From dd2c3cf23afe0c1e11770157a8fdedb3c4146d2b Mon Sep 17 00:00:00 2001
From: Alexander Polcyn <apolcyn@google.com>
Date: Tue, 12 Sep 2017 13:54:37 -0700
Subject: [PATCH 01/12] fix handling of service config choosing when percentage
 is zero

---
 .../client_channel/resolver/dns/c_ares/dns_resolver_ares.c      | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/core/ext/filters/client_channel/resolver/dns/c_ares/dns_resolver_ares.c b/src/core/ext/filters/client_channel/resolver/dns/c_ares/dns_resolver_ares.c
index b87a3b70820..371c59b8cf3 100644
--- a/src/core/ext/filters/client_channel/resolver/dns/c_ares/dns_resolver_ares.c
+++ b/src/core/ext/filters/client_channel/resolver/dns/c_ares/dns_resolver_ares.c
@@ -204,7 +204,7 @@ static char *choose_service_config(char *service_config_choice_json) {
         int random_pct = rand() % 100;
         int percentage;
         if (sscanf(field->value, "%d", &percentage) != 1 ||
-            random_pct > percentage) {
+            random_pct > percentage || percentage == 0) {
           service_config_json = NULL;
           break;
         }

From f7617bb8f6bd4b6993d6cf5bf70a14a5819f5fd6 Mon Sep 17 00:00:00 2001
From: Craig Tiller <ctiller@google.com>
Date: Wed, 13 Sep 2017 09:47:28 -0700
Subject: [PATCH 02/12] Really use measured CPU costs (with a small delta) for
 run_tests

---
 tools/run_tests/run_tests.py | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/tools/run_tests/run_tests.py b/tools/run_tests/run_tests.py
index b66c5f7f71f..591a0bebbde 100755
--- a/tools/run_tests/run_tests.py
+++ b/tools/run_tests/run_tests.py
@@ -80,7 +80,7 @@ def get_bqtest_data(limit=None):
 SELECT
   filtered_test_name,
   SUM(result != 'PASSED' AND result != 'SKIPPED') > 0 as flaky,
-  MAX(cpu_measured) as cpu
+  MAX(cpu_measured) + 0.01 as cpu
   FROM (
   SELECT
     REGEXP_REPLACE(test_name, r'/\d+', '') AS filtered_test_name,
@@ -92,9 +92,7 @@ SELECT
     AND platform = '"""+platform_string()+"""'
     AND NOT REGEXP_MATCH(job_name, '.*portability.*') )
 GROUP BY
-  filtered_test_name
-HAVING
-  flaky OR cpu > 0"""
+  filtered_test_name"""
   if limit:
     query += " limit {}".format(limit)
   query_job = big_query_utils.sync_query_job(bq, 'grpc-testing', query)

From 09a02ec04038e9eb45aae249d65bdf66f305d9d4 Mon Sep 17 00:00:00 2001
From: Nathaniel Manista <nathaniel@google.com>
Date: Wed, 13 Sep 2017 20:05:34 +0000
Subject: [PATCH 03/12] Kill (grpcio_tests/)commands.BuildProtoModules

In 1ff429da2a94bc79300ebce3f8aae7efb10e9a75 it appears to have been
copied out of src/python/grpcio/commands.py and not used, and it seems
to have remained without use since.
---
 src/python/grpcio_tests/commands.py | 49 -----------------------------
 1 file changed, 49 deletions(-)

diff --git a/src/python/grpcio_tests/commands.py b/src/python/grpcio_tests/commands.py
index 162200112af..93f84572b76 100644
--- a/src/python/grpcio_tests/commands.py
+++ b/src/python/grpcio_tests/commands.py
@@ -67,55 +67,6 @@ class GatherProto(setuptools.Command):
             open(path, 'a').close()
 
 
-class BuildProtoModules(setuptools.Command):
-    """Command to generate project *_pb2.py modules from proto files."""
-
-    description = 'build protobuf modules'
-    user_options = [
-        ('include=', None, 'path patterns to include in protobuf generation'),
-        ('exclude=', None, 'path patterns to exclude from protobuf generation')
-    ]
-
-    def initialize_options(self):
-        self.exclude = None
-        self.include = r'.*\.proto$'
-
-    def finalize_options(self):
-        pass
-
-    def run(self):
-        import grpc_tools.protoc as protoc
-
-        include_regex = re.compile(self.include)
-        exclude_regex = re.compile(self.exclude) if self.exclude else None
-        paths = []
-        for walk_root, directories, filenames in os.walk(PROTO_STEM):
-            for filename in filenames:
-                path = os.path.join(walk_root, filename)
-                if include_regex.match(path) and not (
-                        exclude_regex and exclude_regex.match(path)):
-                    paths.append(path)
-
-        # TODO(kpayson): It would be nice to do this in a batch command,
-        # but we currently have name conflicts in src/proto
-        for path in paths:
-            command = [
-                'grpc_tools.protoc',
-                '-I {}'.format(PROTO_STEM),
-                '--python_out={}'.format(PROTO_STEM),
-                '--grpc_python_out={}'.format(PROTO_STEM),
-            ] + [path]
-            if protoc.main(command) != 0:
-                sys.stderr.write(
-                    'warning: Command:\n{}\nFailed'.format(command))
-
-        # Generated proto directories dont include __init__.py, but
-        # these are needed for python package resolution
-        for walk_root, _, _ in os.walk(PROTO_STEM):
-            path = os.path.join(walk_root, '__init__.py')
-            open(path, 'a').close()
-
-
 class BuildPy(build_py.build_py):
     """Custom project build command."""
 

From d01fd422ece32c875abc9ad3cd022b3727cce2f4 Mon Sep 17 00:00:00 2001
From: Nathaniel Manista <nathaniel@google.com>
Date: Wed, 13 Sep 2017 20:13:32 +0000
Subject: [PATCH 04/12] grpc_1_0 flag for gRPC Python Protoc Plug-In

We'll soon be flipping the default behavior of gRPC Python Protoc
Plug-In to the later-than-gRPC-1.0 "code elements only in a
separate _pb2_grpc.py file and no Beta-API-using generated code
elements" behavior; this flag will be the supported (supported for a
while, though not exactly sure how long) means of using the older
"also put gRPC-using code elements in the generated _pb2.py file"
behavior that has been in place since gRPC 1.0.
---
 src/compiler/python_generator.cc | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/compiler/python_generator.cc b/src/compiler/python_generator.cc
index 31b177c28e6..a60b528e3b5 100644
--- a/src/compiler/python_generator.cc
+++ b/src/compiler/python_generator.cc
@@ -769,7 +769,7 @@ bool PythonGrpcGenerator::Generate(const FileDescriptor* file,
   PrivateGenerator generator(config_, &pbfile);
   if (parameter == "grpc_2_0") {
     return GenerateGrpc(context, generator, pb2_grpc_file_name, true);
-  } else if (parameter == "") {
+  } else if (parameter == "grpc_1_0" || parameter == "") {
     return GenerateGrpc(context, generator, pb2_grpc_file_name, true) &&
            GenerateGrpc(context, generator, pb2_file_name, false);
   } else {

From 324ad6a6c239ebb6dfafbe00a825a90a409daa11 Mon Sep 17 00:00:00 2001
From: Juanli Shen <aspirinsjl@gmail.com>
Date: Wed, 13 Sep 2017 15:10:08 -0700
Subject: [PATCH 05/12] Update service_config doc

The current grpclb fallback implementation is to continue using the internal round_robin policy but feed it with the backends from the resolver. We didn't fall back to the policy indicated in service config (or client API) because that's too complex and has more different behavior from the normal situation where we do connect to the balancer.
---
 doc/service_config.md | 5 +----
 1 file changed, 1 insertion(+), 4 deletions(-)

diff --git a/doc/service_config.md b/doc/service_config.md
index 99d985f3bfe..0abbd7f324d 100644
--- a/doc/service_config.md
+++ b/doc/service_config.md
@@ -24,10 +24,7 @@ The service config is a JSON string of the following form:
   // opposed to backend addresses), gRPC will use grpclb (see
   // https://github.com/grpc/grpc/blob/master/doc/load-balancing.md),
   // regardless of what LB policy is requested either here or via the
-  // client API.  However, if the resolver returns at least one backend
-  // address in addition to the balancer address(es), the client may fall
-  // back to the requested policy if it is unable to reach any of the
-  // grpclb load balancers.
+  // client API.
   'loadBalancingPolicy': string,
 
   // Per-method configuration.  Optional.

From 438304960f95169a7a0272ff684b80805ced9cba Mon Sep 17 00:00:00 2001
From: Matt Kwong <mattkwong@google.com>
Date: Wed, 13 Sep 2017 18:27:55 -0700
Subject: [PATCH 06/12] Add allow-ssh tags to newly created GCE VMs

---
 tools/gce/create_interop_worker.sh           | 3 ++-
 tools/gce/create_linux_performance_worker.sh | 3 ++-
 tools/gce/create_linux_worker.sh             | 3 ++-
 3 files changed, 6 insertions(+), 3 deletions(-)

diff --git a/tools/gce/create_interop_worker.sh b/tools/gce/create_interop_worker.sh
index 76e4905272a..3e59dc501ad 100755
--- a/tools/gce/create_interop_worker.sh
+++ b/tools/gce/create_interop_worker.sh
@@ -33,7 +33,8 @@ gcloud compute instances create $INSTANCE_NAME \
     --machine-type n1-standard-16 \
     --image ubuntu-15-10 \
     --boot-disk-size 1000 \
-    --scopes https://www.googleapis.com/auth/xapi.zoo
+    --scopes https://www.googleapis.com/auth/xapi.zoo \
+    --tags=allow-ssh
 
 echo 'Created GCE instance, waiting 60 seconds for it to come online.'
 sleep 60
diff --git a/tools/gce/create_linux_performance_worker.sh b/tools/gce/create_linux_performance_worker.sh
index 7f53732c05d..4270f5cbfb6 100755
--- a/tools/gce/create_linux_performance_worker.sh
+++ b/tools/gce/create_linux_performance_worker.sh
@@ -36,7 +36,8 @@ gcloud compute instances create $INSTANCE_NAME \
     --image-project ubuntu-os-cloud \
     --image-family ubuntu-1704 \
     --boot-disk-size 300 \
-    --scopes https://www.googleapis.com/auth/bigquery
+    --scopes https://www.googleapis.com/auth/bigquery \
+    --tags=allow-ssh
 
 echo 'Created GCE instance, waiting 60 seconds for it to come online.'
 sleep 60
diff --git a/tools/gce/create_linux_worker.sh b/tools/gce/create_linux_worker.sh
index c96f3281fc7..8bf44aa7294 100755
--- a/tools/gce/create_linux_worker.sh
+++ b/tools/gce/create_linux_worker.sh
@@ -31,7 +31,8 @@ gcloud compute instances create $INSTANCE_NAME \
     --image=ubuntu-1510 \
     --image-project=grpc-testing \
     --boot-disk-size 1000 \
-    --scopes https://www.googleapis.com/auth/bigquery
+    --scopes https://www.googleapis.com/auth/bigquery \
+    --tags=allow-ssh
 
 echo 'Created GCE instance, waiting 60 seconds for it to come online.'
 sleep 60

From 01e83b55e4700459ae82efeac088b512d5dfabd7 Mon Sep 17 00:00:00 2001
From: Ken Payson <kpayson@google.com>
Date: Wed, 13 Sep 2017 19:45:07 -0700
Subject: [PATCH 07/12] Revert "Add fallback (use backends from resolver if
 can't reach balancer) to grpclb."

This reverts commit aba0a0a54412fe59bc2090334ae26c99bb148097.
---
 include/grpc++/support/channel_arguments.h    |   6 -
 include/grpc/impl/codegen/grpc_types.h        |   6 +-
 .../client_channel/lb_policy/grpclb/grpclb.c  | 197 ++++--------------
 .../client_channel/lb_policy_factory.c        |   2 +-
 .../client_channel/lb_policy_factory.h        |   2 +-
 src/cpp/common/channel_arguments.cc           |   4 -
 test/cpp/end2end/grpclb_end2end_test.cc       |  74 +------
 7 files changed, 47 insertions(+), 244 deletions(-)

diff --git a/include/grpc++/support/channel_arguments.h b/include/grpc++/support/channel_arguments.h
index 9dc505f0082..7b6befeaf1e 100644
--- a/include/grpc++/support/channel_arguments.h
+++ b/include/grpc++/support/channel_arguments.h
@@ -64,12 +64,6 @@ class ChannelArguments {
   /// Set the compression algorithm for the channel.
   void SetCompressionAlgorithm(grpc_compression_algorithm algorithm);
 
-  /// Set the grpclb fallback timeout (in ms) for the channel. If this amount
-  /// of time has passed but we have not gotten any non-empty \a serverlist from
-  /// the balancer, we will fall back to use the backend address(es) returned by
-  /// the resolver.
-  void SetGrpclbFallbackTimeout(int fallback_timeout);
-
   /// Set the socket mutator for the channel.
   void SetSocketMutator(grpc_socket_mutator* mutator);
 
diff --git a/include/grpc/impl/codegen/grpc_types.h b/include/grpc/impl/codegen/grpc_types.h
index beb6080c944..748dc717a33 100644
--- a/include/grpc/impl/codegen/grpc_types.h
+++ b/include/grpc/impl/codegen/grpc_types.h
@@ -287,11 +287,7 @@ typedef struct {
   "grpc.experimental.tcp_max_read_chunk_size"
 /* Timeout in milliseconds to use for calls to the grpclb load balancer.
    If 0 or unset, the balancer calls will have no deadline. */
-#define GRPC_ARG_GRPCLB_CALL_TIMEOUT_MS "grpc.grpclb_call_timeout_ms"
-/* Timeout in milliseconds to wait for the serverlist from the grpclb load
-   balancer before using fallback backend addresses from the resolver.
-   If 0, fallback will never be used. */
-#define GRPC_ARG_GRPCLB_FALLBACK_TIMEOUT_MS "grpc.grpclb_fallback_timeout_ms"
+#define GRPC_ARG_GRPCLB_CALL_TIMEOUT_MS "grpc.grpclb_timeout_ms"
 /** If non-zero, grpc server's cronet compression workaround will be enabled */
 #define GRPC_ARG_WORKAROUND_CRONET_COMPRESSION \
   "grpc.workaround.cronet_compression"
diff --git a/src/core/ext/filters/client_channel/lb_policy/grpclb/grpclb.c b/src/core/ext/filters/client_channel/lb_policy/grpclb/grpclb.c
index 18979829bd2..5aafed1374d 100644
--- a/src/core/ext/filters/client_channel/lb_policy/grpclb/grpclb.c
+++ b/src/core/ext/filters/client_channel/lb_policy/grpclb/grpclb.c
@@ -122,7 +122,6 @@
 #define GRPC_GRPCLB_RECONNECT_BACKOFF_MULTIPLIER 1.6
 #define GRPC_GRPCLB_RECONNECT_MAX_BACKOFF_SECONDS 120
 #define GRPC_GRPCLB_RECONNECT_JITTER 0.2
-#define GRPC_GRPCLB_DEFAULT_FALLBACK_TIMEOUT_MS 10000
 
 grpc_tracer_flag grpc_lb_glb_trace = GRPC_TRACER_INITIALIZER(false, "glb");
 
@@ -299,10 +298,6 @@ typedef struct glb_lb_policy {
   /** timeout in milliseconds for the LB call. 0 means no deadline. */
   int lb_call_timeout_ms;
 
-  /** timeout in milliseconds for before using fallback backend addresses.
-   * 0 means not using fallback. */
-  int lb_fallback_timeout_ms;
-
   /** for communicating with the LB server */
   grpc_channel *lb_channel;
 
@@ -329,9 +324,6 @@ typedef struct glb_lb_policy {
    * Otherwise, we delegate to the RR policy. */
   size_t serverlist_index;
 
-  /** stores the backend addresses from the resolver */
-  grpc_lb_addresses *fallback_backend_addresses;
-
   /** list of picks that are waiting on RR's policy connectivity */
   pending_pick *pending_picks;
 
@@ -352,9 +344,6 @@ typedef struct glb_lb_policy {
   /** is \a lb_call_retry_timer active? */
   bool retry_timer_active;
 
-  /** is \a lb_fallback_timer active? */
-  bool fallback_timer_active;
-
   /** called upon changes to the LB channel's connectivity. */
   grpc_closure lb_channel_on_connectivity_changed;
 
@@ -377,9 +366,6 @@ typedef struct glb_lb_policy {
   /* LB call retry timer callback. */
   grpc_closure lb_on_call_retry;
 
-  /* LB fallback timer callback. */
-  grpc_closure lb_on_fallback;
-
   grpc_call *lb_call; /* streaming call to the LB server, */
 
   grpc_metadata_array lb_initial_metadata_recv; /* initial MD from LB server */
@@ -403,9 +389,6 @@ typedef struct glb_lb_policy {
   /** LB call retry timer */
   grpc_timer lb_call_retry_timer;
 
-  /** LB fallback timer */
-  grpc_timer lb_fallback_timer;
-
   bool initial_request_sent;
   bool seen_initial_response;
 
@@ -552,32 +535,6 @@ static grpc_lb_addresses *process_serverlist_locked(
   return lb_addresses;
 }
 
-/* Returns the backend addresses extracted from the given addresses */
-static grpc_lb_addresses *extract_backend_addresses_locked(
-    grpc_exec_ctx *exec_ctx, const grpc_lb_addresses *addresses) {
-  /* first pass: count the number of backend addresses */
-  size_t num_backends = 0;
-  for (size_t i = 0; i < addresses->num_addresses; ++i) {
-    if (!addresses->addresses[i].is_balancer) {
-      ++num_backends;
-    }
-  }
-  /* second pass: actually populate the addresses and (empty) LB tokens */
-  grpc_lb_addresses *backend_addresses =
-      grpc_lb_addresses_create(num_backends, &lb_token_vtable);
-  size_t num_copied = 0;
-  for (size_t i = 0; i < addresses->num_addresses; ++i) {
-    if (addresses->addresses[i].is_balancer) continue;
-    const grpc_resolved_address *addr = &addresses->addresses[i].address;
-    grpc_lb_addresses_set_address(backend_addresses, num_copied, &addr->addr,
-                                  addr->len, false /* is_balancer */,
-                                  NULL /* balancer_name */,
-                                  (void *)GRPC_MDELEM_LB_TOKEN_EMPTY.payload);
-    ++num_copied;
-  }
-  return backend_addresses;
-}
-
 static void update_lb_connectivity_status_locked(
     grpc_exec_ctx *exec_ctx, glb_lb_policy *glb_policy,
     grpc_connectivity_state rr_state, grpc_error *rr_state_error) {
@@ -645,38 +602,35 @@ static bool pick_from_internal_rr_locked(
     grpc_exec_ctx *exec_ctx, glb_lb_policy *glb_policy,
     const grpc_lb_policy_pick_args *pick_args, bool force_async,
     grpc_connected_subchannel **target, wrapped_rr_closure_arg *wc_arg) {
-  // Check for drops if we are not using fallback backend addresses.
-  if (glb_policy->serverlist != NULL) {
-    // Look at the index into the serverlist to see if we should drop this call.
-    grpc_grpclb_server *server =
-        glb_policy->serverlist->servers[glb_policy->serverlist_index++];
-    if (glb_policy->serverlist_index == glb_policy->serverlist->num_servers) {
-      glb_policy->serverlist_index = 0;  // Wrap-around.
+  // Look at the index into the serverlist to see if we should drop this call.
+  grpc_grpclb_server *server =
+      glb_policy->serverlist->servers[glb_policy->serverlist_index++];
+  if (glb_policy->serverlist_index == glb_policy->serverlist->num_servers) {
+    glb_policy->serverlist_index = 0;  // Wrap-around.
+  }
+  if (server->drop) {
+    // Not using the RR policy, so unref it.
+    if (GRPC_TRACER_ON(grpc_lb_glb_trace)) {
+      gpr_log(GPR_INFO, "Unreffing RR for drop (0x%" PRIxPTR ")",
+              (intptr_t)wc_arg->rr_policy);
     }
-    if (server->drop) {
-      // Not using the RR policy, so unref it.
-      if (GRPC_TRACER_ON(grpc_lb_glb_trace)) {
-        gpr_log(GPR_INFO, "Unreffing RR for drop (0x%" PRIxPTR ")",
-                (intptr_t)wc_arg->rr_policy);
-      }
-      GRPC_LB_POLICY_UNREF(exec_ctx, wc_arg->rr_policy, "glb_pick_sync");
-      // Update client load reporting stats to indicate the number of
-      // dropped calls.  Note that we have to do this here instead of in
-      // the client_load_reporting filter, because we do not create a
-      // subchannel call (and therefore no client_load_reporting filter)
-      // for dropped calls.
-      grpc_grpclb_client_stats_add_call_dropped_locked(
-          server->load_balance_token, wc_arg->client_stats);
-      grpc_grpclb_client_stats_unref(wc_arg->client_stats);
-      if (force_async) {
-        GPR_ASSERT(wc_arg->wrapped_closure != NULL);
-        GRPC_CLOSURE_SCHED(exec_ctx, wc_arg->wrapped_closure, GRPC_ERROR_NONE);
-        gpr_free(wc_arg->free_when_done);
-        return false;
-      }
+    GRPC_LB_POLICY_UNREF(exec_ctx, wc_arg->rr_policy, "glb_pick_sync");
+    // Update client load reporting stats to indicate the number of
+    // dropped calls.  Note that we have to do this here instead of in
+    // the client_load_reporting filter, because we do not create a
+    // subchannel call (and therefore no client_load_reporting filter)
+    // for dropped calls.
+    grpc_grpclb_client_stats_add_call_dropped_locked(server->load_balance_token,
+                                                     wc_arg->client_stats);
+    grpc_grpclb_client_stats_unref(wc_arg->client_stats);
+    if (force_async) {
+      GPR_ASSERT(wc_arg->wrapped_closure != NULL);
+      GRPC_CLOSURE_SCHED(exec_ctx, wc_arg->wrapped_closure, GRPC_ERROR_NONE);
       gpr_free(wc_arg->free_when_done);
-      return true;
+      return false;
     }
+    gpr_free(wc_arg->free_when_done);
+    return true;
   }
   // Pick via the RR policy.
   const bool pick_done = grpc_lb_policy_pick_locked(
@@ -714,18 +668,8 @@ static bool pick_from_internal_rr_locked(
 
 static grpc_lb_policy_args *lb_policy_args_create(grpc_exec_ctx *exec_ctx,
                                                   glb_lb_policy *glb_policy) {
-  grpc_lb_addresses *addresses;
-  if (glb_policy->serverlist != NULL) {
-    GPR_ASSERT(glb_policy->serverlist->num_servers > 0);
-    addresses = process_serverlist_locked(exec_ctx, glb_policy->serverlist);
-  } else {
-    // If rr_handover_locked() is invoked when we haven't received any
-    // serverlist from the balancer, we use the fallback backends returned by
-    // the resolver. Note that the fallback backend list may be empty, in which
-    // case the new round_robin policy will keep the requested picks pending.
-    GPR_ASSERT(glb_policy->fallback_backend_addresses != NULL);
-    addresses = grpc_lb_addresses_copy(glb_policy->fallback_backend_addresses);
-  }
+  grpc_lb_addresses *addresses =
+      process_serverlist_locked(exec_ctx, glb_policy->serverlist);
   GPR_ASSERT(addresses != NULL);
   grpc_lb_policy_args *args = (grpc_lb_policy_args *)gpr_zalloc(sizeof(*args));
   args->client_channel_factory = glb_policy->cc_factory;
@@ -831,6 +775,8 @@ static void create_rr_locked(grpc_exec_ctx *exec_ctx, glb_lb_policy *glb_policy,
 /* glb_policy->rr_policy may be NULL (initial handover) */
 static void rr_handover_locked(grpc_exec_ctx *exec_ctx,
                                glb_lb_policy *glb_policy) {
+  GPR_ASSERT(glb_policy->serverlist != NULL &&
+             glb_policy->serverlist->num_servers > 0);
   if (glb_policy->shutting_down) return;
   grpc_lb_policy_args *args = lb_policy_args_create(exec_ctx, glb_policy);
   GPR_ASSERT(args != NULL);
@@ -971,7 +917,13 @@ static void glb_lb_channel_on_connectivity_changed_cb(grpc_exec_ctx *exec_ctx,
 static grpc_lb_policy *glb_create(grpc_exec_ctx *exec_ctx,
                                   grpc_lb_policy_factory *factory,
                                   grpc_lb_policy_args *args) {
-  /* Count the number of gRPC-LB addresses. There must be at least one. */
+  /* Count the number of gRPC-LB addresses. There must be at least one.
+   * TODO(roth): For now, we ignore non-balancer addresses, but in the
+   * future, we may change the behavior such that we fall back to using
+   * the non-balancer addresses if we cannot reach any balancers. In the
+   * fallback case, we should use the LB policy indicated by
+   * GRPC_ARG_LB_POLICY_NAME (although if that specifies grpclb or is
+   * unset, we should default to pick_first). */
   const grpc_arg *arg =
       grpc_channel_args_find(args->args, GRPC_ARG_LB_ADDRESSES);
   if (arg == NULL || arg->type != GRPC_ARG_POINTER) {
@@ -1007,11 +959,6 @@ static grpc_lb_policy *glb_create(grpc_exec_ctx *exec_ctx,
   glb_policy->lb_call_timeout_ms =
       grpc_channel_arg_get_integer(arg, (grpc_integer_options){0, 0, INT_MAX});
 
