CLIENT_CONFIG_LB_POLICY_H
 
-#include "src/core/lib/client_config/subchannel.h"
+#include "src/core/ext/client_config/subchannel.h"
 #include "src/core/lib/transport/connectivity_state.h"
 
 /** A load balancing policy: specified by a vtable and a struct (which
@@ -60,9 +60,13 @@ struct grpc_lb_policy_vtable {
   /** implement grpc_lb_policy_pick */
   int (*pick)(grpc_exec_ctx *exec_ctx, grpc_lb_policy *policy,
               grpc_pollset *pollset, grpc_metadata_batch *initial_metadata,
+              uint32_t initial_metadata_flags,
               grpc_connected_subchannel **target, grpc_closure *on_complete);
   void (*cancel_pick)(grpc_exec_ctx *exec_ctx, grpc_lb_policy *policy,
                       grpc_connected_subchannel **target);
+  void (*cancel_picks)(grpc_exec_ctx *exec_ctx, grpc_lb_policy *policy,
+                       uint32_t initial_metadata_flags_mask,
+                       uint32_t initial_metadata_flags_eq);
 
   void (*ping_one)(grpc_exec_ctx *exec_ctx, grpc_lb_policy *policy,
                    grpc_closure *closure);
@@ -122,6 +126,7 @@ void grpc_lb_policy_init(grpc_lb_policy *policy,
 int grpc_lb_policy_pick(grpc_exec_ctx *exec_ctx, grpc_lb_policy *policy,
                         grpc_pollset *pollset,
                         grpc_metadata_batch *initial_metadata,
+                        uint32_t initial_metadata_flags,
                         grpc_connected_subchannel **target,
                         grpc_closure *on_complete);
 
@@ -131,6 +136,14 @@ void grpc_lb_policy_ping_one(grpc_exec_ctx *exec_ctx, grpc_lb_policy *policy,
 void grpc_lb_policy_cancel_pick(grpc_exec_ctx *exec_ctx, grpc_lb_policy *policy,
                                 grpc_connected_subchannel **target);
 
+/** Cancel all pending picks which have:
+    (initial_metadata_flags & initial_metadata_flags_mask) ==
+         initial_metadata_flags_eq */
+void grpc_lb_policy_cancel_picks(grpc_exec_ctx *exec_ctx,
+                                 grpc_lb_policy *policy,
+                                 uint32_t initial_metadata_flags_mask,
+                                 uint32_t initial_metadata_flags_eq);
+
 void grpc_lb_policy_exit_idle(grpc_exec_ctx *exec_ctx, grpc_lb_policy *policy);
 
 void grpc_lb_policy_notify_on_state_change(grpc_exec_ctx *exec_ctx,
@@ -141,4 +154,4 @@ void grpc_lb_policy_notify_on_state_change(grpc_exec_ctx *exec_ctx,
 grpc_connectivity_state grpc_lb_policy_check_connectivity(
     grpc_exec_ctx *exec_ctx, grpc_lb_policy *policy);
 
-#endif /* GRPC_CORE_LIB_CLIENT_CONFIG_LB_POLICY_H */
+#endif /* GRPC_CORE_EXT_CLIENT_CONFIG_LB_POLICY_H */
diff --git a/src/core/lib/client_config/lb_policy_factory.c b/src/core/ext/client_config/lb_policy_factory.c
index 92e1f5f08b..70e46ef3cf 100644
--- a/src/core/lib/client_config/lb_policy_factory.c
+++ b/src/core/ext/client_config/lb_policy_factory.c
@@ -31,7 +31,7 @@
  *
  */
 
-#include "src/core/lib/client_config/lb_policy_factory.h"
+#include "src/core/ext/client_config/lb_policy_factory.h"
 
 void grpc_lb_policy_factory_ref(grpc_lb_policy_factory* factory) {
   factory->vtable->ref(factory);
diff --git a/src/core/lib/client_config/lb_policy_factory.h b/src/core/ext/client_config/lb_policy_factory.h
index 6f21912821..1c89b28b59 100644
--- a/src/core/lib/client_config/lb_policy_factory.h
+++ b/src/core/ext/client_config/lb_policy_factory.h
@@ -31,11 +31,11 @@
  *
  */
 
-#ifndef GRPC_CORE_LIB_CLIENT_CONFIG_LB_POLICY_FACTORY_H
-#define GRPC_CORE_LIB_CLIENT_CONFIG_LB_POLICY_FACTORY_H
+#ifndef GRPC_CORE_EXT_CLIENT_CONFIG_LB_POLICY_FACTORY_H
+#define GRPC_CORE_EXT_CLIENT_CONFIG_LB_POLICY_FACTORY_H
 
-#include "src/core/lib/client_config/lb_policy.h"
-#include "src/core/lib/client_config/subchannel_factory.h"
+#include "src/core/ext/client_config/client_channel_factory.h"
+#include "src/core/ext/client_config/lb_policy.h"
 #include "src/core/lib/iomgr/resolve_address.h"
 
 #include "src/core/lib/iomgr/exec_ctx.h"
@@ -51,7 +51,7 @@ struct grpc_lb_policy_factory {
 
 typedef struct grpc_lb_policy_args {
   grpc_resolved_addresses *addresses;
-  grpc_subchannel_factory *subchannel_factory;
+  grpc_client_channel_factory *client_channel_factory;
 } grpc_lb_policy_args;
 
 struct grpc_lb_policy_factory_vtable {
@@ -75,4 +75,4 @@ 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_LIB_CLIENT_CONFIG_LB_POLICY_FACTORY_H */
+#endif /* GRPC_CORE_EXT_CLIENT_CONFIG_LB_POLICY_FACTORY_H */
diff --git a/src/core/lib/client_config/lb_policy_registry.c b/src/core/ext/client_config/lb_policy_registry.c
index af396362a1..a23643ecc6 100644
--- a/src/core/lib/client_config/lb_policy_registry.c
+++ b/src/core/ext/client_config/lb_policy_registry.c
@@ -31,7 +31,7 @@
  *
  */
 
-#include "src/core/lib/client_config/lb_policy_registry.h"
+#include "src/core/ext/client_config/lb_policy_registry.h"
 
 #include <string.h>
 
diff --git a/src/core/lib/client_config/lb_policy_registry.h b/src/core/ext/client_config/lb_policy_registry.h
index 4b8495d8a1..92f38d6de6 100644
--- a/src/core/lib/client_config/lb_policy_registry.h
+++ b/src/core/ext/client_config/lb_policy_registry.h
@@ -31,10 +31,10 @@
  *
  */
 
-#ifndef GRPC_CORE_LIB_CLIENT_CONFIG_LB_POLICY_REGISTRY_H
-#define GRPC_CORE_LIB_CLIENT_CONFIG_LB_POLICY_REGISTRY_H
+#ifndef GRPC_CORE_EXT_CLIENT_CONFIG_LB_POLICY_REGISTRY_H
+#define GRPC_CORE_EXT_CLIENT_CONFIG_LB_POLICY_REGISTRY_H
 
-#include "src/core/lib/client_config/lb_policy_factory.h"
+#include "src/core/ext/client_config/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_LIB_CLIENT_CONFIG_LB_POLICY_REGISTRY_H */
+#endif /* GRPC_CORE_EXT_CLIENT_CONFIG_LB_POLICY_REGISTRY_H */
diff --git a/src/core/lib/client_config/resolver.c b/src/core/ext/client_config/resolver.c
index b9eef5575f..eb004455bd 100644
--- a/src/core/lib/client_config/resolver.c
+++ b/src/core/ext/client_config/resolver.c
@@ -31,7 +31,7 @@
  *
  */
 
-#include "src/core/lib/client_config/resolver.h"
+#include "src/core/ext/client_config/resolver.h"
 
 void grpc_resolver_init(grpc_resolver *resolver,
                         const grpc_resolver_vtable *vtable) {
diff --git a/src/core/lib/client_config/resolver.h b/src/core/ext/client_config/resolver.h
index cf0bb2bc7a..6ecb5d2774 100644
--- a/src/core/lib/client_config/resolver.h
+++ b/src/core/ext/client_config/resolver.h
@@ -31,11 +31,11 @@
  *
  */
 
-#ifndef GRPC_CORE_LIB_CLIENT_CONFIG_RESOLVER_H
-#define GRPC_CORE_LIB_CLIENT_CONFIG_RESOLVER_H
+#ifndef GRPC_CORE_EXT_CLIENT_CONFIG_RESOLVER_H
+#define GRPC_CORE_EXT_CLIENT_CONFIG_RESOLVER_H
 
-#include "src/core/lib/client_config/client_config.h"
-#include "src/core/lib/client_config/subchannel.h"
+#include "src/core/ext/client_config/client_config.h"
+#include "src/core/ext/client_config/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_client_config **target_config,
                         grpc_closure *on_complete);
 
-#endif /* GRPC_CORE_LIB_CLIENT_CONFIG_RESOLVER_H */
+#endif /* GRPC_CORE_EXT_CLIENT_CONFIG_RESOLVER_H */
diff --git a/src/core/lib/client_config/resolver_factory.c b/src/core/ext/client_config/resolver_factory.c
index 001fa28536..67832dcf59 100644
--- a/src/core/lib/client_config/resolver_factory.c
+++ b/src/core/ext/client_config/resolver_factory.c
@@ -31,7 +31,7 @@
  *
  */
 
-#include "src/core/lib/client_config/resolver_factory.h"
+#include "src/core/ext/client_config/resolver_factory.h"
 
 void grpc_resolver_factory_ref(grpc_resolver_factory* factory) {
   factory->vtable->ref(factory);
diff --git a/src/core/lib/client_config/resolver_factory.h b/src/core/ext/client_config/resolver_factory.h
index a5bca06475..4eb6979aad 100644
--- a/src/core/lib/client_config/resolver_factory.h
+++ b/src/core/ext/client_config/resolver_factory.h
@@ -31,12 +31,12 @@
  *
  */
 
-#ifndef GRPC_CORE_LIB_CLIENT_CONFIG_RESOLVER_FACTORY_H
-#define GRPC_CORE_LIB_CLIENT_CONFIG_RESOLVER_FACTORY_H
+#ifndef GRPC_CORE_EXT_CLIENT_CONFIG_RESOLVER_FACTORY_H
+#define GRPC_CORE_EXT_CLIENT_CONFIG_RESOLVER_FACTORY_H
 
-#include "src/core/lib/client_config/resolver.h"
-#include "src/core/lib/client_config/subchannel_factory.h"
-#include "src/core/lib/client_config/uri_parser.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"
 
 typedef struct grpc_resolver_factory grpc_resolver_factory;
 typedef struct grpc_resolver_factory_vtable grpc_resolver_factory_vtable;
@@ -49,7 +49,7 @@ struct grpc_resolver_factory {
 
 typedef struct grpc_resolver_args {
   grpc_uri *uri;
-  grpc_subchannel_factory *subchannel_factory;
+  grpc_client_channel_factory *client_channel_factory;
 } grpc_resolver_args;
 
 struct grpc_resolver_factory_vtable {
@@ -79,4 +79,4 @@ grpc_resolver *grpc_resolver_factory_create_resolver(
 char *grpc_resolver_factory_get_default_authority(
     grpc_resolver_factory *factory, grpc_uri *uri);
 
-#endif /* GRPC_CORE_LIB_CLIENT_CONFIG_RESOLVER_FACTORY_H */
+#endif /* GRPC_CORE_EXT_CLIENT_CONFIG_RESOLVER_FACTORY_H */
diff --git a/src/core/lib/client_config/resolver_registry.c b/src/core/ext/client_config/resolver_registry.c
index 5f3db273b5..07f29bcb27 100644
--- a/src/core/lib/client_config/resolver_registry.c
+++ b/src/core/ext/client_config/resolver_registry.c
@@ -31,7 +31,7 @@
  *
  */
 
