[export]

Not needed, will delete later

----
DO NOT SUBMIT. This PR is for testing purposes only. [cl/625488709](http://cl/625488709)

PiperOrigin-RevId: 625488709

BUILD

@@ -4833,6 +4833,8 @@ grpc_cc_library(
         "//src/core:connectivity_state",
         "//src/core:error",
         "//src/core:error_utils",
+        "//src/core:event_engine_extensions",
+        "//src/core:event_engine_query_extensions",
         "//src/core:experiments",
         "//src/core:gpr_manual_constructor",
         "//src/core:http2_errors",

CMakeLists.txt

@@ -2256,6 +2256,7 @@ add_library(grpc
   src/core/lib/event_engine/default_event_engine.cc
   src/core/lib/event_engine/default_event_engine_factory.cc
   src/core/lib/event_engine/event_engine.cc
+  src/core/lib/event_engine/extensions/tcp_trace.cc
   src/core/lib/event_engine/forkable.cc
   src/core/lib/event_engine/posix_engine/ev_epoll1_linux.cc
   src/core/lib/event_engine/posix_engine/ev_poll_posix.cc
@@ -3049,6 +3050,7 @@ add_library(grpc_unsecure
   src/core/lib/event_engine/default_event_engine.cc
   src/core/lib/event_engine/default_event_engine_factory.cc
   src/core/lib/event_engine/event_engine.cc
+  src/core/lib/event_engine/extensions/tcp_trace.cc
   src/core/lib/event_engine/forkable.cc
   src/core/lib/event_engine/posix_engine/ev_epoll1_linux.cc
   src/core/lib/event_engine/posix_engine/ev_poll_posix.cc
@@ -5167,6 +5169,7 @@ add_library(grpc_authorization_provider
   src/core/lib/event_engine/default_event_engine.cc
   src/core/lib/event_engine/default_event_engine_factory.cc
   src/core/lib/event_engine/event_engine.cc
+  src/core/lib/event_engine/extensions/tcp_trace.cc
   src/core/lib/event_engine/forkable.cc
   src/core/lib/event_engine/posix_engine/ev_epoll1_linux.cc
   src/core/lib/event_engine/posix_engine/ev_poll_posix.cc
@@ -17796,6 +17799,7 @@ add_executable(interception_chain_test
   src/core/lib/event_engine/default_event_engine.cc
   src/core/lib/event_engine/default_event_engine_factory.cc
   src/core/lib/event_engine/event_engine.cc
+  src/core/lib/event_engine/extensions/tcp_trace.cc
   src/core/lib/event_engine/forkable.cc
   src/core/lib/event_engine/posix_engine/ev_epoll1_linux.cc
   src/core/lib/event_engine/posix_engine/ev_poll_posix.cc

Makefile

@@ -1099,6 +1099,7 @@ LIBGRPC_SRC = \
     src/core/lib/event_engine/default_event_engine.cc \
     src/core/lib/event_engine/default_event_engine_factory.cc \
     src/core/lib/event_engine/event_engine.cc \
+    src/core/lib/event_engine/extensions/tcp_trace.cc \
     src/core/lib/event_engine/forkable.cc \
     src/core/lib/event_engine/posix_engine/ev_epoll1_linux.cc \
     src/core/lib/event_engine/posix_engine/ev_poll_posix.cc \

Package.swift

@@ -1160,6 +1160,8 @@ let package = Package(
         "src/core/lib/event_engine/extensions/can_track_errors.h",
         "src/core/lib/event_engine/extensions/chaotic_good_extension.h",
         "src/core/lib/event_engine/extensions/supports_fd.h",
+        "src/core/lib/event_engine/extensions/tcp_trace.cc",
+        "src/core/lib/event_engine/extensions/tcp_trace.h",
         "src/core/lib/event_engine/forkable.cc",
         "src/core/lib/event_engine/forkable.h",
         "src/core/lib/event_engine/grpc_polled_fd.h",