-  arg = grpc_channel_args_find(args->args, GRPC_ARG_GRPCLB_FALLBACK_TIMEOUT_MS);
-  glb_policy->lb_fallback_timeout_ms = grpc_channel_arg_get_integer(
-      arg, (grpc_integer_options){GRPC_GRPCLB_DEFAULT_FALLBACK_TIMEOUT_MS, 0,
-                                  INT_MAX});
-
   // Make sure that GRPC_ARG_LB_POLICY_NAME is set in channel args,
   // since we use this to trigger the client_load_reporting filter.
   grpc_arg new_arg =
@@ -1020,11 +967,6 @@ static grpc_lb_policy *glb_create(grpc_exec_ctx *exec_ctx,
   glb_policy->args = grpc_channel_args_copy_and_add_and_remove(
       args->args, args_to_remove, GPR_ARRAY_SIZE(args_to_remove), &new_arg, 1);
 
-  /* Extract the backend addresses (may be empty) from the resolver for
-   * fallback. */
-  glb_policy->fallback_backend_addresses =
-      extract_backend_addresses_locked(exec_ctx, addresses);
-
   /* Create a client channel over them to communicate with a LB service */
   glb_policy->response_generator =
       grpc_fake_resolver_response_generator_create();
@@ -1068,9 +1010,6 @@ static void glb_destroy(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol) {
   if (glb_policy->serverlist != NULL) {
     grpc_grpclb_destroy_serverlist(glb_policy->serverlist);
   }
-  if (glb_policy->fallback_backend_addresses != NULL) {
-    grpc_lb_addresses_destroy(exec_ctx, glb_policy->fallback_backend_addresses);
-  }
   grpc_fake_resolver_response_generator_unref(glb_policy->response_generator);
   if (glb_policy->pending_update_args != NULL) {
     grpc_channel_args_destroy(exec_ctx, glb_policy->pending_update_args->args);
@@ -1211,28 +1150,10 @@ static void glb_cancel_picks_locked(grpc_exec_ctx *exec_ctx,
   GRPC_ERROR_UNREF(error);
 }
 
-static void lb_on_fallback_timer_locked(grpc_exec_ctx *exec_ctx, void *arg,
-                                        grpc_error *error);
 static void query_for_backends_locked(grpc_exec_ctx *exec_ctx,
                                       glb_lb_policy *glb_policy);
 static void start_picking_locked(grpc_exec_ctx *exec_ctx,
                                  glb_lb_policy *glb_policy) {
-  /* start a timer to fall back */
-  if (glb_policy->lb_fallback_timeout_ms > 0 &&
-      glb_policy->serverlist == NULL) {
-    gpr_timespec now = gpr_now(GPR_CLOCK_MONOTONIC);
-    gpr_timespec deadline = gpr_time_add(
-        now,
-        gpr_time_from_millis(glb_policy->lb_fallback_timeout_ms, GPR_TIMESPAN));
-    GRPC_LB_POLICY_WEAK_REF(&glb_policy->base, "grpclb_fallback_timer");
-    GRPC_CLOSURE_INIT(&glb_policy->lb_on_fallback, lb_on_fallback_timer_locked,
-                      glb_policy,
-                      grpc_combiner_scheduler(glb_policy->base.combiner));
-    glb_policy->fallback_timer_active = true;
-    grpc_timer_init(exec_ctx, &glb_policy->lb_fallback_timer, deadline,
-                    &glb_policy->lb_on_fallback, now);
-  }
-
   glb_policy->started_picking = true;
   gpr_backoff_reset(&glb_policy->lb_call_backoff_state);
   query_for_backends_locked(exec_ctx, glb_policy);
@@ -1686,15 +1607,6 @@ static void lb_on_response_received_locked(grpc_exec_ctx *exec_ctx, void *arg,
             if (glb_policy->serverlist != NULL) {
               /* dispose of the old serverlist */
               grpc_grpclb_destroy_serverlist(glb_policy->serverlist);
-            } else {
-              /* or dispose of the fallback */
-              grpc_lb_addresses_destroy(exec_ctx,
-                                        glb_policy->fallback_backend_addresses);
-              glb_policy->fallback_backend_addresses = NULL;
-              if (glb_policy->fallback_timer_active) {
-                grpc_timer_cancel(exec_ctx, &glb_policy->lb_fallback_timer);
-                glb_policy->fallback_timer_active = false;
-              }
             }
             /* and update the copy in the glb_lb_policy instance. This
              * serverlist instance will be destroyed either upon the next
@@ -1705,7 +1617,9 @@ static void lb_on_response_received_locked(grpc_exec_ctx *exec_ctx, void *arg,
           }
         } else {
           if (GRPC_TRACER_ON(grpc_lb_glb_trace)) {
-            gpr_log(GPR_INFO, "Received empty server list, ignoring.");
+            gpr_log(GPR_INFO,
+                    "Received empty server list. Picks will stay pending until "
+                    "a response with > 0 servers is received");
           }
           grpc_grpclb_destroy_serverlist(serverlist);
         }
@@ -1752,26 +1666,6 @@ static void lb_call_on_retry_timer_locked(grpc_exec_ctx *exec_ctx, void *arg,
   GRPC_LB_POLICY_WEAK_UNREF(exec_ctx, &glb_policy->base, "grpclb_retry_timer");
 }
 
-static void lb_on_fallback_timer_locked(grpc_exec_ctx *exec_ctx, void *arg,
-                                        grpc_error *error) {
-  glb_lb_policy *glb_policy = arg;
-  /* If we receive a serverlist after the timer fires but before this callback
-   * actually runs, don't do anything. */
-  if (glb_policy->serverlist != NULL) return;
-  glb_policy->fallback_timer_active = false;
-  if (!glb_policy->shutting_down && error == GRPC_ERROR_NONE) {
-    if (GRPC_TRACER_ON(grpc_lb_glb_trace)) {
-      gpr_log(GPR_INFO,
-              "Falling back to use backends from resolver (grpclb %p)",
-              (void *)glb_policy);
-    }
-    GPR_ASSERT(glb_policy->fallback_backend_addresses != NULL);
-    rr_handover_locked(exec_ctx, glb_policy);
-  }
-  GRPC_LB_POLICY_WEAK_UNREF(exec_ctx, &glb_policy->base,
-                            "grpclb_fallback_timer");
-}
-
 static void lb_on_server_status_received_locked(grpc_exec_ctx *exec_ctx,
                                                 void *arg, grpc_error *error) {
   glb_lb_policy *glb_policy = (glb_lb_policy *)arg;
@@ -1892,17 +1786,6 @@ static void glb_update_locked(grpc_exec_ctx *exec_ctx, grpc_lb_policy *policy,
         &glb_policy->lb_channel_connectivity,
         &glb_policy->lb_channel_on_connectivity_changed, NULL);
   }
-
-  // Propagate update to fallback_backend_addresses if a non-empty serverlist
-  // hasn't been received from the balancer.
-  if (glb_policy->serverlist == NULL) {
-    grpc_lb_addresses_destroy(exec_ctx, glb_policy->fallback_backend_addresses);
-    glb_policy->fallback_backend_addresses =
-        extract_backend_addresses_locked(exec_ctx, addresses);
-    if (glb_policy->rr_policy != NULL) {
-      rr_handover_locked(exec_ctx, glb_policy);
-    }
-  }
 }
 
 // Invoked as part of the update process. It continues watching the LB channel
diff --git a/src/core/ext/filters/client_channel/lb_policy_factory.c b/src/core/ext/filters/client_channel/lb_policy_factory.c
index 918bab745c6..cdcaf17544b 100644
--- a/src/core/ext/filters/client_channel/lb_policy_factory.c
+++ b/src/core/ext/filters/client_channel/lb_policy_factory.c
@@ -56,7 +56,7 @@ grpc_lb_addresses* grpc_lb_addresses_copy(const grpc_lb_addresses* addresses) {
 }
 
 void grpc_lb_addresses_set_address(grpc_lb_addresses* addresses, size_t index,
-                                   const void* address, size_t address_len,
+                                   void* address, size_t address_len,
                                    bool is_balancer, const char* balancer_name,
                                    void* user_data) {
   GPR_ASSERT(index < addresses->num_addresses);
diff --git a/src/core/ext/filters/client_channel/lb_policy_factory.h b/src/core/ext/filters/client_channel/lb_policy_factory.h
index cf0f8cb6157..9d9fb143df5 100644
--- a/src/core/ext/filters/client_channel/lb_policy_factory.h
+++ b/src/core/ext/filters/client_channel/lb_policy_factory.h
@@ -73,7 +73,7 @@ grpc_lb_addresses *grpc_lb_addresses_copy(const grpc_lb_addresses *addresses);
  * \a address is a socket address of length \a address_len.
  * Takes ownership of \a balancer_name. */
 void grpc_lb_addresses_set_address(grpc_lb_addresses *addresses, size_t index,
-                                   const void *address, size_t address_len,
+                                   void *address, size_t address_len,
                                    bool is_balancer, const char *balancer_name,
                                    void *user_data);
 
diff --git a/src/cpp/common/channel_arguments.cc b/src/cpp/common/channel_arguments.cc
index f89f5f1f03d..f130aecd4b5 100644
--- a/src/cpp/common/channel_arguments.cc
+++ b/src/cpp/common/channel_arguments.cc
@@ -86,10 +86,6 @@ void ChannelArguments::SetCompressionAlgorithm(
   SetInt(GRPC_COMPRESSION_CHANNEL_DEFAULT_ALGORITHM, algorithm);
 }
 
-void ChannelArguments::SetGrpclbFallbackTimeout(int fallback_timeout) {
-  SetInt(GRPC_ARG_GRPCLB_FALLBACK_TIMEOUT_MS, fallback_timeout);
-}
-
 void ChannelArguments::SetSocketMutator(grpc_socket_mutator* mutator) {
   if (!mutator) {
     return;
diff --git a/test/cpp/end2end/grpclb_end2end_test.cc b/test/cpp/end2end/grpclb_end2end_test.cc
index 17a094f7a21..570a3d10677 100644
--- a/test/cpp/end2end/grpclb_end2end_test.cc
+++ b/test/cpp/end2end/grpclb_end2end_test.cc
@@ -368,9 +368,8 @@ class GrpclbEnd2endTest : public ::testing::Test {
     grpc_fake_resolver_response_generator_unref(response_generator_);
   }
 
-  void ResetStub(int fallback_timeout = 0) {
+  void ResetStub() {
     ChannelArguments args;
-    args.SetGrpclbFallbackTimeout(fallback_timeout);
     args.SetPointer(GRPC_ARG_FAKE_RESOLVER_RESPONSE_GENERATOR,
                     response_generator_);
     std::ostringstream uri;
@@ -442,10 +441,10 @@ class GrpclbEnd2endTest : public ::testing::Test {
     grpc_exec_ctx_finish(&exec_ctx);
   }
 
-  const std::vector<int> GetBackendPorts(const size_t start_index = 0) const {
+  const std::vector<int> GetBackendPorts() const {
     std::vector<int> backend_ports;
-    for (size_t i = start_index; i < backend_servers_.size(); ++i) {
-      backend_ports.push_back(backend_servers_[i].port_);
+    for (const auto& bs : backend_servers_) {
+      backend_ports.push_back(bs.port_);
     }
     return backend_ports;
   }
@@ -616,71 +615,6 @@ TEST_F(SingleBalancerTest, InitiallyEmptyServerlist) {
   EXPECT_EQ("grpclb", channel_->GetLoadBalancingPolicyName());
 }
 
-TEST_F(SingleBalancerTest, Fallback) {
-  const int kFallbackTimeoutMs = 200 * grpc_test_slowdown_factor();
-  const int kServerlistDelayMs = 500 * grpc_test_slowdown_factor();
-  const size_t kNumBackendInResolution = backends_.size() / 2;
-
-  ResetStub(kFallbackTimeoutMs);
-  std::vector<AddressData> addresses;
-  addresses.emplace_back(AddressData{balancer_servers_[0].port_, true, ""});
-  for (size_t i = 0; i < kNumBackendInResolution; ++i) {
-    addresses.emplace_back(AddressData{backend_servers_[i].port_, false, ""});
-  }
-  SetNextResolution(addresses);
-
-  // Send non-empty serverlist only after kServerlistDelayMs
-  ScheduleResponseForBalancer(
-      0, BalancerServiceImpl::BuildResponseForBackends(
-             GetBackendPorts(kNumBackendInResolution /* start_index */), {}),
-      kServerlistDelayMs);
-
-  // The first request. The client will block while it's still trying to
-  // contact the balancer.
-  gpr_log(GPR_INFO, "========= BEFORE FIRST BATCH ==========");
-  CheckRpcSendOk(kNumBackendInResolution);
-  gpr_log(GPR_INFO, "========= DONE WITH FIRST BATCH ==========");
-
-  // Fallback is used: each backend returned by the resolver should have
-  // gotten one request.
-  for (size_t i = 0; i < kNumBackendInResolution; ++i) {
-    EXPECT_EQ(1U, backend_servers_[i].service_->request_count());
-  }
-  for (size_t i = kNumBackendInResolution; i < backends_.size(); ++i) {
-    EXPECT_EQ(0U, backend_servers_[i].service_->request_count());
-  }
-
-  // Wait until update has been processed, as signaled by the backend returned
-  // by the balancer receiving a request.
-  do {
-    CheckRpcSendOk(1);
-  } while (
-      backend_servers_[kNumBackendInResolution].service_->request_count() == 0);
-  for (size_t i = 0; i < backends_.size(); ++i) {
-    backend_servers_[i].service_->ResetCounters();
-  }
-
-  // Send out the second request.
-  gpr_log(GPR_INFO, "========= BEFORE SECOND BATCH ==========");
-  CheckRpcSendOk(backends_.size() - kNumBackendInResolution);
-  gpr_log(GPR_INFO, "========= DONE WITH SECOND BATCH ==========");
-
-  // Serverlist is used: each backend returned by the balancer should
-  // have gotten one request.
-  for (size_t i = 0; i < kNumBackendInResolution; ++i) {
-    EXPECT_EQ(0U, backend_servers_[i].service_->request_count());
-  }
-  for (size_t i = kNumBackendInResolution; i < backends_.size(); ++i) {
-    EXPECT_EQ(1U, backend_servers_[i].service_->request_count());
-  }
-
-  balancers_[0]->NotifyDoneWithServerlists();
-  // The balancer got a single request.
-  EXPECT_EQ(1U, balancer_servers_[0].service_->request_count());
-  // and sent a single response.
-  EXPECT_EQ(1U, balancer_servers_[0].service_->response_count());
-}
-
 TEST_F(SingleBalancerTest, BackendsRestart) {
   const size_t kNumRpcsPerAddress = 100;
   ScheduleResponseForBalancer(

From 5432dd887430984713f9fc3ad595c85e995d6451 Mon Sep 17 00:00:00 2001
From: Jan Tattermusch <jtattermusch@users.noreply.github.com>
Date: Thu, 14 Sep 2017 17:55:42 +0200
Subject: [PATCH 08/12] Revert "Allow SerializationTraits to use
 grpc::ByteBuffer rather than only grpc_byte_buffer"

---
 BUILD                                         |   2 -
 CMakeLists.txt                                |  15 --
 Makefile                                      |  15 --
 build.yaml                                    |   2 -
 gRPC-Core.podspec                             |   1 -
 grpc.def                                      |  20 +--
 grpc.gemspec                                  |   1 -
 include/grpc++/impl/codegen/byte_buffer.h     | 141 ------------------
 include/grpc++/impl/codegen/call.h            | 114 +++-----------
 .../grpc++/impl/codegen/method_handler_impl.h |   9 +-
 .../grpc++/impl/codegen/rpc_service_method.h  |  14 +-
 .../impl/codegen/serialization_traits.h       |  25 +---
 include/grpc++/impl/codegen/slice.h           |  78 ----------
 include/grpc++/support/byte_buffer.h          |  68 ++++++++-
 include/grpc++/support/slice.h                |  80 +++++++++-
 include/grpc/byte_buffer.h                    |  64 +++++++-
 include/grpc/impl/codegen/byte_buffer.h       |  86 -----------
 package.xml                                   |   1 -
 src/core/lib/iomgr/resource_quota.c           |   1 -
 .../health/default_health_check_service.cc    |   1 -
 src/cpp/util/byte_buffer_cc.cc                |  37 ++---
 src/cpp/util/slice_cc.cc                      |   2 -
 src/ruby/ext/grpc/rb_grpc_imports.generated.c |  40 ++---
 src/ruby/ext/grpc/rb_grpc_imports.generated.h |  62 ++++----
 .../core/surface/public_headers_must_be_c89.c |   1 -
 test/cpp/util/byte_buffer_test.cc             |   5 +-
 tools/doxygen/Doxyfile.c++                    |   2 -
 tools/doxygen/Doxyfile.c++.internal           |   2 -
 tools/doxygen/Doxyfile.core                   |   1 -
 tools/doxygen/Doxyfile.core.internal          |   1 -
 .../generated/sources_and_headers.json        |   4 -
 31 files changed, 330 insertions(+), 565 deletions(-)
 delete mode 100644 include/grpc++/impl/codegen/byte_buffer.h
 delete mode 100644 include/grpc/impl/codegen/byte_buffer.h

diff --git a/BUILD b/BUILD
index d76b821be92..281375fc1db 100644
--- a/BUILD
+++ b/BUILD
@@ -989,7 +989,6 @@ grpc_cc_library(
     name = "grpc_codegen",
     language = "c",
     public_hdrs = [
-        "include/grpc/impl/codegen/byte_buffer.h",
         "include/grpc/impl/codegen/byte_buffer_reader.h",
         "include/grpc/impl/codegen/compression_types.h",
         "include/grpc/impl/codegen/connectivity_state.h",
@@ -1488,7 +1487,6 @@ grpc_cc_library(
     public_hdrs = [
         "include/grpc++/impl/codegen/async_stream.h",
         "include/grpc++/impl/codegen/async_unary_call.h",
-        "include/grpc++/impl/codegen/byte_buffer.h",
         "include/grpc++/impl/codegen/call.h",
         "include/grpc++/impl/codegen/call_hook.h",
         "include/grpc++/impl/codegen/channel_interface.h",
diff --git a/CMakeLists.txt b/CMakeLists.txt
index eac63a9fe3c..fa1d7d87dd3 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -1238,7 +1238,6 @@ target_link_libraries(grpc
 )
 
 foreach(_hdr
-  include/grpc/impl/codegen/byte_buffer.h
   include/grpc/impl/codegen/byte_buffer_reader.h
   include/grpc/impl/codegen/compression_types.h
   include/grpc/impl/codegen/connectivity_state.h
@@ -1545,7 +1544,6 @@ target_link_libraries(grpc_cronet
 )
 
 foreach(_hdr
-  include/grpc/impl/codegen/byte_buffer.h
   include/grpc/impl/codegen/byte_buffer_reader.h
   include/grpc/impl/codegen/compression_types.h
   include/grpc/impl/codegen/connectivity_state.h
@@ -1822,7 +1820,6 @@ target_link_libraries(grpc_test_util
 )
 
 foreach(_hdr
-  include/grpc/impl/codegen/byte_buffer.h
   include/grpc/impl/codegen/byte_buffer_reader.h
   include/grpc/impl/codegen/compression_types.h
   include/grpc/impl/codegen/connectivity_state.h
@@ -2083,7 +2080,6 @@ target_link_libraries(grpc_test_util_unsecure
 )
 
 foreach(_hdr
-  include/grpc/impl/codegen/byte_buffer.h
   include/grpc/impl/codegen/byte_buffer_reader.h
   include/grpc/impl/codegen/compression_types.h
   include/grpc/impl/codegen/connectivity_state.h
@@ -2379,7 +2375,6 @@ target_link_libraries(grpc_unsecure
 )
 
 foreach(_hdr
-  include/grpc/impl/codegen/byte_buffer.h
   include/grpc/impl/codegen/byte_buffer_reader.h
   include/grpc/impl/codegen/compression_types.h
   include/grpc/impl/codegen/connectivity_state.h
@@ -2689,7 +2684,6 @@ foreach(_hdr
   include/grpc/slice_buffer.h
   include/grpc/status.h
   include/grpc/support/workaround_list.h
-  include/grpc/impl/codegen/byte_buffer.h
   include/grpc/impl/codegen/byte_buffer_reader.h
   include/grpc/impl/codegen/compression_types.h
   include/grpc/impl/codegen/connectivity_state.h
@@ -2700,7 +2694,6 @@ foreach(_hdr
   include/grpc/impl/codegen/status.h
   include/grpc++/impl/codegen/async_stream.h
   include/grpc++/impl/codegen/async_unary_call.h
-  include/grpc++/impl/codegen/byte_buffer.h
   include/grpc++/impl/codegen/call.h
   include/grpc++/impl/codegen/call_hook.h
   include/grpc++/impl/codegen/channel_interface.h
@@ -3183,7 +3176,6 @@ foreach(_hdr
   include/grpc/slice_buffer.h
   include/grpc/status.h
   include/grpc/support/workaround_list.h
-  include/grpc/impl/codegen/byte_buffer.h
   include/grpc/impl/codegen/byte_buffer_reader.h
   include/grpc/impl/codegen/compression_types.h
   include/grpc/impl/codegen/connectivity_state.h
@@ -3194,7 +3186,6 @@ foreach(_hdr
   include/grpc/impl/codegen/status.h
   include/grpc++/impl/codegen/async_stream.h
   include/grpc++/impl/codegen/async_unary_call.h
-  include/grpc++/impl/codegen/byte_buffer.h
   include/grpc++/impl/codegen/call.h
   include/grpc++/impl/codegen/call_hook.h
   include/grpc++/impl/codegen/channel_interface.h
@@ -3555,7 +3546,6 @@ target_link_libraries(grpc++_test_util
 foreach(_hdr
   include/grpc++/impl/codegen/async_stream.h
   include/grpc++/impl/codegen/async_unary_call.h
-  include/grpc++/impl/codegen/byte_buffer.h
   include/grpc++/impl/codegen/call.h
   include/grpc++/impl/codegen/call_hook.h
   include/grpc++/impl/codegen/channel_interface.h
@@ -3583,7 +3573,6 @@ foreach(_hdr
   include/grpc++/impl/codegen/stub_options.h
   include/grpc++/impl/codegen/sync_stream.h
   include/grpc++/impl/codegen/time.h
-  include/grpc/impl/codegen/byte_buffer.h
   include/grpc/impl/codegen/byte_buffer_reader.h
   include/grpc/impl/codegen/compression_types.h
   include/grpc/impl/codegen/connectivity_state.h
@@ -3695,7 +3684,6 @@ target_link_libraries(grpc++_test_util_unsecure
 foreach(_hdr
   include/grpc++/impl/codegen/async_stream.h
   include/grpc++/impl/codegen/async_unary_call.h
-  include/grpc++/impl/codegen/byte_buffer.h
   include/grpc++/impl/codegen/call.h
   include/grpc++/impl/codegen/call_hook.h
   include/grpc++/impl/codegen/channel_interface.h
@@ -3723,7 +3711,6 @@ foreach(_hdr
   include/grpc++/impl/codegen/stub_options.h
   include/grpc++/impl/codegen/sync_stream.h
   include/grpc++/impl/codegen/time.h
-  include/grpc/impl/codegen/byte_buffer.h
   include/grpc/impl/codegen/byte_buffer_reader.h
   include/grpc/impl/codegen/compression_types.h
   include/grpc/impl/codegen/connectivity_state.h
@@ -3926,7 +3913,6 @@ foreach(_hdr
   include/grpc/slice_buffer.h
   include/grpc/status.h
   include/grpc/support/workaround_list.h
-  include/grpc/impl/codegen/byte_buffer.h
   include/grpc/impl/codegen/byte_buffer_reader.h
   include/grpc/impl/codegen/compression_types.h
   include/grpc/impl/codegen/connectivity_state.h
@@ -3937,7 +3923,6 @@ foreach(_hdr
   include/grpc/impl/codegen/status.h
   include/grpc++/impl/codegen/async_stream.h
   include/grpc++/impl/codegen/async_unary_call.h
-  include/grpc++/impl/codegen/byte_buffer.h
   include/grpc++/impl/codegen/call.h
   include/grpc++/impl/codegen/call_hook.h
   include/grpc++/impl/codegen/channel_interface.h
diff --git a/Makefile b/Makefile
index 1ed1877f77c..0c3648566a9 100644
--- a/Makefile
+++ b/Makefile
@@ -3190,7 +3190,6 @@ LIBGRPC_SRC = \
     src/core/plugin_registry/grpc_plugin_registry.c \
 
 PUBLIC_HEADERS_C += \
-    include/grpc/impl/codegen/byte_buffer.h \
     include/grpc/impl/codegen/byte_buffer_reader.h \
     include/grpc/impl/codegen/compression_types.h \
     include/grpc/impl/codegen/connectivity_state.h \
@@ -3497,7 +3496,6 @@ LIBGRPC_CRONET_SRC = \
     src/core/plugin_registry/grpc_cronet_plugin_registry.c \
 
 PUBLIC_HEADERS_C += \
-    include/grpc/impl/codegen/byte_buffer.h \
     include/grpc/impl/codegen/byte_buffer_reader.h \
     include/grpc/impl/codegen/compression_types.h \
     include/grpc/impl/codegen/connectivity_state.h \
@@ -3775,7 +3773,6 @@ LIBGRPC_TEST_UTIL_SRC = \
     src/core/ext/filters/http/server/http_server_filter.c \
 
 PUBLIC_HEADERS_C += \
-    include/grpc/impl/codegen/byte_buffer.h \
     include/grpc/impl/codegen/byte_buffer_reader.h \
     include/grpc/impl/codegen/compression_types.h \
     include/grpc/impl/codegen/connectivity_state.h \
@@ -4027,7 +4024,6 @@ LIBGRPC_TEST_UTIL_UNSECURE_SRC = \
     src/core/ext/filters/http/server/http_server_filter.c \
 