-#include "src/core/lib/client_config/resolver_registry.h"
+#include "src/core/ext/client_config/resolver_registry.h"
 
 #include <string.h>
 
@@ -123,14 +123,14 @@ static grpc_resolver_factory *resolve_factory(const char *target,
 }
 
 grpc_resolver *grpc_resolver_create(
-    const char *target, grpc_subchannel_factory *subchannel_factory) {
+    const char *target, grpc_client_channel_factory *client_channel_factory) {
   grpc_uri *uri = NULL;
   grpc_resolver_factory *factory = resolve_factory(target, &uri);
   grpc_resolver *resolver;
   grpc_resolver_args args;
   memset(&args, 0, sizeof(args));
   args.uri = uri;
-  args.subchannel_factory = subchannel_factory;
+  args.client_channel_factory = client_channel_factory;
   resolver = grpc_resolver_factory_create_resolver(factory, &args);
   grpc_uri_destroy(uri);
   return resolver;
diff --git a/src/core/lib/client_config/resolver_registry.h b/src/core/ext/client_config/resolver_registry.h
index 36c4f2fe03..5ef1383cd3 100644
--- a/src/core/lib/client_config/resolver_registry.h
+++ b/src/core/ext/client_config/resolver_registry.h
@@ -31,10 +31,10 @@
  *
  */
 
-#ifndef GRPC_CORE_LIB_CLIENT_CONFIG_RESOLVER_REGISTRY_H
-#define GRPC_CORE_LIB_CLIENT_CONFIG_RESOLVER_REGISTRY_H
+#ifndef GRPC_CORE_EXT_CLIENT_CONFIG_RESOLVER_REGISTRY_H
+#define GRPC_CORE_EXT_CLIENT_CONFIG_RESOLVER_REGISTRY_H
 
-#include "src/core/lib/client_config/resolver_factory.h"
+#include "src/core/ext/client_config/resolver_factory.h"
 
 void grpc_resolver_registry_init(const char *default_prefix);
 void grpc_resolver_registry_shutdown(void);
@@ -56,7 +56,7 @@ void grpc_register_resolver_type(grpc_resolver_factory *factory);
     return it.
     If a resolver factory was not found, return NULL. */
 grpc_resolver *grpc_resolver_create(
-    const char *target, grpc_subchannel_factory *subchannel_factory);
+    const char *target, grpc_client_channel_factory *client_channel_factory);
 
 /** Find a resolver factory given a name and return an (owned-by-the-caller)
  *  reference to it */
@@ -66,4 +66,4 @@ 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_LIB_CLIENT_CONFIG_RESOLVER_REGISTRY_H */
+#endif /* GRPC_CORE_EXT_CLIENT_CONFIG_RESOLVER_REGISTRY_H */
diff --git a/src/core/lib/client_config/subchannel.c b/src/core/ext/client_config/subchannel.c
index 47c53a16ba..20cf245a5b 100644
--- a/src/core/lib/client_config/subchannel.c
+++ b/src/core/ext/client_config/subchannel.c
@@ -31,18 +31,18 @@
  *
  */
 
-#include "src/core/lib/client_config/subchannel.h"
+#include "src/core/ext/client_config/subchannel.h"
 
 #include <string.h>
 
 #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/lib/channel/channel_args.h"
-#include "src/core/lib/channel/client_channel.h"
 #include "src/core/lib/channel/connected_channel.h"
-#include "src/core/lib/client_config/initial_connect_string.h"
-#include "src/core/lib/client_config/subchannel_index.h"
 #include "src/core/lib/iomgr/timer.h"
 #include "src/core/lib/profiling/timers.h"
 #include "src/core/lib/support/backoff.h"
@@ -54,7 +54,7 @@
 #define STRONG_REF_MASK (~(gpr_atm)((1 << INTERNAL_REF_BITS) - 1))
 
 #define GRPC_SUBCHANNEL_MIN_CONNECT_TIMEOUT_SECONDS 20
-#define GRPC_SUBCHANNEL_INITIAL_CONNECT_BACKOFF_SECONDS 1
+#define GRPC_SUBCHANNEL_INITIAL_CONNECT_BACKOFF_SECONDS 2
 #define GRPC_SUBCHANNEL_RECONNECT_BACKOFF_MULTIPLIER 1.6
 #define GRPC_SUBCHANNEL_RECONNECT_MAX_BACKOFF_SECONDS 120
 #define GRPC_SUBCHANNEL_RECONNECT_JITTER 0.2
@@ -352,6 +352,25 @@ grpc_subchannel *grpc_subchannel_create(grpc_exec_ctx *exec_ctx,
                          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)) {
+        if (c->args->args[i].type == GRPC_ARG_INTEGER) {
+          if (c->args->args[i].value.integer >= 0) {
+            gpr_backoff_init(
+                &c->backoff_state, GRPC_SUBCHANNEL_RECONNECT_BACKOFF_MULTIPLIER,
+                GRPC_SUBCHANNEL_RECONNECT_JITTER,
+                GPR_MIN(c->args->args[i].value.integer,
+                        GRPC_SUBCHANNEL_INITIAL_CONNECT_BACKOFF_SECONDS * 1000),
+                c->args->args[i].value.integer);
+          } else {
+            gpr_log(GPR_ERROR, GRPC_ARG_MAX_RECONNECT_BACKOFF_MS
+                    " : must be non-negative");
+          }
+        } else {
+          gpr_log(GPR_ERROR,
+                  GRPC_ARG_MAX_RECONNECT_BACKOFF_MS " : must be an integer");
+        }
+      }
     }
   }
   gpr_mu_init(&c->mu);
diff --git a/src/core/lib/client_config/subchannel.h b/src/core/ext/client_config/subchannel.h
index 68aeff39a1..0765a544e8 100644
--- a/src/core/lib/client_config/subchannel.h
+++ b/src/core/ext/client_config/subchannel.h
@@ -31,11 +31,11 @@
  *
  */
 
-#ifndef GRPC_CORE_LIB_CLIENT_CONFIG_SUBCHANNEL_H
-#define GRPC_CORE_LIB_CLIENT_CONFIG_SUBCHANNEL_H
+#ifndef GRPC_CORE_EXT_CLIENT_CONFIG_SUBCHANNEL_H
+#define GRPC_CORE_EXT_CLIENT_CONFIG_SUBCHANNEL_H
 
+#include "src/core/ext/client_config/connector.h"
 #include "src/core/lib/channel/channel_stack.h"
-#include "src/core/lib/client_config/connector.h"
 #include "src/core/lib/transport/connectivity_state.h"
 
 /** A (sub-)channel that knows how to connect to exactly one target
@@ -171,4 +171,4 @@ grpc_subchannel *grpc_subchannel_create(grpc_exec_ctx *exec_ctx,
                                         grpc_connector *connector,
                                         grpc_subchannel_args *args);
 
-#endif /* GRPC_CORE_LIB_CLIENT_CONFIG_SUBCHANNEL_H */
+#endif /* GRPC_CORE_EXT_CLIENT_CONFIG_SUBCHANNEL_H */
diff --git a/src/core/lib/channel/subchannel_call_holder.c b/src/core/ext/client_config/subchannel_call_holder.c
index 22f3679bf5..3db462b246 100644
--- a/src/core/lib/channel/subchannel_call_holder.c
+++ b/src/core/ext/client_config/subchannel_call_holder.c
@@ -31,7 +31,7 @@
  *
  */
 
-#include "src/core/lib/channel/subchannel_call_holder.h"
+#include "src/core/ext/client_config/subchannel_call_holder.h"
 
 #include <grpc/support/alloc.h>
 
@@ -127,7 +127,7 @@ retry:
           break;
         case GRPC_SUBCHANNEL_CALL_HOLDER_PICKING_SUBCHANNEL:
           holder->pick_subchannel(exec_ctx, holder->pick_subchannel_arg, NULL,
-                                  &holder->connected_subchannel, NULL);
+                                  0, &holder->connected_subchannel, NULL);
           break;
       }
       gpr_mu_unlock(&holder->mu);
@@ -145,7 +145,8 @@ retry:
     GRPC_CALL_STACK_REF(holder->owning_call, "pick_subchannel");
     if (holder->pick_subchannel(
             exec_ctx, holder->pick_subchannel_arg, op->send_initial_metadata,
-            &holder->connected_subchannel, &holder->next_step)) {
+            op->send_initial_metadata_flags, &holder->connected_subchannel,
+            &holder->next_step)) {
       holder->creation_phase = GRPC_SUBCHANNEL_CALL_HOLDER_NOT_CREATING;
       GRPC_CALL_STACK_UNREF(exec_ctx, holder->owning_call, "pick_subchannel");
     }
diff --git a/src/core/lib/channel/subchannel_call_holder.h b/src/core/ext/client_config/subchannel_call_holder.h
index 5cf291a266..9299908788 100644
--- a/src/core/lib/channel/subchannel_call_holder.h
+++ b/src/core/ext/client_config/subchannel_call_holder.h
@@ -31,10 +31,10 @@
  *
  */
 
-#ifndef GRPC_CORE_LIB_CHANNEL_SUBCHANNEL_CALL_HOLDER_H
-#define GRPC_CORE_LIB_CHANNEL_SUBCHANNEL_CALL_HOLDER_H
+#ifndef GRPC_CORE_EXT_CLIENT_CONFIG_SUBCHANNEL_CALL_HOLDER_H
+#define GRPC_CORE_EXT_CLIENT_CONFIG_SUBCHANNEL_CALL_HOLDER_H
 
-#include "src/core/lib/client_config/subchannel.h"
+#include "src/core/ext/client_config/subchannel.h"
 
 /** Pick a subchannel for grpc_subchannel_call_holder;
     Return 1 if subchannel is available immediately (in which case on_ready
@@ -42,6 +42,7 @@
     called when the subchannel is available) */
 typedef int (*grpc_subchannel_call_holder_pick_subchannel)(
     grpc_exec_ctx *exec_ctx, void *arg, grpc_metadata_batch *initial_metadata,
+    uint32_t initial_metadata_flags,
     grpc_connected_subchannel **connected_subchannel, grpc_closure *on_ready);
 
 typedef enum {
@@ -94,4 +95,4 @@ void grpc_subchannel_call_holder_perform_op(grpc_exec_ctx *exec_ctx,
 char *grpc_subchannel_call_holder_get_peer(grpc_exec_ctx *exec_ctx,
                                            grpc_subchannel_call_holder *holder);
 
-#endif /* GRPC_CORE_LIB_CHANNEL_SUBCHANNEL_CALL_HOLDER_H */
+#endif /* GRPC_CORE_EXT_CLIENT_CONFIG_SUBCHANNEL_CALL_HOLDER_H */
diff --git a/src/core/lib/client_config/subchannel_factory.c b/src/core/ext/client_config/subchannel_factory.c
index 541368ec96..d1e4d75a02 100644
--- a/src/core/lib/client_config/subchannel_factory.c
+++ b/src/core/ext/client_config/subchannel_factory.c
@@ -31,7 +31,7 @@
  *
  */
 
-#include "src/core/lib/client_config/subchannel_factory.h"
+#include "src/core/ext/client_config/subchannel_factory.h"
 
 void grpc_subchannel_factory_ref(grpc_subchannel_factory* factory) {
   factory->vtable->ref(factory);
diff --git a/src/core/lib/client_config/subchannel_factory.h b/src/core/ext/client_config/subchannel_factory.h
index 96d68a2079..0fb806d081 100644
--- a/src/core/lib/client_config/subchannel_factory.h
+++ b/src/core/ext/client_config/subchannel_factory.h
@@ -31,11 +31,11 @@
  *
  */
 