build_autogenerated.yaml

@@ -830,6 +830,7 @@ libs:
   - src/core/lib/event_engine/extensions/can_track_errors.h
   - src/core/lib/event_engine/extensions/chaotic_good_extension.h
   - src/core/lib/event_engine/extensions/supports_fd.h
+  - src/core/lib/event_engine/extensions/tcp_trace.h
   - src/core/lib/event_engine/forkable.h
   - src/core/lib/event_engine/grpc_polled_fd.h
   - src/core/lib/event_engine/handle_containers.h
@@ -1677,6 +1678,7 @@ libs:
   - src/core/lib/event_engine/default_event_engine.cc
   - src/core/lib/event_engine/default_event_engine_factory.cc
   - src/core/lib/event_engine/event_engine.cc
+  - src/core/lib/event_engine/extensions/tcp_trace.cc
   - src/core/lib/event_engine/forkable.cc
   - src/core/lib/event_engine/posix_engine/ev_epoll1_linux.cc
   - src/core/lib/event_engine/posix_engine/ev_poll_posix.cc
@@ -2368,6 +2370,7 @@ libs:
   - src/core/lib/event_engine/extensions/can_track_errors.h
   - src/core/lib/event_engine/extensions/chaotic_good_extension.h
   - src/core/lib/event_engine/extensions/supports_fd.h
+  - src/core/lib/event_engine/extensions/tcp_trace.h
   - src/core/lib/event_engine/forkable.h
   - src/core/lib/event_engine/grpc_polled_fd.h
   - src/core/lib/event_engine/handle_containers.h
@@ -2830,6 +2833,7 @@ libs:
   - src/core/lib/event_engine/default_event_engine.cc
   - src/core/lib/event_engine/default_event_engine_factory.cc
   - src/core/lib/event_engine/event_engine.cc
+  - src/core/lib/event_engine/extensions/tcp_trace.cc
   - src/core/lib/event_engine/forkable.cc
   - src/core/lib/event_engine/posix_engine/ev_epoll1_linux.cc
   - src/core/lib/event_engine/posix_engine/ev_poll_posix.cc
@@ -4458,6 +4462,7 @@ libs:
   - src/core/lib/event_engine/extensions/can_track_errors.h
   - src/core/lib/event_engine/extensions/chaotic_good_extension.h
   - src/core/lib/event_engine/extensions/supports_fd.h
+  - src/core/lib/event_engine/extensions/tcp_trace.h
   - src/core/lib/event_engine/forkable.h
   - src/core/lib/event_engine/grpc_polled_fd.h
   - src/core/lib/event_engine/handle_containers.h
@@ -4796,6 +4801,7 @@ libs:
   - src/core/lib/event_engine/default_event_engine.cc
   - src/core/lib/event_engine/default_event_engine_factory.cc
   - src/core/lib/event_engine/event_engine.cc
+  - src/core/lib/event_engine/extensions/tcp_trace.cc
   - src/core/lib/event_engine/forkable.cc
   - src/core/lib/event_engine/posix_engine/ev_epoll1_linux.cc
   - src/core/lib/event_engine/posix_engine/ev_poll_posix.cc
@@ -11616,6 +11622,7 @@ targets:
   - src/core/lib/event_engine/extensions/can_track_errors.h
   - src/core/lib/event_engine/extensions/chaotic_good_extension.h
   - src/core/lib/event_engine/extensions/supports_fd.h
+  - src/core/lib/event_engine/extensions/tcp_trace.h
   - src/core/lib/event_engine/forkable.h
   - src/core/lib/event_engine/grpc_polled_fd.h
   - src/core/lib/event_engine/handle_containers.h
@@ -11923,6 +11930,7 @@ targets:
   - src/core/lib/event_engine/default_event_engine.cc
   - src/core/lib/event_engine/default_event_engine_factory.cc
   - src/core/lib/event_engine/event_engine.cc
+  - src/core/lib/event_engine/extensions/tcp_trace.cc
   - src/core/lib/event_engine/forkable.cc
   - src/core/lib/event_engine/posix_engine/ev_epoll1_linux.cc
   - src/core/lib/event_engine/posix_engine/ev_poll_posix.cc