 PUBLIC_HEADERS_C += \
-    include/grpc/impl/codegen/byte_buffer.h \
     include/grpc/impl/codegen/byte_buffer_reader.h \
     include/grpc/impl/codegen/compression_types.h \
     include/grpc/impl/codegen/connectivity_state.h \
@@ -4300,7 +4296,6 @@ LIBGRPC_UNSECURE_SRC = \
     src/core/plugin_registry/grpc_unsecure_plugin_registry.c \
 
 PUBLIC_HEADERS_C += \
-    include/grpc/impl/codegen/byte_buffer.h \
     include/grpc/impl/codegen/byte_buffer_reader.h \
     include/grpc/impl/codegen/compression_types.h \
     include/grpc/impl/codegen/connectivity_state.h \
@@ -4589,7 +4584,6 @@ PUBLIC_HEADERS_CXX += \
     include/grpc/slice_buffer.h \
     include/grpc/status.h \
     include/grpc/support/workaround_list.h \
-    include/grpc/impl/codegen/byte_buffer.h \
     include/grpc/impl/codegen/byte_buffer_reader.h \
     include/grpc/impl/codegen/compression_types.h \
     include/grpc/impl/codegen/connectivity_state.h \
@@ -4600,7 +4594,6 @@ PUBLIC_HEADERS_CXX += \
     include/grpc/impl/codegen/status.h \
     include/grpc++/impl/codegen/async_stream.h \
     include/grpc++/impl/codegen/async_unary_call.h \
-    include/grpc++/impl/codegen/byte_buffer.h \
     include/grpc++/impl/codegen/call.h \
     include/grpc++/impl/codegen/call_hook.h \
     include/grpc++/impl/codegen/channel_interface.h \
@@ -5084,7 +5077,6 @@ PUBLIC_HEADERS_CXX += \
     include/grpc/slice_buffer.h \
     include/grpc/status.h \
     include/grpc/support/workaround_list.h \
-    include/grpc/impl/codegen/byte_buffer.h \
     include/grpc/impl/codegen/byte_buffer_reader.h \
     include/grpc/impl/codegen/compression_types.h \
     include/grpc/impl/codegen/connectivity_state.h \
@@ -5095,7 +5087,6 @@ PUBLIC_HEADERS_CXX += \
     include/grpc/impl/codegen/status.h \
     include/grpc++/impl/codegen/async_stream.h \
     include/grpc++/impl/codegen/async_unary_call.h \
-    include/grpc++/impl/codegen/byte_buffer.h \
     include/grpc++/impl/codegen/call.h \
     include/grpc++/impl/codegen/call_hook.h \
     include/grpc++/impl/codegen/channel_interface.h \
@@ -5449,7 +5440,6 @@ LIBGRPC++_TEST_UTIL_SRC = \
 PUBLIC_HEADERS_CXX += \
     include/grpc++/impl/codegen/async_stream.h \
     include/grpc++/impl/codegen/async_unary_call.h \
-    include/grpc++/impl/codegen/byte_buffer.h \
     include/grpc++/impl/codegen/call.h \
     include/grpc++/impl/codegen/call_hook.h \
     include/grpc++/impl/codegen/channel_interface.h \
@@ -5477,7 +5467,6 @@ PUBLIC_HEADERS_CXX += \
     include/grpc++/impl/codegen/stub_options.h \
     include/grpc++/impl/codegen/sync_stream.h \
     include/grpc++/impl/codegen/time.h \
-    include/grpc/impl/codegen/byte_buffer.h \
     include/grpc/impl/codegen/byte_buffer_reader.h \
     include/grpc/impl/codegen/compression_types.h \
     include/grpc/impl/codegen/connectivity_state.h \
@@ -5566,7 +5555,6 @@ LIBGRPC++_TEST_UTIL_UNSECURE_SRC = \
 PUBLIC_HEADERS_CXX += \
     include/grpc++/impl/codegen/async_stream.h \
     include/grpc++/impl/codegen/async_unary_call.h \
-    include/grpc++/impl/codegen/byte_buffer.h \
     include/grpc++/impl/codegen/call.h \
     include/grpc++/impl/codegen/call_hook.h \
     include/grpc++/impl/codegen/channel_interface.h \
@@ -5594,7 +5582,6 @@ PUBLIC_HEADERS_CXX += \
     include/grpc++/impl/codegen/stub_options.h \
     include/grpc++/impl/codegen/sync_stream.h \
     include/grpc++/impl/codegen/time.h \
-    include/grpc/impl/codegen/byte_buffer.h \
     include/grpc/impl/codegen/byte_buffer_reader.h \
     include/grpc/impl/codegen/compression_types.h \
     include/grpc/impl/codegen/connectivity_state.h \
@@ -5802,7 +5789,6 @@ PUBLIC_HEADERS_CXX += \
     include/grpc/slice_buffer.h \
     include/grpc/status.h \
     include/grpc/support/workaround_list.h \
-    include/grpc/impl/codegen/byte_buffer.h \
     include/grpc/impl/codegen/byte_buffer_reader.h \
     include/grpc/impl/codegen/compression_types.h \
     include/grpc/impl/codegen/connectivity_state.h \
@@ -5813,7 +5799,6 @@ PUBLIC_HEADERS_CXX += \
     include/grpc/impl/codegen/status.h \
     include/grpc++/impl/codegen/async_stream.h \
     include/grpc++/impl/codegen/async_unary_call.h \
-    include/grpc++/impl/codegen/byte_buffer.h \
     include/grpc++/impl/codegen/call.h \
     include/grpc++/impl/codegen/call_hook.h \
     include/grpc++/impl/codegen/channel_interface.h \
diff --git a/build.yaml b/build.yaml
index 92ca2b6237b..d15cf0339ca 100644
--- a/build.yaml
+++ b/build.yaml
@@ -502,7 +502,6 @@ filegroups:
   - grpc_deadline_filter
 - name: grpc_codegen
   public_headers:
-  - include/grpc/impl/codegen/byte_buffer.h
   - include/grpc/impl/codegen/byte_buffer_reader.h
   - include/grpc/impl/codegen/compression_types.h
   - include/grpc/impl/codegen/connectivity_state.h
@@ -970,7 +969,6 @@ filegroups:
   public_headers:
   - include/grpc++/impl/codegen/async_stream.h
   - include/grpc++/impl/codegen/async_unary_call.h
-  - include/grpc++/impl/codegen/byte_buffer.h
   - include/grpc++/impl/codegen/call.h
   - include/grpc++/impl/codegen/call_hook.h
   - include/grpc++/impl/codegen/channel_interface.h
diff --git a/gRPC-Core.podspec b/gRPC-Core.podspec
index 6f84ef235db..2f1f4158662 100644
--- a/gRPC-Core.podspec
+++ b/gRPC-Core.podspec
@@ -141,7 +141,6 @@ Pod::Spec.new do |s|
                       'include/grpc/impl/codegen/sync_generic.h',
                       'include/grpc/impl/codegen/sync_posix.h',
                       'include/grpc/impl/codegen/sync_windows.h',
-                      'include/grpc/impl/codegen/byte_buffer.h',
                       'include/grpc/impl/codegen/byte_buffer_reader.h',
                       'include/grpc/impl/codegen/compression_types.h',
                       'include/grpc/impl/codegen/connectivity_state.h',
diff --git a/grpc.def b/grpc.def
index 558be60c3c1..a7a11601ed9 100644
--- a/grpc.def
+++ b/grpc.def
@@ -1,4 +1,14 @@
 EXPORTS
+    grpc_raw_byte_buffer_create
+    grpc_raw_compressed_byte_buffer_create
+    grpc_byte_buffer_copy
+    grpc_byte_buffer_length
+    grpc_byte_buffer_destroy
+    grpc_byte_buffer_reader_init
+    grpc_byte_buffer_reader_destroy
+    grpc_byte_buffer_reader_next
+    grpc_byte_buffer_reader_readall
+    grpc_raw_byte_buffer_from_reader
     census_initialize
     census_shutdown
     census_supported
@@ -135,16 +145,6 @@ EXPORTS
     grpc_server_add_secure_http2_port
     grpc_call_set_credentials
     grpc_server_credentials_set_auth_metadata_processor
-    grpc_raw_byte_buffer_create
-    grpc_raw_compressed_byte_buffer_create
-    grpc_byte_buffer_copy
-    grpc_byte_buffer_length
-    grpc_byte_buffer_destroy
-    grpc_byte_buffer_reader_init
-    grpc_byte_buffer_reader_destroy
-    grpc_byte_buffer_reader_next
-    grpc_byte_buffer_reader_readall
-    grpc_raw_byte_buffer_from_reader
     grpc_slice_ref
     grpc_slice_unref
     grpc_slice_copy
diff --git a/grpc.gemspec b/grpc.gemspec
index a226e9bc31a..2d0f9fd4504 100644
--- a/grpc.gemspec
+++ b/grpc.gemspec
@@ -145,7 +145,6 @@ Gem::Specification.new do |s|
   s.files += %w( src/core/lib/support/tmpfile_posix.c )
   s.files += %w( src/core/lib/support/tmpfile_windows.c )
   s.files += %w( src/core/lib/support/wrap_memcpy.c )
-  s.files += %w( include/grpc/impl/codegen/byte_buffer.h )
   s.files += %w( include/grpc/impl/codegen/byte_buffer_reader.h )
   s.files += %w( include/grpc/impl/codegen/compression_types.h )
   s.files += %w( include/grpc/impl/codegen/connectivity_state.h )
diff --git a/include/grpc++/impl/codegen/byte_buffer.h b/include/grpc++/impl/codegen/byte_buffer.h
deleted file mode 100644
index 87d390c688a..00000000000
--- a/include/grpc++/impl/codegen/byte_buffer.h
+++ /dev/null
@@ -1,141 +0,0 @@
-/*
- *
- * Copyright 2017 gRPC authors.
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- *
- */
-
-#ifndef GRPCXX_IMPL_CODEGEN_BYTE_BUFFER_H
-#define GRPCXX_IMPL_CODEGEN_BYTE_BUFFER_H
-
-#include <grpc/impl/codegen/byte_buffer.h>
-
-#include <grpc++/impl/codegen/config.h>
-#include <grpc++/impl/codegen/core_codegen_interface.h>
-#include <grpc++/impl/codegen/serialization_traits.h>
-#include <grpc++/impl/codegen/slice.h>
-#include <grpc++/impl/codegen/status.h>
-
-#include <vector>
-
-namespace grpc {
-
-template <class R>
-class CallOpRecvMessage;
-class MethodHandler;
-namespace internal {
-template <class M, class T>
-class MessageDeserializer;
-}
-
-/// A sequence of bytes.
-class ByteBuffer final {
- public:
-  /// Constuct an empty buffer.
-  ByteBuffer() : buffer_(nullptr) {}
-
-  /// Construct buffer from \a slices, of which there are \a nslices.
-  ByteBuffer(const Slice* slices, size_t nslices);
-
-  /// Constuct a byte buffer by referencing elements of existing buffer
-  /// \a buf. Wrapper of core function grpc_byte_buffer_copy
-  ByteBuffer(const ByteBuffer& buf);
-
-  ~ByteBuffer() {
-    if (buffer_) {
-      g_core_codegen_interface->grpc_byte_buffer_destroy(buffer_);
-    }
-  }
-
-  ByteBuffer& operator=(const ByteBuffer&);
-
-  /// Dump (read) the buffer contents into \a slices.
-  Status Dump(std::vector<Slice>* slices) const;
-
-  /// Remove all data.
-  void Clear() {
-    if (buffer_) {
-      g_core_codegen_interface->grpc_byte_buffer_destroy(buffer_);
-      buffer_ = nullptr;
-    }
-  }
-
-  /// Make a duplicate copy of the internals of this byte
-  /// buffer so that we have our own owned version of it.
-  /// bbuf.Duplicate(); is equivalent to bbuf=bbuf; but is actually readable
-  void Duplicate() {
-    buffer_ = g_core_codegen_interface->grpc_byte_buffer_copy(buffer_);
-  }
-
-  /// Forget underlying byte buffer without destroying
-  /// Use this only for un-owned byte buffers
-  void Release() { buffer_ = nullptr; }
-
-  /// Buffer size in bytes.
-  size_t Length() const;
-
-  /// Swap the state of *this and *other.
-  void Swap(ByteBuffer* other);
-
-  /// Is this ByteBuffer valid?
-  bool Valid() const { return (buffer_ != nullptr); }
-
- private:
-  friend class SerializationTraits<ByteBuffer, void>;
-  friend class CallOpSendMessage;
-  template <class R>
-  friend class CallOpRecvMessage;
-  friend class CallOpGenericRecvMessage;
-  friend class MethodHandler;
-  template <class M, class T>
-  friend class internal::MessageDeserializer;
-
-  // takes ownership
-  void set_buffer(grpc_byte_buffer* buf) {
-    if (buffer_) {
-      Clear();
-    }
-    buffer_ = buf;
-  }
-
-  grpc_byte_buffer* c_buffer() { return buffer_; }
-  grpc_byte_buffer** c_buffer_ptr() { return &buffer_; }
-
-  // DEPRECATED: Implicit conversion to transparently
-  // support deprecated SerializationTraits API
-  // No need to inline since deprecated
-  operator grpc_byte_buffer*();
-  operator const grpc_byte_buffer*() const;
-
-  grpc_byte_buffer* buffer_;
-};
-
-template <>
-class SerializationTraits<ByteBuffer, void> {
- public:
-  static Status Deserialize(const ByteBuffer& byte_buffer, ByteBuffer* dest) {
-    dest->set_buffer(byte_buffer.buffer_);
-    return Status::OK;
-  }
-  static Status Serialize(const ByteBuffer& source, ByteBuffer* buffer,
-                          bool* own_buffer) {
-    *buffer = source;
-    *own_buffer = true;
-    return Status::OK;
-  }
-};
-
-}  // namespace grpc
-
-#endif  // GRPCXX_IMPL_CODEGEN_BYTE_BUFFER_H
diff --git a/include/grpc++/impl/codegen/call.h b/include/grpc++/impl/codegen/call.h
index 3c418c7ae2b..74ed5cbfb9e 100644
--- a/include/grpc++/impl/codegen/call.h
+++ b/include/grpc++/impl/codegen/call.h
@@ -25,7 +25,6 @@
 #include <map>
 #include <memory>
 
-#include <grpc++/impl/codegen/byte_buffer.h>
 #include <grpc++/impl/codegen/call_hook.h>
 #include <grpc++/impl/codegen/client_context.h>
 #include <grpc++/impl/codegen/completion_queue_tag.h>
@@ -40,6 +39,8 @@
 #include <grpc/impl/codegen/compression_types.h>
 #include <grpc/impl/codegen/grpc_types.h>
 
+struct grpc_byte_buffer;
+
 namespace grpc {
 
 class ByteBuffer;
@@ -280,7 +281,7 @@ class CallOpSendInitialMetadata {
 
 class CallOpSendMessage {
  public:
-  CallOpSendMessage() : send_buf_() {}
+  CallOpSendMessage() : send_buf_(nullptr) {}
 
   /// Send \a message using \a options for the write. The \a options are cleared
   /// after use.
@@ -293,67 +294,33 @@ class CallOpSendMessage {
 
  protected:
   void AddOp(grpc_op* ops, size_t* nops) {
-    if (!send_buf_.Valid()) return;
+    if (send_buf_ == nullptr) return;
     grpc_op* op = &ops[(*nops)++];
     op->op = GRPC_OP_SEND_MESSAGE;
     op->flags = write_options_.flags();
     op->reserved = NULL;
-    op->data.send_message.send_message = send_buf_.c_buffer();
+    op->data.send_message.send_message = send_buf_;
     // Flags are per-message: clear them after use.
     write_options_.Clear();
   }
-  void FinishOp(bool* status) { send_buf_.Clear(); }
+  void FinishOp(bool* status) {
+    g_core_codegen_interface->grpc_byte_buffer_destroy(send_buf_);
+    send_buf_ = nullptr;
+  }
 
  private:
-  template <class M, class T = void>
-  class MessageSerializer;
-
-  ByteBuffer send_buf_;
+  grpc_byte_buffer* send_buf_;
   WriteOptions write_options_;
 };
 
-namespace internal {
-template <class T>
-T Example();
-}  // namespace internal
-
-template <class M>
-class CallOpSendMessage::MessageSerializer<
-    M, typename std::enable_if<std::is_same<
-           ::grpc::Status, decltype(SerializationTraits<M>::Serialize(
-                               internal::Example<const M&>(),
-                               internal::Example<grpc_byte_buffer**>(),
-                               internal::Example<bool*>()))>::value>::type> {
- public:
-  static Status SendMessageInternal(const M& message, ByteBuffer* bbuf,
-                                    bool* own_buf) {
-    return SerializationTraits<M>::Serialize(message, bbuf->c_buffer_ptr(),
-                                             own_buf);
-  }
-};
-
-template <class M>
-class CallOpSendMessage::MessageSerializer<
-    M, typename std::enable_if<std::is_same<
-           ::grpc::Status, decltype(SerializationTraits<M>::Serialize(
-                               internal::Example<const M&>(),
-                               internal::Example<::grpc::ByteBuffer*>(),
-                               internal::Example<bool*>()))>::value>::type> {
- public:
-  static Status SendMessageInternal(const M& message, ByteBuffer* bbuf,
-                                    bool* own_buf) {
-    return SerializationTraits<M>::Serialize(message, bbuf, own_buf);
-  }
-};
-
 template <class M>
 Status CallOpSendMessage::SendMessage(const M& message, WriteOptions options) {
   write_options_ = options;
   bool own_buf;
   Status result =
-      MessageSerializer<M>::SendMessageInternal(message, &send_buf_, &own_buf);
+      SerializationTraits<M>::Serialize(message, &send_buf_, &own_buf);
   if (!own_buf) {
-    send_buf_.Duplicate();
+    send_buf_ = g_core_codegen_interface->grpc_byte_buffer_copy(send_buf_);
   }
   return result;
 }
@@ -363,36 +330,6 @@ Status CallOpSendMessage::SendMessage(const M& message) {
   return SendMessage(message, WriteOptions());
 }
 
-namespace internal {
-template <class M, class T = void>
-class MessageDeserializer;
-
-template <class M>
-class MessageDeserializer<
-    M, typename std::enable_if<std::is_same<
-           ::grpc::Status, decltype(SerializationTraits<M>::Deserialize(
-                               internal::Example<const ::grpc::ByteBuffer&>(),
-                               internal::Example<M*>()))>::value>::type> {
- public:
-  static Status Deserialize(const ByteBuffer& bbuf, M* message) {
-    return SerializationTraits<M>::Deserialize(bbuf, message);
-  }
-};
-
-template <class M>
-class MessageDeserializer<
-    M, typename std::enable_if<std::is_same<
-           ::grpc::Status, decltype(SerializationTraits<M>::Deserialize(
-                               internal::Example<grpc_byte_buffer*>(),
-                               internal::Example<M*>()))>::value>::type> {
- public:
-  static Status Deserialize(const ByteBuffer& bbuf, M* message) {
-    return SerializationTraits<M>::Deserialize(
-        const_cast<ByteBuffer&>(bbuf).c_buffer(), message);
-  }
-};
-}  // namespace internal
-
 template <class R>
 class CallOpRecvMessage {
  public:
@@ -415,20 +352,18 @@ class CallOpRecvMessage {
     op->op = GRPC_OP_RECV_MESSAGE;
     op->flags = 0;
     op->reserved = NULL;
-    op->data.recv_message.recv_message = recv_buf_.c_buffer_ptr();
+    op->data.recv_message.recv_message = &recv_buf_;
   }
 
   void FinishOp(bool* status) {
     if (message_ == nullptr) return;
-    if (recv_buf_.Valid()) {
+    if (recv_buf_) {
       if (*status) {
         got_message = *status =
-            internal::MessageDeserializer<R>::Deserialize(recv_buf_, message_)
-                .ok();
-        recv_buf_.Release();
+            SerializationTraits<R>::Deserialize(recv_buf_, message_).ok();
       } else {
         got_message = false;
-        recv_buf_.Clear();
+        g_core_codegen_interface->grpc_byte_buffer_destroy(recv_buf_);
       }
     } else {
       got_message = false;
@@ -441,14 +376,14 @@ class CallOpRecvMessage {
 
  private:
   R* message_;
-  ByteBuffer recv_buf_;
+  grpc_byte_buffer* recv_buf_;
   bool allow_not_getting_message_;
 };
 
 namespace CallOpGenericRecvMessageHelper {
 class DeserializeFunc {
  public:
-  virtual Status Deserialize(const ByteBuffer& buf) = 0;
+  virtual Status Deserialize(grpc_byte_buffer* buf) = 0;
   virtual ~DeserializeFunc() {}
 };
 
@@ -456,8 +391,8 @@ template <class R>
 class DeserializeFuncType final : public DeserializeFunc {
  public:
   DeserializeFuncType(R* message) : message_(message) {}
-  Status Deserialize(const ByteBuffer& buf) override {
-    return grpc::internal::MessageDeserializer<R>::Deserialize(buf, message_);
+  Status Deserialize(grpc_byte_buffer* buf) override {
+    return SerializationTraits<R>::Deserialize(buf, message_);
   }
 
   ~DeserializeFuncType() override {}
@@ -493,19 +428,18 @@ class CallOpGenericRecvMessage {
     op->op = GRPC_OP_RECV_MESSAGE;
     op->flags = 0;
     op->reserved = NULL;
-    op->data.recv_message.recv_message = recv_buf_.c_buffer_ptr();
+    op->data.recv_message.recv_message = &recv_buf_;
   }
 
   void FinishOp(bool* status) {
     if (!deserialize_) return;
-    if (recv_buf_.Valid()) {
+    if (recv_buf_) {
       if (*status) {
         got_message = true;
         *status = deserialize_->Deserialize(recv_buf_).ok();
-        recv_buf_.Release();
       } else {
         got_message = false;
-        recv_buf_.Clear();
+        g_core_codegen_interface->grpc_byte_buffer_destroy(recv_buf_);
       }
     } else {
       got_message = false;
@@ -518,7 +452,7 @@ class CallOpGenericRecvMessage {
 
  private:
   std::unique_ptr<CallOpGenericRecvMessageHelper::DeserializeFunc> deserialize_;
-  ByteBuffer recv_buf_;
+  grpc_byte_buffer* recv_buf_;
   bool allow_not_getting_message_;
 };
 
diff --git a/include/grpc++/impl/codegen/method_handler_impl.h b/include/grpc++/impl/codegen/method_handler_impl.h
index 8125e0a6513..15e24bdcdcb 100644
--- a/include/grpc++/impl/codegen/method_handler_impl.h
+++ b/include/grpc++/impl/codegen/method_handler_impl.h
@@ -19,7 +19,6 @@
 #ifndef GRPCXX_IMPL_CODEGEN_METHOD_HANDLER_IMPL_H
 #define GRPCXX_IMPL_CODEGEN_METHOD_HANDLER_IMPL_H
 
-#include <grpc++/impl/codegen/byte_buffer.h>
 #include <grpc++/impl/codegen/core_codegen_interface.h>
 #include <grpc++/impl/codegen/rpc_service_method.h>
 #include <grpc++/impl/codegen/sync_stream.h>
@@ -38,8 +37,8 @@ class RpcMethodHandler : public MethodHandler {
 
   void RunHandler(const HandlerParameter& param) final {
     RequestType req;
-    Status status = internal::MessageDeserializer<RequestType>::Deserialize(
-        param.request, &req);
+    Status status =
+        SerializationTraits<RequestType>::Deserialize(param.request, &req);
     ResponseType rsp;
     if (status.ok()) {
       status = func_(service_, param.server_context, &req, &rsp);
@@ -124,8 +123,8 @@ class ServerStreamingHandler : public MethodHandler {
 
   void RunHandler(const HandlerParameter& param) final {
     RequestType req;
-    Status status = internal::MessageDeserializer<RequestType>::Deserialize(
-        param.request, &req);
+    Status status =
+        SerializationTraits<RequestType>::Deserialize(param.request, &req);
 
     if (status.ok()) {
       ServerWriter<ResponseType> writer(param.call, param.server_context);
diff --git a/include/grpc++/impl/codegen/rpc_service_method.h b/include/grpc++/impl/codegen/rpc_service_method.h
index d356012ad60..7165774172c 100644
--- a/include/grpc++/impl/codegen/rpc_service_method.h
+++ b/include/grpc++/impl/codegen/rpc_service_method.h
@@ -25,11 +25,14 @@
 #include <memory>
 #include <vector>
 
-#include <grpc++/impl/codegen/byte_buffer.h>
 #include <grpc++/impl/codegen/config.h>
 #include <grpc++/impl/codegen/rpc_method.h>
 #include <grpc++/impl/codegen/status.h>
 