-#ifndef GRPC_CORE_LIB_CLIENT_CONFIG_SUBCHANNEL_FACTORY_H
-#define GRPC_CORE_LIB_CLIENT_CONFIG_SUBCHANNEL_FACTORY_H
+#ifndef GRPC_CORE_EXT_CLIENT_CONFIG_SUBCHANNEL_FACTORY_H
+#define GRPC_CORE_EXT_CLIENT_CONFIG_SUBCHANNEL_FACTORY_H
 
+#include "src/core/ext/client_config/subchannel.h"
 #include "src/core/lib/channel/channel_stack.h"
-#include "src/core/lib/client_config/subchannel.h"
 
 typedef struct grpc_subchannel_factory grpc_subchannel_factory;
 typedef struct grpc_subchannel_factory_vtable grpc_subchannel_factory_vtable;
@@ -63,4 +63,4 @@ grpc_subchannel *grpc_subchannel_factory_create_subchannel(
     grpc_exec_ctx *exec_ctx, grpc_subchannel_factory *factory,
     grpc_subchannel_args *args);
 
-#endif /* GRPC_CORE_LIB_CLIENT_CONFIG_SUBCHANNEL_FACTORY_H */
+#endif /* GRPC_CORE_EXT_CLIENT_CONFIG_SUBCHANNEL_FACTORY_H */
diff --git a/src/core/lib/client_config/subchannel_index.c b/src/core/ext/client_config/subchannel_index.c
index 2c545002a2..ab8d9bd91d 100644
--- a/src/core/lib/client_config/subchannel_index.c
+++ b/src/core/ext/client_config/subchannel_index.c
@@ -31,7 +31,7 @@
 //
 //
 
-#include "src/core/lib/client_config/subchannel_index.h"
+#include "src/core/ext/client_config/subchannel_index.h"
 
 #include <stdbool.h>
 #include <string.h>
diff --git a/src/core/lib/client_config/subchannel_index.h b/src/core/ext/client_config/subchannel_index.h
index bc5f03beb4..6b8d063855 100644
--- a/src/core/lib/client_config/subchannel_index.h
+++ b/src/core/ext/client_config/subchannel_index.h
@@ -31,11 +31,11 @@
  *
  */
 
-#ifndef GRPC_CORE_LIB_CLIENT_CONFIG_SUBCHANNEL_INDEX_H
-#define GRPC_CORE_LIB_CLIENT_CONFIG_SUBCHANNEL_INDEX_H
+#ifndef GRPC_CORE_EXT_CLIENT_CONFIG_SUBCHANNEL_INDEX_H
+#define GRPC_CORE_EXT_CLIENT_CONFIG_SUBCHANNEL_INDEX_H
 
-#include "src/core/lib/client_config/connector.h"
-#include "src/core/lib/client_config/subchannel.h"
+#include "src/core/ext/client_config/connector.h"
+#include "src/core/ext/client_config/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_LIB_CLIENT_CONFIG_SUBCHANNEL_INDEX_H */
+#endif /* GRPC_CORE_EXT_CLIENT_CONFIG_SUBCHANNEL_INDEX_H */
diff --git a/src/core/lib/client_config/uri_parser.c b/src/core/ext/client_config/uri_parser.c
index 6bec70da2d..3ca1a58e69 100644
--- a/src/core/lib/client_config/uri_parser.c
+++ b/src/core/ext/client_config/uri_parser.c
@@ -31,7 +31,7 @@
  *
  */
 
-#include "src/core/lib/client_config/uri_parser.h"
+#include "src/core/ext/client_config/uri_parser.h"
 
 #include <string.h>
 
diff --git a/src/core/lib/client_config/uri_parser.h b/src/core/ext/client_config/uri_parser.h
index 5d6785d293..875a7cb07c 100644
--- a/src/core/lib/client_config/uri_parser.h
+++ b/src/core/ext/client_config/uri_parser.h
@@ -31,8 +31,8 @@
  *
  */
 
-#ifndef GRPC_CORE_LIB_CLIENT_CONFIG_URI_PARSER_H
-#define GRPC_CORE_LIB_CLIENT_CONFIG_URI_PARSER_H
+#ifndef GRPC_CORE_EXT_CLIENT_CONFIG_URI_PARSER_H
+#define GRPC_CORE_EXT_CLIENT_CONFIG_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_LIB_CLIENT_CONFIG_URI_PARSER_H */
+#endif /* GRPC_CORE_EXT_CLIENT_CONFIG_URI_PARSER_H */
diff --git a/src/core/ext/lb_policy/grpclb/load_balancer_api.c b/src/core/ext/lb_policy/grpclb/load_balancer_api.c
index d8af644870..459d6d9954 100644
--- a/src/core/ext/lb_policy/grpclb/load_balancer_api.c
+++ b/src/core/ext/lb_policy/grpclb/load_balancer_api.c
@@ -110,13 +110,15 @@ grpc_grpclb_response *grpc_grpclb_response_parse(gpr_slice encoded_response) {
   grpc_grpclb_response *res = gpr_malloc(sizeof(grpc_grpclb_response));
   memset(res, 0, sizeof(*res));
   status = pb_decode(&stream, grpc_lb_v0_LoadBalanceResponse_fields, res);
-  GPR_ASSERT(status == true);
+  if (!status) {
+    grpc_grpclb_response_destroy(res);
+    return NULL;
+  }
   return res;
 }
 
 grpc_grpclb_serverlist *grpc_grpclb_response_parse_serverlist(
     gpr_slice encoded_response) {
-  grpc_grpclb_serverlist *sl = gpr_malloc(sizeof(grpc_grpclb_serverlist));
   bool status;
   decode_serverlist_arg arg;
   pb_istream_t stream =
@@ -131,15 +133,20 @@ grpc_grpclb_serverlist *grpc_grpclb_response_parse_serverlist(
   res->server_list.servers.arg = &arg;
   arg.first_pass = 1;
   status = pb_decode(&stream, grpc_lb_v0_LoadBalanceResponse_fields, res);
-  GPR_ASSERT(status == true);
-  GPR_ASSERT(arg.num_servers > 0);
+  if (!status) {
+    grpc_grpclb_response_destroy(res);
+    return NULL;
+  }
 
   arg.first_pass = 0;
   status =
       pb_decode(&stream_at_start, grpc_lb_v0_LoadBalanceResponse_fields, res);
-  GPR_ASSERT(status == true);
-  GPR_ASSERT(arg.servers != NULL);
+  if (!status) {
+    grpc_grpclb_response_destroy(res);
+    return NULL;
+  }
 
+  grpc_grpclb_serverlist *sl = gpr_malloc(sizeof(grpc_grpclb_serverlist));
   sl->num_servers = arg.num_servers;
   sl->servers = arg.servers;
   if (res->server_list.has_expiration_interval) {
@@ -150,8 +157,10 @@ grpc_grpclb_serverlist *grpc_grpclb_response_parse_serverlist(
 }
 
 void grpc_grpclb_destroy_serverlist(grpc_grpclb_serverlist *serverlist) {
-  size_t i;
-  for (i = 0; i < serverlist->num_servers; i++) {
+  if (serverlist == NULL) {
+    return;
+  }
+  for (size_t i = 0; i < serverlist->num_servers; i++) {
     gpr_free(serverlist->servers[i]);
   }
   gpr_free(serverlist->servers);
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 d329a2ffe8..968f7d278a 100644
--- a/src/core/ext/lb_policy/grpclb/load_balancer_api.h
+++ b/src/core/ext/lb_policy/grpclb/load_balancer_api.h
@@ -36,8 +36,8 @@
 
 #include <grpc/support/slice_buffer.h>
 
+#include "src/core/ext/client_config/lb_policy_factory.h"
 #include "src/core/ext/lb_policy/grpclb/proto/grpc/lb/v0/load_balancer.pb.h"
-#include "src/core/lib/client_config/lb_policy_factory.h"
 
 #ifdef __cplusplus
 extern "C" {
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 cb5c40501e..5926f9d70b 100644
--- a/src/core/ext/lb_policy/pick_first/pick_first.c
+++ b/src/core/ext/lb_policy/pick_first/pick_first.c
@@ -34,12 +34,13 @@
 #include <string.h>
 
 #include <grpc/support/alloc.h>
-#include "src/core/lib/client_config/lb_policy_registry.h"
+#include "src/core/ext/client_config/lb_policy_registry.h"
 #include "src/core/lib/transport/connectivity_state.h"
 
 typedef struct pending_pick {
   struct pending_pick *next;
   grpc_pollset *pollset;
+  uint32_t initial_metadata_flags;
   grpc_connected_subchannel **target;
   grpc_closure *on_complete;
 } pending_pick;
@@ -149,6 +150,31 @@ static void pf_cancel_pick(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol,
   gpr_mu_unlock(&p->mu);
 }
 
+static void pf_cancel_picks(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol,
+                            uint32_t initial_metadata_flags_mask,
+                            uint32_t initial_metadata_flags_eq) {
+  pick_first_lb_policy *p = (pick_first_lb_policy *)pol;
+  pending_pick *pp;
+  gpr_mu_lock(&p->mu);
+  pp = p->pending_picks;
+  p->pending_picks = NULL;
+  while (pp != NULL) {
+    pending_pick *next = pp->next;
+    if ((pp->initial_metadata_flags & initial_metadata_flags_mask) ==
+        initial_metadata_flags_eq) {
+      grpc_pollset_set_del_pollset(exec_ctx, p->base.interested_parties,
+                                   pp->pollset);
+      grpc_exec_ctx_enqueue(exec_ctx, pp->on_complete, false, NULL);
+      gpr_free(pp);
+    } else {
+      pp->next = p->pending_picks;
+      p->pending_picks = pp;
+    }
+    pp = next;
+  }
+  gpr_mu_unlock(&p->mu);
+}
+
 static void start_picking(grpc_exec_ctx *exec_ctx, pick_first_lb_policy *p) {
   p->started_picking = 1;
   p->checking_subchannel = 0;
@@ -171,6 +197,7 @@ static void pf_exit_idle(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol) {
 
 static int pf_pick(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol,
                    grpc_pollset *pollset, grpc_metadata_batch *initial_metadata,
+                   uint32_t initial_metadata_flags,
                    grpc_connected_subchannel **target,
                    grpc_closure *on_complete) {
   pick_first_lb_policy *p = (pick_first_lb_policy *)pol;
@@ -199,6 +226,7 @@ static int pf_pick(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol,
     pp->next = p->pending_picks;
     pp->pollset = pollset;
     pp->target = target;
+    pp->initial_metadata_flags = initial_metadata_flags;
     pp->on_complete = on_complete;
     p->pending_picks = pp;
     gpr_mu_unlock(&p->mu);
@@ -286,11 +314,14 @@ static void pf_connectivity_changed(grpc_exec_ctx *exec_ctx, void *arg,
             &p->checking_connectivity, &p->connectivity_changed);
         break;
       case GRPC_CHANNEL_TRANSIENT_FAILURE:
-        grpc_connectivity_state_set(exec_ctx, &p->state_tracker,
-                                    GRPC_CHANNEL_TRANSIENT_FAILURE,
-                                    "connecting_transient_failure");
         p->checking_subchannel =
             (p->checking_subchannel + 1) % p->num_subchannels;
+        if (p->checking_subchannel == 0) {
+          /* only trigger transient failure when we've tried all alternatives */
+          grpc_connectivity_state_set(exec_ctx, &p->state_tracker,
+                                      GRPC_CHANNEL_TRANSIENT_FAILURE,
+                                      "connecting_transient_failure");
+        }
         p->checking_connectivity = grpc_subchannel_check_connectivity(
             p->subchannels[p->checking_subchannel]);
         if (p->checking_connectivity == GRPC_CHANNEL_TRANSIENT_FAILURE) {
@@ -378,14 +409,9 @@ static void pf_ping_one(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol,
 }
 
 static const grpc_lb_policy_vtable pick_first_lb_policy_vtable = {
-    pf_destroy,
-    pf_shutdown,
-    pf_pick,
-    pf_cancel_pick,
-    pf_ping_one,
-    pf_exit_idle,
-    pf_check_connectivity,
-    pf_notify_on_state_change};
+    pf_destroy,     pf_shutdown,           pf_pick,
+    pf_cancel_pick, pf_cancel_picks,       pf_ping_one,
+    pf_exit_idle,   pf_check_connectivity, pf_notify_on_state_change};
 
 static void pick_first_factory_ref(grpc_lb_policy_factory *factory) {}
 
@@ -395,7 +421,7 @@ static grpc_lb_policy *create_pick_first(grpc_exec_ctx *exec_ctx,
                                          grpc_lb_policy_factory *factory,
                                          grpc_lb_policy_args *args) {
   GPR_ASSERT(args->addresses != NULL);
-  GPR_ASSERT(args->subchannel_factory != NULL);
+  GPR_ASSERT(args->client_channel_factory != NULL);
 
   if (args->addresses->naddrs == 0) return NULL;
 