config.m4

@@ -474,6 +474,7 @@ if test "$PHP_GRPC" != "no"; then
     src/core/lib/event_engine/default_event_engine.cc \
     src/core/lib/event_engine/default_event_engine_factory.cc \
     src/core/lib/event_engine/event_engine.cc \
+    src/core/lib/event_engine/extensions/tcp_trace.cc \
     src/core/lib/event_engine/forkable.cc \
     src/core/lib/event_engine/posix_engine/ev_epoll1_linux.cc \
     src/core/lib/event_engine/posix_engine/ev_poll_posix.cc \
@@ -1520,6 +1521,7 @@ if test "$PHP_GRPC" != "no"; then
   PHP_ADD_BUILD_DIR($ext_builddir/src/core/lib/debug)
   PHP_ADD_BUILD_DIR($ext_builddir/src/core/lib/event_engine)
   PHP_ADD_BUILD_DIR($ext_builddir/src/core/lib/event_engine/cf_engine)
+  PHP_ADD_BUILD_DIR($ext_builddir/src/core/lib/event_engine/extensions)
   PHP_ADD_BUILD_DIR($ext_builddir/src/core/lib/event_engine/posix_engine)
   PHP_ADD_BUILD_DIR($ext_builddir/src/core/lib/event_engine/thread_pool)
   PHP_ADD_BUILD_DIR($ext_builddir/src/core/lib/event_engine/thready_event_engine)

config.w32

@@ -439,6 +439,7 @@ if (PHP_GRPC != "no") {
     "src\\core\\lib\\event_engine\\default_event_engine.cc " +
     "src\\core\\lib\\event_engine\\default_event_engine_factory.cc " +
     "src\\core\\lib\\event_engine\\event_engine.cc " +
+    "src\\core\\lib\\event_engine\\extensions\\tcp_trace.cc " +
     "src\\core\\lib\\event_engine\\forkable.cc " +
     "src\\core\\lib\\event_engine\\posix_engine\\ev_epoll1_linux.cc " +
     "src\\core\\lib\\event_engine\\posix_engine\\ev_poll_posix.cc " +
@@ -1657,6 +1658,7 @@ if (PHP_GRPC != "no") {
   FSO.CreateFolder(base_dir+"\\ext\\grpc\\src\\core\\lib\\debug");
   FSO.CreateFolder(base_dir+"\\ext\\grpc\\src\\core\\lib\\event_engine");
   FSO.CreateFolder(base_dir+"\\ext\\grpc\\src\\core\\lib\\event_engine\\cf_engine");
+  FSO.CreateFolder(base_dir+"\\ext\\grpc\\src\\core\\lib\\event_engine\\extensions");
   FSO.CreateFolder(base_dir+"\\ext\\grpc\\src\\core\\lib\\event_engine\\posix_engine");
   FSO.CreateFolder(base_dir+"\\ext\\grpc\\src\\core\\lib\\event_engine\\thread_pool");
   FSO.CreateFolder(base_dir+"\\ext\\grpc\\src\\core\\lib\\event_engine\\thready_event_engine");

gRPC-C++.podspec

@@ -911,6 +911,7 @@ Pod::Spec.new do |s|
                       'src/core/lib/event_engine/extensions/can_track_errors.h',
                       'src/core/lib/event_engine/extensions/chaotic_good_extension.h',
                       'src/core/lib/event_engine/extensions/supports_fd.h',
+                      'src/core/lib/event_engine/extensions/tcp_trace.h',
                       'src/core/lib/event_engine/forkable.h',
                       'src/core/lib/event_engine/grpc_polled_fd.h',
                       'src/core/lib/event_engine/handle_containers.h',
@@ -2182,6 +2183,7 @@ Pod::Spec.new do |s|
                               'src/core/lib/event_engine/extensions/can_track_errors.h',
                               'src/core/lib/event_engine/extensions/chaotic_good_extension.h',
                               'src/core/lib/event_engine/extensions/supports_fd.h',
+                              'src/core/lib/event_engine/extensions/tcp_trace.h',
                               'src/core/lib/event_engine/forkable.h',
                               'src/core/lib/event_engine/grpc_polled_fd.h',
                               'src/core/lib/event_engine/handle_containers.h',