+extern "C" {
+struct grpc_byte_buffer;
+}
+
 namespace grpc {
 class ServerContext;
 class StreamContextInterface;
@@ -40,14 +43,11 @@ class MethodHandler {
   virtual ~MethodHandler() {}
   struct HandlerParameter {
     HandlerParameter(Call* c, ServerContext* context, grpc_byte_buffer* req)
-        : call(c), server_context(context) {
-      request.set_buffer(req);
-    }
-    ~HandlerParameter() { request.Release(); }
+        : call(c), server_context(context), request(req) {}
     Call* call;
     ServerContext* server_context;
-    // Handler required to destroy these contents
-    ByteBuffer request;
+    // Handler required to grpc_byte_buffer_destroy this
+    grpc_byte_buffer* request;
   };
   virtual void RunHandler(const HandlerParameter& param) = 0;
 };
diff --git a/include/grpc++/impl/codegen/serialization_traits.h b/include/grpc++/impl/codegen/serialization_traits.h
index 7fc4e24172f..b72d4741267 100644
--- a/include/grpc++/impl/codegen/serialization_traits.h
+++ b/include/grpc++/impl/codegen/serialization_traits.h
@@ -26,24 +26,15 @@ namespace grpc {
 /// Used for hooking different message serialization API's into GRPC.
 /// Each SerializationTraits implementation must provide the following
 /// functions:
-/// 1.  static Status Serialize(const Message& msg,
-///                             ByteBuffer* buffer,
-///                             bool* own_buffer);
-///     AND/OR
-///     static Status Serialize(const Message& msg,
-///                             grpc_byte_buffer** buffer,
-///                             bool* own_buffer);
-///     The former is preferred; the latter is deprecated
+///   static Status Serialize(const Message& msg,
+///                           grpc_byte_buffer** buffer,
+///                           bool* own_buffer);
+///   static Status Deserialize(grpc_byte_buffer* buffer,
+///                             Message* msg,
+///                             int max_receive_message_size);
 ///
-/// 2.  static Status Deserialize(const ByteBuffer& buffer,
-///                               Message* msg);
-///     AND/OR
-///     static Status Deserialize(grpc_byte_buffer* buffer,
-///                               Message* msg);
-///     The former is preferred; the latter is deprecated
-///
-/// Serialize is required to convert message to a ByteBuffer, and
-/// return that byte buffer through *buffer. *own_buffer should
+/// Serialize is required to convert message to a grpc_byte_buffer, and
+/// to store a pointer to that byte buffer at *buffer. *own_buffer should
 /// be set to true if the caller owns said byte buffer, or false if
 /// ownership is retained elsewhere.
 ///
diff --git a/include/grpc++/impl/codegen/slice.h b/include/grpc++/impl/codegen/slice.h
index c185bf4fd01..e682bdef6af 100644
--- a/include/grpc++/impl/codegen/slice.h
+++ b/include/grpc++/impl/codegen/slice.h
@@ -19,89 +19,11 @@
 #ifndef GRPCXX_IMPL_CODEGEN_SLICE_H
 #define GRPCXX_IMPL_CODEGEN_SLICE_H
 
-#include <grpc++/impl/codegen/config.h>
 #include <grpc++/impl/codegen/core_codegen_interface.h>
 #include <grpc++/impl/codegen/string_ref.h>
 
-#include <grpc/impl/codegen/slice.h>
-
 namespace grpc {
 
-/// A wrapper around \a grpc_slice.
-///
-/// A slice represents a contiguous reference counted array of bytes.
-/// It is cheap to take references to a slice, and it is cheap to create a
-/// slice pointing to a subset of another slice.
-class Slice final {
- public:
-  /// Construct an empty slice.
-  Slice();
-  /// Destructor - drops one reference.
-  ~Slice();
-
-  enum AddRef { ADD_REF };
-  /// Construct a slice from \a slice, adding a reference.
-  Slice(grpc_slice slice, AddRef);
-
-  enum StealRef { STEAL_REF };
-  /// Construct a slice from \a slice, stealing a reference.
-  Slice(grpc_slice slice, StealRef);
-
-  /// Allocate a slice of specified size
-  Slice(size_t len);
-
-  /// Construct a slice from a copied buffer
-  Slice(const void* buf, size_t len);
-
-  /// Construct a slice from a copied string
-  Slice(const grpc::string& str);
-
-  enum StaticSlice { STATIC_SLICE };
-
-  /// Construct a slice from a static buffer
-  Slice(const void* buf, size_t len, StaticSlice);
-
-  /// Copy constructor, adds a reference.
-  Slice(const Slice& other);
-
-  /// Assignment, reference count is unchanged.
-  Slice& operator=(Slice other) {
-    std::swap(slice_, other.slice_);
-    return *this;
-  }
-
-  /// Create a slice pointing at some data. Calls malloc to allocate a refcount
-  /// for the object, and arranges that destroy will be called with the
-  /// user data pointer passed in at destruction. Can be the same as buf or
-  /// different (e.g., if data is part of a larger structure that must be
-  /// destroyed when the data is no longer needed)
-  Slice(void* buf, size_t len, void (*destroy)(void*), void* user_data);
-
-  /// Specialization of above for common case where buf == user_data
-  Slice(void* buf, size_t len, void (*destroy)(void*))
-      : Slice(buf, len, destroy, buf) {}
-
-  /// Similar to the above but has a destroy that also takes slice length
-  Slice(void* buf, size_t len, void (*destroy)(void*, size_t));
-
-  /// Byte size.
-  size_t size() const { return GRPC_SLICE_LENGTH(slice_); }
-
-  /// Raw pointer to the beginning (first element) of the slice.
-  const uint8_t* begin() const { return GRPC_SLICE_START_PTR(slice_); }
-
-  /// Raw pointer to the end (one byte \em past the last element) of the slice.
-  const uint8_t* end() const { return GRPC_SLICE_END_PTR(slice_); }
-
-  /// Raw C slice. Caller needs to call grpc_slice_unref when done.
-  grpc_slice c_slice() const;
-
- private:
-  friend class ByteBuffer;
-
-  grpc_slice slice_;
-};
-
 inline grpc::string_ref StringRefFromSlice(const grpc_slice* slice) {
   return grpc::string_ref(
       reinterpret_cast<const char*>(GRPC_SLICE_START_PTR(*slice)),
diff --git a/include/grpc++/support/byte_buffer.h b/include/grpc++/support/byte_buffer.h
index 81fa3b0a184..df16c6a75e4 100644
--- a/include/grpc++/support/byte_buffer.h
+++ b/include/grpc++/support/byte_buffer.h
@@ -19,7 +19,6 @@
 #ifndef GRPCXX_SUPPORT_BYTE_BUFFER_H
 #define GRPCXX_SUPPORT_BYTE_BUFFER_H
 
-#include <grpc++/impl/codegen/byte_buffer.h>
 #include <grpc++/impl/serialization_traits.h>
 #include <grpc++/support/config.h>
 #include <grpc++/support/slice.h>
@@ -28,4 +27,71 @@
 #include <grpc/grpc.h>
 #include <grpc/support/log.h>
 
+#include <vector>
+
+namespace grpc {
+
+/// A sequence of bytes.
+class ByteBuffer final {
+ public:
+  /// Constuct an empty buffer.
+  ByteBuffer() : buffer_(nullptr) {}
+
+  /// Construct buffer from \a slices, of which there are \a nslices.
+  ByteBuffer(const Slice* slices, size_t nslices);
+
+  /// Constuct a byte buffer by referencing elements of existing buffer
+  /// \a buf. Wrapper of core function grpc_byte_buffer_copy
+  ByteBuffer(const ByteBuffer& buf);
+
+  ~ByteBuffer();
+
+  ByteBuffer& operator=(const ByteBuffer&);
+
+  /// Dump (read) the buffer contents into \a slices.
+  Status Dump(std::vector<Slice>* slices) const;
+
+  /// Remove all data.
+  void Clear();
+
+  /// Buffer size in bytes.
+  size_t Length() const;
+
+  /// Swap the state of *this and *other.
+  void Swap(ByteBuffer* other);
+
+ private:
+  friend class SerializationTraits<ByteBuffer, void>;
+
+  // takes ownership
+  void set_buffer(grpc_byte_buffer* buf) {
+    if (buffer_) {
+      Clear();
+    }
+    buffer_ = buf;
+  }
+
+  // For \a SerializationTraits's usage.
+  grpc_byte_buffer* buffer() const { return buffer_; }
+
+  grpc_byte_buffer* buffer_;
+};
+
+template <>
+class SerializationTraits<ByteBuffer, void> {
+ public:
+  static Status Deserialize(grpc_byte_buffer* byte_buffer, ByteBuffer* dest) {
+    dest->set_buffer(byte_buffer);
+    return Status::OK;
+  }
+  static Status Serialize(const ByteBuffer& source, grpc_byte_buffer** buffer,
+                          bool* own_buffer) {
+    *buffer = grpc_byte_buffer_copy(source.buffer());
+    *own_buffer = true;
+    return Status::OK;
+  }
+};
+
+}  // namespace grpc
+
 #endif  // GRPCXX_SUPPORT_BYTE_BUFFER_H
diff --git a/include/grpc++/support/slice.h b/include/grpc++/support/slice.h
index 10db10d79c3..bbf97f280ef 100644
--- a/include/grpc++/support/slice.h
+++ b/include/grpc++/support/slice.h
@@ -19,8 +19,86 @@
 #ifndef GRPCXX_SUPPORT_SLICE_H
 #define GRPCXX_SUPPORT_SLICE_H
 
-#include <grpc++/impl/codegen/slice.h>
 #include <grpc++/support/config.h>
 #include <grpc/slice.h>
 
+namespace grpc {
+
+/// A wrapper around \a grpc_slice.
+///
+/// A slice represents a contiguous reference counted array of bytes.
+/// It is cheap to take references to a slice, and it is cheap to create a
+/// slice pointing to a subset of another slice.
+class Slice final {
+ public:
+  /// Construct an empty slice.
+  Slice();
+  /// Destructor - drops one reference.
+  ~Slice();
+
+  enum AddRef { ADD_REF };
+  /// Construct a slice from \a slice, adding a reference.
+  Slice(grpc_slice slice, AddRef);
+
+  enum StealRef { STEAL_REF };
+  /// Construct a slice from \a slice, stealing a reference.
+  Slice(grpc_slice slice, StealRef);
+
+  /// Allocate a slice of specified size
+  Slice(size_t len);
+
+  /// Construct a slice from a copied buffer
+  Slice(const void* buf, size_t len);
+
+  /// Construct a slice from a copied string
+  Slice(const grpc::string& str);
+
+  enum StaticSlice { STATIC_SLICE };
+
+  /// Construct a slice from a static buffer
+  Slice(const void* buf, size_t len, StaticSlice);
+
+  /// Copy constructor, adds a reference.
+  Slice(const Slice& other);
+
+  /// Assignment, reference count is unchanged.
+  Slice& operator=(Slice other) {
+    std::swap(slice_, other.slice_);
+    return *this;
+  }
+
+  /// Create a slice pointing at some data. Calls malloc to allocate a refcount
+  /// for the object, and arranges that destroy will be called with the
+  /// user data pointer passed in at destruction. Can be the same as buf or
+  /// different (e.g., if data is part of a larger structure that must be
+  /// destroyed when the data is no longer needed)
+  Slice(void* buf, size_t len, void (*destroy)(void*), void* user_data);
+
+  /// Specialization of above for common case where buf == user_data
+  Slice(void* buf, size_t len, void (*destroy)(void*))
+      : Slice(buf, len, destroy, buf) {}
+
+  /// Similar to the above but has a destroy that also takes slice length
+  Slice(void* buf, size_t len, void (*destroy)(void*, size_t));
+
+  /// Byte size.
+  size_t size() const { return GRPC_SLICE_LENGTH(slice_); }
+
+  /// Raw pointer to the beginning (first element) of the slice.
+  const uint8_t* begin() const { return GRPC_SLICE_START_PTR(slice_); }
+
+  /// Raw pointer to the end (one byte \em past the last element) of the slice.
+  const uint8_t* end() const { return GRPC_SLICE_END_PTR(slice_); }
+
+  /// Raw C slice. Caller needs to call grpc_slice_unref when done.
+  grpc_slice c_slice() const { return grpc_slice_ref(slice_); }
+
+ private:
+  friend class ByteBuffer;
+
+  grpc_slice slice_;
+};
+
+}  // namespace grpc
+
 #endif  // GRPCXX_SUPPORT_SLICE_H
diff --git a/include/grpc/byte_buffer.h b/include/grpc/byte_buffer.h
index 7669582af27..55e191da315 100644
--- a/include/grpc/byte_buffer.h
+++ b/include/grpc/byte_buffer.h
@@ -19,7 +19,69 @@
 #ifndef GRPC_BYTE_BUFFER_H
 #define GRPC_BYTE_BUFFER_H
 
-#include <grpc/impl/codegen/byte_buffer.h>
+#include <grpc/impl/codegen/grpc_types.h>
 #include <grpc/slice_buffer.h>
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/** Returns a RAW byte buffer instance over the given slices (up to \a nslices).
+ *
+ * Increases the reference count for all \a slices processed. The user is
+ * responsible for invoking grpc_byte_buffer_destroy on the returned instance.*/
+GRPCAPI grpc_byte_buffer *grpc_raw_byte_buffer_create(grpc_slice *slices,
+                                                      size_t nslices);
+
+/** Returns a *compressed* RAW byte buffer instance over the given slices (up to
+ * \a nslices). The \a compression argument defines the compression algorithm
+ * used to generate the data in \a slices.
+ *
+ * Increases the reference count for all \a slices processed. The user is
+ * responsible for invoking grpc_byte_buffer_destroy on the returned instance.*/
+GRPCAPI grpc_byte_buffer *grpc_raw_compressed_byte_buffer_create(
+    grpc_slice *slices, size_t nslices, grpc_compression_algorithm compression);
+
+/** Copies input byte buffer \a bb.
+ *
+ * Increases the reference count of all the source slices. The user is
+ * responsible for calling grpc_byte_buffer_destroy over the returned copy. */
+GRPCAPI grpc_byte_buffer *grpc_byte_buffer_copy(grpc_byte_buffer *bb);
+
+/** Returns the size of the given byte buffer, in bytes. */
+GRPCAPI size_t grpc_byte_buffer_length(grpc_byte_buffer *bb);
+
+/** Destroys \a byte_buffer deallocating all its memory. */
+GRPCAPI void grpc_byte_buffer_destroy(grpc_byte_buffer *byte_buffer);
+
+/** Reader for byte buffers. Iterates over slices in the byte buffer */
+struct grpc_byte_buffer_reader;
+typedef struct grpc_byte_buffer_reader grpc_byte_buffer_reader;
+
+/** Initialize \a reader to read over \a buffer.
+ * Returns 1 upon success, 0 otherwise. */
+GRPCAPI int grpc_byte_buffer_reader_init(grpc_byte_buffer_reader *reader,
+                                         grpc_byte_buffer *buffer);
+
+/** Cleanup and destroy \a reader */
+GRPCAPI void grpc_byte_buffer_reader_destroy(grpc_byte_buffer_reader *reader);
+
+/** Updates \a slice with the next piece of data from from \a reader and returns
+ * 1. Returns 0 at the end of the stream. Caller is responsible for calling
+ * grpc_slice_unref on the result. */
+GRPCAPI int grpc_byte_buffer_reader_next(grpc_byte_buffer_reader *reader,
+                                         grpc_slice *slice);
+
+/** Merge all data from \a reader into single slice */
+GRPCAPI grpc_slice
+grpc_byte_buffer_reader_readall(grpc_byte_buffer_reader *reader);
+
+/** Returns a RAW byte buffer instance from the output of \a reader. */
+GRPCAPI grpc_byte_buffer *grpc_raw_byte_buffer_from_reader(
+    grpc_byte_buffer_reader *reader);
+
+#ifdef __cplusplus
+}
+#endif
+
 #endif /* GRPC_BYTE_BUFFER_H */
diff --git a/include/grpc/impl/codegen/byte_buffer.h b/include/grpc/impl/codegen/byte_buffer.h
deleted file mode 100644
index fc333057134..00000000000
--- a/include/grpc/impl/codegen/byte_buffer.h
+++ /dev/null
@@ -1,86 +0,0 @@
-/*
- *
- * Copyright 2015 gRPC authors.
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- *
- */
-
-#ifndef GRPC_IMPL_CODEGEN_BYTE_BUFFER_H
-#define GRPC_IMPL_CODEGEN_BYTE_BUFFER_H
-
-#include <grpc/impl/codegen/grpc_types.h>
-
-#ifdef __cplusplus
-extern "C" {
-#endif
-
-/** Returns a RAW byte buffer instance over the given slices (up to \a nslices).
- *
- * Increases the reference count for all \a slices processed. The user is
- * responsible for invoking grpc_byte_buffer_destroy on the returned instance.*/
-GRPCAPI grpc_byte_buffer *grpc_raw_byte_buffer_create(grpc_slice *slices,
-                                                      size_t nslices);
-
-/** Returns a *compressed* RAW byte buffer instance over the given slices (up to
- * \a nslices). The \a compression argument defines the compression algorithm
- * used to generate the data in \a slices.
- *
- * Increases the reference count for all \a slices processed. The user is
- * responsible for invoking grpc_byte_buffer_destroy on the returned instance.*/
-GRPCAPI grpc_byte_buffer *grpc_raw_compressed_byte_buffer_create(
-    grpc_slice *slices, size_t nslices, grpc_compression_algorithm compression);
-
-/** Copies input byte buffer \a bb.
- *
- * Increases the reference count of all the source slices. The user is
- * responsible for calling grpc_byte_buffer_destroy over the returned copy. */
-GRPCAPI grpc_byte_buffer *grpc_byte_buffer_copy(grpc_byte_buffer *bb);
-
-/** Returns the size of the given byte buffer, in bytes. */
-GRPCAPI size_t grpc_byte_buffer_length(grpc_byte_buffer *bb);
-
-/** Destroys \a byte_buffer deallocating all its memory. */
-GRPCAPI void grpc_byte_buffer_destroy(grpc_byte_buffer *byte_buffer);
-
-/** Reader for byte buffers. Iterates over slices in the byte buffer */
-struct grpc_byte_buffer_reader;
-typedef struct grpc_byte_buffer_reader grpc_byte_buffer_reader;
-
-/** Initialize \a reader to read over \a buffer.
- * Returns 1 upon success, 0 otherwise. */
-GRPCAPI int grpc_byte_buffer_reader_init(grpc_byte_buffer_reader *reader,
-                                         grpc_byte_buffer *buffer);
-
-/** Cleanup and destroy \a reader */
-GRPCAPI void grpc_byte_buffer_reader_destroy(grpc_byte_buffer_reader *reader);
-
-/** Updates \a slice with the next piece of data from from \a reader and returns
- * 1. Returns 0 at the end of the stream. Caller is responsible for calling
- * grpc_slice_unref on the result. */
-GRPCAPI int grpc_byte_buffer_reader_next(grpc_byte_buffer_reader *reader,
-                                         grpc_slice *slice);
-
-/** Merge all data from \a reader into single slice */
-GRPCAPI grpc_slice
-grpc_byte_buffer_reader_readall(grpc_byte_buffer_reader *reader);
-
-/** Returns a RAW byte buffer instance from the output of \a reader. */
-GRPCAPI grpc_byte_buffer *grpc_raw_byte_buffer_from_reader(
-    grpc_byte_buffer_reader *reader);
-
-#ifdef __cplusplus
-}
-#endif
-
-#endif /* GRPC_IMPL_CODEGEN_BYTE_BUFFER_H */
diff --git a/package.xml b/package.xml
index 4f67e46673b..b7c0e679e5d 100644
--- a/package.xml
+++ b/package.xml
@@ -155,7 +155,6 @@
     <file baseinstalldir="/" name="src/core/lib/support/tmpfile_posix.c" role="src" />
     <file baseinstalldir="/" name="src/core/lib/support/tmpfile_windows.c" role="src" />
     <file baseinstalldir="/" name="src/core/lib/support/wrap_memcpy.c" role="src" />
-    <file baseinstalldir="/" name="include/grpc/impl/codegen/byte_buffer.h" role="src" />
     <file baseinstalldir="/" name="include/grpc/impl/codegen/byte_buffer_reader.h" role="src" />
     <file baseinstalldir="/" name="include/grpc/impl/codegen/compression_types.h" role="src" />
     <file baseinstalldir="/" name="include/grpc/impl/codegen/connectivity_state.h" role="src" />
diff --git a/src/core/lib/iomgr/resource_quota.c b/src/core/lib/iomgr/resource_quota.c
index 4d69986fbc2..4895e0d1c92 100644
--- a/src/core/lib/iomgr/resource_quota.c
+++ b/src/core/lib/iomgr/resource_quota.c
@@ -22,7 +22,6 @@
 #include <stdint.h>
 #include <string.h>
 
-#include <grpc/slice_buffer.h>
 #include <grpc/support/alloc.h>
 #include <grpc/support/log.h>
 #include <grpc/support/string_util.h>
diff --git a/src/cpp/server/health/default_health_check_service.cc b/src/cpp/server/health/default_health_check_service.cc
index d2cba6d6627..815b6070320 100644
--- a/src/cpp/server/health/default_health_check_service.cc
+++ b/src/cpp/server/health/default_health_check_service.cc
@@ -20,7 +20,6 @@
 #include <mutex>
 
 #include <grpc++/impl/codegen/method_handler_impl.h>
-#include <grpc/slice.h>
 #include <grpc/support/alloc.h>
 #include <grpc/support/log.h>
 
diff --git a/src/cpp/util/byte_buffer_cc.cc b/src/cpp/util/byte_buffer_cc.cc
index 1ebe22b6a49..b1ff25252a1 100644
--- a/src/cpp/util/byte_buffer_cc.cc
+++ b/src/cpp/util/byte_buffer_cc.cc
@@ -16,15 +16,11 @@
  *
  */
 
-#include <grpc++/impl/grpc_library.h>
 #include <grpc++/support/byte_buffer.h>
-#include <grpc/byte_buffer.h>
 #include <grpc/byte_buffer_reader.h>
 
 namespace grpc {
 
-static internal::GrpcLibraryInitializer g_gli_initializer;
-
 ByteBuffer::ByteBuffer(const Slice* slices, size_t nslices) {
   // The following assertions check that the representation of a grpc::Slice is
   // identical to that of a grpc_slice:  it has a grpc_slice field, and nothing
@@ -33,7 +29,6 @@ ByteBuffer::ByteBuffer(const Slice* slices, size_t nslices) {
                 "Slice must have same representation as grpc_slice");
   static_assert(sizeof(Slice) == sizeof(grpc_slice),
                 "Slice must have same representation as grpc_slice");
-  g_gli_initializer.summon();  // Make sure that initializer linked in
   // The const_cast is legal if grpc_raw_byte_buffer_create() does no more
   // than its advertised side effect of increasing the reference count of the
   // slices it processes, and such an increase does not affect the semantics
@@ -42,6 +37,19 @@ ByteBuffer::ByteBuffer(const Slice* slices, size_t nslices) {
       reinterpret_cast<grpc_slice*>(const_cast<Slice*>(slices)), nslices);
 }
 
+ByteBuffer::~ByteBuffer() {
+  if (buffer_) {
+    grpc_byte_buffer_destroy(buffer_);
+  }
+}
+
+void ByteBuffer::Clear() {
+  if (buffer_) {
+    grpc_byte_buffer_destroy(buffer_);
+    buffer_ = nullptr;
+  }
+}
+
 Status ByteBuffer::Dump(std::vector<Slice>* slices) const {
   slices->clear();
   if (!buffer_) {
@@ -72,9 +80,7 @@ ByteBuffer::ByteBuffer(const ByteBuffer& buf)
     : buffer_(grpc_byte_buffer_copy(buf.buffer_)) {}
 
 ByteBuffer& ByteBuffer::operator=(const ByteBuffer& buf) {
-  if (this != &buf) {
-    Clear();  // first remove existing data
-  }
+  Clear();  // first remove existing data
   if (buf.buffer_) {
     buffer_ = grpc_byte_buffer_copy(buf.buffer_);  // then copy
   }
@@ -87,19 +93,4 @@ void ByteBuffer::Swap(ByteBuffer* other) {
   buffer_ = tmp;
 }
 
-ByteBuffer::operator grpc_byte_buffer*() {
-  // The following assertions check that the representation of a ByteBuffer is
-  // identical to grpc_byte_buffer*:  it has a grpc_byte_buffer* field,
-  // and nothing else.
-  static_assert(std::is_same<decltype(buffer_), grpc_byte_buffer*>::value,
-                "ByteBuffer must have same representation as "
-                "grpc_byte_buffer*");
-  static_assert(sizeof(ByteBuffer) == sizeof(grpc_byte_buffer*),
-                "ByteBuffer must have same representation as "
-                "grpc_byte_buffer*");
-  return buffer_;
-}
-
-ByteBuffer::operator const grpc_byte_buffer*() const { return buffer_; }
-
 }  // namespace grpc
diff --git a/src/cpp/util/slice_cc.cc b/src/cpp/util/slice_cc.cc
index 3ae17e80520..486d0cdf0ec 100644
--- a/src/cpp/util/slice_cc.cc
+++ b/src/cpp/util/slice_cc.cc
@@ -50,6 +50,4 @@ Slice::Slice(void* buf, size_t len, void (*destroy)(void*), void* user_data)
 Slice::Slice(void* buf, size_t len, void (*destroy)(void*, size_t))
     : slice_(grpc_slice_new_with_len(buf, len, destroy)) {}
 
-grpc_slice Slice::c_slice() const { return grpc_slice_ref(slice_); }
-
 }  // namespace grpc
diff --git a/src/ruby/ext/grpc/rb_grpc_imports.generated.c b/src/ruby/ext/grpc/rb_grpc_imports.generated.c
index 70831494fad..57b543967eb 100644
--- a/src/ruby/ext/grpc/rb_grpc_imports.generated.c
+++ b/src/ruby/ext/grpc/rb_grpc_imports.generated.c
@@ -22,6 +22,16 @@
 
 #include "rb_grpc_imports.generated.h"
 