@@ -412,8 +438,8 @@ static grpc_lb_policy *create_pick_first(grpc_exec_ctx *exec_ctx,
     sc_args.addr = (struct sockaddr *)(args->addresses->addrs[i].addr);
     sc_args.addr_len = (size_t)args->addresses->addrs[i].len;
 
-    grpc_subchannel *subchannel = grpc_subchannel_factory_create_subchannel(
-        exec_ctx, args->subchannel_factory, &sc_args);
+    grpc_subchannel *subchannel = grpc_client_channel_factory_create_subchannel(
+        exec_ctx, args->client_channel_factory, &sc_args);
 
     if (subchannel != NULL) {
       p->subchannels[subchannel_idx++] = subchannel;
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 d94c081494..3f6051b892 100644
--- a/src/core/ext/lb_policy/round_robin/round_robin.c
+++ b/src/core/ext/lb_policy/round_robin/round_robin.c
@@ -35,7 +35,7 @@
 
 #include <grpc/support/alloc.h>
 
-#include "src/core/lib/client_config/lb_policy_registry.h"
+#include "src/core/ext/client_config/lb_policy_registry.h"
 #include "src/core/lib/debug/trace.h"
 #include "src/core/lib/transport/connectivity_state.h"
 
@@ -49,6 +49,7 @@ int grpc_lb_round_robin_trace = 0;
 typedef struct pending_pick {
   struct pending_pick *next;
   grpc_pollset *pollset;
+  uint32_t initial_metadata_flags;
   grpc_connected_subchannel **target;
   grpc_closure *on_complete;
 } pending_pick;
@@ -275,6 +276,32 @@ static void rr_cancel_pick(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol,
   gpr_mu_unlock(&p->mu);
 }
 
+static void rr_cancel_picks(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol,
+                            uint32_t initial_metadata_flags_mask,
+                            uint32_t initial_metadata_flags_eq) {
+  round_robin_lb_policy *p = (round_robin_lb_policy *)pol;
+  pending_pick *pp;
+  gpr_mu_lock(&p->mu);
+  pp = p->pending_picks;
+  p->pending_picks = NULL;
+  while (pp != NULL) {
+    pending_pick *next = pp->next;
+    if ((pp->initial_metadata_flags & initial_metadata_flags_mask) ==
+        initial_metadata_flags_eq) {
+      grpc_pollset_set_del_pollset(exec_ctx, p->base.interested_parties,
+                                   pp->pollset);
+      *pp->target = NULL;
+      grpc_exec_ctx_enqueue(exec_ctx, pp->on_complete, false, NULL);
+      gpr_free(pp);
+    } else {
+      pp->next = p->pending_picks;
+      p->pending_picks = pp;
+    }
+    pp = next;
+  }
+  gpr_mu_unlock(&p->mu);
+}
+
 static void start_picking(grpc_exec_ctx *exec_ctx, round_robin_lb_policy *p) {
   size_t i;
   p->started_picking = 1;
@@ -303,6 +330,7 @@ static void rr_exit_idle(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol) {
 
 static int rr_pick(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol,
                    grpc_pollset *pollset, grpc_metadata_batch *initial_metadata,
+                   uint32_t initial_metadata_flags,
                    grpc_connected_subchannel **target,
                    grpc_closure *on_complete) {
   round_robin_lb_policy *p = (round_robin_lb_policy *)pol;
@@ -330,6 +358,7 @@ static int rr_pick(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol,
     pp->pollset = pollset;
     pp->target = target;
     pp->on_complete = on_complete;
+    pp->initial_metadata_flags = initial_metadata_flags;
     p->pending_picks = pp;
     gpr_mu_unlock(&p->mu);
     return 0;
@@ -485,14 +514,9 @@ static void rr_ping_one(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol,
 }
 
 static const grpc_lb_policy_vtable round_robin_lb_policy_vtable = {
-    rr_destroy,
-    rr_shutdown,
-    rr_pick,
-    rr_cancel_pick,
-    rr_ping_one,
-    rr_exit_idle,
-    rr_check_connectivity,
-    rr_notify_on_state_change};
+    rr_destroy,     rr_shutdown,           rr_pick,
+    rr_cancel_pick, rr_cancel_picks,       rr_ping_one,
+    rr_exit_idle,   rr_check_connectivity, rr_notify_on_state_change};
 
 static void round_robin_factory_ref(grpc_lb_policy_factory *factory) {}
 
@@ -502,7 +526,7 @@ static grpc_lb_policy *create_round_robin(grpc_exec_ctx *exec_ctx,
                                           grpc_lb_policy_factory *factory,
                                           grpc_lb_policy_args *args) {
   GPR_ASSERT(args->addresses != NULL);
-  GPR_ASSERT(args->subchannel_factory != NULL);
+  GPR_ASSERT(args->client_channel_factory != NULL);
 
   round_robin_lb_policy *p = gpr_malloc(sizeof(*p));
   memset(p, 0, sizeof(*p));
@@ -518,8 +542,8 @@ static grpc_lb_policy *create_round_robin(grpc_exec_ctx *exec_ctx,
     sc_args.addr = (struct sockaddr *)(args->addresses->addrs[i].addr);
     sc_args.addr_len = (size_t)args->addresses->addrs[i].len;
 
-    grpc_subchannel *subchannel = grpc_subchannel_factory_create_subchannel(
-        exec_ctx, args->subchannel_factory, &sc_args);
+    grpc_subchannel *subchannel = grpc_client_channel_factory_create_subchannel(
+        exec_ctx, args->client_channel_factory, &sc_args);
 
     if (subchannel != NULL) {
       subchannel_data *sd = gpr_malloc(sizeof(*sd));
diff --git a/src/core/ext/resolver/dns/native/dns_resolver.c b/src/core/ext/resolver/dns/native/dns_resolver.c
index 70d8a3fe2d..2749b0ca01 100644
--- a/src/core/ext/resolver/dns/native/dns_resolver.c
+++ b/src/core/ext/resolver/dns/native/dns_resolver.c
@@ -37,8 +37,8 @@
 #include <grpc/support/host_port.h>
 #include <grpc/support/string_util.h>
 
-#include "src/core/lib/client_config/lb_policy_registry.h"
-#include "src/core/lib/client_config/resolver_registry.h"
+#include "src/core/ext/client_config/lb_policy_registry.h"
+#include "src/core/ext/client_config/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"
@@ -59,7 +59,7 @@ typedef struct {
   /** default port to use */
   char *default_port;
   /** subchannel factory */
-  grpc_subchannel_factory *subchannel_factory;
+  grpc_client_channel_factory *client_channel_factory;
   /** load balancing policy name */
   char *lb_policy_name;
 
@@ -170,7 +170,7 @@ static void dns_on_resolved(grpc_exec_ctx *exec_ctx, void *arg,
     config = grpc_client_config_create();
     memset(&lb_policy_args, 0, sizeof(lb_policy_args));
     lb_policy_args.addresses = addresses;
-    lb_policy_args.subchannel_factory = r->subchannel_factory;
+    lb_policy_args.client_channel_factory = r->client_channel_factory;
     lb_policy =
         grpc_lb_policy_create(exec_ctx, r->lb_policy_name, &lb_policy_args);
     if (lb_policy != NULL) {
@@ -228,7 +228,7 @@ static void dns_destroy(grpc_exec_ctx *exec_ctx, grpc_resolver *gr) {
   if (r->resolved_config) {
     grpc_client_config_unref(exec_ctx, r->resolved_config);
   }
-  grpc_subchannel_factory_unref(exec_ctx, r->subchannel_factory);
+  grpc_client_channel_factory_unref(exec_ctx, r->client_channel_factory);
   gpr_free(r->name);
   gpr_free(r->default_port);
   gpr_free(r->lb_policy_name);
@@ -255,10 +255,10 @@ static grpc_resolver *dns_create(grpc_resolver_args *args,
   grpc_resolver_init(&r->base, &dns_resolver_vtable);
   r->name = gpr_strdup(path);
   r->default_port = gpr_strdup(default_port);
-  r->subchannel_factory = args->subchannel_factory;
+  r->client_channel_factory = args->client_channel_factory;
   gpr_backoff_init(&r->backoff_state, BACKOFF_MULTIPLIER, BACKOFF_JITTER,
                    BACKOFF_MIN_SECONDS * 1000, BACKOFF_MAX_SECONDS * 1000);
-  grpc_subchannel_factory_ref(r->subchannel_factory);
+  grpc_client_channel_factory_ref(r->client_channel_factory);
   r->lb_policy_name = gpr_strdup(lb_policy_name);
   return &r->base;
 }
diff --git a/src/core/ext/resolver/sockaddr/sockaddr_resolver.c b/src/core/ext/resolver/sockaddr/sockaddr_resolver.c
index 69595ca3db..1f14b40e18 100644
--- a/src/core/ext/resolver/sockaddr/sockaddr_resolver.c
+++ b/src/core/ext/resolver/sockaddr/sockaddr_resolver.c
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015, Google Inc.
+ * Copyright 2015-2016, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -31,17 +31,17 @@
  *
  */
 
-#include <grpc/support/port_platform.h>
-
+#include <stdbool.h>
 #include <stdio.h>
 #include <string.h>
 
 #include <grpc/support/alloc.h>
 #include <grpc/support/host_port.h>
+#include <grpc/support/port_platform.h>
 #include <grpc/support/string_util.h>
 
-#include "src/core/lib/client_config/lb_policy_registry.h"
-#include "src/core/lib/client_config/resolver_registry.h"
+#include "src/core/ext/client_config/lb_policy_registry.h"
+#include "src/core/ext/client_config/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"
@@ -52,7 +52,7 @@ typedef struct {
   /** refcount */
   gpr_refcount refs;
   /** subchannel factory */
-  grpc_subchannel_factory *subchannel_factory;
+  grpc_client_channel_factory *client_channel_factory;
   /** load balancing policy name */
   char *lb_policy_name;
 
@@ -125,7 +125,7 @@ static void sockaddr_maybe_finish_next_locked(grpc_exec_ctx *exec_ctx,
     grpc_lb_policy_args lb_policy_args;
     memset(&lb_policy_args, 0, sizeof(lb_policy_args));
     lb_policy_args.addresses = r->addresses;
-    lb_policy_args.subchannel_factory = r->subchannel_factory;
+    lb_policy_args.client_channel_factory = r->client_channel_factory;
     grpc_lb_policy *lb_policy =
         grpc_lb_policy_create(exec_ctx, r->lb_policy_name, &lb_policy_args);
     grpc_client_config_set_lb_policy(cfg, lb_policy);
@@ -140,7 +140,7 @@ static void sockaddr_maybe_finish_next_locked(grpc_exec_ctx *exec_ctx,
 static void sockaddr_destroy(grpc_exec_ctx *exec_ctx, grpc_resolver *gr) {
   sockaddr_resolver *r = (sockaddr_resolver *)gr;
   gpr_mu_destroy(&r->mu);
-  grpc_subchannel_factory_unref(exec_ctx, r->subchannel_factory);
+  grpc_client_channel_factory_unref(exec_ctx, r->client_channel_factory);
   grpc_resolved_addresses_destroy(r->addresses);
   gpr_free(r->lb_policy_name);
   gpr_free(r);
@@ -263,22 +263,24 @@ static grpc_resolver *sockaddr_create(
   r = gpr_malloc(sizeof(sockaddr_resolver));
   memset(r, 0, sizeof(*r));
 