gRPC-Core.podspec

@@ -1279,6 +1279,8 @@ Pod::Spec.new do |s|
                       'src/core/lib/event_engine/extensions/can_track_errors.h',
                       'src/core/lib/event_engine/extensions/chaotic_good_extension.h',
                       'src/core/lib/event_engine/extensions/supports_fd.h',
+                      'src/core/lib/event_engine/extensions/tcp_trace.cc',
+                      'src/core/lib/event_engine/extensions/tcp_trace.h',
                       'src/core/lib/event_engine/forkable.cc',
                       'src/core/lib/event_engine/forkable.h',
                       'src/core/lib/event_engine/grpc_polled_fd.h',
@@ -2962,6 +2964,7 @@ Pod::Spec.new do |s|
                               'src/core/lib/event_engine/extensions/can_track_errors.h',
                               'src/core/lib/event_engine/extensions/chaotic_good_extension.h',
                               'src/core/lib/event_engine/extensions/supports_fd.h',
+                              'src/core/lib/event_engine/extensions/tcp_trace.h',
                               'src/core/lib/event_engine/forkable.h',
                               'src/core/lib/event_engine/grpc_polled_fd.h',
                               'src/core/lib/event_engine/handle_containers.h',

grpc.gemspec

@@ -1166,6 +1166,8 @@ Gem::Specification.new do |s|
   s.files += %w( src/core/lib/event_engine/extensions/can_track_errors.h )
   s.files += %w( src/core/lib/event_engine/extensions/chaotic_good_extension.h )
   s.files += %w( src/core/lib/event_engine/extensions/supports_fd.h )
+  s.files += %w( src/core/lib/event_engine/extensions/tcp_trace.cc )
+  s.files += %w( src/core/lib/event_engine/extensions/tcp_trace.h )
   s.files += %w( src/core/lib/event_engine/forkable.cc )
   s.files += %w( src/core/lib/event_engine/forkable.h )
   s.files += %w( src/core/lib/event_engine/grpc_polled_fd.h )

include/grpc/impl/channel_arg_names.h

@@ -259,6 +259,8 @@
   "grpc.experimental.tcp_tx_zerocopy_max_simultaneous_sends"
 /* Overrides the TCP socket recieve buffer size, SO_RCVBUF. */
 #define GRPC_ARG_TCP_RECEIVE_BUFFER_SIZE "grpc.tcp_receive_buffer_size"
+/** If non-zero, enable TCP tracing and stats collection. */
+#define GRPC_ARG_TCP_TRACING_ENABLED "grpc.tcp_tracing_enabled"
 /* 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"

package.xml

@@ -1148,6 +1148,8 @@
     <file baseinstalldir="/" name="src/core/lib/event_engine/extensions/can_track_errors.h" role="src" />
     <file baseinstalldir="/" name="src/core/lib/event_engine/extensions/chaotic_good_extension.h" role="src" />
     <file baseinstalldir="/" name="src/core/lib/event_engine/extensions/supports_fd.h" role="src" />
+    <file baseinstalldir="/" name="src/core/lib/event_engine/extensions/tcp_trace.cc" role="src" />
+    <file baseinstalldir="/" name="src/core/lib/event_engine/extensions/tcp_trace.h" role="src" />
     <file baseinstalldir="/" name="src/core/lib/event_engine/forkable.cc" role="src" />
     <file baseinstalldir="/" name="src/core/lib/event_engine/forkable.h" role="src" />
     <file baseinstalldir="/" name="src/core/lib/event_engine/grpc_polled_fd.h" role="src" />