+grpc_raw_byte_buffer_create_type grpc_raw_byte_buffer_create_import;
+grpc_raw_compressed_byte_buffer_create_type grpc_raw_compressed_byte_buffer_create_import;
+grpc_byte_buffer_copy_type grpc_byte_buffer_copy_import;
+grpc_byte_buffer_length_type grpc_byte_buffer_length_import;
+grpc_byte_buffer_destroy_type grpc_byte_buffer_destroy_import;
+grpc_byte_buffer_reader_init_type grpc_byte_buffer_reader_init_import;
+grpc_byte_buffer_reader_destroy_type grpc_byte_buffer_reader_destroy_import;
+grpc_byte_buffer_reader_next_type grpc_byte_buffer_reader_next_import;
+grpc_byte_buffer_reader_readall_type grpc_byte_buffer_reader_readall_import;
+grpc_raw_byte_buffer_from_reader_type grpc_raw_byte_buffer_from_reader_import;
 census_initialize_type census_initialize_import;
 census_shutdown_type census_shutdown_import;
 census_supported_type census_supported_import;
@@ -158,16 +168,6 @@ grpc_ssl_server_credentials_create_ex_type grpc_ssl_server_credentials_create_ex
 grpc_server_add_secure_http2_port_type grpc_server_add_secure_http2_port_import;
 grpc_call_set_credentials_type grpc_call_set_credentials_import;
 grpc_server_credentials_set_auth_metadata_processor_type grpc_server_credentials_set_auth_metadata_processor_import;
-grpc_raw_byte_buffer_create_type grpc_raw_byte_buffer_create_import;
-grpc_raw_compressed_byte_buffer_create_type grpc_raw_compressed_byte_buffer_create_import;
-grpc_byte_buffer_copy_type grpc_byte_buffer_copy_import;
-grpc_byte_buffer_length_type grpc_byte_buffer_length_import;
-grpc_byte_buffer_destroy_type grpc_byte_buffer_destroy_import;
-grpc_byte_buffer_reader_init_type grpc_byte_buffer_reader_init_import;
-grpc_byte_buffer_reader_destroy_type grpc_byte_buffer_reader_destroy_import;
-grpc_byte_buffer_reader_next_type grpc_byte_buffer_reader_next_import;
-grpc_byte_buffer_reader_readall_type grpc_byte_buffer_reader_readall_import;
-grpc_raw_byte_buffer_from_reader_type grpc_raw_byte_buffer_from_reader_import;
 grpc_slice_ref_type grpc_slice_ref_import;
 grpc_slice_unref_type grpc_slice_unref_import;
 grpc_slice_copy_type grpc_slice_copy_import;
@@ -330,6 +330,16 @@ gpr_sleep_until_type gpr_sleep_until_import;
 gpr_timespec_to_micros_type gpr_timespec_to_micros_import;
 
 void grpc_rb_load_imports(HMODULE library) {
+  grpc_raw_byte_buffer_create_import = (grpc_raw_byte_buffer_create_type) GetProcAddress(library, "grpc_raw_byte_buffer_create");
+  grpc_raw_compressed_byte_buffer_create_import = (grpc_raw_compressed_byte_buffer_create_type) GetProcAddress(library, "grpc_raw_compressed_byte_buffer_create");
+  grpc_byte_buffer_copy_import = (grpc_byte_buffer_copy_type) GetProcAddress(library, "grpc_byte_buffer_copy");
+  grpc_byte_buffer_length_import = (grpc_byte_buffer_length_type) GetProcAddress(library, "grpc_byte_buffer_length");
+  grpc_byte_buffer_destroy_import = (grpc_byte_buffer_destroy_type) GetProcAddress(library, "grpc_byte_buffer_destroy");
+  grpc_byte_buffer_reader_init_import = (grpc_byte_buffer_reader_init_type) GetProcAddress(library, "grpc_byte_buffer_reader_init");
+  grpc_byte_buffer_reader_destroy_import = (grpc_byte_buffer_reader_destroy_type) GetProcAddress(library, "grpc_byte_buffer_reader_destroy");
+  grpc_byte_buffer_reader_next_import = (grpc_byte_buffer_reader_next_type) GetProcAddress(library, "grpc_byte_buffer_reader_next");
+  grpc_byte_buffer_reader_readall_import = (grpc_byte_buffer_reader_readall_type) GetProcAddress(library, "grpc_byte_buffer_reader_readall");
+  grpc_raw_byte_buffer_from_reader_import = (grpc_raw_byte_buffer_from_reader_type) GetProcAddress(library, "grpc_raw_byte_buffer_from_reader");
   census_initialize_import = (census_initialize_type) GetProcAddress(library, "census_initialize");
   census_shutdown_import = (census_shutdown_type) GetProcAddress(library, "census_shutdown");
   census_supported_import = (census_supported_type) GetProcAddress(library, "census_supported");
@@ -466,16 +476,6 @@ void grpc_rb_load_imports(HMODULE library) {
   grpc_server_add_secure_http2_port_import = (grpc_server_add_secure_http2_port_type) GetProcAddress(library, "grpc_server_add_secure_http2_port");
   grpc_call_set_credentials_import = (grpc_call_set_credentials_type) GetProcAddress(library, "grpc_call_set_credentials");
   grpc_server_credentials_set_auth_metadata_processor_import = (grpc_server_credentials_set_auth_metadata_processor_type) GetProcAddress(library, "grpc_server_credentials_set_auth_metadata_processor");
-  grpc_raw_byte_buffer_create_import = (grpc_raw_byte_buffer_create_type) GetProcAddress(library, "grpc_raw_byte_buffer_create");
-  grpc_raw_compressed_byte_buffer_create_import = (grpc_raw_compressed_byte_buffer_create_type) GetProcAddress(library, "grpc_raw_compressed_byte_buffer_create");
-  grpc_byte_buffer_copy_import = (grpc_byte_buffer_copy_type) GetProcAddress(library, "grpc_byte_buffer_copy");
-  grpc_byte_buffer_length_import = (grpc_byte_buffer_length_type) GetProcAddress(library, "grpc_byte_buffer_length");
-  grpc_byte_buffer_destroy_import = (grpc_byte_buffer_destroy_type) GetProcAddress(library, "grpc_byte_buffer_destroy");
-  grpc_byte_buffer_reader_init_import = (grpc_byte_buffer_reader_init_type) GetProcAddress(library, "grpc_byte_buffer_reader_init");
-  grpc_byte_buffer_reader_destroy_import = (grpc_byte_buffer_reader_destroy_type) GetProcAddress(library, "grpc_byte_buffer_reader_destroy");
-  grpc_byte_buffer_reader_next_import = (grpc_byte_buffer_reader_next_type) GetProcAddress(library, "grpc_byte_buffer_reader_next");
-  grpc_byte_buffer_reader_readall_import = (grpc_byte_buffer_reader_readall_type) GetProcAddress(library, "grpc_byte_buffer_reader_readall");
-  grpc_raw_byte_buffer_from_reader_import = (grpc_raw_byte_buffer_from_reader_type) GetProcAddress(library, "grpc_raw_byte_buffer_from_reader");
   grpc_slice_ref_import = (grpc_slice_ref_type) GetProcAddress(library, "grpc_slice_ref");
   grpc_slice_unref_import = (grpc_slice_unref_type) GetProcAddress(library, "grpc_slice_unref");
   grpc_slice_copy_import = (grpc_slice_copy_type) GetProcAddress(library, "grpc_slice_copy");
diff --git a/src/ruby/ext/grpc/rb_grpc_imports.generated.h b/src/ruby/ext/grpc/rb_grpc_imports.generated.h
index 263057f309f..c5c848ae447 100644
--- a/src/ruby/ext/grpc/rb_grpc_imports.generated.h
+++ b/src/ruby/ext/grpc/rb_grpc_imports.generated.h
@@ -25,12 +25,12 @@
 
 #include <windows.h>
 
+#include <grpc/byte_buffer.h>
 #include <grpc/census.h>
 #include <grpc/compression.h>
 #include <grpc/grpc.h>
 #include <grpc/grpc_posix.h>
 #include <grpc/grpc_security.h>
-#include <grpc/impl/codegen/byte_buffer.h>
 #include <grpc/slice.h>
 #include <grpc/slice_buffer.h>
 #include <grpc/support/alloc.h>
@@ -47,6 +47,36 @@
 #include <grpc/support/thd.h>
 #include <grpc/support/time.h>
 
+typedef grpc_byte_buffer *(*grpc_raw_byte_buffer_create_type)(grpc_slice *slices, size_t nslices);
+extern grpc_raw_byte_buffer_create_type grpc_raw_byte_buffer_create_import;
+#define grpc_raw_byte_buffer_create grpc_raw_byte_buffer_create_import
+typedef grpc_byte_buffer *(*grpc_raw_compressed_byte_buffer_create_type)(grpc_slice *slices, size_t nslices, grpc_compression_algorithm compression);
+extern grpc_raw_compressed_byte_buffer_create_type grpc_raw_compressed_byte_buffer_create_import;
+#define grpc_raw_compressed_byte_buffer_create grpc_raw_compressed_byte_buffer_create_import
+typedef grpc_byte_buffer *(*grpc_byte_buffer_copy_type)(grpc_byte_buffer *bb);
+extern grpc_byte_buffer_copy_type grpc_byte_buffer_copy_import;
+#define grpc_byte_buffer_copy grpc_byte_buffer_copy_import
+typedef size_t(*grpc_byte_buffer_length_type)(grpc_byte_buffer *bb);
+extern grpc_byte_buffer_length_type grpc_byte_buffer_length_import;
+#define grpc_byte_buffer_length grpc_byte_buffer_length_import
+typedef void(*grpc_byte_buffer_destroy_type)(grpc_byte_buffer *byte_buffer);
+extern grpc_byte_buffer_destroy_type grpc_byte_buffer_destroy_import;
+#define grpc_byte_buffer_destroy grpc_byte_buffer_destroy_import
+typedef int(*grpc_byte_buffer_reader_init_type)(grpc_byte_buffer_reader *reader, grpc_byte_buffer *buffer);
+extern grpc_byte_buffer_reader_init_type grpc_byte_buffer_reader_init_import;
+#define grpc_byte_buffer_reader_init grpc_byte_buffer_reader_init_import
+typedef void(*grpc_byte_buffer_reader_destroy_type)(grpc_byte_buffer_reader *reader);
+extern grpc_byte_buffer_reader_destroy_type grpc_byte_buffer_reader_destroy_import;
+#define grpc_byte_buffer_reader_destroy grpc_byte_buffer_reader_destroy_import
+typedef int(*grpc_byte_buffer_reader_next_type)(grpc_byte_buffer_reader *reader, grpc_slice *slice);
+extern grpc_byte_buffer_reader_next_type grpc_byte_buffer_reader_next_import;
+#define grpc_byte_buffer_reader_next grpc_byte_buffer_reader_next_import
+typedef grpc_slice(*grpc_byte_buffer_reader_readall_type)(grpc_byte_buffer_reader *reader);
+extern grpc_byte_buffer_reader_readall_type grpc_byte_buffer_reader_readall_import;
+#define grpc_byte_buffer_reader_readall grpc_byte_buffer_reader_readall_import
+typedef grpc_byte_buffer *(*grpc_raw_byte_buffer_from_reader_type)(grpc_byte_buffer_reader *reader);
+extern grpc_raw_byte_buffer_from_reader_type grpc_raw_byte_buffer_from_reader_import;
+#define grpc_raw_byte_buffer_from_reader grpc_raw_byte_buffer_from_reader_import
 typedef int(*census_initialize_type)(int features);
 extern census_initialize_type census_initialize_import;
 #define census_initialize census_initialize_import
@@ -455,36 +485,6 @@ extern grpc_call_set_credentials_type grpc_call_set_credentials_import;
 typedef void(*grpc_server_credentials_set_auth_metadata_processor_type)(grpc_server_credentials *creds, grpc_auth_metadata_processor processor);
 extern grpc_server_credentials_set_auth_metadata_processor_type grpc_server_credentials_set_auth_metadata_processor_import;
 #define grpc_server_credentials_set_auth_metadata_processor grpc_server_credentials_set_auth_metadata_processor_import
-typedef grpc_byte_buffer *(*grpc_raw_byte_buffer_create_type)(grpc_slice *slices, size_t nslices);
-extern grpc_raw_byte_buffer_create_type grpc_raw_byte_buffer_create_import;
-#define grpc_raw_byte_buffer_create grpc_raw_byte_buffer_create_import
-typedef grpc_byte_buffer *(*grpc_raw_compressed_byte_buffer_create_type)(grpc_slice *slices, size_t nslices, grpc_compression_algorithm compression);
-extern grpc_raw_compressed_byte_buffer_create_type grpc_raw_compressed_byte_buffer_create_import;
-#define grpc_raw_compressed_byte_buffer_create grpc_raw_compressed_byte_buffer_create_import
-typedef grpc_byte_buffer *(*grpc_byte_buffer_copy_type)(grpc_byte_buffer *bb);
-extern grpc_byte_buffer_copy_type grpc_byte_buffer_copy_import;
-#define grpc_byte_buffer_copy grpc_byte_buffer_copy_import
-typedef size_t(*grpc_byte_buffer_length_type)(grpc_byte_buffer *bb);
-extern grpc_byte_buffer_length_type grpc_byte_buffer_length_import;
-#define grpc_byte_buffer_length grpc_byte_buffer_length_import
-typedef void(*grpc_byte_buffer_destroy_type)(grpc_byte_buffer *byte_buffer);
-extern grpc_byte_buffer_destroy_type grpc_byte_buffer_destroy_import;
-#define grpc_byte_buffer_destroy grpc_byte_buffer_destroy_import
-typedef int(*grpc_byte_buffer_reader_init_type)(grpc_byte_buffer_reader *reader, grpc_byte_buffer *buffer);
-extern grpc_byte_buffer_reader_init_type grpc_byte_buffer_reader_init_import;
-#define grpc_byte_buffer_reader_init grpc_byte_buffer_reader_init_import
-typedef void(*grpc_byte_buffer_reader_destroy_type)(grpc_byte_buffer_reader *reader);
-extern grpc_byte_buffer_reader_destroy_type grpc_byte_buffer_reader_destroy_import;
-#define grpc_byte_buffer_reader_destroy grpc_byte_buffer_reader_destroy_import
-typedef int(*grpc_byte_buffer_reader_next_type)(grpc_byte_buffer_reader *reader, grpc_slice *slice);
-extern grpc_byte_buffer_reader_next_type grpc_byte_buffer_reader_next_import;
-#define grpc_byte_buffer_reader_next grpc_byte_buffer_reader_next_import
-typedef grpc_slice(*grpc_byte_buffer_reader_readall_type)(grpc_byte_buffer_reader *reader);
-extern grpc_byte_buffer_reader_readall_type grpc_byte_buffer_reader_readall_import;
-#define grpc_byte_buffer_reader_readall grpc_byte_buffer_reader_readall_import
-typedef grpc_byte_buffer *(*grpc_raw_byte_buffer_from_reader_type)(grpc_byte_buffer_reader *reader);
-extern grpc_raw_byte_buffer_from_reader_type grpc_raw_byte_buffer_from_reader_import;
-#define grpc_raw_byte_buffer_from_reader grpc_raw_byte_buffer_from_reader_import
 typedef grpc_slice(*grpc_slice_ref_type)(grpc_slice s);
 extern grpc_slice_ref_type grpc_slice_ref_import;
 #define grpc_slice_ref grpc_slice_ref_import
diff --git a/test/core/surface/public_headers_must_be_c89.c b/test/core/surface/public_headers_must_be_c89.c
index d36d116afb8..0d7f68c0add 100644
--- a/test/core/surface/public_headers_must_be_c89.c
+++ b/test/core/surface/public_headers_must_be_c89.c
@@ -24,7 +24,6 @@
 #include <grpc/grpc_security.h>
 #include <grpc/grpc_security_constants.h>
 #include <grpc/impl/codegen/atm.h>
-#include <grpc/impl/codegen/byte_buffer.h>
 #include <grpc/impl/codegen/byte_buffer_reader.h>
 #include <grpc/impl/codegen/compression_types.h>
 #include <grpc/impl/codegen/connectivity_state.h>
diff --git a/test/cpp/util/byte_buffer_test.cc b/test/cpp/util/byte_buffer_test.cc
index 8fb51bc6635..cac01a73078 100644
--- a/test/cpp/util/byte_buffer_test.cc
+++ b/test/cpp/util/byte_buffer_test.cc
@@ -93,7 +93,7 @@ TEST_F(ByteBufferTest, SerializationMakesCopy) {
   std::vector<Slice> slices;
   slices.push_back(Slice(hello, Slice::STEAL_REF));
   slices.push_back(Slice(world, Slice::STEAL_REF));
-  ByteBuffer send_buffer;
+  grpc_byte_buffer* send_buffer = nullptr;
   bool owned = false;
   ByteBuffer buffer(&slices[0], 2);
   slices.clear();
@@ -101,7 +101,8 @@ TEST_F(ByteBufferTest, SerializationMakesCopy) {
       buffer, &send_buffer, &owned);
   EXPECT_TRUE(status.ok());
   EXPECT_TRUE(owned);
-  EXPECT_TRUE(send_buffer.Valid());
+  EXPECT_TRUE(send_buffer != nullptr);
+  grpc_byte_buffer_destroy(send_buffer);
 }
 
 }  // namespace
diff --git a/tools/doxygen/Doxyfile.c++ b/tools/doxygen/Doxyfile.c++
index d81b7b4d115..62f113907db 100644
--- a/tools/doxygen/Doxyfile.c++
+++ b/tools/doxygen/Doxyfile.c++
@@ -811,7 +811,6 @@ include/grpc++/impl/channel_argument_option.h \
 include/grpc++/impl/client_unary_call.h \
 include/grpc++/impl/codegen/async_stream.h \
 include/grpc++/impl/codegen/async_unary_call.h \
-include/grpc++/impl/codegen/byte_buffer.h \
 include/grpc++/impl/codegen/call.h \
 include/grpc++/impl/codegen/call_hook.h \
 include/grpc++/impl/codegen/channel_interface.h \
@@ -882,7 +881,6 @@ include/grpc/impl/codegen/atm.h \
 include/grpc/impl/codegen/atm_gcc_atomic.h \
 include/grpc/impl/codegen/atm_gcc_sync.h \
 include/grpc/impl/codegen/atm_windows.h \
-include/grpc/impl/codegen/byte_buffer.h \
 include/grpc/impl/codegen/byte_buffer_reader.h \
 include/grpc/impl/codegen/compression_types.h \
 include/grpc/impl/codegen/connectivity_state.h \
diff --git a/tools/doxygen/Doxyfile.c++.internal b/tools/doxygen/Doxyfile.c++.internal
index 263c6c1afbc..49919415bd5 100644
--- a/tools/doxygen/Doxyfile.c++.internal
+++ b/tools/doxygen/Doxyfile.c++.internal
@@ -811,7 +811,6 @@ include/grpc++/impl/channel_argument_option.h \
 include/grpc++/impl/client_unary_call.h \
 include/grpc++/impl/codegen/async_stream.h \
 include/grpc++/impl/codegen/async_unary_call.h \
-include/grpc++/impl/codegen/byte_buffer.h \
 include/grpc++/impl/codegen/call.h \
 include/grpc++/impl/codegen/call_hook.h \
 include/grpc++/impl/codegen/channel_interface.h \
@@ -883,7 +882,6 @@ include/grpc/impl/codegen/atm.h \
 include/grpc/impl/codegen/atm_gcc_atomic.h \
 include/grpc/impl/codegen/atm_gcc_sync.h \
 include/grpc/impl/codegen/atm_windows.h \
-include/grpc/impl/codegen/byte_buffer.h \
 include/grpc/impl/codegen/byte_buffer_reader.h \
 include/grpc/impl/codegen/compression_types.h \
 include/grpc/impl/codegen/connectivity_state.h \
diff --git a/tools/doxygen/Doxyfile.core b/tools/doxygen/Doxyfile.core
index b8514fe3114..632735342b3 100644
--- a/tools/doxygen/Doxyfile.core
+++ b/tools/doxygen/Doxyfile.core
@@ -811,7 +811,6 @@ include/grpc/impl/codegen/atm_gcc_sync.h \
 include/grpc/impl/codegen/atm_gcc_sync.h \
 include/grpc/impl/codegen/atm_windows.h \
 include/grpc/impl/codegen/atm_windows.h \
-include/grpc/impl/codegen/byte_buffer.h \
 include/grpc/impl/codegen/byte_buffer_reader.h \
 include/grpc/impl/codegen/compression_types.h \
 include/grpc/impl/codegen/connectivity_state.h \
diff --git a/tools/doxygen/Doxyfile.core.internal b/tools/doxygen/Doxyfile.core.internal
index 77cd28e9dfd..e352cb78f10 100644
--- a/tools/doxygen/Doxyfile.core.internal
+++ b/tools/doxygen/Doxyfile.core.internal
@@ -811,7 +811,6 @@ include/grpc/impl/codegen/atm_gcc_sync.h \
 include/grpc/impl/codegen/atm_gcc_sync.h \
 include/grpc/impl/codegen/atm_windows.h \
 include/grpc/impl/codegen/atm_windows.h \
-include/grpc/impl/codegen/byte_buffer.h \
 include/grpc/impl/codegen/byte_buffer_reader.h \
 include/grpc/impl/codegen/compression_types.h \
 include/grpc/impl/codegen/connectivity_state.h \
diff --git a/tools/run_tests/generated/sources_and_headers.json b/tools/run_tests/generated/sources_and_headers.json
index 5581240a9a1..2f6e34bfb38 100644
--- a/tools/run_tests/generated/sources_and_headers.json
+++ b/tools/run_tests/generated/sources_and_headers.json
@@ -8395,7 +8395,6 @@
       "gpr_codegen"
     ], 
     "headers": [
-      "include/grpc/impl/codegen/byte_buffer.h", 
       "include/grpc/impl/codegen/byte_buffer_reader.h", 
       "include/grpc/impl/codegen/compression_types.h", 
       "include/grpc/impl/codegen/connectivity_state.h", 
@@ -8409,7 +8408,6 @@
     "language": "c", 
     "name": "grpc_codegen", 
     "src": [
-      "include/grpc/impl/codegen/byte_buffer.h", 
       "include/grpc/impl/codegen/byte_buffer_reader.h", 
       "include/grpc/impl/codegen/compression_types.h", 
       "include/grpc/impl/codegen/connectivity_state.h", 
@@ -9288,7 +9286,6 @@
     "headers": [
       "include/grpc++/impl/codegen/async_stream.h", 
       "include/grpc++/impl/codegen/async_unary_call.h", 
-      "include/grpc++/impl/codegen/byte_buffer.h", 
       "include/grpc++/impl/codegen/call.h", 
       "include/grpc++/impl/codegen/call_hook.h", 
       "include/grpc++/impl/codegen/channel_interface.h", 
@@ -9323,7 +9320,6 @@
     "src": [
       "include/grpc++/impl/codegen/async_stream.h", 
       "include/grpc++/impl/codegen/async_unary_call.h", 
-      "include/grpc++/impl/codegen/byte_buffer.h", 
       "include/grpc++/impl/codegen/call.h", 
       "include/grpc++/impl/codegen/call_hook.h", 
       "include/grpc++/impl/codegen/channel_interface.h", 

From 3ff1fa6e05726fb40cc60271a8e6a189bf901eb8 Mon Sep 17 00:00:00 2001
From: Craig Tiller <ctiller@google.com>
Date: Thu, 14 Sep 2017 11:07:48 -0700
Subject: [PATCH 09/12] Collect stats on why writes are initiated

---
 .../chttp2/transport/chttp2_transport.c       | 239 +++++++++++++----
 .../transport/chttp2/transport/frame_ping.c   |   3 +-
 .../chttp2/transport/frame_window_update.c    |  10 +-
 .../transport/chttp2/transport/hpack_parser.c |   3 +-
 .../ext/transport/chttp2/transport/internal.h |  37 ++-
 .../ext/transport/chttp2/transport/writing.c  |   5 +-
 src/core/lib/debug/stats_data.c               |  45 ++++
 src/core/lib/debug/stats_data.h               | 110 ++++++++
 src/core/lib/debug/stats_data.yaml            |  42 +++
 src/core/lib/debug/stats_data_bq_schema.sql   |  25 ++
 .../performance/massage_qps_stats.py          |  25 ++
 .../performance/scenario_result_schema.json   | 250 ++++++++++++++++++
 12 files changed, 733 insertions(+), 61 deletions(-)

diff --git a/src/core/ext/transport/chttp2/transport/chttp2_transport.c b/src/core/ext/transport/chttp2/transport/chttp2_transport.c
index 930fa805a09..7e392b6d630 100644
--- a/src/core/ext/transport/chttp2/transport/chttp2_transport.c
+++ b/src/core/ext/transport/chttp2/transport/chttp2_transport.c
@@ -144,10 +144,11 @@ static void finish_bdp_ping_locked(grpc_exec_ctx *exec_ctx, void *tp,
 
 static void cancel_pings(grpc_exec_ctx *exec_ctx, grpc_chttp2_transport *t,
                          grpc_error *error);
-static void send_ping_locked(grpc_exec_ctx *exec_ctx, grpc_chttp2_transport *t,
-                             grpc_chttp2_ping_type ping_type,
-                             grpc_closure *on_initiate,
-                             grpc_closure *on_complete);
+static void send_ping_locked(
+    grpc_exec_ctx *exec_ctx, grpc_chttp2_transport *t,
+    grpc_chttp2_ping_type ping_type, grpc_closure *on_initiate,
+    grpc_closure *on_complete,
+    grpc_chttp2_initiate_write_reason initiate_write_reason);
 static void retry_initiate_ping_locked(grpc_exec_ctx *exec_ctx, void *tp,
                                        grpc_error *error);
 
@@ -346,7 +347,6 @@ static void init_transport(grpc_exec_ctx *exec_ctx, grpc_chttp2_transport *t,
   if (is_client) {
     grpc_slice_buffer_add(&t->outbuf, grpc_slice_from_copied_string(
                                           GRPC_CHTTP2_CLIENT_CONNECT_STRING));
-    grpc_chttp2_initiate_write(exec_ctx, t, "initial_write");
   }
 