-  r->lb_policy_name = NULL;
-  if (0 != strcmp(args->uri->query, "")) {
-    gpr_slice query_slice;
-    gpr_slice_buffer query_parts;
-
-    query_slice =
-        gpr_slice_new(args->uri->query, strlen(args->uri->query), do_nothing);
-    gpr_slice_buffer_init(&query_parts);
-    gpr_slice_split(query_slice, "=", &query_parts);
-    GPR_ASSERT(query_parts.count == 2);
-    if (0 == gpr_slice_str_cmp(query_parts.slices[0], "lb_policy")) {
-      r->lb_policy_name = gpr_dump_slice(query_parts.slices[1], GPR_DUMP_ASCII);
-    }
-    gpr_slice_buffer_destroy(&query_parts);
-    gpr_slice_unref(query_slice);
+  r->lb_policy_name =
+      gpr_strdup(grpc_uri_get_query_arg(args->uri, "lb_policy"));
+  const char *lb_enabled_qpart =
+      grpc_uri_get_query_arg(args->uri, "lb_enabled");
+  /* anything other than "0" is interpreted as true */
+  const bool lb_enabled =
+      (lb_enabled_qpart != NULL && (strcmp("0", lb_enabled_qpart) != 0));
+
+  if (r->lb_policy_name != NULL && strcmp("grpclb", r->lb_policy_name) == 0 &&
+      !lb_enabled) {
+    /* we want grpclb but the "resolved" addresses aren't LB enabled. Bail
+     * out, as this is meant mostly for tests. */
+    gpr_log(GPR_ERROR,
+            "Requested 'grpclb' LB policy but resolved addresses don't "
+            "support load balancing.");
+    abort();
   }
+
   if (r->lb_policy_name == NULL) {
     r->lb_policy_name = gpr_strdup(default_lb_policy_name);
   }
@@ -318,8 +320,8 @@ static grpc_resolver *sockaddr_create(
   gpr_ref_init(&r->refs, 1);
   gpr_mu_init(&r->mu);
   grpc_resolver_init(&r->base, &sockaddr_resolver_vtable);
-  r->subchannel_factory = args->subchannel_factory;
-  grpc_subchannel_factory_ref(r->subchannel_factory);
+  r->client_channel_factory = args->client_channel_factory;
+  grpc_client_channel_factory_ref(r->client_channel_factory);
 
   return &r->base;
 }
diff --git a/src/core/ext/resolver/zookeeper/zookeeper_resolver.c b/src/core/ext/resolver/zookeeper/zookeeper_resolver.c
index 5acb0940c6..898632c3cd 100644
--- a/src/core/ext/resolver/zookeeper/zookeeper_resolver.c
+++ b/src/core/ext/resolver/zookeeper/zookeeper_resolver.c
@@ -39,8 +39,8 @@
 #include <grpc/grpc_zookeeper.h>
 #include <zookeeper/zookeeper.h>
 
-#include "src/core/lib/client_config/lb_policy_registry.h"
-#include "src/core/lib/client_config/resolver_registry.h"
+#include "src/core/ext/client_config/lb_policy_registry.h"
+#include "src/core/ext/client_config/resolver_registry.h"
 #include "src/core/lib/iomgr/resolve_address.h"
 #include "src/core/lib/json/json.h"
 #include "src/core/lib/support/string.h"
@@ -57,7 +57,7 @@ typedef struct {
   /** name to resolve */
   char *name;
   /** subchannel factory */
-  grpc_subchannel_factory *subchannel_factory;
+  grpc_client_channel_factory *client_channel_factory;
   /** load balancing policy name */
   char *lb_policy_name;
 
@@ -187,9 +187,8 @@ static void zookeeper_on_resolved(grpc_exec_ctx *exec_ctx, void *arg,
   if (addresses != NULL) {
     grpc_lb_policy_args lb_policy_args;
     config = grpc_client_config_create();
-
     lb_policy_args.addresses = addresses;
-    lb_policy_args.subchannel_factory = r->subchannel_factory;
+    lb_policy_args.client_channel_factory = r->client_channel_factory;
     lb_policy =
         grpc_lb_policy_create(exec_ctx, r->lb_policy_name, &lb_policy_args);
 
@@ -424,7 +423,7 @@ static void zookeeper_destroy(grpc_exec_ctx *exec_ctx, grpc_resolver *gr) {
   if (r->resolved_config != NULL) {
     grpc_client_config_unref(exec_ctx, r->resolved_config);
   }
-  grpc_subchannel_factory_unref(exec_ctx, r->subchannel_factory);
+  grpc_client_channel_factory_unref(exec_ctx, r->client_channel_factory);
   gpr_free(r->name);
   gpr_free(r->lb_policy_name);
   gpr_free(r);
@@ -454,8 +453,8 @@ static grpc_resolver *zookeeper_create(grpc_resolver_args *args,
   grpc_resolver_init(&r->base, &zookeeper_resolver_vtable);
   r->name = gpr_strdup(path);
 
-  r->subchannel_factory = args->subchannel_factory;
-  grpc_subchannel_factory_ref(r->subchannel_factory);
+  r->client_channel_factory = args->client_channel_factory;
+  grpc_client_channel_factory_ref(r->client_channel_factory);
 
   r->lb_policy_name = gpr_strdup(lb_policy_name);
 
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 606fff5fb4..5484438f0a 100644
--- a/src/core/ext/transport/chttp2/client/insecure/channel_create.c
+++ b/src/core/ext/transport/chttp2/client/insecure/channel_create.c
@@ -41,12 +41,12 @@
 #include <grpc/support/slice_buffer.h>
 
 #include "src/core/ext/census/grpc_filter.h"
+#include "src/core/ext/client_config/client_channel.h"
+#include "src/core/ext/client_config/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/client_channel.h"
 #include "src/core/lib/channel/compress_filter.h"
 #include "src/core/lib/channel/http_client_filter.h"
-#include "src/core/lib/client_config/resolver_registry.h"
 #include "src/core/lib/iomgr/tcp_client.h"
 #include "src/core/lib/surface/api_trace.h"
 #include "src/core/lib/surface/channel.h"
@@ -136,31 +136,35 @@ static const grpc_connector_vtable connector_vtable = {
     connector_ref, connector_unref, connector_shutdown, connector_connect};
 
 typedef struct {
-  grpc_subchannel_factory base;
+  grpc_client_channel_factory base;
   gpr_refcount refs;
   grpc_channel_args *merge_args;
   grpc_channel *master;
-} subchannel_factory;
+} client_channel_factory;
 
-static void subchannel_factory_ref(grpc_subchannel_factory *scf) {
-  subchannel_factory *f = (subchannel_factory *)scf;
+static void client_channel_factory_ref(
+    grpc_client_channel_factory *cc_factory) {
+  client_channel_factory *f = (client_channel_factory *)cc_factory;
   gpr_ref(&f->refs);
 }
 
-static void subchannel_factory_unref(grpc_exec_ctx *exec_ctx,
-                                     grpc_subchannel_factory *scf) {
-  subchannel_factory *f = (subchannel_factory *)scf;
+static void client_channel_factory_unref(
+    grpc_exec_ctx *exec_ctx, grpc_client_channel_factory *cc_factory) {
+  client_channel_factory *f = (client_channel_factory *)cc_factory;
   if (gpr_unref(&f->refs)) {
-    GRPC_CHANNEL_INTERNAL_UNREF(exec_ctx, f->master, "subchannel_factory");
+    if (f->master != NULL) {
+      GRPC_CHANNEL_INTERNAL_UNREF(exec_ctx, f->master,
+                                  "client_channel_factory");
+    }
     grpc_channel_args_destroy(f->merge_args);
     gpr_free(f);
   }
 }
 
-static grpc_subchannel *subchannel_factory_create_subchannel(
-    grpc_exec_ctx *exec_ctx, grpc_subchannel_factory *scf,
+static grpc_subchannel *client_channel_factory_create_subchannel(
+    grpc_exec_ctx *exec_ctx, grpc_client_channel_factory *cc_factory,
     grpc_subchannel_args *args) {
-  subchannel_factory *f = (subchannel_factory *)scf;
+  client_channel_factory *f = (client_channel_factory *)cc_factory;
   connector *c = gpr_malloc(sizeof(*c));
   grpc_channel_args *final_args =
       grpc_channel_args_merge(args->args, f->merge_args);
@@ -175,9 +179,33 @@ static grpc_subchannel *subchannel_factory_create_subchannel(
   return s;
 }
 
-static const grpc_subchannel_factory_vtable subchannel_factory_vtable = {
-    subchannel_factory_ref, subchannel_factory_unref,
-    subchannel_factory_create_subchannel};
+static grpc_channel *client_channel_factory_create_channel(
+    grpc_exec_ctx *exec_ctx, grpc_client_channel_factory *cc_factory,
+    const char *target, grpc_client_channel_type type,
+    grpc_channel_args *args) {
+  client_channel_factory *f = (client_channel_factory *)cc_factory;
+  grpc_channel_args *final_args = grpc_channel_args_merge(args, f->merge_args);
+  grpc_channel *channel = grpc_channel_create(exec_ctx, target, final_args,
+                                              GRPC_CLIENT_CHANNEL, NULL);
+  grpc_channel_args_destroy(final_args);
+  grpc_resolver *resolver = grpc_resolver_create(target, &f->base);
+  if (!resolver) {
+    GRPC_CHANNEL_INTERNAL_UNREF(exec_ctx, channel,
+                                "client_channel_factory_create_channel");
+    return NULL;
+  }
+
+  grpc_client_channel_set_resolver(
+      exec_ctx, grpc_channel_get_channel_stack(channel), resolver);
+  GRPC_RESOLVER_UNREF(exec_ctx, resolver, "create_channel");
+
+  return channel;
+}
+
+static const grpc_client_channel_factory_vtable client_channel_factory_vtable =
+    {client_channel_factory_ref, client_channel_factory_unref,
+     client_channel_factory_create_subchannel,
+     client_channel_factory_create_channel};
 
 /* Create a client channel:
    Asynchronously: - resolve target
@@ -186,38 +214,27 @@ static const grpc_subchannel_factory_vtable subchannel_factory_vtable = {
 grpc_channel *grpc_insecure_channel_create(const char *target,
                                            const grpc_channel_args *args,
                                            void *reserved) {
-  grpc_channel *channel = NULL;
-  grpc_resolver *resolver;
-  subchannel_factory *f;
   grpc_exec_ctx exec_ctx = GRPC_EXEC_CTX_INIT;
   GRPC_API_TRACE(
       "grpc_insecure_channel_create(target=%p, args=%p, reserved=%p)", 3,
       (target, args, reserved));
   GPR_ASSERT(!reserved);
 