src/core/BUILD

@@ -76,20 +76,27 @@ grpc_cc_library(
 
 grpc_cc_library(
     name = "event_engine_extensions",
+    srcs = ["lib/event_engine/extensions/tcp_trace.cc"],
     hdrs = [
         "lib/event_engine/extensions/can_track_errors.h",
         "lib/event_engine/extensions/chaotic_good_extension.h",
         "lib/event_engine/extensions/supports_fd.h",
+        "lib/event_engine/extensions/tcp_trace.h",
     ],
     external_deps = [
         "absl/status:statusor",
         "absl/functional:any_invocable",
         "absl/strings",
+        "absl/time",
+        "absl/types:optional",
     ],
     deps = [
         ":memory_quota",
+        ":metrics",
         "//:event_engine_base_hdrs",
+        "//:gpr",
         "//:gpr_platform",
+        "//:tcp_tracer",
     ],
 )
 

src/core/ext/transport/chttp2/transport/chttp2_transport.cc

@@ -79,6 +79,8 @@
 #include "src/core/lib/channel/tcp_tracer.h"
 #include "src/core/lib/debug/stats.h"
 #include "src/core/lib/debug/stats_data.h"
+#include "src/core/lib/event_engine/extensions/tcp_trace.h"
+#include "src/core/lib/event_engine/query_extensions.h"
 #include "src/core/lib/experiments/experiments.h"
 #include "src/core/lib/gpr/string.h"
 #include "src/core/lib/gpr/useful.h"
@@ -91,6 +93,7 @@
 #include "src/core/lib/http/parser.h"
 #include "src/core/lib/iomgr/combiner.h"
 #include "src/core/lib/iomgr/error.h"
+#include "src/core/lib/iomgr/event_engine_shims/endpoint.h"
 #include "src/core/lib/iomgr/exec_ctx.h"
 #include "src/core/lib/iomgr/iomgr_fwd.h"
 #include "src/core/lib/iomgr/port.h"
@@ -591,6 +594,10 @@ static void init_keepalive_pings_if_enabled_locked(
   }
 }
 
+using grpc_event_engine::experimental::Http2TransportTcpTracer;
+using grpc_event_engine::experimental::QueryExtension;
+using grpc_event_engine::experimental::TcpTraceExtension;
+
 grpc_chttp2_transport::grpc_chttp2_transport(
     const grpc_core::ChannelArgs& channel_args, grpc_endpoint* ep,
     bool is_client)
@@ -618,6 +625,18 @@ grpc_chttp2_transport::grpc_chttp2_transport(
       deframe_state(is_client ? GRPC_DTS_FH_0 : GRPC_DTS_CLIENT_PREFIX_0),
       is_client(is_client) {
   cl = new grpc_core::ContextList();
+
+  if (channel_args.GetBool(GRPC_ARG_TCP_TRACING_ENABLED).value_or(false) &&
+      grpc_event_engine::experimental::grpc_is_event_engine_endpoint(ep)) {
+    epte = QueryExtension<TcpTraceExtension>(
+        grpc_event_engine::experimental::grpc_get_wrapped_event_engine_endpoint(
+            ep));
+    if (epte != nullptr) {
+      tcp_tracer = std::make_shared<Http2TransportTcpTracer>();
+      epte->SetTcpTracer(tcp_tracer);
+    }
+  }
+
   CHECK(strlen(GRPC_CHTTP2_CLIENT_CONNECT_STRING) ==
         GRPC_CHTTP2_CLIENT_CONNECT_STRLEN);
 