   /* configure http2 the way we like it */
@@ -578,7 +578,8 @@ static void init_transport(grpc_exec_ctx *exec_ctx, grpc_chttp2_transport *t,
     t->keepalive_state = GRPC_CHTTP2_KEEPALIVE_STATE_DISABLED;
   }
 
-  grpc_chttp2_initiate_write(exec_ctx, t, "init");
+  grpc_chttp2_initiate_write(exec_ctx, t,
+                             GRPC_CHTTP2_INITIATE_WRITE_INITIAL_WRITE);
   post_benign_reclaimer(exec_ctx, t);
 }
 
@@ -846,13 +847,91 @@ static void set_write_state(grpc_exec_ctx *exec_ctx, grpc_chttp2_transport *t,
   }
 }
 
+static void inc_initiate_write_reason(
+    grpc_exec_ctx *exec_ctx, grpc_chttp2_initiate_write_reason reason) {
+  switch (reason) {
+    case GRPC_CHTTP2_INITIATE_WRITE_INITIAL_WRITE:
+      GRPC_STATS_INC_HTTP2_INITIATE_WRITE_DUE_TO_INITIAL_WRITE(exec_ctx);
+      break;
+    case GRPC_CHTTP2_INITIATE_WRITE_START_NEW_STREAM:
+      GRPC_STATS_INC_HTTP2_INITIATE_WRITE_DUE_TO_START_NEW_STREAM(exec_ctx);
+      break;
+    case GRPC_CHTTP2_INITIATE_WRITE_SEND_MESSAGE:
+      GRPC_STATS_INC_HTTP2_INITIATE_WRITE_DUE_TO_SEND_MESSAGE(exec_ctx);
+      break;
+    case GRPC_CHTTP2_INITIATE_WRITE_SEND_INITIAL_METADATA:
+      GRPC_STATS_INC_HTTP2_INITIATE_WRITE_DUE_TO_SEND_INITIAL_METADATA(
+          exec_ctx);
+      break;
+    case GRPC_CHTTP2_INITIATE_WRITE_SEND_TRAILING_METADATA:
+      GRPC_STATS_INC_HTTP2_INITIATE_WRITE_DUE_TO_SEND_TRAILING_METADATA(
+          exec_ctx);
+      break;
+    case GRPC_CHTTP2_INITIATE_WRITE_RETRY_SEND_PING:
+      GRPC_STATS_INC_HTTP2_INITIATE_WRITE_DUE_TO_RETRY_SEND_PING(exec_ctx);
+      break;
+    case GRPC_CHTTP2_INITIATE_WRITE_CONTINUE_PINGS:
+      GRPC_STATS_INC_HTTP2_INITIATE_WRITE_DUE_TO_CONTINUE_PINGS(exec_ctx);
+      break;
+    case GRPC_CHTTP2_INITIATE_WRITE_GOAWAY_SENT:
+      GRPC_STATS_INC_HTTP2_INITIATE_WRITE_DUE_TO_GOAWAY_SENT(exec_ctx);
+      break;
+    case GRPC_CHTTP2_INITIATE_WRITE_RST_STREAM:
+      GRPC_STATS_INC_HTTP2_INITIATE_WRITE_DUE_TO_RST_STREAM(exec_ctx);
+      break;
+    case GRPC_CHTTP2_INITIATE_WRITE_CLOSE_FROM_API:
+      GRPC_STATS_INC_HTTP2_INITIATE_WRITE_DUE_TO_CLOSE_FROM_API(exec_ctx);
+      break;
+    case GRPC_CHTTP2_INITIATE_WRITE_STREAM_FLOW_CONTROL:
+      GRPC_STATS_INC_HTTP2_INITIATE_WRITE_DUE_TO_STREAM_FLOW_CONTROL(exec_ctx);
+      break;
+    case GRPC_CHTTP2_INITIATE_WRITE_TRANSPORT_FLOW_CONTROL:
+      GRPC_STATS_INC_HTTP2_INITIATE_WRITE_DUE_TO_TRANSPORT_FLOW_CONTROL(
+          exec_ctx);
+      break;
+    case GRPC_CHTTP2_INITIATE_WRITE_SEND_SETTINGS:
+      GRPC_STATS_INC_HTTP2_INITIATE_WRITE_DUE_TO_SEND_SETTINGS(exec_ctx);
+      break;
+    case GRPC_CHTTP2_INITIATE_WRITE_BDP_ESTIMATOR_PING:
+      GRPC_STATS_INC_HTTP2_INITIATE_WRITE_DUE_TO_BDP_ESTIMATOR_PING(exec_ctx);
+      break;
+    case GRPC_CHTTP2_INITIATE_WRITE_FLOW_CONTROL_UNSTALLED_BY_SETTING:
+      GRPC_STATS_INC_HTTP2_INITIATE_WRITE_DUE_TO_FLOW_CONTROL_UNSTALLED_BY_SETTING(
+          exec_ctx);
+      break;
+    case GRPC_CHTTP2_INITIATE_WRITE_FLOW_CONTROL_UNSTALLED_BY_UPDATE:
+      GRPC_STATS_INC_HTTP2_INITIATE_WRITE_DUE_TO_FLOW_CONTROL_UNSTALLED_BY_UPDATE(
+          exec_ctx);
+      break;
+    case GRPC_CHTTP2_INITIATE_WRITE_APPLICATION_PING:
+      GRPC_STATS_INC_HTTP2_INITIATE_WRITE_DUE_TO_APPLICATION_PING(exec_ctx);
+      break;
+    case GRPC_CHTTP2_INITIATE_WRITE_KEEPALIVE_PING:
+      GRPC_STATS_INC_HTTP2_INITIATE_WRITE_DUE_TO_KEEPALIVE_PING(exec_ctx);
+      break;
+    case GRPC_CHTTP2_INITIATE_WRITE_TRANSPORT_FLOW_CONTROL_UNSTALLED:
+      GRPC_STATS_INC_HTTP2_INITIATE_WRITE_DUE_TO_TRANSPORT_FLOW_CONTROL_UNSTALLED(
+          exec_ctx);
+      break;
+    case GRPC_CHTTP2_INITIATE_WRITE_PING_RESPONSE:
+      GRPC_STATS_INC_HTTP2_INITIATE_WRITE_DUE_TO_PING_RESPONSE(exec_ctx);
+      break;
+    case GRPC_CHTTP2_INITIATE_WRITE_FORCE_RST_STREAM:
+      GRPC_STATS_INC_HTTP2_INITIATE_WRITE_DUE_TO_FORCE_RST_STREAM(exec_ctx);
+      break;
+  }
+}
+
 void grpc_chttp2_initiate_write(grpc_exec_ctx *exec_ctx,
-                                grpc_chttp2_transport *t, const char *reason) {
+                                grpc_chttp2_transport *t,
+                                grpc_chttp2_initiate_write_reason reason) {
   GPR_TIMER_BEGIN("grpc_chttp2_initiate_write", 0);
 
   switch (t->write_state) {
     case GRPC_CHTTP2_WRITE_STATE_IDLE:
-      set_write_state(exec_ctx, t, GRPC_CHTTP2_WRITE_STATE_WRITING, reason);
+      inc_initiate_write_reason(exec_ctx, reason);
+      set_write_state(exec_ctx, t, GRPC_CHTTP2_WRITE_STATE_WRITING,
+                      grpc_chttp2_initiate_write_reason_string(reason));
       t->is_first_write_in_batch = true;
       GRPC_CHTTP2_REF_TRANSPORT(t, "writing");
       GRPC_CLOSURE_SCHED(
@@ -864,7 +943,7 @@ void grpc_chttp2_initiate_write(grpc_exec_ctx *exec_ctx,
       break;
     case GRPC_CHTTP2_WRITE_STATE_WRITING:
       set_write_state(exec_ctx, t, GRPC_CHTTP2_WRITE_STATE_WRITING_WITH_MORE,
-                      reason);
+                      grpc_chttp2_initiate_write_reason_string(reason));
       break;
     case GRPC_CHTTP2_WRITE_STATE_WRITING_WITH_MORE:
       break;
@@ -872,16 +951,12 @@ void grpc_chttp2_initiate_write(grpc_exec_ctx *exec_ctx,
   GPR_TIMER_END("grpc_chttp2_initiate_write", 0);
 }
 
-void grpc_chttp2_become_writable(grpc_exec_ctx *exec_ctx,
-                                 grpc_chttp2_transport *t,
-                                 grpc_chttp2_stream *s,
-                                 bool also_initiate_write, const char *reason) {
+void grpc_chttp2_mark_stream_writable(grpc_exec_ctx *exec_ctx,
+                                      grpc_chttp2_transport *t,
+                                      grpc_chttp2_stream *s) {
   if (!t->closed && grpc_chttp2_list_add_writable_stream(t, s)) {
     GRPC_CHTTP2_STREAM_REF(s, "chttp2_writing:become");
   }
-  if (also_initiate_write) {
-    grpc_chttp2_initiate_write(exec_ctx, t, reason);
-  }
 }
 
 static grpc_closure_scheduler *write_scheduler(grpc_chttp2_transport *t,
@@ -1105,7 +1180,9 @@ static void maybe_start_some_streams(grpc_exec_ctx *exec_ctx,
 
     grpc_chttp2_stream_map_add(&t->stream_map, s->id, s);
     post_destructive_reclaimer(exec_ctx, t);
-    grpc_chttp2_become_writable(exec_ctx, t, s, true, "new_stream");
+    grpc_chttp2_mark_stream_writable(exec_ctx, t, s);
+    grpc_chttp2_initiate_write(exec_ctx, t,
+                               GRPC_CHTTP2_INITIATE_WRITE_START_NEW_STREAM);
   }
   /* cancel out streams that will never be started */
   while (t->next_stream_id >= MAX_CLIENT_STREAM_ID &&
@@ -1202,7 +1279,9 @@ static void maybe_become_writable_due_to_send_msg(grpc_exec_ctx *exec_ctx,
                                                   grpc_chttp2_stream *s) {
   if (s->id != 0 && (!s->write_buffering ||
                      s->flow_controlled_buffer.length > t->write_buffer_size)) {
-    grpc_chttp2_become_writable(exec_ctx, t, s, true, "op.send_message");
+    grpc_chttp2_mark_stream_writable(exec_ctx, t, s);
+    grpc_chttp2_initiate_write(exec_ctx, t,
+                               GRPC_CHTTP2_INITIATE_WRITE_SEND_MESSAGE);
   }
 }
 
@@ -1404,14 +1483,13 @@ static void perform_stream_op_locked(grpc_exec_ctx *exec_ctx, void *stream_op,
           }
         } else {
           GPR_ASSERT(s->id != 0);
-          bool initiate_write = true;
-          if (op->send_message &&
-              (op->payload->send_message.send_message->flags &
-               GRPC_WRITE_BUFFER_HINT)) {
-            initiate_write = false;
+          grpc_chttp2_mark_stream_writable(exec_ctx, t, s);
+          if (!(op->send_message &&
+                (op->payload->send_message.send_message->flags &
+                 GRPC_WRITE_BUFFER_HINT))) {
+            grpc_chttp2_initiate_write(
+                exec_ctx, t, GRPC_CHTTP2_INITIATE_WRITE_SEND_INITIAL_METADATA);
           }
-          grpc_chttp2_become_writable(exec_ctx, t, s, initiate_write,
-                                      "op.send_initial_metadata");
         }
       } else {
         s->send_initial_metadata = NULL;
@@ -1519,8 +1597,9 @@ static void perform_stream_op_locked(grpc_exec_ctx *exec_ctx, void *stream_op,
       } else if (s->id != 0) {
         /* TODO(ctiller): check if there's flow control for any outstanding
            bytes before going writable */
-        grpc_chttp2_become_writable(exec_ctx, t, s, true,
-                                    "op.send_trailing_metadata");
+        grpc_chttp2_mark_stream_writable(exec_ctx, t, s);
+        grpc_chttp2_initiate_write(
+            exec_ctx, t, GRPC_CHTTP2_INITIATE_WRITE_SEND_TRAILING_METADATA);
       }
     }
   }
@@ -1632,15 +1711,17 @@ static void cancel_pings(grpc_exec_ctx *exec_ctx, grpc_chttp2_transport *t,
   GRPC_ERROR_UNREF(error);
 }
 
-static void send_ping_locked(grpc_exec_ctx *exec_ctx, grpc_chttp2_transport *t,
-                             grpc_chttp2_ping_type ping_type,
-                             grpc_closure *on_initiate, grpc_closure *on_ack) {
+static void send_ping_locked(
+    grpc_exec_ctx *exec_ctx, grpc_chttp2_transport *t,
+    grpc_chttp2_ping_type ping_type, grpc_closure *on_initiate,
+    grpc_closure *on_ack,
+    grpc_chttp2_initiate_write_reason initiate_write_reason) {
   grpc_chttp2_ping_queue *pq = &t->ping_queues[ping_type];
   grpc_closure_list_append(&pq->lists[GRPC_CHTTP2_PCL_INITIATE], on_initiate,
                            GRPC_ERROR_NONE);
   if (grpc_closure_list_append(&pq->lists[GRPC_CHTTP2_PCL_NEXT], on_ack,
                                GRPC_ERROR_NONE)) {
-    grpc_chttp2_initiate_write(exec_ctx, t, "send_ping");
+    grpc_chttp2_initiate_write(exec_ctx, t, initiate_write_reason);
   }
 }
 
@@ -1648,7 +1729,8 @@ static void retry_initiate_ping_locked(grpc_exec_ctx *exec_ctx, void *tp,
                                        grpc_error *error) {
   grpc_chttp2_transport *t = (grpc_chttp2_transport *)tp;
   t->ping_state.is_delayed_ping_timer_set = false;
-  grpc_chttp2_initiate_write(exec_ctx, t, "retry_send_ping");
+  grpc_chttp2_initiate_write(exec_ctx, t,
+                             GRPC_CHTTP2_INITIATE_WRITE_RETRY_SEND_PING);
 }
 
 void grpc_chttp2_ack_ping(grpc_exec_ctx *exec_ctx, grpc_chttp2_transport *t,
@@ -1663,7 +1745,8 @@ void grpc_chttp2_ack_ping(grpc_exec_ctx *exec_ctx, grpc_chttp2_transport *t,
   }
   GRPC_CLOSURE_LIST_SCHED(exec_ctx, &pq->lists[GRPC_CHTTP2_PCL_INFLIGHT]);
   if (!grpc_closure_list_empty(pq->lists[GRPC_CHTTP2_PCL_NEXT])) {
-    grpc_chttp2_initiate_write(exec_ctx, t, "continue_pings");
+    grpc_chttp2_initiate_write(exec_ctx, t,
+                               GRPC_CHTTP2_INITIATE_WRITE_CONTINUE_PINGS);
   }
 }
 
@@ -1676,7 +1759,8 @@ static void send_goaway(grpc_exec_ctx *exec_ctx, grpc_chttp2_transport *t,
                         &slice, &http_error);
   grpc_chttp2_goaway_append(t->last_new_stream_id, (uint32_t)http_error,
                             grpc_slice_ref_internal(slice), &t->qbuf);
-  grpc_chttp2_initiate_write(exec_ctx, t, "goaway_sent");
+  grpc_chttp2_initiate_write(exec_ctx, t,
+                             GRPC_CHTTP2_INITIATE_WRITE_GOAWAY_SENT);
   GRPC_ERROR_UNREF(error);
 }
 
@@ -1723,7 +1807,8 @@ static void perform_transport_op_locked(grpc_exec_ctx *exec_ctx,
 
   if (op->send_ping) {
     send_ping_locked(exec_ctx, t, GRPC_CHTTP2_PING_ON_NEXT_WRITE, NULL,
-                     op->send_ping);
+                     op->send_ping,
+                     GRPC_CHTTP2_INITIATE_WRITE_APPLICATION_PING);
   }
 
   if (op->on_connectivity_state_change != NULL) {
@@ -1968,7 +2053,8 @@ void grpc_chttp2_cancel_stream(grpc_exec_ctx *exec_ctx,
       grpc_slice_buffer_add(
           &t->qbuf, grpc_chttp2_rst_stream_create(s->id, (uint32_t)http_error,
                                                   &s->stats.outgoing));
-      grpc_chttp2_initiate_write(exec_ctx, t, "rst_stream");
+      grpc_chttp2_initiate_write(exec_ctx, t,
+                                 GRPC_CHTTP2_INITIATE_WRITE_RST_STREAM);
     }
   }
   if (due_to_error != GRPC_ERROR_NONE && !s->seen_error) {
@@ -2289,7 +2375,8 @@ static void close_from_api(grpc_exec_ctx *exec_ctx, grpc_chttp2_transport *t,
                                               &s->stats.outgoing));
 
   grpc_chttp2_mark_stream_closed(exec_ctx, t, s, 1, 1, error);
-  grpc_chttp2_initiate_write(exec_ctx, t, "close_from_api");
+  grpc_chttp2_initiate_write(exec_ctx, t,
+                             GRPC_CHTTP2_INITIATE_WRITE_CLOSE_FROM_API);
 }
 
 typedef struct {
@@ -2324,19 +2411,20 @@ void grpc_chttp2_act_on_flowctl_action(grpc_exec_ctx *exec_ctx,
     case GRPC_CHTTP2_FLOWCTL_NO_ACTION_NEEDED:
       break;
     case GRPC_CHTTP2_FLOWCTL_UPDATE_IMMEDIATELY:
-      grpc_chttp2_become_writable(exec_ctx, t, s, true,
-                                  "immediate stream flowctl");
+      grpc_chttp2_mark_stream_writable(exec_ctx, t, s);
+      grpc_chttp2_initiate_write(
+          exec_ctx, t, GRPC_CHTTP2_INITIATE_WRITE_STREAM_FLOW_CONTROL);
       break;
     case GRPC_CHTTP2_FLOWCTL_QUEUE_UPDATE:
-      grpc_chttp2_become_writable(exec_ctx, t, s, false,
-                                  "queue stream flowctl");
+      grpc_chttp2_mark_stream_writable(exec_ctx, t, s);
       break;
   }
   switch (action.send_transport_update) {
     case GRPC_CHTTP2_FLOWCTL_NO_ACTION_NEEDED:
       break;
     case GRPC_CHTTP2_FLOWCTL_UPDATE_IMMEDIATELY:
-      grpc_chttp2_initiate_write(exec_ctx, t, "immediate transport flowctl");
+      grpc_chttp2_initiate_write(
+          exec_ctx, t, GRPC_CHTTP2_INITIATE_WRITE_TRANSPORT_FLOW_CONTROL);
       break;
     // this is the same as no action b/c every time the transport enters the
     // writing path it will maybe do an update
@@ -2354,7 +2442,8 @@ void grpc_chttp2_act_on_flowctl_action(grpc_exec_ctx *exec_ctx,
                            (uint32_t)action.max_frame_size);
     }
     if (action.send_setting_update == GRPC_CHTTP2_FLOWCTL_UPDATE_IMMEDIATELY) {
-      grpc_chttp2_initiate_write(exec_ctx, t, "immediate setting update");
+      grpc_chttp2_initiate_write(exec_ctx, t,
+                                 GRPC_CHTTP2_INITIATE_WRITE_SEND_SETTINGS);
     }
   }
   if (action.need_ping) {
@@ -2362,7 +2451,8 @@ void grpc_chttp2_act_on_flowctl_action(grpc_exec_ctx *exec_ctx,
     grpc_bdp_estimator_schedule_ping(&t->flow_control.bdp_estimator);
     send_ping_locked(exec_ctx, t,
                      GRPC_CHTTP2_PING_BEFORE_TRANSPORT_WINDOW_UPDATE,
-                     &t->start_bdp_ping_locked, &t->finish_bdp_ping_locked);
+                     &t->start_bdp_ping_locked, &t->finish_bdp_ping_locked,
+                     GRPC_CHTTP2_INITIATE_WRITE_BDP_ESTIMATOR_PING);
   }
 }
 
@@ -2441,7 +2531,10 @@ static void read_action_locked(grpc_exec_ctx *exec_ctx, void *tp,
       if (t->flow_control.initial_window_update > 0) {
         grpc_chttp2_stream *s;
         while (grpc_chttp2_list_pop_stalled_by_stream(t, &s)) {
-          grpc_chttp2_become_writable(exec_ctx, t, s, true, "unstalled");
+          grpc_chttp2_mark_stream_writable(exec_ctx, t, s);
+          grpc_chttp2_initiate_write(
+              exec_ctx, t,
+              GRPC_CHTTP2_INITIATE_WRITE_FLOW_CONTROL_UNSTALLED_BY_SETTING);
         }
       }
       t->flow_control.initial_window_update = 0;
@@ -2556,7 +2649,8 @@ static void init_keepalive_ping_locked(grpc_exec_ctx *exec_ctx, void *arg,
       GRPC_CHTTP2_REF_TRANSPORT(t, "keepalive ping end");
       send_ping_locked(exec_ctx, t, GRPC_CHTTP2_PING_ON_NEXT_WRITE,
                        &t->start_keepalive_ping_locked,
-                       &t->finish_keepalive_ping_locked);
+                       &t->finish_keepalive_ping_locked,
+                       GRPC_CHTTP2_INITIATE_WRITE_KEEPALIVE_PING);
     } else {
       GRPC_CHTTP2_REF_TRANSPORT(t, "init keepalive ping");
       grpc_timer_init(
@@ -2912,8 +3006,7 @@ grpc_chttp2_incoming_byte_stream *grpc_chttp2_incoming_byte_stream_create(
     grpc_exec_ctx *exec_ctx, grpc_chttp2_transport *t, grpc_chttp2_stream *s,
     uint32_t frame_size, uint32_t flags) {
   grpc_chttp2_incoming_byte_stream *incoming_byte_stream =
-      (grpc_chttp2_incoming_byte_stream *)gpr_malloc(
-          sizeof(*incoming_byte_stream));
+      gpr_malloc(sizeof(*incoming_byte_stream));
   incoming_byte_stream->base.length = frame_size;
   incoming_byte_stream->remaining_bytes = frame_size;
   incoming_byte_stream->base.flags = flags;
@@ -3017,6 +3110,56 @@ static void destructive_reclaimer_locked(grpc_exec_ctx *exec_ctx, void *arg,
 /*******************************************************************************
  * MONITORING
  */
+
+const char *grpc_chttp2_initiate_write_reason_string(
+    grpc_chttp2_initiate_write_reason reason) {
+  switch (reason) {
+    case GRPC_CHTTP2_INITIATE_WRITE_INITIAL_WRITE:
+      return "INITIAL_WRITE";
+    case GRPC_CHTTP2_INITIATE_WRITE_START_NEW_STREAM:
+      return "START_NEW_STREAM";
+    case GRPC_CHTTP2_INITIATE_WRITE_SEND_MESSAGE:
+      return "SEND_MESSAGE";
+    case GRPC_CHTTP2_INITIATE_WRITE_SEND_INITIAL_METADATA:
+      return "SEND_INITIAL_METADATA";
+    case GRPC_CHTTP2_INITIATE_WRITE_SEND_TRAILING_METADATA:
+      return "SEND_TRAILING_METADATA";
+    case GRPC_CHTTP2_INITIATE_WRITE_RETRY_SEND_PING:
+      return "RETRY_SEND_PING";
+    case GRPC_CHTTP2_INITIATE_WRITE_CONTINUE_PINGS:
+      return "CONTINUE_PINGS";
+    case GRPC_CHTTP2_INITIATE_WRITE_GOAWAY_SENT:
+      return "GOAWAY_SENT";
+    case GRPC_CHTTP2_INITIATE_WRITE_RST_STREAM:
+      return "RST_STREAM";
+    case GRPC_CHTTP2_INITIATE_WRITE_CLOSE_FROM_API:
+      return "CLOSE_FROM_API";
+    case GRPC_CHTTP2_INITIATE_WRITE_STREAM_FLOW_CONTROL:
+      return "STREAM_FLOW_CONTROL";
+    case GRPC_CHTTP2_INITIATE_WRITE_TRANSPORT_FLOW_CONTROL:
+      return "TRANSPORT_FLOW_CONTROL";
+    case GRPC_CHTTP2_INITIATE_WRITE_SEND_SETTINGS:
+      return "SEND_SETTINGS";
+    case GRPC_CHTTP2_INITIATE_WRITE_BDP_ESTIMATOR_PING:
+      return "BDP_ESTIMATOR_PING";
+    case GRPC_CHTTP2_INITIATE_WRITE_FLOW_CONTROL_UNSTALLED_BY_SETTING:
+      return "FLOW_CONTROL_UNSTALLED_BY_SETTING";
+    case GRPC_CHTTP2_INITIATE_WRITE_FLOW_CONTROL_UNSTALLED_BY_UPDATE:
+      return "FLOW_CONTROL_UNSTALLED_BY_UPDATE";
+    case GRPC_CHTTP2_INITIATE_WRITE_APPLICATION_PING:
+      return "APPLICATION_PING";
+    case GRPC_CHTTP2_INITIATE_WRITE_KEEPALIVE_PING:
+      return "KEEPALIVE_PING";
+    case GRPC_CHTTP2_INITIATE_WRITE_TRANSPORT_FLOW_CONTROL_UNSTALLED:
+      return "TRANSPORT_FLOW_CONTROL_UNSTALLED";
+    case GRPC_CHTTP2_INITIATE_WRITE_PING_RESPONSE:
+      return "PING_RESPONSE";
+    case GRPC_CHTTP2_INITIATE_WRITE_FORCE_RST_STREAM:
+      return "FORCE_RST_STREAM";
+  }
+  GPR_UNREACHABLE_CODE(return "unknown");
+}
+
 static grpc_endpoint *chttp2_get_endpoint(grpc_exec_ctx *exec_ctx,
                                           grpc_transport *t) {
   return ((grpc_chttp2_transport *)t)->ep;
diff --git a/src/core/ext/transport/chttp2/transport/frame_ping.c b/src/core/ext/transport/chttp2/transport/frame_ping.c
index 582fd7bfaac..81bd02ae702 100644
--- a/src/core/ext/transport/chttp2/transport/frame_ping.c
+++ b/src/core/ext/transport/chttp2/transport/frame_ping.c
@@ -117,7 +117,8 @@ grpc_error *grpc_chttp2_ping_parser_parse(grpc_exec_ctx *exec_ctx, void *parser,
               t->ping_acks, t->ping_ack_capacity * sizeof(*t->ping_acks));
         }
         t->ping_acks[t->ping_ack_count++] = p->opaque_8bytes;
-        grpc_chttp2_initiate_write(exec_ctx, t, "ping response");
+        grpc_chttp2_initiate_write(exec_ctx, t,
+                                   GRPC_CHTTP2_INITIATE_WRITE_PING_RESPONSE);
       }
     }
   }
diff --git a/src/core/ext/transport/chttp2/transport/frame_window_update.c b/src/core/ext/transport/chttp2/transport/frame_window_update.c
index c94f7725bf6..c9ab8d1b50f 100644
--- a/src/core/ext/transport/chttp2/transport/frame_window_update.c
+++ b/src/core/ext/transport/chttp2/transport/frame_window_update.c
@@ -99,8 +99,10 @@ grpc_error *grpc_chttp2_window_update_parser_parse(
         grpc_chttp2_flowctl_recv_stream_update(
             &t->flow_control, &s->flow_control, received_update);
         if (grpc_chttp2_list_remove_stalled_by_stream(t, s)) {
-          grpc_chttp2_become_writable(exec_ctx, t, s, true,
-                                      "stream.read_flow_control");
+          grpc_chttp2_mark_stream_writable(exec_ctx, t, s);
+          grpc_chttp2_initiate_write(
+              exec_ctx, t,
+              GRPC_CHTTP2_INITIATE_WRITE_FLOW_CONTROL_UNSTALLED_BY_UPDATE);
         }
       }
     } else {
@@ -109,7 +111,9 @@ grpc_error *grpc_chttp2_window_update_parser_parse(
                                                 received_update);
       bool is_zero = t->flow_control.remote_window <= 0;
       if (was_zero && !is_zero) {
-        grpc_chttp2_initiate_write(exec_ctx, t, "new_global_flow_control");
+        grpc_chttp2_initiate_write(
+            exec_ctx, t,
+            GRPC_CHTTP2_INITIATE_WRITE_TRANSPORT_FLOW_CONTROL_UNSTALLED);
       }
     }
   }
diff --git a/src/core/ext/transport/chttp2/transport/hpack_parser.c b/src/core/ext/transport/chttp2/transport/hpack_parser.c
index 82ff2c8e2cf..901e7413c0a 100644
--- a/src/core/ext/transport/chttp2/transport/hpack_parser.c
+++ b/src/core/ext/transport/chttp2/transport/hpack_parser.c
@@ -1649,7 +1649,8 @@ static void force_client_rst_stream(grpc_exec_ctx *exec_ctx, void *sp,
     grpc_slice_buffer_add(
         &t->qbuf, grpc_chttp2_rst_stream_create(s->id, GRPC_HTTP2_NO_ERROR,
                                                 &s->stats.outgoing));
-    grpc_chttp2_initiate_write(exec_ctx, t, "force_rst_stream");
+    grpc_chttp2_initiate_write(exec_ctx, t,
+                               GRPC_CHTTP2_INITIATE_WRITE_FORCE_RST_STREAM);
     grpc_chttp2_mark_stream_closed(exec_ctx, t, s, true, true, GRPC_ERROR_NONE);
   }
   GRPC_CHTTP2_STREAM_UNREF(exec_ctx, s, "final_rst");
diff --git a/src/core/ext/transport/chttp2/transport/internal.h b/src/core/ext/transport/chttp2/transport/internal.h
index 0fbedd1e567..c2dfce7c9c7 100644
--- a/src/core/ext/transport/chttp2/transport/internal.h
+++ b/src/core/ext/transport/chttp2/transport/internal.h
@@ -79,6 +79,33 @@ typedef enum {
   GRPC_CHTTP2_PCL_COUNT /* must be last */
 } grpc_chttp2_ping_closure_list;
 