-  channel =
-      grpc_channel_create(&exec_ctx, target, args, GRPC_CLIENT_CHANNEL, NULL);
-
-  f = gpr_malloc(sizeof(*f));
-  f->base.vtable = &subchannel_factory_vtable;
+  client_channel_factory *f = gpr_malloc(sizeof(*f));
+  memset(f, 0, sizeof(*f));
+  f->base.vtable = &client_channel_factory_vtable;
   gpr_ref_init(&f->refs, 1);
   f->merge_args = grpc_channel_args_copy(args);
-  f->master = channel;
-  GRPC_CHANNEL_INTERNAL_REF(f->master, "subchannel_factory");
-  resolver = grpc_resolver_create(target, &f->base);
-  if (!resolver) {
-    GRPC_CHANNEL_INTERNAL_UNREF(&exec_ctx, f->master, "subchannel_factory");
-    grpc_subchannel_factory_unref(&exec_ctx, &f->base);
-    grpc_exec_ctx_finish(&exec_ctx);
-    return NULL;
-  }
 
-  grpc_client_channel_set_resolver(
-      &exec_ctx, grpc_channel_get_channel_stack(channel), resolver);
-  GRPC_RESOLVER_UNREF(&exec_ctx, resolver, "create");
-  grpc_subchannel_factory_unref(&exec_ctx, &f->base);
+  grpc_channel *channel = client_channel_factory_create_channel(
+      &exec_ctx, &f->base, target, GRPC_CLIENT_CHANNEL_TYPE_REGULAR, NULL);
+  if (channel != NULL) {
+    f->master = channel;
+    GRPC_CHANNEL_INTERNAL_REF(f->master, "grpc_insecure_channel_create");
+  }
+  grpc_client_channel_factory_unref(&exec_ctx, &f->base);
 
   grpc_exec_ctx_finish(&exec_ctx);
 
-  return channel;
+  return channel; /* may be NULL */
 }
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 3465d2b6c4..58af6f995a 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
@@ -40,10 +40,10 @@
 #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/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/client_channel.h"
-#include "src/core/lib/client_config/resolver_registry.h"
 #include "src/core/lib/iomgr/tcp_client.h"
 #include "src/core/lib/security/auth_filters.h"
 #include "src/core/lib/security/credentials.h"
@@ -192,34 +192,38 @@ static const grpc_connector_vtable connector_vtable = {
     connector_ref, connector_unref, connector_shutdown, connector_connect};
 
 typedef struct {
-  grpc_subchannel_factory base;
+  grpc_client_channel_factory base;
   gpr_refcount refs;
   grpc_channel_args *merge_args;
   grpc_channel_security_connector *security_connector;
   grpc_channel *master;
-} subchannel_factory;
+} client_channel_factory;
 
-static void subchannel_factory_ref(grpc_subchannel_factory *scf) {
-  subchannel_factory *f = (subchannel_factory *)scf;
+static void client_channel_factory_ref(
+    grpc_client_channel_factory *cc_factory) {
+  client_channel_factory *f = (client_channel_factory *)cc_factory;
   gpr_ref(&f->refs);
 }
 
-static void subchannel_factory_unref(grpc_exec_ctx *exec_ctx,
-                                     grpc_subchannel_factory *scf) {
-  subchannel_factory *f = (subchannel_factory *)scf;
+static void client_channel_factory_unref(
+    grpc_exec_ctx *exec_ctx, grpc_client_channel_factory *cc_factory) {
+  client_channel_factory *f = (client_channel_factory *)cc_factory;
   if (gpr_unref(&f->refs)) {
     GRPC_SECURITY_CONNECTOR_UNREF(&f->security_connector->base,
-                                  "subchannel_factory");
-    GRPC_CHANNEL_INTERNAL_UNREF(exec_ctx, f->master, "subchannel_factory");
+                                  "client_channel_factory");
+    if (f->master != NULL) {
+      GRPC_CHANNEL_INTERNAL_UNREF(exec_ctx, f->master,
+                                  "client_channel_factory");
+    }
     grpc_channel_args_destroy(f->merge_args);
     gpr_free(f);
   }
 }
 
-static grpc_subchannel *subchannel_factory_create_subchannel(
-    grpc_exec_ctx *exec_ctx, grpc_subchannel_factory *scf,
+static grpc_subchannel *client_channel_factory_create_subchannel(
+    grpc_exec_ctx *exec_ctx, grpc_client_channel_factory *cc_factory,
     grpc_subchannel_args *args) {
-  subchannel_factory *f = (subchannel_factory *)scf;
+  client_channel_factory *f = (client_channel_factory *)cc_factory;
   connector *c = gpr_malloc(sizeof(*c));
   grpc_channel_args *final_args =
       grpc_channel_args_merge(args->args, f->merge_args);
@@ -236,9 +240,37 @@ static grpc_subchannel *subchannel_factory_create_subchannel(
   return s;
 }
 
-static const grpc_subchannel_factory_vtable subchannel_factory_vtable = {
-    subchannel_factory_ref, subchannel_factory_unref,
-    subchannel_factory_create_subchannel};
+static grpc_channel *client_channel_factory_create_channel(
+    grpc_exec_ctx *exec_ctx, grpc_client_channel_factory *cc_factory,
+    const char *target, grpc_client_channel_type type,
+    grpc_channel_args *args) {
+  client_channel_factory *f = (client_channel_factory *)cc_factory;
+
+  grpc_channel_args *final_args = grpc_channel_args_merge(args, f->merge_args);
+  grpc_channel *channel = grpc_channel_create(exec_ctx, target, final_args,
+                                              GRPC_CLIENT_CHANNEL, NULL);
+  grpc_channel_args_destroy(final_args);
+
+  grpc_resolver *resolver = grpc_resolver_create(target, &f->base);
+  if (resolver != NULL) {
+    grpc_client_channel_set_resolver(
+        exec_ctx, grpc_channel_get_channel_stack(channel), resolver);
+    GRPC_RESOLVER_UNREF(exec_ctx, resolver, "create");
+  } else {
+    GRPC_CHANNEL_INTERNAL_UNREF(exec_ctx, channel,
+                                "client_channel_factory_create_channel");
+    channel = NULL;
+  }
+
+  GRPC_SECURITY_CONNECTOR_UNREF(&f->security_connector->base,
+                                "client_channel_factory_create_channel");
+  return channel;
+}
+
+static const grpc_client_channel_factory_vtable client_channel_factory_vtable =
+    {client_channel_factory_ref, client_channel_factory_unref,
+     client_channel_factory_create_subchannel,
+     client_channel_factory_create_channel};
 
 /* Create a secure client channel:
    Asynchronously: - resolve target
@@ -248,13 +280,11 @@ grpc_channel *grpc_secure_channel_create(grpc_channel_credentials *creds,
                                          const char *target,
                                          const grpc_channel_args *args,
                                          void *reserved) {
-  grpc_channel *channel;
   grpc_arg connector_arg;
   grpc_channel_args *args_copy;
   grpc_channel_args *new_args_from_connector;
   grpc_channel_security_connector *security_connector;
-  grpc_resolver *resolver;
-  subchannel_factory *f;
+  client_channel_factory *f;
   grpc_exec_ctx exec_ctx = GRPC_EXEC_CTX_INIT;
 
   GRPC_API_TRACE(
@@ -284,35 +314,30 @@ grpc_channel *grpc_secure_channel_create(grpc_channel_credentials *creds,
       new_args_from_connector != NULL ? new_args_from_connector : args,
       &connector_arg, 1);
 
-  channel = grpc_channel_create(&exec_ctx, target, args_copy,
-                                GRPC_CLIENT_CHANNEL, NULL);
-
   f = gpr_malloc(sizeof(*f));
-  f->base.vtable = &subchannel_factory_vtable;
+  memset(f, 0, sizeof(*f));
+  f->base.vtable = &client_channel_factory_vtable;
   gpr_ref_init(&f->refs, 1);
-  GRPC_SECURITY_CONNECTOR_REF(&security_connector->base, "subchannel_factory");
-  f->security_connector = security_connector;
+
   f->merge_args = grpc_channel_args_copy(args_copy);
-  f->master = channel;
-  GRPC_CHANNEL_INTERNAL_REF(channel, "subchannel_factory");
-  resolver = grpc_resolver_create(target, &f->base);
-  if (resolver) {
-    grpc_client_channel_set_resolver(
-        &exec_ctx, grpc_channel_get_channel_stack(channel), resolver);
-    GRPC_RESOLVER_UNREF(&exec_ctx, resolver, "create");
-  }
-  grpc_subchannel_factory_unref(&exec_ctx, &f->base);
-  GRPC_SECURITY_CONNECTOR_UNREF(&security_connector->base, "channel_create");
   grpc_channel_args_destroy(args_copy);
   if (new_args_from_connector != NULL) {
     grpc_channel_args_destroy(new_args_from_connector);
   }
 
-  if (!resolver) {
-    GRPC_CHANNEL_INTERNAL_UNREF(&exec_ctx, channel, "subchannel_factory");
-    channel = NULL;
+  GRPC_SECURITY_CONNECTOR_REF(&security_connector->base,
+                              "grpc_secure_channel_create");
+  f->security_connector = security_connector;
+
+  grpc_channel *channel = client_channel_factory_create_channel(
+      &exec_ctx, &f->base, target, GRPC_CLIENT_CHANNEL_TYPE_REGULAR, NULL);
+  if (channel != NULL) {
+    f->master = channel;
+    GRPC_CHANNEL_INTERNAL_REF(f->master, "grpc_secure_channel_create");
   }
+
+  grpc_client_channel_factory_unref(&exec_ctx, &f->base);
   grpc_exec_ctx_finish(&exec_ctx);
 
-  return channel;
+  return channel; /* may be NULL */
 }
diff --git a/src/core/lib/channel/http_client_filter.c b/src/core/lib/channel/http_client_filter.c
index deba23e21f..211f537c69 100644
--- a/src/core/lib/channel/http_client_filter.c
+++ b/src/core/lib/channel/http_client_filter.c
@@ -111,10 +111,12 @@ static void hc_mutate_op(grpc_call_element *elem,
                                elem);
     /* Send : prefixed headers, which have to be before any application
        layer headers. */
-    grpc_metadata_batch_add_head(op->send_initial_metadata, &calld->method,
-                                 op->send_idempotent_request
-                                     ? GRPC_MDELEM_METHOD_PUT
-                                     : GRPC_MDELEM_METHOD_POST);
+    grpc_metadata_batch_add_head(
+        op->send_initial_metadata, &calld->method,
+        op->send_initial_metadata_flags &
+                GRPC_INITIAL_METADATA_IDEMPOTENT_REQUEST
+            ? GRPC_MDELEM_METHOD_PUT
+            : GRPC_MDELEM_METHOD_POST);
     grpc_metadata_batch_add_head(op->send_initial_metadata, &calld->scheme,
                                  channeld->static_scheme);
     grpc_metadata_batch_add_tail(op->send_initial_metadata, &calld->te_trailers,
diff --git a/src/core/lib/iomgr/ev_poll_and_epoll_posix.c b/src/core/lib/iomgr/ev_poll_and_epoll_posix.c
index dba335490b..3c8127e1a8 100644
--- a/src/core/lib/iomgr/ev_poll_and_epoll_posix.c
+++ b/src/core/lib/iomgr/ev_poll_and_epoll_posix.c
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015-2016, Google Inc.
+ * Copyright 2015, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
diff --git a/src/core/lib/iomgr/ev_posix.c b/src/core/lib/iomgr/ev_posix.c
index 235a7df08d..0eb95a2e09 100644
--- a/src/core/lib/iomgr/ev_posix.c
+++ b/src/core/lib/iomgr/ev_posix.c
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015-2016, Google Inc.
+ * Copyright 2015, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
diff --git a/src/core/lib/iomgr/ev_posix.h b/src/core/lib/iomgr/ev_posix.h
index 9d27b2bcda..1fa9f5ef2d 100644
--- a/src/core/lib/iomgr/ev_posix.h
+++ b/src/core/lib/iomgr/ev_posix.h
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015-2016, Google Inc.
+ * Copyright 2015, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
diff --git a/src/core/lib/iomgr/unix_sockets_posix.h b/src/core/lib/iomgr/unix_sockets_posix.h
index 752cab85a5..22d6af5044 100644
--- a/src/core/lib/iomgr/unix_sockets_posix.h
+++ b/src/core/lib/iomgr/unix_sockets_posix.h
@@ -38,8 +38,8 @@
 