src/core/ext/transport/chttp2/transport/internal.h

@@ -61,6 +61,7 @@
 #include "src/core/lib/channel/channel_args.h"
 #include "src/core/lib/channel/tcp_tracer.h"
 #include "src/core/lib/debug/trace.h"
+#include "src/core/lib/event_engine/extensions/tcp_trace.h"
 #include "src/core/lib/gprpp/bitset.h"
 #include "src/core/lib/gprpp/debug_location.h"
 #include "src/core/lib/gprpp/ref_counted.h"
@@ -535,6 +536,10 @@ struct grpc_chttp2_transport final : public grpc_core::FilterStackTransport,
   // What percentage of rst_stream frames on the server should cause a ping
   // frame to be generated.
   uint8_t ping_on_rst_stream_percent;
+
+  /// Only set when enabled.
+  grpc_event_engine::experimental::TcpTraceExtension* epte;
+  std::shared_ptr<grpc_core::TcpTracerInterface> tcp_tracer;
 };
 
 typedef enum {

src/core/lib/channel/metrics.h

@@ -40,6 +40,8 @@
 namespace grpc_core {
 
 constexpr absl::string_view kMetricLabelTarget = "grpc.target";
+constexpr absl::string_view kMetricLabelPeerAddress = "grpc.tcp.peer_address";
+constexpr absl::string_view kMetricLabelLocalAddress = "grpc.tcp.local_address";
 
 // A global registry of instruments(metrics). This API is designed to be used
 // to register instruments (Counter, Histogram, and Gauge) as part of program