+typedef enum {
+  GRPC_CHTTP2_INITIATE_WRITE_INITIAL_WRITE,
+  GRPC_CHTTP2_INITIATE_WRITE_START_NEW_STREAM,
+  GRPC_CHTTP2_INITIATE_WRITE_SEND_MESSAGE,
+  GRPC_CHTTP2_INITIATE_WRITE_SEND_INITIAL_METADATA,
+  GRPC_CHTTP2_INITIATE_WRITE_SEND_TRAILING_METADATA,
+  GRPC_CHTTP2_INITIATE_WRITE_RETRY_SEND_PING,
+  GRPC_CHTTP2_INITIATE_WRITE_CONTINUE_PINGS,
+  GRPC_CHTTP2_INITIATE_WRITE_GOAWAY_SENT,
+  GRPC_CHTTP2_INITIATE_WRITE_RST_STREAM,
+  GRPC_CHTTP2_INITIATE_WRITE_CLOSE_FROM_API,
+  GRPC_CHTTP2_INITIATE_WRITE_STREAM_FLOW_CONTROL,
+  GRPC_CHTTP2_INITIATE_WRITE_TRANSPORT_FLOW_CONTROL,
+  GRPC_CHTTP2_INITIATE_WRITE_SEND_SETTINGS,
+  GRPC_CHTTP2_INITIATE_WRITE_BDP_ESTIMATOR_PING,
+  GRPC_CHTTP2_INITIATE_WRITE_FLOW_CONTROL_UNSTALLED_BY_SETTING,
+  GRPC_CHTTP2_INITIATE_WRITE_FLOW_CONTROL_UNSTALLED_BY_UPDATE,
+  GRPC_CHTTP2_INITIATE_WRITE_APPLICATION_PING,
+  GRPC_CHTTP2_INITIATE_WRITE_KEEPALIVE_PING,
+  GRPC_CHTTP2_INITIATE_WRITE_TRANSPORT_FLOW_CONTROL_UNSTALLED,
+  GRPC_CHTTP2_INITIATE_WRITE_PING_RESPONSE,
+  GRPC_CHTTP2_INITIATE_WRITE_FORCE_RST_STREAM,
+} grpc_chttp2_initiate_write_reason;
+
+const char *grpc_chttp2_initiate_write_reason_string(
+    grpc_chttp2_initiate_write_reason reason);
+
 typedef struct {
   grpc_closure_list lists[GRPC_CHTTP2_PCL_COUNT];
   uint64_t inflight_id;
@@ -599,7 +626,8 @@ struct grpc_chttp2_stream {
     The actual call chain is documented in the implementation of this function.
     */
 void grpc_chttp2_initiate_write(grpc_exec_ctx *exec_ctx,
-                                grpc_chttp2_transport *t, const char *reason);
+                                grpc_chttp2_transport *t,
+                                grpc_chttp2_initiate_write_reason reason);
 
 typedef struct {
   /** are we writing? */
@@ -851,10 +879,9 @@ void grpc_chttp2_add_ping_strike(grpc_exec_ctx *exec_ctx,
 
 /** add a ref to the stream and add it to the writable list;
     ref will be dropped in writing.c */
-void grpc_chttp2_become_writable(grpc_exec_ctx *exec_ctx,
-                                 grpc_chttp2_transport *t,
-                                 grpc_chttp2_stream *s,
-                                 bool also_initiate_write, const char *reason);
+void grpc_chttp2_mark_stream_writable(grpc_exec_ctx *exec_ctx,
+                                      grpc_chttp2_transport *t,
+                                      grpc_chttp2_stream *s);
 
 void grpc_chttp2_cancel_stream(grpc_exec_ctx *exec_ctx,
                                grpc_chttp2_transport *t, grpc_chttp2_stream *s,
diff --git a/src/core/ext/transport/chttp2/transport/writing.c b/src/core/ext/transport/chttp2/transport/writing.c
index 3fa38db4db6..3ded801985d 100644
--- a/src/core/ext/transport/chttp2/transport/writing.c
+++ b/src/core/ext/transport/chttp2/transport/writing.c
@@ -201,9 +201,8 @@ grpc_chttp2_begin_write_result grpc_chttp2_begin_write(
 