 #include <grpc/support/string_util.h>
 
-#include "src/core/lib/client_config/resolver_factory.h"
-#include "src/core/lib/client_config/uri_parser.h"
+#include "src/core/ext/client_config/resolver_factory.h"
+#include "src/core/ext/client_config/uri_parser.h"
 #include "src/core/lib/iomgr/resolve_address.h"
 #include "src/core/lib/iomgr/sockaddr.h"
 
diff --git a/src/core/lib/surface/call.c b/src/core/lib/surface/call.c
index 37cc724b53..ba94852f9a 100644
--- a/src/core/lib/surface/call.c
+++ b/src/core/lib/surface/call.c
@@ -81,11 +81,11 @@ typedef enum {
   /* Status came from the application layer overriding whatever
      the wire says */
   STATUS_FROM_API_OVERRIDE = 0,
-  /* Status was created by some internal channel stack operation */
-  STATUS_FROM_CORE,
   /* Status came from 'the wire' - or somewhere below the surface
      layer */
   STATUS_FROM_WIRE,
+  /* Status was created by some internal channel stack operation */
+  STATUS_FROM_CORE,
   /* Status came from the server sending status */
   STATUS_FROM_SERVER_STATUS,
   STATUS_SOURCE_COUNT
@@ -1110,6 +1110,9 @@ static void finish_batch(grpc_exec_ctx *exec_ctx, void *bctlp, bool success) {
 
   gpr_mu_lock(&call->mu);
   if (bctl->send_initial_metadata) {
+    if (!success) {
+      set_status_code(call, STATUS_FROM_CORE, GRPC_STATUS_UNAVAILABLE);
+    }
     grpc_metadata_batch_destroy(
         &call->metadata_batch[0 /* is_receiving */][0 /* is_trailing */]);
   }
@@ -1232,8 +1235,7 @@ static grpc_call_error call_start_batch(grpc_exec_ctx *exec_ctx,
         call->metadata_batch[0][0].deadline = call->send_deadline;
         stream_op.send_initial_metadata =
             &call->metadata_batch[0 /* is_receiving */][0 /* is_trailing */];
-        stream_op.send_idempotent_request =
-            (op->flags & GRPC_INITIAL_METADATA_IDEMPOTENT_REQUEST) != 0;
+        stream_op.send_initial_metadata_flags = op->flags;
         break;
       case GRPC_OP_SEND_MESSAGE:
         if (!are_write_flags_valid(op->flags)) {
diff --git a/src/core/lib/surface/channel.c b/src/core/lib/surface/channel.c
index 06f991b085..332f504507 100644
--- a/src/core/lib/surface/channel.c
+++ b/src/core/lib/surface/channel.c
@@ -40,7 +40,7 @@
 #include <grpc/support/log.h>
 #include <grpc/support/string_util.h>
 
-#include "src/core/lib/client_config/resolver_registry.h"
+#include "src/core/ext/client_config/resolver_registry.h"
 #include "src/core/lib/iomgr/iomgr.h"
 #include "src/core/lib/support/string.h"
 #include "src/core/lib/surface/api_trace.h"
diff --git a/src/core/lib/surface/channel.h b/src/core/lib/surface/channel.h
index 640fd7e137..22dae930e4 100644
--- a/src/core/lib/surface/channel.h
+++ b/src/core/lib/surface/channel.h
@@ -35,7 +35,6 @@
 #define GRPC_CORE_LIB_SURFACE_CHANNEL_H
 
 #include "src/core/lib/channel/channel_stack.h"
-#include "src/core/lib/client_config/subchannel_factory.h"
 #include "src/core/lib/surface/channel_stack_type.h"
 
 grpc_channel *grpc_channel_create(grpc_exec_ctx *exec_ctx, const char *target,
diff --git a/src/core/lib/surface/init.c b/src/core/lib/surface/init.c
index aca4ce9d07..f221d8db35 100644
--- a/src/core/lib/surface/init.c
+++ b/src/core/lib/surface/init.c
@@ -39,17 +39,17 @@
 #include <grpc/grpc.h>
 #include <grpc/support/alloc.h>
 #include <grpc/support/time.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.h"
+#include "src/core/ext/client_config/subchannel_index.h"
 #include "src/core/ext/transport/chttp2/transport/chttp2_transport.h"
 #include "src/core/lib/channel/channel_stack.h"
-#include "src/core/lib/channel/client_channel.h"
 #include "src/core/lib/channel/compress_filter.h"
 #include "src/core/lib/channel/connected_channel.h"
 #include "src/core/lib/channel/http_client_filter.h"
 #include "src/core/lib/channel/http_server_filter.h"
-#include "src/core/lib/client_config/lb_policy_registry.h"
-#include "src/core/lib/client_config/resolver_registry.h"
-#include "src/core/lib/client_config/subchannel.h"
-#include "src/core/lib/client_config/subchannel_index.h"
 #include "src/core/lib/debug/trace.h"
 #include "src/core/lib/iomgr/executor.h"
 #include "src/core/lib/iomgr/iomgr.h"
diff --git a/src/core/lib/surface/server.c b/src/core/lib/surface/server.c
index 1898bee1c1..37cc2bd101 100644
--- a/src/core/lib/surface/server.c
+++ b/src/core/lib/surface/server.c
@@ -95,7 +95,6 @@ typedef struct requested_call {
       grpc_byte_buffer **optional_payload;
     } registered;
   } data;
-  grpc_closure publish;
 } requested_call;
 
 typedef struct channel_registered_method {
@@ -156,15 +155,21 @@ struct call_data {
   bool recv_idempotent_request;
   grpc_metadata_array initial_metadata;
 
+  request_matcher *request_matcher;
+  grpc_byte_buffer *payload;
+
   grpc_closure got_initial_metadata;
   grpc_closure server_on_recv_initial_metadata;
   grpc_closure kill_zombie_closure;
   grpc_closure *on_done_recv_initial_metadata;
 
+  grpc_closure publish;
+
   call_data *pending_next;
 };
 
 struct request_matcher {
+  grpc_server *server;
   call_data *pending_head;
   call_data *pending_tail;
   gpr_stack_lockfree *requests;
@@ -173,6 +178,7 @@ struct request_matcher {
 struct registered_method {
   char *method;
   char *host;
+  grpc_server_register_method_payload_handling payload_handling;
   uint32_t flags;
   request_matcher request_matcher;
   registered_method *next;
@@ -226,8 +232,7 @@ struct grpc_server {
 #define SERVER_FROM_CALL_ELEM(elem) \
   (((channel_data *)(elem)->channel_data)->server)
 
-static void begin_call(grpc_exec_ctx *exec_ctx, grpc_server *server,
-                       call_data *calld, requested_call *rc);
+static void publish_new_rpc(grpc_exec_ctx *exec_ctx, void *calld, bool success);
 static void fail_call(grpc_exec_ctx *exec_ctx, grpc_server *server,
                       requested_call *rc);
 /* Before calling maybe_finish_shutdown, we must hold mu_global and not
@@ -303,8 +308,10 @@ static void channel_broadcaster_shutdown(grpc_exec_ctx *exec_ctx,
  * request_matcher
  */
 
-static void request_matcher_init(request_matcher *rm, size_t entries) {
+static void request_matcher_init(request_matcher *rm, size_t entries,
+                                 grpc_server *server) {
   memset(rm, 0, sizeof(*rm));
+  rm->server = server;
   rm->requests = gpr_stack_lockfree_create(entries);
 }
 
@@ -417,21 +424,90 @@ static void destroy_channel(grpc_exec_ctx *exec_ctx, channel_data *chand) {
                        &op);
 }
 
-static void finish_start_new_rpc(grpc_exec_ctx *exec_ctx, grpc_server *server,
-                                 grpc_call_element *elem, request_matcher *rm) {
-  call_data *calld = elem->call_data;
-  int request_id;
+static void cpstr(char **dest, size_t *capacity, grpc_mdstr *value) {
+  gpr_slice slice = value->slice;
+  size_t len = GPR_SLICE_LENGTH(slice);
 
-  if (gpr_atm_acq_load(&server->shutdown_flag)) {
+  if (len + 1 > *capacity) {
+    *capacity = GPR_MAX(len + 1, *capacity * 2);
+    *dest = gpr_realloc(*dest, *capacity);
+  }
+  memcpy(*dest, grpc_mdstr_as_c_string(value), len + 1);
+}
+
+static void done_request_event(grpc_exec_ctx *exec_ctx, void *req,
+                               grpc_cq_completion *c) {
+  requested_call *rc = req;
+  grpc_server *server = rc->server;
+
+  if (rc >= server->requested_calls &&
+      rc < server->requested_calls + server->max_requested_calls) {
+    GPR_ASSERT(rc - server->requested_calls <= INT_MAX);
+    gpr_stack_lockfree_push(server->request_freelist,
+                            (int)(rc - server->requested_calls));
+  } else {
+    gpr_free(req);
+  }
+
+  server_unref(exec_ctx, server);
+}
+
+static void publish_call(grpc_exec_ctx *exec_ctx, grpc_server *server,
+                         call_data *calld, requested_call *rc) {
+  grpc_call_set_completion_queue(exec_ctx, calld->call, rc->cq_bound_to_call);
+  grpc_call *call = calld->call;
+  *rc->call = call;
+  calld->cq_new = rc->cq_for_notification;
+  GPR_SWAP(grpc_metadata_array, *rc->initial_metadata, calld->initial_metadata);
+  switch (rc->type) {
+    case BATCH_CALL:
+      GPR_ASSERT(calld->host != NULL);
+      GPR_ASSERT(calld->path != NULL);
+      cpstr(&rc->data.batch.details->host,
+            &rc->data.batch.details->host_capacity, calld->host);
+      cpstr(&rc->data.batch.details->method,
+            &rc->data.batch.details->method_capacity, calld->path);
+      rc->data.batch.details->deadline = calld->deadline;
+      rc->data.batch.details->flags =
+          0 | (calld->recv_idempotent_request
+                   ? GRPC_INITIAL_METADATA_IDEMPOTENT_REQUEST
+                   : 0);
+      break;
+    case REGISTERED_CALL:
+      *rc->data.registered.deadline = calld->deadline;
+      if (rc->data.registered.optional_payload) {
+        *rc->data.registered.optional_payload = calld->payload;
+      }
+      break;
+    default:
+      GPR_UNREACHABLE_CODE(return );
+  }
+
+  grpc_call_element *elem =
+      grpc_call_stack_element(grpc_call_get_call_stack(call), 0);
+  channel_data *chand = elem->channel_data;
+  server_ref(chand->server);
+  grpc_cq_end_op(exec_ctx, calld->cq_new, rc->tag, true, done_request_event, rc,
+                 &rc->completion);
+}
+
+static void publish_new_rpc(grpc_exec_ctx *exec_ctx, void *arg, bool success) {
+  call_data *calld = arg;
+  request_matcher *rm = calld->request_matcher;
+  grpc_server *server = rm->server;
+
+  if (!success || gpr_atm_acq_load(&server->shutdown_flag)) {
     gpr_mu_lock(&calld->mu_state);
     calld->state = ZOMBIED;
     gpr_mu_unlock(&calld->mu_state);
-    grpc_closure_init(&calld->kill_zombie_closure, kill_zombie, elem);
+    grpc_closure_init(
+        &calld->kill_zombie_closure, kill_zombie,
+        grpc_call_stack_element(grpc_call_get_call_stack(calld->call), 0));
     grpc_exec_ctx_enqueue(exec_ctx, &calld->kill_zombie_closure, true, NULL);
     return;
   }
 