src/core/lib/event_engine/extensions/tcp_trace.cc

@@ -0,0 +1,134 @@
+// Copyright 2024 gRPC authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#include "src/core/lib/event_engine/extensions/tcp_trace.h"
+
+#include "absl/strings/string_view.h"
+
+#include <grpc/support/metrics.h>
+
+#include "src/core/lib/channel/metrics.h"
+#include "src/core/lib/channel/tcp_tracer.h"
+#include "src/core/lib/gprpp/sync.h"
+
+namespace grpc_event_engine {
+namespace experimental {
+
+const auto kTCPConnectionMetricsMinRtt =
+    grpc_core::GlobalInstrumentsRegistry::RegisterDoubleHistogram(
+        "grpc.tcp.min_rtt",
+        "EXPERIMENTAL. Records TCP's current estimate of minimum round trip "
+        "time (RTT), typically used as an indication of the network health "
+        "between two endpoints.",
+        "{s}", /*enable_by_default=*/true)
+        .OptionalLabels(grpc_core::kMetricLabelPeerAddress,
+                        grpc_core::kMetricLabelLocalAddress)
+        .Build();
+
+const auto kTCPConnectionMetricsDeliveryRate =
+    grpc_core::GlobalInstrumentsRegistry::RegisterDoubleHistogram(
+        "grpc.tcp.delivery_rate",
+        "EXPERIMENTAL. Records latest throughput measured of the TCP "
+        "connection.",
+        "{bit/s}", /*enable_by_default=*/true)
+        .OptionalLabels(grpc_core::kMetricLabelPeerAddress,
+                        grpc_core::kMetricLabelLocalAddress)
+        .Build();
+
+const auto kTCPConnectionMetricsPacketSend =
+    grpc_core::GlobalInstrumentsRegistry::RegisterUInt64Counter(
+        "grpc.tcp.packets_sent",
+        "EXPERIMENTAL. Records total packets TCP sends in the calculation "
+        "period.",
+        "{packet}", /*enable_by_default=*/true)
+        .OptionalLabels(grpc_core::kMetricLabelPeerAddress,
+                        grpc_core::kMetricLabelLocalAddress)
+        .Build();
+
+const auto kTCPConnectionMetricsPacketRetx =
+    grpc_core::GlobalInstrumentsRegistry::RegisterUInt64Counter(
+        "grpc.tcp.packets_retransmitted",
+        "EXPERIMENTAL. Records total packets lost in the calculation period, "
+        "including lost or spuriously retransmitted packets.",
+        "{packet}", /*enable_by_default=*/true)
+        .OptionalLabels(grpc_core::kMetricLabelPeerAddress,
+                        grpc_core::kMetricLabelLocalAddress)
+        .Build();
+
+const auto kTCPConnectionMetricsPacketSpuriousRetx =
+    grpc_core::GlobalInstrumentsRegistry::RegisterUInt64Counter(
+        "grpc.tcp.packets_spurious_retransmitted",
+        "EXPERIMENTAL. Records total packets spuriously retransmitted packets "
+        "in the calculation period. These are retransmissions that TCP later "
+        "discovered unnecessary.",
+        "{packet}", /*enable_by_default=*/true)
+        .OptionalLabels(grpc_core::kMetricLabelPeerAddress,
+                        grpc_core::kMetricLabelLocalAddress)
+        .Build();
+
+void Http2TransportTcpTracer::RecordConnectionMetrics(
+    ConnectionMetrics metrics) {
+  // This will be called periodically by Fathom.
+  // For cumulative stats, compute and get deltas to stats plugins.
+  if (metrics.packet_sent.has_value() && metrics.packet_retx.has_value() &&
+      metrics.packet_spurious_retx.has_value()) {
+    grpc_core::MutexLock lock(&mu_);
+    int packet_sent = metrics.packet_sent.value() -
+                      connection_metrics_.packet_sent.value_or(0);
+    int packet_retx = metrics.packet_retx.value() -
+                      connection_metrics_.packet_retx.value_or(0);
+    int packet_spurious_retx =
+        metrics.packet_spurious_retx.value() -
+        connection_metrics_.packet_spurious_retx.value_or(0);
+    grpc_core::GlobalStatsPluginRegistry::GetStatsPluginsForChannel(
+        grpc_core::experimental::StatsPluginChannelScope("", ""))
+        .AddCounter(kTCPConnectionMetricsPacketSend, packet_sent, {},
+                    {grpc_core::kMetricLabelPeerAddress,
+                     grpc_core::kMetricLabelLocalAddress});
+    grpc_core::GlobalStatsPluginRegistry::GetStatsPluginsForChannel(
+        grpc_core::experimental::StatsPluginChannelScope("", ""))
+        .AddCounter(kTCPConnectionMetricsPacketRetx, packet_retx, {},
+                    {grpc_core::kMetricLabelPeerAddress,
+                     grpc_core::kMetricLabelLocalAddress});
+    grpc_core::GlobalStatsPluginRegistry::GetStatsPluginsForChannel(
+        grpc_core::experimental::StatsPluginChannelScope("", ""))
+        .AddCounter(kTCPConnectionMetricsPacketSpuriousRetx,
+                    packet_spurious_retx, {},
+                    {grpc_core::kMetricLabelPeerAddress,
+                     grpc_core::kMetricLabelLocalAddress});
+    connection_metrics_.packet_sent = metrics.packet_sent;
+    connection_metrics_.packet_retx = metrics.packet_retx;
+    connection_metrics_.packet_spurious_retx = metrics.packet_spurious_retx;
+  }
+  // For non-cumulative stats: Report to stats plugins.
+  if (metrics.min_rtt.has_value()) {
+    grpc_core::GlobalStatsPluginRegistry::GetStatsPluginsForChannel(
+        grpc_core::experimental::StatsPluginChannelScope("", ""))
+        .RecordHistogram(
+            kTCPConnectionMetricsMinRtt,
+            static_cast<float>(metrics.min_rtt.value()) / 1000000.0, {},
+            {grpc_core::kMetricLabelPeerAddress,
+             grpc_core::kMetricLabelLocalAddress});
+  }
+  if (metrics.delivery_rate.has_value()) {
+    grpc_core::GlobalStatsPluginRegistry::GetStatsPluginsForChannel(
+        grpc_core::experimental::StatsPluginChannelScope("", ""))
+        .RecordHistogram(kTCPConnectionMetricsDeliveryRate,
+                         metrics.delivery_rate.value(), {},
+                         {grpc_core::kMetricLabelPeerAddress,
+                          grpc_core::kMetricLabelLocalAddress});
+  }
+}
+}  // namespace experimental
+}  // namespace grpc_event_engine