   if (t->flow_control.remote_window > 0) {
     while (grpc_chttp2_list_pop_stalled_by_transport(t, &s)) {
-      if (!t->closed && grpc_chttp2_list_add_writable_stream(t, s) &&
-          stream_ref_if_not_destroyed(&s->refcount->refs)) {
-        grpc_chttp2_initiate_write(exec_ctx, t, "transport.read_flow_control");
+      if (!t->closed && grpc_chttp2_list_add_writable_stream(t, s)) {
+        stream_ref_if_not_destroyed(&s->refcount->refs);
       }
     }
   }
diff --git a/src/core/lib/debug/stats_data.c b/src/core/lib/debug/stats_data.c
index 2c567653432..b3e1ee9b4ec 100644
--- a/src/core/lib/debug/stats_data.c
+++ b/src/core/lib/debug/stats_data.c
@@ -50,6 +50,27 @@ const char *grpc_stats_counter_name[GRPC_STATS_COUNTER_COUNT] = {
     "http2_writes_offloaded",
     "http2_writes_continued",
     "http2_partial_writes",
+    "http2_initiate_write_due_to_initial_write",
+    "http2_initiate_write_due_to_start_new_stream",
+    "http2_initiate_write_due_to_send_message",
+    "http2_initiate_write_due_to_send_initial_metadata",
+    "http2_initiate_write_due_to_send_trailing_metadata",
+    "http2_initiate_write_due_to_retry_send_ping",
+    "http2_initiate_write_due_to_continue_pings",
+    "http2_initiate_write_due_to_goaway_sent",
+    "http2_initiate_write_due_to_rst_stream",
+    "http2_initiate_write_due_to_close_from_api",
+    "http2_initiate_write_due_to_stream_flow_control",
+    "http2_initiate_write_due_to_transport_flow_control",
+    "http2_initiate_write_due_to_send_settings",
+    "http2_initiate_write_due_to_bdp_estimator_ping",
+    "http2_initiate_write_due_to_flow_control_unstalled_by_setting",
+    "http2_initiate_write_due_to_flow_control_unstalled_by_update",
+    "http2_initiate_write_due_to_application_ping",
+    "http2_initiate_write_due_to_keepalive_ping",
+    "http2_initiate_write_due_to_transport_flow_control_unstalled",
+    "http2_initiate_write_due_to_ping_response",
+    "http2_initiate_write_due_to_force_rst_stream",
     "combiner_locks_initiated",
     "combiner_locks_scheduled_items",
     "combiner_locks_scheduled_final_items",
@@ -92,6 +113,30 @@ const char *grpc_stats_counter_doc[GRPC_STATS_COUNTER_COUNT] = {
     "written",
     "Number of HTTP2 writes that were made knowing there was still more data "
     "to be written (we cap maximum write size to syscall_write)",
+    "Number of HTTP2 writes initiated due to 'initial_write'",
+    "Number of HTTP2 writes initiated due to 'start_new_stream'",
+    "Number of HTTP2 writes initiated due to 'send_message'",
+    "Number of HTTP2 writes initiated due to 'send_initial_metadata'",
+    "Number of HTTP2 writes initiated due to 'send_trailing_metadata'",
+    "Number of HTTP2 writes initiated due to 'retry_send_ping'",
+    "Number of HTTP2 writes initiated due to 'continue_pings'",
+    "Number of HTTP2 writes initiated due to 'goaway_sent'",
+    "Number of HTTP2 writes initiated due to 'rst_stream'",
+    "Number of HTTP2 writes initiated due to 'close_from_api'",
+    "Number of HTTP2 writes initiated due to 'stream_flow_control'",
+    "Number of HTTP2 writes initiated due to 'transport_flow_control'",
+    "Number of HTTP2 writes initiated due to 'send_settings'",
+    "Number of HTTP2 writes initiated due to 'bdp_estimator_ping'",
+    "Number of HTTP2 writes initiated due to "
+    "'flow_control_unstalled_by_setting'",
+    "Number of HTTP2 writes initiated due to "
+    "'flow_control_unstalled_by_update'",
+    "Number of HTTP2 writes initiated due to 'application_ping'",
+    "Number of HTTP2 writes initiated due to 'keepalive_ping'",
+    "Number of HTTP2 writes initiated due to "
+    "'transport_flow_control_unstalled'",
+    "Number of HTTP2 writes initiated due to 'ping_response'",
+    "Number of HTTP2 writes initiated due to 'force_rst_stream'",
     "Number of combiner lock entries by process (first items queued to a "
     "combiner)",
     "Number of items scheduled against combiner locks",
diff --git a/src/core/lib/debug/stats_data.h b/src/core/lib/debug/stats_data.h
index e93db32c6a0..c9871c4a56c 100644
--- a/src/core/lib/debug/stats_data.h
+++ b/src/core/lib/debug/stats_data.h
@@ -52,6 +52,27 @@ typedef enum {
   GRPC_STATS_COUNTER_HTTP2_WRITES_OFFLOADED,
   GRPC_STATS_COUNTER_HTTP2_WRITES_CONTINUED,
   GRPC_STATS_COUNTER_HTTP2_PARTIAL_WRITES,
+  GRPC_STATS_COUNTER_HTTP2_INITIATE_WRITE_DUE_TO_INITIAL_WRITE,
+  GRPC_STATS_COUNTER_HTTP2_INITIATE_WRITE_DUE_TO_START_NEW_STREAM,
+  GRPC_STATS_COUNTER_HTTP2_INITIATE_WRITE_DUE_TO_SEND_MESSAGE,
+  GRPC_STATS_COUNTER_HTTP2_INITIATE_WRITE_DUE_TO_SEND_INITIAL_METADATA,
+  GRPC_STATS_COUNTER_HTTP2_INITIATE_WRITE_DUE_TO_SEND_TRAILING_METADATA,
+  GRPC_STATS_COUNTER_HTTP2_INITIATE_WRITE_DUE_TO_RETRY_SEND_PING,
+  GRPC_STATS_COUNTER_HTTP2_INITIATE_WRITE_DUE_TO_CONTINUE_PINGS,
+  GRPC_STATS_COUNTER_HTTP2_INITIATE_WRITE_DUE_TO_GOAWAY_SENT,
+  GRPC_STATS_COUNTER_HTTP2_INITIATE_WRITE_DUE_TO_RST_STREAM,
+  GRPC_STATS_COUNTER_HTTP2_INITIATE_WRITE_DUE_TO_CLOSE_FROM_API,
+  GRPC_STATS_COUNTER_HTTP2_INITIATE_WRITE_DUE_TO_STREAM_FLOW_CONTROL,
+  GRPC_STATS_COUNTER_HTTP2_INITIATE_WRITE_DUE_TO_TRANSPORT_FLOW_CONTROL,
+  GRPC_STATS_COUNTER_HTTP2_INITIATE_WRITE_DUE_TO_SEND_SETTINGS,
+  GRPC_STATS_COUNTER_HTTP2_INITIATE_WRITE_DUE_TO_BDP_ESTIMATOR_PING,
+  GRPC_STATS_COUNTER_HTTP2_INITIATE_WRITE_DUE_TO_FLOW_CONTROL_UNSTALLED_BY_SETTING,
+  GRPC_STATS_COUNTER_HTTP2_INITIATE_WRITE_DUE_TO_FLOW_CONTROL_UNSTALLED_BY_UPDATE,
+  GRPC_STATS_COUNTER_HTTP2_INITIATE_WRITE_DUE_TO_APPLICATION_PING,
+  GRPC_STATS_COUNTER_HTTP2_INITIATE_WRITE_DUE_TO_KEEPALIVE_PING,
+  GRPC_STATS_COUNTER_HTTP2_INITIATE_WRITE_DUE_TO_TRANSPORT_FLOW_CONTROL_UNSTALLED,
+  GRPC_STATS_COUNTER_HTTP2_INITIATE_WRITE_DUE_TO_PING_RESPONSE,
+  GRPC_STATS_COUNTER_HTTP2_INITIATE_WRITE_DUE_TO_FORCE_RST_STREAM,
   GRPC_STATS_COUNTER_COMBINER_LOCKS_INITIATED,
   GRPC_STATS_COUNTER_COMBINER_LOCKS_SCHEDULED_ITEMS,
   GRPC_STATS_COUNTER_COMBINER_LOCKS_SCHEDULED_FINAL_ITEMS,
@@ -169,6 +190,95 @@ typedef enum {
   GRPC_STATS_INC_COUNTER((exec_ctx), GRPC_STATS_COUNTER_HTTP2_WRITES_CONTINUED)
 #define GRPC_STATS_INC_HTTP2_PARTIAL_WRITES(exec_ctx) \
   GRPC_STATS_INC_COUNTER((exec_ctx), GRPC_STATS_COUNTER_HTTP2_PARTIAL_WRITES)
+#define GRPC_STATS_INC_HTTP2_INITIATE_WRITE_DUE_TO_INITIAL_WRITE(exec_ctx) \
+  GRPC_STATS_INC_COUNTER(                                                  \
+      (exec_ctx),                                                          \
+      GRPC_STATS_COUNTER_HTTP2_INITIATE_WRITE_DUE_TO_INITIAL_WRITE)
+#define GRPC_STATS_INC_HTTP2_INITIATE_WRITE_DUE_TO_START_NEW_STREAM(exec_ctx) \
+  GRPC_STATS_INC_COUNTER(                                                     \
+      (exec_ctx),                                                             \
+      GRPC_STATS_COUNTER_HTTP2_INITIATE_WRITE_DUE_TO_START_NEW_STREAM)
+#define GRPC_STATS_INC_HTTP2_INITIATE_WRITE_DUE_TO_SEND_MESSAGE(exec_ctx) \
+  GRPC_STATS_INC_COUNTER(                                                 \
+      (exec_ctx), GRPC_STATS_COUNTER_HTTP2_INITIATE_WRITE_DUE_TO_SEND_MESSAGE)
+#define GRPC_STATS_INC_HTTP2_INITIATE_WRITE_DUE_TO_SEND_INITIAL_METADATA( \
+    exec_ctx)                                                             \
+  GRPC_STATS_INC_COUNTER(                                                 \
+      (exec_ctx),                                                         \
+      GRPC_STATS_COUNTER_HTTP2_INITIATE_WRITE_DUE_TO_SEND_INITIAL_METADATA)
+#define GRPC_STATS_INC_HTTP2_INITIATE_WRITE_DUE_TO_SEND_TRAILING_METADATA( \
+    exec_ctx)                                                              \
+  GRPC_STATS_INC_COUNTER(                                                  \
+      (exec_ctx),                                                          \
+      GRPC_STATS_COUNTER_HTTP2_INITIATE_WRITE_DUE_TO_SEND_TRAILING_METADATA)
+#define GRPC_STATS_INC_HTTP2_INITIATE_WRITE_DUE_TO_RETRY_SEND_PING(exec_ctx) \
+  GRPC_STATS_INC_COUNTER(                                                    \
+      (exec_ctx),                                                            \
+      GRPC_STATS_COUNTER_HTTP2_INITIATE_WRITE_DUE_TO_RETRY_SEND_PING)
+#define GRPC_STATS_INC_HTTP2_INITIATE_WRITE_DUE_TO_CONTINUE_PINGS(exec_ctx) \
+  GRPC_STATS_INC_COUNTER(                                                   \
+      (exec_ctx),                                                           \
+      GRPC_STATS_COUNTER_HTTP2_INITIATE_WRITE_DUE_TO_CONTINUE_PINGS)
+#define GRPC_STATS_INC_HTTP2_INITIATE_WRITE_DUE_TO_GOAWAY_SENT(exec_ctx) \
+  GRPC_STATS_INC_COUNTER(                                                \
+      (exec_ctx), GRPC_STATS_COUNTER_HTTP2_INITIATE_WRITE_DUE_TO_GOAWAY_SENT)
+#define GRPC_STATS_INC_HTTP2_INITIATE_WRITE_DUE_TO_RST_STREAM(exec_ctx) \
+  GRPC_STATS_INC_COUNTER(                                               \
+      (exec_ctx), GRPC_STATS_COUNTER_HTTP2_INITIATE_WRITE_DUE_TO_RST_STREAM)
+#define GRPC_STATS_INC_HTTP2_INITIATE_WRITE_DUE_TO_CLOSE_FROM_API(exec_ctx) \
+  GRPC_STATS_INC_COUNTER(                                                   \
+      (exec_ctx),                                                           \
+      GRPC_STATS_COUNTER_HTTP2_INITIATE_WRITE_DUE_TO_CLOSE_FROM_API)
+#define GRPC_STATS_INC_HTTP2_INITIATE_WRITE_DUE_TO_STREAM_FLOW_CONTROL( \
+    exec_ctx)                                                           \
+  GRPC_STATS_INC_COUNTER(                                               \
+      (exec_ctx),                                                       \
+      GRPC_STATS_COUNTER_HTTP2_INITIATE_WRITE_DUE_TO_STREAM_FLOW_CONTROL)
+#define GRPC_STATS_INC_HTTP2_INITIATE_WRITE_DUE_TO_TRANSPORT_FLOW_CONTROL( \
+    exec_ctx)                                                              \
+  GRPC_STATS_INC_COUNTER(                                                  \
+      (exec_ctx),                                                          \
+      GRPC_STATS_COUNTER_HTTP2_INITIATE_WRITE_DUE_TO_TRANSPORT_FLOW_CONTROL)
+#define GRPC_STATS_INC_HTTP2_INITIATE_WRITE_DUE_TO_SEND_SETTINGS(exec_ctx) \
+  GRPC_STATS_INC_COUNTER(                                                  \
+      (exec_ctx),                                                          \
+      GRPC_STATS_COUNTER_HTTP2_INITIATE_WRITE_DUE_TO_SEND_SETTINGS)
+#define GRPC_STATS_INC_HTTP2_INITIATE_WRITE_DUE_TO_BDP_ESTIMATOR_PING( \
+    exec_ctx)                                                          \
+  GRPC_STATS_INC_COUNTER(                                              \
+      (exec_ctx),                                                      \
+      GRPC_STATS_COUNTER_HTTP2_INITIATE_WRITE_DUE_TO_BDP_ESTIMATOR_PING)
+#define GRPC_STATS_INC_HTTP2_INITIATE_WRITE_DUE_TO_FLOW_CONTROL_UNSTALLED_BY_SETTING( \
+    exec_ctx)                                                                         \
+  GRPC_STATS_INC_COUNTER(                                                             \
+      (exec_ctx),                                                                     \
+      GRPC_STATS_COUNTER_HTTP2_INITIATE_WRITE_DUE_TO_FLOW_CONTROL_UNSTALLED_BY_SETTING)
+#define GRPC_STATS_INC_HTTP2_INITIATE_WRITE_DUE_TO_FLOW_CONTROL_UNSTALLED_BY_UPDATE( \
+    exec_ctx)                                                                        \
+  GRPC_STATS_INC_COUNTER(                                                            \
+      (exec_ctx),                                                                    \
+      GRPC_STATS_COUNTER_HTTP2_INITIATE_WRITE_DUE_TO_FLOW_CONTROL_UNSTALLED_BY_UPDATE)
+#define GRPC_STATS_INC_HTTP2_INITIATE_WRITE_DUE_TO_APPLICATION_PING(exec_ctx) \
+  GRPC_STATS_INC_COUNTER(                                                     \
+      (exec_ctx),                                                             \
+      GRPC_STATS_COUNTER_HTTP2_INITIATE_WRITE_DUE_TO_APPLICATION_PING)
+#define GRPC_STATS_INC_HTTP2_INITIATE_WRITE_DUE_TO_KEEPALIVE_PING(exec_ctx) \
+  GRPC_STATS_INC_COUNTER(                                                   \
+      (exec_ctx),                                                           \
+      GRPC_STATS_COUNTER_HTTP2_INITIATE_WRITE_DUE_TO_KEEPALIVE_PING)
+#define GRPC_STATS_INC_HTTP2_INITIATE_WRITE_DUE_TO_TRANSPORT_FLOW_CONTROL_UNSTALLED( \
+    exec_ctx)                                                                        \
+  GRPC_STATS_INC_COUNTER(                                                            \
+      (exec_ctx),                                                                    \
+      GRPC_STATS_COUNTER_HTTP2_INITIATE_WRITE_DUE_TO_TRANSPORT_FLOW_CONTROL_UNSTALLED)
+#define GRPC_STATS_INC_HTTP2_INITIATE_WRITE_DUE_TO_PING_RESPONSE(exec_ctx) \
+  GRPC_STATS_INC_COUNTER(                                                  \
+      (exec_ctx),                                                          \
+      GRPC_STATS_COUNTER_HTTP2_INITIATE_WRITE_DUE_TO_PING_RESPONSE)
+#define GRPC_STATS_INC_HTTP2_INITIATE_WRITE_DUE_TO_FORCE_RST_STREAM(exec_ctx) \
+  GRPC_STATS_INC_COUNTER(                                                     \
+      (exec_ctx),                                                             \
+      GRPC_STATS_COUNTER_HTTP2_INITIATE_WRITE_DUE_TO_FORCE_RST_STREAM)
 #define GRPC_STATS_INC_COMBINER_LOCKS_INITIATED(exec_ctx) \
   GRPC_STATS_INC_COUNTER((exec_ctx),                      \
                          GRPC_STATS_COUNTER_COMBINER_LOCKS_INITIATED)
diff --git a/src/core/lib/debug/stats_data.yaml b/src/core/lib/debug/stats_data.yaml
index 37dff9c5f48..84727fe6c47 100644
--- a/src/core/lib/debug/stats_data.yaml
+++ b/src/core/lib/debug/stats_data.yaml
@@ -117,6 +117,48 @@
 - counter: http2_partial_writes
   doc: Number of HTTP2 writes that were made knowing there was still more data
        to be written (we cap maximum write size to syscall_write)
+- counter: http2_initiate_write_due_to_initial_write
+  doc: Number of HTTP2 writes initiated due to 'initial_write'
+- counter: http2_initiate_write_due_to_start_new_stream
+  doc: Number of HTTP2 writes initiated due to 'start_new_stream'
+- counter: http2_initiate_write_due_to_send_message
+  doc: Number of HTTP2 writes initiated due to 'send_message'
+- counter: http2_initiate_write_due_to_send_initial_metadata
+  doc: Number of HTTP2 writes initiated due to 'send_initial_metadata'
+- counter: http2_initiate_write_due_to_send_trailing_metadata
+  doc: Number of HTTP2 writes initiated due to 'send_trailing_metadata'
+- counter: http2_initiate_write_due_to_retry_send_ping
+  doc: Number of HTTP2 writes initiated due to 'retry_send_ping'
+- counter: http2_initiate_write_due_to_continue_pings
+  doc: Number of HTTP2 writes initiated due to 'continue_pings'
+- counter: http2_initiate_write_due_to_goaway_sent
+  doc: Number of HTTP2 writes initiated due to 'goaway_sent'
+- counter: http2_initiate_write_due_to_rst_stream
+  doc: Number of HTTP2 writes initiated due to 'rst_stream'
+- counter: http2_initiate_write_due_to_close_from_api
+  doc: Number of HTTP2 writes initiated due to 'close_from_api'
+- counter: http2_initiate_write_due_to_stream_flow_control
+  doc: Number of HTTP2 writes initiated due to 'stream_flow_control'
+- counter: http2_initiate_write_due_to_transport_flow_control
+  doc: Number of HTTP2 writes initiated due to 'transport_flow_control'
+- counter: http2_initiate_write_due_to_send_settings
+  doc: Number of HTTP2 writes initiated due to 'send_settings'
+- counter: http2_initiate_write_due_to_bdp_estimator_ping
+  doc: Number of HTTP2 writes initiated due to 'bdp_estimator_ping'
+- counter: http2_initiate_write_due_to_flow_control_unstalled_by_setting
+  doc: Number of HTTP2 writes initiated due to 'flow_control_unstalled_by_setting'
+- counter: http2_initiate_write_due_to_flow_control_unstalled_by_update
+  doc: Number of HTTP2 writes initiated due to 'flow_control_unstalled_by_update'
+- counter: http2_initiate_write_due_to_application_ping
+  doc: Number of HTTP2 writes initiated due to 'application_ping'
+- counter: http2_initiate_write_due_to_keepalive_ping
+  doc: Number of HTTP2 writes initiated due to 'keepalive_ping'
+- counter: http2_initiate_write_due_to_transport_flow_control_unstalled
+  doc: Number of HTTP2 writes initiated due to 'transport_flow_control_unstalled'
+- counter: http2_initiate_write_due_to_ping_response
+  doc: Number of HTTP2 writes initiated due to 'ping_response'
+- counter: http2_initiate_write_due_to_force_rst_stream
+  doc: Number of HTTP2 writes initiated due to 'force_rst_stream'
 # combiner locks
 - counter: combiner_locks_initiated
   doc: Number of combiner lock entries by process
diff --git a/src/core/lib/debug/stats_data_bq_schema.sql b/src/core/lib/debug/stats_data_bq_schema.sql
index 53547692918..d21afbbfe45 100644
--- a/src/core/lib/debug/stats_data_bq_schema.sql
+++ b/src/core/lib/debug/stats_data_bq_schema.sql
@@ -1,5 +1,9 @@
 client_calls_created_per_iteration:FLOAT,
 server_calls_created_per_iteration:FLOAT,
+cqs_created_per_iteration:FLOAT,
+client_channels_created_per_iteration:FLOAT,
+client_subchannels_created_per_iteration:FLOAT,
+server_channels_created_per_iteration:FLOAT,
 syscall_poll_per_iteration:FLOAT,
 syscall_wait_per_iteration:FLOAT,
 histogram_slow_lookups_per_iteration:FLOAT,
@@ -21,6 +25,27 @@ http2_writes_begun_per_iteration:FLOAT,
 http2_writes_offloaded_per_iteration:FLOAT,
 http2_writes_continued_per_iteration:FLOAT,
 http2_partial_writes_per_iteration:FLOAT,
+http2_initiate_write_due_to_initial_write_per_iteration:FLOAT,
+http2_initiate_write_due_to_start_new_stream_per_iteration:FLOAT,
+http2_initiate_write_due_to_send_message_per_iteration:FLOAT,
+http2_initiate_write_due_to_send_initial_metadata_per_iteration:FLOAT,
+http2_initiate_write_due_to_send_trailing_metadata_per_iteration:FLOAT,
+http2_initiate_write_due_to_retry_send_ping_per_iteration:FLOAT,
+http2_initiate_write_due_to_continue_pings_per_iteration:FLOAT,
+http2_initiate_write_due_to_goaway_sent_per_iteration:FLOAT,
+http2_initiate_write_due_to_rst_stream_per_iteration:FLOAT,
+http2_initiate_write_due_to_close_from_api_per_iteration:FLOAT,
+http2_initiate_write_due_to_stream_flow_control_per_iteration:FLOAT,
+http2_initiate_write_due_to_transport_flow_control_per_iteration:FLOAT,
+http2_initiate_write_due_to_send_settings_per_iteration:FLOAT,
+http2_initiate_write_due_to_bdp_estimator_ping_per_iteration:FLOAT,
+http2_initiate_write_due_to_flow_control_unstalled_by_setting_per_iteration:FLOAT,
+http2_initiate_write_due_to_flow_control_unstalled_by_update_per_iteration:FLOAT,
+http2_initiate_write_due_to_application_ping_per_iteration:FLOAT,
+http2_initiate_write_due_to_keepalive_ping_per_iteration:FLOAT,
+http2_initiate_write_due_to_transport_flow_control_unstalled_per_iteration:FLOAT,
+http2_initiate_write_due_to_ping_response_per_iteration:FLOAT,
+http2_initiate_write_due_to_force_rst_stream_per_iteration:FLOAT,
 combiner_locks_initiated_per_iteration:FLOAT,
 combiner_locks_scheduled_items_per_iteration:FLOAT,
 combiner_locks_scheduled_final_items_per_iteration:FLOAT,
diff --git a/tools/run_tests/performance/massage_qps_stats.py b/tools/run_tests/performance/massage_qps_stats.py
index 30a94ca7cdf..7994b544ac2 100644
--- a/tools/run_tests/performance/massage_qps_stats.py
+++ b/tools/run_tests/performance/massage_qps_stats.py
@@ -22,6 +22,10 @@ def massage_qps_stats(scenario_result):
     del stats["coreStats"]
     stats["core_client_calls_created"] = massage_qps_stats_helpers.counter(core_stats, "client_calls_created")
     stats["core_server_calls_created"] = massage_qps_stats_helpers.counter(core_stats, "server_calls_created")
+    stats["core_cqs_created"] = massage_qps_stats_helpers.counter(core_stats, "cqs_created")
+    stats["core_client_channels_created"] = massage_qps_stats_helpers.counter(core_stats, "client_channels_created")
+    stats["core_client_subchannels_created"] = massage_qps_stats_helpers.counter(core_stats, "client_subchannels_created")
+    stats["core_server_channels_created"] = massage_qps_stats_helpers.counter(core_stats, "server_channels_created")
     stats["core_syscall_poll"] = massage_qps_stats_helpers.counter(core_stats, "syscall_poll")
     stats["core_syscall_wait"] = massage_qps_stats_helpers.counter(core_stats, "syscall_wait")
     stats["core_histogram_slow_lookups"] = massage_qps_stats_helpers.counter(core_stats, "histogram_slow_lookups")
@@ -43,6 +47,27 @@ def massage_qps_stats(scenario_result):
     stats["core_http2_writes_offloaded"] = massage_qps_stats_helpers.counter(core_stats, "http2_writes_offloaded")
     stats["core_http2_writes_continued"] = massage_qps_stats_helpers.counter(core_stats, "http2_writes_continued")
     stats["core_http2_partial_writes"] = massage_qps_stats_helpers.counter(core_stats, "http2_partial_writes")
+    stats["core_http2_initiate_write_due_to_initial_write"] = massage_qps_stats_helpers.counter(core_stats, "http2_initiate_write_due_to_initial_write")
+    stats["core_http2_initiate_write_due_to_start_new_stream"] = massage_qps_stats_helpers.counter(core_stats, "http2_initiate_write_due_to_start_new_stream")
+    stats["core_http2_initiate_write_due_to_send_message"] = massage_qps_stats_helpers.counter(core_stats, "http2_initiate_write_due_to_send_message")
+    stats["core_http2_initiate_write_due_to_send_initial_metadata"] = massage_qps_stats_helpers.counter(core_stats, "http2_initiate_write_due_to_send_initial_metadata")
+    stats["core_http2_initiate_write_due_to_send_trailing_metadata"] = massage_qps_stats_helpers.counter(core_stats, "http2_initiate_write_due_to_send_trailing_metadata")
+    stats["core_http2_initiate_write_due_to_retry_send_ping"] = massage_qps_stats_helpers.counter(core_stats, "http2_initiate_write_due_to_retry_send_ping")
+    stats["core_http2_initiate_write_due_to_continue_pings"] = massage_qps_stats_helpers.counter(core_stats, "http2_initiate_write_due_to_continue_pings")
+    stats["core_http2_initiate_write_due_to_goaway_sent"] = massage_qps_stats_helpers.counter(core_stats, "http2_initiate_write_due_to_goaway_sent")
+    stats["core_http2_initiate_write_due_to_rst_stream"] = massage_qps_stats_helpers.counter(core_stats, "http2_initiate_write_due_to_rst_stream")
+    stats["core_http2_initiate_write_due_to_close_from_api"] = massage_qps_stats_helpers.counter(core_stats, "http2_initiate_write_due_to_close_from_api")
+    stats["core_http2_initiate_write_due_to_stream_flow_control"] = massage_qps_stats_helpers.counter(core_stats, "http2_initiate_write_due_to_stream_flow_control")
+    stats["core_http2_initiate_write_due_to_transport_flow_control"] = massage_qps_stats_helpers.counter(core_stats, "http2_initiate_write_due_to_transport_flow_control")
+    stats["core_http2_initiate_write_due_to_send_settings"] = massage_qps_stats_helpers.counter(core_stats, "http2_initiate_write_due_to_send_settings")
+    stats["core_http2_initiate_write_due_to_bdp_estimator_ping"] = massage_qps_stats_helpers.counter(core_stats, "http2_initiate_write_due_to_bdp_estimator_ping")
+    stats["core_http2_initiate_write_due_to_flow_control_unstalled_by_setting"] = massage_qps_stats_helpers.counter(core_stats, "http2_initiate_write_due_to_flow_control_unstalled_by_setting")
+    stats["core_http2_initiate_write_due_to_flow_control_unstalled_by_update"] = massage_qps_stats_helpers.counter(core_stats, "http2_initiate_write_due_to_flow_control_unstalled_by_update")
+    stats["core_http2_initiate_write_due_to_application_ping"] = massage_qps_stats_helpers.counter(core_stats, "http2_initiate_write_due_to_application_ping")
+    stats["core_http2_initiate_write_due_to_keepalive_ping"] = massage_qps_stats_helpers.counter(core_stats, "http2_initiate_write_due_to_keepalive_ping")
+    stats["core_http2_initiate_write_due_to_transport_flow_control_unstalled"] = massage_qps_stats_helpers.counter(core_stats, "http2_initiate_write_due_to_transport_flow_control_unstalled")
+    stats["core_http2_initiate_write_due_to_ping_response"] = massage_qps_stats_helpers.counter(core_stats, "http2_initiate_write_due_to_ping_response")
+    stats["core_http2_initiate_write_due_to_force_rst_stream"] = massage_qps_stats_helpers.counter(core_stats, "http2_initiate_write_due_to_force_rst_stream")
     stats["core_combiner_locks_initiated"] = massage_qps_stats_helpers.counter(core_stats, "combiner_locks_initiated")
     stats["core_combiner_locks_scheduled_items"] = massage_qps_stats_helpers.counter(core_stats, "combiner_locks_scheduled_items")
     stats["core_combiner_locks_scheduled_final_items"] = massage_qps_stats_helpers.counter(core_stats, "combiner_locks_scheduled_final_items")
diff --git a/tools/run_tests/performance/scenario_result_schema.json b/tools/run_tests/performance/scenario_result_schema.json
index 84b3cb7c0a3..12a56dbec0e 100644
--- a/tools/run_tests/performance/scenario_result_schema.json
+++ b/tools/run_tests/performance/scenario_result_schema.json
@@ -120,6 +120,26 @@
         "name": "core_server_calls_created", 
         "type": "INTEGER"
       }, 
+      {
+        "mode": "NULLABLE", 
+        "name": "core_cqs_created", 
+        "type": "INTEGER"
+      }, 
+      {
+        "mode": "NULLABLE", 
+        "name": "core_client_channels_created", 
+        "type": "INTEGER"
+      }, 
+      {
+        "mode": "NULLABLE", 
+        "name": "core_client_subchannels_created", 
+        "type": "INTEGER"
+      }, 
+      {
+        "mode": "NULLABLE", 
+        "name": "core_server_channels_created", 
+        "type": "INTEGER"
+      }, 
       {
         "mode": "NULLABLE", 
         "name": "core_syscall_poll", 
@@ -225,6 +245,111 @@
         "name": "core_http2_partial_writes", 
         "type": "INTEGER"
       }, 
+      {
+        "mode": "NULLABLE", 
+        "name": "core_http2_initiate_write_due_to_initial_write", 
+        "type": "INTEGER"
+      }, 
+      {
+        "mode": "NULLABLE", 
+        "name": "core_http2_initiate_write_due_to_start_new_stream", 
+        "type": "INTEGER"
+      }, 
+      {
+        "mode": "NULLABLE", 
+        "name": "core_http2_initiate_write_due_to_send_message", 
+        "type": "INTEGER"
+      }, 
+      {
+        "mode": "NULLABLE", 
+        "name": "core_http2_initiate_write_due_to_send_initial_metadata", 
+        "type": "INTEGER"
+      }, 
+      {
+        "mode": "NULLABLE", 
+        "name": "core_http2_initiate_write_due_to_send_trailing_metadata", 
+        "type": "INTEGER"
+      }, 
+      {
+        "mode": "NULLABLE", 
+        "name": "core_http2_initiate_write_due_to_retry_send_ping", 
+        "type": "INTEGER"
+      }, 
+      {
+        "mode": "NULLABLE", 
+        "name": "core_http2_initiate_write_due_to_continue_pings", 
+        "type": "INTEGER"
+      }, 
+      {
+        "mode": "NULLABLE", 
+        "name": "core_http2_initiate_write_due_to_goaway_sent", 
+        "type": "INTEGER"
+      }, 
+      {
+        "mode": "NULLABLE", 
+        "name": "core_http2_initiate_write_due_to_rst_stream", 
+        "type": "INTEGER"
+      }, 
+      {
+        "mode": "NULLABLE", 
+        "name": "core_http2_initiate_write_due_to_close_from_api", 
+        "type": "INTEGER"
+      }, 
+      {
+        "mode": "NULLABLE", 
+        "name": "core_http2_initiate_write_due_to_stream_flow_control", 
+        "type": "INTEGER"
+      }, 
+      {
+        "mode": "NULLABLE", 
+        "name": "core_http2_initiate_write_due_to_transport_flow_control", 
+        "type": "INTEGER"
+      }, 
+      {
+        "mode": "NULLABLE", 
+        "name": "core_http2_initiate_write_due_to_send_settings", 
+        "type": "INTEGER"
+      }, 
+      {
+        "mode": "NULLABLE", 
+        "name": "core_http2_initiate_write_due_to_bdp_estimator_ping", 
+        "type": "INTEGER"
+      }, 
+      {
+        "mode": "NULLABLE", 
+        "name": "core_http2_initiate_write_due_to_flow_control_unstalled_by_setting", 
+        "type": "INTEGER"
+      }, 
+      {
+        "mode": "NULLABLE", 
+        "name": "core_http2_initiate_write_due_to_flow_control_unstalled_by_update", 
+        "type": "INTEGER"
+      }, 
+      {
+        "mode": "NULLABLE", 
+        "name": "core_http2_initiate_write_due_to_application_ping", 
+        "type": "INTEGER"
+      }, 
+      {
+        "mode": "NULLABLE", 
+        "name": "core_http2_initiate_write_due_to_keepalive_ping", 
+        "type": "INTEGER"
+      }, 
+      {
+        "mode": "NULLABLE", 
+        "name": "core_http2_initiate_write_due_to_transport_flow_control_unstalled", 
+        "type": "INTEGER"
+      }, 
+      {
+        "mode": "NULLABLE", 
+        "name": "core_http2_initiate_write_due_to_ping_response", 
+        "type": "INTEGER"
+      }, 
+      {
+        "mode": "NULLABLE", 
+        "name": "core_http2_initiate_write_due_to_force_rst_stream", 
+        "type": "INTEGER"
+      }, 
       {
         "mode": "NULLABLE", 
         "name": "core_combiner_locks_initiated", 
@@ -597,6 +722,26 @@
         "name": "core_server_calls_created", 
         "type": "INTEGER"
       }, 
+      {
+        "mode": "NULLABLE", 
+        "name": "core_cqs_created", 
+        "type": "INTEGER"
+      }, 
+      {
+        "mode": "NULLABLE", 
+        "name": "core_client_channels_created", 
+        "type": "INTEGER"
+      }, 
+      {
+        "mode": "NULLABLE", 
+        "name": "core_client_subchannels_created", 
+        "type": "INTEGER"
+      }, 
+      {
+        "mode": "NULLABLE", 
+        "name": "core_server_channels_created", 
+        "type": "INTEGER"
+      }, 
       {
         "mode": "NULLABLE", 
         "name": "core_syscall_poll", 
@@ -702,6 +847,111 @@
         "name": "core_http2_partial_writes", 
         "type": "INTEGER"
       }, 
+      {
+        "mode": "NULLABLE", 
+        "name": "core_http2_initiate_write_due_to_initial_write", 
+        "type": "INTEGER"
+      }, 
+      {
+        "mode": "NULLABLE", 
+        "name": "core_http2_initiate_write_due_to_start_new_stream", 
+        "type": "INTEGER"
+      }, 
+      {
+        "mode": "NULLABLE", 
+        "name": "core_http2_initiate_write_due_to_send_message", 
+        "type": "INTEGER"
+      }, 
+      {
+        "mode": "NULLABLE", 
+        "name": "core_http2_initiate_write_due_to_send_initial_metadata", 
+        "type": "INTEGER"
+      }, 
+      {
+        "mode": "NULLABLE", 
+        "name": "core_http2_initiate_write_due_to_send_trailing_metadata", 
+        "type": "INTEGER"
+      }, 
+      {
+        "mode": "NULLABLE", 
+        "name": "core_http2_initiate_write_due_to_retry_send_ping", 
+        "type": "INTEGER"
+      }, 
+      {
+        "mode": "NULLABLE", 
+        "name": "core_http2_initiate_write_due_to_continue_pings", 
+        "type": "INTEGER"
+      }, 
+      {
+        "mode": "NULLABLE", 
+        "name": "core_http2_initiate_write_due_to_goaway_sent", 
+        "type": "INTEGER"
+      }, 
+      {
+        "mode": "NULLABLE", 
+        "name": "core_http2_initiate_write_due_to_rst_stream", 
+        "type": "INTEGER"
+      }, 
+      {
+        "mode": "NULLABLE", 
+        "name": "core_http2_initiate_write_due_to_close_from_api", 
+        "type": "INTEGER"
+      }, 
+      {
+        "mode": "NULLABLE", 
+        "name": "core_http2_initiate_write_due_to_stream_flow_control", 
+        "type": "INTEGER"
+      }, 
+      {
+        "mode": "NULLABLE", 
+        "name": "core_http2_initiate_write_due_to_transport_flow_control", 
+        "type": "INTEGER"
+      }, 
+      {
+        "mode": "NULLABLE", 
+        "name": "core_http2_initiate_write_due_to_send_settings", 
+        "type": "INTEGER"
+      }, 
+      {
+        "mode": "NULLABLE", 
+        "name": "core_http2_initiate_write_due_to_bdp_estimator_ping", 
+        "type": "INTEGER"
+      }, 
+      {
+        "mode": "NULLABLE", 
+        "name": "core_http2_initiate_write_due_to_flow_control_unstalled_by_setting", 
+        "type": "INTEGER"
+      }, 
+      {
+        "mode": "NULLABLE", 
+        "name": "core_http2_initiate_write_due_to_flow_control_unstalled_by_update", 
+        "type": "INTEGER"
+      }, 
+      {
+        "mode": "NULLABLE", 
+        "name": "core_http2_initiate_write_due_to_application_ping", 
+        "type": "INTEGER"
+      }, 
+      {
+        "mode": "NULLABLE", 
+        "name": "core_http2_initiate_write_due_to_keepalive_ping", 
+        "type": "INTEGER"
+      }, 
+      {
+        "mode": "NULLABLE", 
+        "name": "core_http2_initiate_write_due_to_transport_flow_control_unstalled", 
+        "type": "INTEGER"
+      }, 
+      {
+        "mode": "NULLABLE", 
+        "name": "core_http2_initiate_write_due_to_ping_response", 
+        "type": "INTEGER"
+      }, 
+      {
+        "mode": "NULLABLE", 
+        "name": "core_http2_initiate_write_due_to_force_rst_stream", 
+        "type": "INTEGER"
+      }, 
       {
         "mode": "NULLABLE", 
         "name": "core_combiner_locks_initiated", 

From 1c87515f8da87dd96182dc3070029599b0a7165f Mon Sep 17 00:00:00 2001
From: ZhouyihaiDing <ddyihai@google.com>
Date: Mon, 11 Sep 2017 16:11:46 -0700
Subject: [PATCH 10/12] add php extension

---
 src/ruby/qps/proxy-worker.rb | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/ruby/qps/proxy-worker.rb b/src/ruby/qps/proxy-worker.rb
index d7a9f114bdb..488610ae74d 100755
--- a/src/ruby/qps/proxy-worker.rb
+++ b/src/ruby/qps/proxy-worker.rb
@@ -41,7 +41,7 @@ class ProxyBenchmarkClientServiceImpl < Grpc::Testing::ProxyClientService::Servi
     @histogram = Histogram.new(@histres, @histmax)
     @start_time = Time.now
     # TODO(vjpai): Support multiple client channels by spawning off a PHP client per channel
-    command = "php " + File.expand_path(File.dirname(__FILE__)) + "/../../php/tests/qps/client.php " + @mytarget
+    command = "php -d extension=" + File.expand_path(File.dirname(__FILE__)) + "/../../php/ext/grpc/modules/grpc.so " + File.expand_path(File.dirname(__FILE__)) + "/../../php/tests/qps/client.php " + @mytarget
     puts "Starting command: " + command
     @php_pid = spawn(command)
   end

From 3ad5c74311b6f603ed590c5330ac71d3387c7710 Mon Sep 17 00:00:00 2001
From: Craig Tiller <ctiller@google.com>
Date: Thu, 14 Sep 2017 11:29:30 -0700
Subject: [PATCH 11/12] Fix errant change

---
 src/core/ext/transport/chttp2/transport/chttp2_transport.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/src/core/ext/transport/chttp2/transport/chttp2_transport.c b/src/core/ext/transport/chttp2/transport/chttp2_transport.c
index 7e392b6d630..79a9ed827f7 100644
--- a/src/core/ext/transport/chttp2/transport/chttp2_transport.c
+++ b/src/core/ext/transport/chttp2/transport/chttp2_transport.c
@@ -3006,7 +3006,8 @@ grpc_chttp2_incoming_byte_stream *grpc_chttp2_incoming_byte_stream_create(
     grpc_exec_ctx *exec_ctx, grpc_chttp2_transport *t, grpc_chttp2_stream *s,
     uint32_t frame_size, uint32_t flags) {
   grpc_chttp2_incoming_byte_stream *incoming_byte_stream =
-      gpr_malloc(sizeof(*incoming_byte_stream));
+      (grpc_chttp2_incoming_byte_stream *)gpr_malloc(
+          sizeof(*incoming_byte_stream));
   incoming_byte_stream->base.length = frame_size;
   incoming_byte_stream->remaining_bytes = frame_size;
   incoming_byte_stream->base.flags = flags;

From 9fa10cce9ffe2689174af7b69940c8c2f2b51d0f Mon Sep 17 00:00:00 2001
From: Ken Payson <kpayson@google.com>
Date: Thu, 14 Sep 2017 11:49:52 -0700
Subject: [PATCH 12/12] Fix merge issue

---
 src/core/ext/filters/client_channel/lb_policy/grpclb/grpclb.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/src/core/ext/filters/client_channel/lb_policy/grpclb/grpclb.c b/src/core/ext/filters/client_channel/lb_policy/grpclb/grpclb.c
index 707fc293adb..a776a07d99a 100644
--- a/src/core/ext/filters/client_channel/lb_policy/grpclb/grpclb.c
+++ b/src/core/ext/filters/client_channel/lb_policy/grpclb/grpclb.c
@@ -1857,6 +1857,7 @@ static grpc_lb_policy *glb_create(grpc_exec_ctx *exec_ctx,
     gpr_free(glb_policy);
     return NULL;
   }
+  grpc_subchannel_index_ref();
   GRPC_CLOSURE_INIT(&glb_policy->lb_channel_on_connectivity_changed,
                     glb_lb_channel_on_connectivity_changed_cb, glb_policy,
                     grpc_combiner_scheduler(args->combiner));