-  request_id = gpr_stack_lockfree_pop(rm->requests);
+  int request_id = gpr_stack_lockfree_pop(rm->requests);
   if (request_id == -1) {
     gpr_mu_lock(&server->mu_call);
     gpr_mu_lock(&calld->mu_state);
@@ -449,7 +525,41 @@ static void finish_start_new_rpc(grpc_exec_ctx *exec_ctx, grpc_server *server,
     gpr_mu_lock(&calld->mu_state);
     calld->state = ACTIVATED;
     gpr_mu_unlock(&calld->mu_state);
-    begin_call(exec_ctx, server, calld, &server->requested_calls[request_id]);
+    publish_call(exec_ctx, server, calld, &server->requested_calls[request_id]);
+  }
+}
+
+static void finish_start_new_rpc(
+    grpc_exec_ctx *exec_ctx, grpc_server *server, grpc_call_element *elem,
+    request_matcher *rm,
+    grpc_server_register_method_payload_handling payload_handling) {
+  call_data *calld = elem->call_data;
+
+  if (gpr_atm_acq_load(&server->shutdown_flag)) {
+    gpr_mu_lock(&calld->mu_state);
+    calld->state = ZOMBIED;
+    gpr_mu_unlock(&calld->mu_state);
+    grpc_closure_init(&calld->kill_zombie_closure, kill_zombie, elem);
+    grpc_exec_ctx_enqueue(exec_ctx, &calld->kill_zombie_closure, true, NULL);
+    return;
+  }
+
+  calld->request_matcher = rm;
+
+  switch (payload_handling) {
+    case GRPC_SRM_PAYLOAD_NONE:
+      publish_new_rpc(exec_ctx, calld, true);
+      break;
+    case GRPC_SRM_PAYLOAD_READ_INITIAL_BYTE_BUFFER: {
+      grpc_op op;
+      memset(&op, 0, sizeof(op));
+      op.op = GRPC_OP_RECV_MESSAGE;
+      op.data.recv_message = &calld->payload;
+      grpc_closure_init(&calld->publish, publish_new_rpc, calld);
+      grpc_call_start_batch_and_execute(exec_ctx, calld->call, &op, 1,
+                                        &calld->publish);
+      break;
+    }
   }
 }
 
@@ -475,7 +585,8 @@ static void start_new_rpc(grpc_exec_ctx *exec_ctx, grpc_call_element *elem) {
           !calld->recv_idempotent_request)
         continue;
       finish_start_new_rpc(exec_ctx, server, elem,
-                           &rm->server_registered_method->request_matcher);
+                           &rm->server_registered_method->request_matcher,
+                           rm->server_registered_method->payload_handling);
       return;
     }
     /* check for a wildcard method definition (no host set) */
@@ -490,12 +601,14 @@ static void start_new_rpc(grpc_exec_ctx *exec_ctx, grpc_call_element *elem) {
           !calld->recv_idempotent_request)
         continue;
       finish_start_new_rpc(exec_ctx, server, elem,
-                           &rm->server_registered_method->request_matcher);
+                           &rm->server_registered_method->request_matcher,
+                           rm->server_registered_method->payload_handling);
       return;
     }
   }
   finish_start_new_rpc(exec_ctx, server, elem,
-                       &server->unregistered_request_matcher);
+                       &server->unregistered_request_matcher,
+                       GRPC_SRM_PAYLOAD_NONE);
 }
 
 static int num_listeners(grpc_server *server) {
@@ -824,7 +937,7 @@ grpc_server *grpc_server_create(const grpc_channel_args *args, void *reserved) {
     gpr_stack_lockfree_push(server->request_freelist, (int)i);
   }
   request_matcher_init(&server->unregistered_request_matcher,
-                       server->max_requested_calls);
+                       server->max_requested_calls, server);
   server->requested_calls = gpr_malloc(server->max_requested_calls *
                                        sizeof(*server->requested_calls));
 
@@ -840,8 +953,10 @@ static int streq(const char *a, const char *b) {
   return 0 == strcmp(a, b);
 }
 
-void *grpc_server_register_method(grpc_server *server, const char *method,
-                                  const char *host, uint32_t flags) {
+void *grpc_server_register_method(
+    grpc_server *server, const char *method, const char *host,
+    grpc_server_register_method_payload_handling payload_handling,
+    uint32_t flags) {
   registered_method *m;
   GRPC_API_TRACE(
       "grpc_server_register_method(server=%p, method=%s, host=%s, "
@@ -866,10 +981,12 @@ void *grpc_server_register_method(grpc_server *server, const char *method,
   }
   m = gpr_malloc(sizeof(registered_method));
   memset(m, 0, sizeof(*m));
-  request_matcher_init(&m->request_matcher, server->max_requested_calls);
+  request_matcher_init(&m->request_matcher, server->max_requested_calls,
+                       server);
   m->method = gpr_strdup(method);
   m->host = gpr_strdup(host);
   m->next = server->registered_methods;
+  m->payload_handling = payload_handling;
   m->flags = flags;
   server->registered_methods = m;
   return m;
@@ -1143,8 +1260,8 @@ static grpc_call_error queue_call_request(grpc_exec_ctx *exec_ctx,
         GPR_ASSERT(calld->state == PENDING);
         calld->state = ACTIVATED;
         gpr_mu_unlock(&calld->mu_state);
-        begin_call(exec_ctx, server, calld,
-                   &server->requested_calls[request_id]);
+        publish_call(exec_ctx, server, calld,
+                     &server->requested_calls[request_id]);
       }
       gpr_mu_lock(&server->mu_call);
     }
@@ -1209,6 +1326,12 @@ grpc_call_error grpc_server_request_registered_call(
     error = GRPC_CALL_ERROR_NOT_SERVER_COMPLETION_QUEUE;
     goto done;
   }
+  if ((optional_payload == NULL) !=
+      (rm->payload_handling == GRPC_SRM_PAYLOAD_NONE)) {
+    gpr_free(rc);
+    error = GRPC_CALL_ERROR_PAYLOAD_TYPE_MISMATCH;
+    goto done;
+  }
   grpc_cq_begin_op(cq_for_notification, tag);
   rc->type = REGISTERED_CALL;
   rc->server = server;
@@ -1226,86 +1349,6 @@ done:
   return error;
 }
 
-static void publish_registered_or_batch(grpc_exec_ctx *exec_ctx,
-                                        void *user_data, bool success);
-
-static void cpstr(char **dest, size_t *capacity, grpc_mdstr *value) {
-  gpr_slice slice = value->slice;
-  size_t len = GPR_SLICE_LENGTH(slice);
-
-  if (len + 1 > *capacity) {
-    *capacity = GPR_MAX(len + 1, *capacity * 2);
-    *dest = gpr_realloc(*dest, *capacity);
-  }
-  memcpy(*dest, grpc_mdstr_as_c_string(value), len + 1);
-}
-
-static void begin_call(grpc_exec_ctx *exec_ctx, grpc_server *server,
-                       call_data *calld, requested_call *rc) {
-  grpc_op ops[1];
-  grpc_op *op = ops;
-
-  memset(ops, 0, sizeof(ops));
-
-  /* called once initial metadata has been read by the call, but BEFORE
-     the ioreq to fetch it out of the call has been executed.
-     This means metadata related fields can be relied on in calld, but to
-     fill in the metadata array passed by the client, we need to perform
-     an ioreq op, that should complete immediately. */
-
-  grpc_call_set_completion_queue(exec_ctx, calld->call, rc->cq_bound_to_call);
-  grpc_closure_init(&rc->publish, publish_registered_or_batch, rc);
-  *rc->call = calld->call;
-  calld->cq_new = rc->cq_for_notification;
-  GPR_SWAP(grpc_metadata_array, *rc->initial_metadata, calld->initial_metadata);
-  switch (rc->type) {
-    case BATCH_CALL:
-      GPR_ASSERT(calld->host != NULL);
-      GPR_ASSERT(calld->path != NULL);
-      cpstr(&rc->data.batch.details->host,
-            &rc->data.batch.details->host_capacity, calld->host);
-      cpstr(&rc->data.batch.details->method,
-            &rc->data.batch.details->method_capacity, calld->path);
-      rc->data.batch.details->deadline = calld->deadline;
-      rc->data.batch.details->flags =
-          0 | (calld->recv_idempotent_request
-                   ? GRPC_INITIAL_METADATA_IDEMPOTENT_REQUEST
-                   : 0);
-      break;
-    case REGISTERED_CALL:
-      *rc->data.registered.deadline = calld->deadline;
-      if (rc->data.registered.optional_payload) {
-        op->op = GRPC_OP_RECV_MESSAGE;
-        op->data.recv_message = rc->data.registered.optional_payload;
-        op++;
-      }
-      break;
-    default:
-      GPR_UNREACHABLE_CODE(return );
-  }
-
-  GRPC_CALL_INTERNAL_REF(calld->call, "server");
-  grpc_call_start_batch_and_execute(exec_ctx, calld->call, ops,
-                                    (size_t)(op - ops), &rc->publish);
-}
-
-static void done_request_event(grpc_exec_ctx *exec_ctx, void *req,
-                               grpc_cq_completion *c) {
-  requested_call *rc = req;
-  grpc_server *server = rc->server;
-
-  if (rc >= server->requested_calls &&
-      rc < server->requested_calls + server->max_requested_calls) {
-    GPR_ASSERT(rc - server->requested_calls <= INT_MAX);
-    gpr_stack_lockfree_push(server->request_freelist,
-                            (int)(rc - server->requested_calls));
-  } else {
-    gpr_free(req);
-  }
-
-  server_unref(exec_ctx, server);
-}
-
 static void fail_call(grpc_exec_ctx *exec_ctx, grpc_server *server,
                       requested_call *rc) {
   *rc->call = NULL;
@@ -1316,20 +1359,6 @@ static void fail_call(grpc_exec_ctx *exec_ctx, grpc_server *server,
                  done_request_event, rc, &rc->completion);
 }
 
-static void publish_registered_or_batch(grpc_exec_ctx *exec_ctx, void *prc,
-                                        bool success) {
-  requested_call *rc = prc;
-  grpc_call *call = *rc->call;
-  grpc_call_element *elem =
-      grpc_call_stack_element(grpc_call_get_call_stack(call), 0);
-  call_data *calld = elem->call_data;
-  channel_data *chand = elem->channel_data;
-  server_ref(chand->server);
-  grpc_cq_end_op(exec_ctx, calld->cq_new, rc->tag, success, done_request_event,
-                 rc, &rc->completion);
-  GRPC_CALL_INTERNAL_UNREF(exec_ctx, call, "server");
-}
-
 const grpc_channel_args *grpc_server_get_channel_args(grpc_server *server) {
   return server->channel_args;
 }
diff --git a/src/core/lib/transport/transport.h b/src/core/lib/transport/transport.h
index 460e4dcedc..bb1120ee3a 100644
--- a/src/core/lib/transport/transport.h
+++ b/src/core/lib/transport/transport.h
@@ -101,9 +101,9 @@ typedef struct grpc_transport_stream_op {
   /** Send initial metadata to the peer, from the provided metadata batch.
       idempotent_request MUST be set if this is non-null */
   grpc_metadata_batch *send_initial_metadata;
-  /** Iff send_initial_metadata != NULL, flags if this is an idempotent request
-      or not */
-  bool send_idempotent_request;
+  /** Iff send_initial_metadata != NULL, flags associated with
+      send_initial_metadata: a bitfield of GRPC_INITIAL_METADATA_xxx */
+  uint32_t send_initial_metadata_flags;
 
   /** Send trailing metadata to the peer, from the provided metadata batch. */
   grpc_metadata_batch *send_trailing_metadata;