src/core/lib/event_engine/extensions/tcp_trace.h

@@ -0,0 +1,58 @@
+// Copyright 2024 gRPC authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#ifndef GRPC_SRC_CORE_LIB_EVENT_ENGINE_EXTENSIONS_TCP_TRACE_H
+#define GRPC_SRC_CORE_LIB_EVENT_ENGINE_EXTENSIONS_TCP_TRACE_H
+
+#include <memory>
+
+#include "absl/strings/string_view.h"
+#include "absl/time/time.h"
+#include "absl/types/optional.h"
+
+#include "src/core/lib/channel/tcp_tracer.h"
+#include "src/core/lib/gprpp/sync.h"
+
+namespace grpc_event_engine {
+namespace experimental {
+
+class Http2TransportTcpTracer : public grpc_core::TcpTracerInterface {
+ public:
+  Http2TransportTcpTracer() {}
+  ~Http2TransportTcpTracer() override {}
+  // Records a per-message event, unused.
+  void RecordEvent(Type /*type*/, absl::Time /*time*/, size_t /*byte_offset*/,
+                   absl::optional<ConnectionMetrics> /*metrics*/) override {}
+  // Records per-connection metrics.
+  void RecordConnectionMetrics(ConnectionMetrics metrics) override;
+
+ private:
+  grpc_core::Mutex mu_;
+  ConnectionMetrics connection_metrics_ ABSL_GUARDED_BY(mu_);
+};
+
+class TcpTraceExtension {
+ public:
+  virtual ~TcpTraceExtension() = default;
+  static absl::string_view EndpointExtensionName() {
+    return "io.grpc.event_engine.extension.tcp_trace";
+  }
+  virtual void SetTcpTracer(
+      std::shared_ptr<grpc_core::TcpTracerInterface> tcp_tracer) = 0;
+};
+
+}  // namespace experimental
+}  // namespace grpc_event_engine
+
+#endif  // GRPC_SRC_CORE_LIB_EVENT_ENGINE_EXTENSIONS_TCP_TRACE_H

src/python/grpcio/grpc_core_dependencies.py

@@ -448,6 +448,7 @@ CORE_SOURCE_FILES = [
     'src/core/lib/event_engine/default_event_engine.cc',
     'src/core/lib/event_engine/default_event_engine_factory.cc',
     'src/core/lib/event_engine/event_engine.cc',
+    'src/core/lib/event_engine/extensions/tcp_trace.cc',
     'src/core/lib/event_engine/forkable.cc',
     'src/core/lib/event_engine/posix_engine/ev_epoll1_linux.cc',
     'src/core/lib/event_engine/posix_engine/ev_poll_posix.cc',

tools/doxygen/Doxyfile.c++.internal

@@ -2165,6 +2165,8 @@ src/core/lib/event_engine/event_engine_context.h \
 src/core/lib/event_engine/extensions/can_track_errors.h \
 src/core/lib/event_engine/extensions/chaotic_good_extension.h \
 src/core/lib/event_engine/extensions/supports_fd.h \
+src/core/lib/event_engine/extensions/tcp_trace.cc \
+src/core/lib/event_engine/extensions/tcp_trace.h \
 src/core/lib/event_engine/forkable.cc \
 src/core/lib/event_engine/forkable.h \
 src/core/lib/event_engine/grpc_polled_fd.h \

tools/doxygen/Doxyfile.core.internal

@@ -1937,6 +1937,8 @@ src/core/lib/event_engine/event_engine_context.h \
 src/core/lib/event_engine/extensions/can_track_errors.h \
 src/core/lib/event_engine/extensions/chaotic_good_extension.h \
 src/core/lib/event_engine/extensions/supports_fd.h \
+src/core/lib/event_engine/extensions/tcp_trace.cc \
+src/core/lib/event_engine/extensions/tcp_trace.h \
 src/core/lib/event_engine/forkable.cc \
 src/core/lib/event_engine/forkable.h \
 src/core/lib/event_engine/grpc_polled_fd.h \