Stabilize call tracer transport fix experiment (grpc#39465)

yashykt · copybara-github · commit 66ef4ca71dd0 · 2025-05-05T13:46:44.000-07:00
Closes grpc#39465 COPYBARA_INTEGRATE_REVIEW=grpc#39465 from yashykt:RemoveCallTracerTransportFix 2f338a5 PiperOrigin-RevId: 755058234
diff --git a/bazel/experiments.bzl b/bazel/experiments.bzl
diff --git a/src/core/ext/transport/chttp2/transport/chttp2_transport.cc b/src/core/ext/transport/chttp2/transport/chttp2_transport.cc
@@ -1478,22 +1478,12 @@ static void log_metadata(const grpc_metadata_batch* md_batch, uint32_t id,
 }
 
 static void trace_annotations(grpc_chttp2_stream* s) {
-  if (!grpc_core::IsCallTracerTransportFixEnabled()) {
-    if (s->parent_call_tracer != nullptr) {
-      s->parent_call_tracer->RecordAnnotation(
-          grpc_core::HttpAnnotation(grpc_core::HttpAnnotation::Type::kStart,
-                                    gpr_now(GPR_CLOCK_REALTIME))
-              .Add(s->t->flow_control.stats())
-              .Add(s->flow_control.stats()));
-    }
-  } else {
-    if (s->call_tracer != nullptr && s->call_tracer->IsSampled()) {
-      s->call_tracer->RecordAnnotation(
-          grpc_core::HttpAnnotation(grpc_core::HttpAnnotation::Type::kStart,
-                                    gpr_now(GPR_CLOCK_REALTIME))
-              .Add(s->t->flow_control.stats())
-              .Add(s->flow_control.stats()));
-    }
+  if (s->call_tracer != nullptr && s->call_tracer->IsSampled()) {
+    s->call_tracer->RecordAnnotation(
+        grpc_core::HttpAnnotation(grpc_core::HttpAnnotation::Type::kStart,
+                                  gpr_now(GPR_CLOCK_REALTIME))
+            .Add(s->t->flow_control.stats())
+            .Add(s->flow_control.stats()));
   }
 }
 
@@ -1742,9 +1732,6 @@ static void perform_stream_op_locked(void* stream_op,
   grpc_chttp2_transport* t = s->t.get();
 
   s->traced = op->is_traced;
-  if (!grpc_core::IsCallTracerTransportFixEnabled()) {
-    s->parent_call_tracer = ParentCallTracerIfSampled(s);
-  }
   // Some server filters populate CallTracerInterface in the context only after
   // reading initial metadata. (Client-side population is done by
   // client_channel filter.)
diff --git a/src/core/ext/transport/chttp2/transport/parsing.cc b/src/core/ext/transport/chttp2/transport/parsing.cc
@@ -981,10 +981,7 @@ grpc_error_handle grpc_chttp2_header_parser_parse(void* hpack_parser,
   if (s != nullptr) {
     s->call_tracer_wrapper.RecordIncomingBytes(
         {0, 0, GRPC_SLICE_LENGTH(slice)});
-    call_tracer =
-        grpc_core::IsCallTracerTransportFixEnabled()
-            ? s->call_tracer
-            : s->arena->GetContext<grpc_core::CallTracerAnnotationInterface>();
+    call_tracer = s->call_tracer;
   }
   grpc_core::SharedBitGen g;
   grpc_error_handle error =
diff --git a/src/core/ext/transport/chttp2/transport/writing.cc b/src/core/ext/transport/chttp2/transport/writing.cc
@@ -491,30 +491,16 @@ class StreamWriteContext {
     grpc_chttp2_complete_closure_step(t_, &s_->send_initial_metadata_finished,
                                       absl::OkStatus(),
                                       "send_initial_metadata_finished");
-    if (!grpc_core::IsCallTracerTransportFixEnabled()) {
-      if (s_->parent_call_tracer != nullptr) {
-        grpc_core::HttpAnnotation::WriteStats write_stats;
-        write_stats.target_write_size = write_context_->target_write_size();
-        s_->parent_call_tracer->RecordAnnotation(
-            grpc_core::HttpAnnotation(
-                grpc_core::HttpAnnotation::Type::kHeadWritten,
-                gpr_now(GPR_CLOCK_REALTIME))
-                .Add(s_->t->flow_control.stats())
-                .Add(s_->flow_control.stats())
-                .Add(write_stats));
-      }
-    } else {
-      if (s_->call_tracer != nullptr && s_->call_tracer->IsSampled()) {
-        grpc_core::HttpAnnotation::WriteStats write_stats;
-        write_stats.target_write_size = write_context_->target_write_size();
-        s_->call_tracer->RecordAnnotation(
-            grpc_core::HttpAnnotation(
-                grpc_core::HttpAnnotation::Type::kHeadWritten,
-                gpr_now(GPR_CLOCK_REALTIME))
-                .Add(s_->t->flow_control.stats())
-                .Add(s_->flow_control.stats())
-                .Add(write_stats));
-      }
+    if (s_->call_tracer != nullptr && s_->call_tracer->IsSampled()) {
+      grpc_core::HttpAnnotation::WriteStats write_stats;
+      write_stats.target_write_size = write_context_->target_write_size();
+      s_->call_tracer->RecordAnnotation(
+          grpc_core::HttpAnnotation(
+              grpc_core::HttpAnnotation::Type::kHeadWritten,
+              gpr_now(GPR_CLOCK_REALTIME))
+              .Add(s_->t->flow_control.stats())
+              .Add(s_->flow_control.stats())
+              .Add(write_stats));
     }
   }
 
@@ -670,22 +656,12 @@ class StreamWriteContext {
     }
     grpc_chttp2_mark_stream_closed(t_, s_, !t_->is_client, true,
                                    absl::OkStatus());
-    if (!grpc_core::IsCallTracerTransportFixEnabled()) {
-      if (s_->parent_call_tracer != nullptr) {
-        s_->parent_call_tracer->RecordAnnotation(
-            grpc_core::HttpAnnotation(grpc_core::HttpAnnotation::Type::kEnd,
-                                      gpr_now(GPR_CLOCK_REALTIME))
-                .Add(s_->t->flow_control.stats())
-                .Add(s_->flow_control.stats()));
-      }
-    } else {
-      if (s_->call_tracer != nullptr && s_->call_tracer->IsSampled()) {
-        s_->call_tracer->RecordAnnotation(
-            grpc_core::HttpAnnotation(grpc_core::HttpAnnotation::Type::kEnd,
-                                      gpr_now(GPR_CLOCK_REALTIME))
-                .Add(s_->t->flow_control.stats())
-                .Add(s_->flow_control.stats()));
-      }
+    if (s_->call_tracer != nullptr && s_->call_tracer->IsSampled()) {
+      s_->call_tracer->RecordAnnotation(
+          grpc_core::HttpAnnotation(grpc_core::HttpAnnotation::Type::kEnd,
+                                    gpr_now(GPR_CLOCK_REALTIME))
+              .Add(s_->t->flow_control.stats())
+              .Add(s_->flow_control.stats()));
     }
   }
 
diff --git a/src/core/lib/experiments/experiments.cc b/src/core/lib/experiments/experiments.cc
diff --git a/src/core/lib/experiments/experiments.h b/src/core/lib/experiments/experiments.h
diff --git a/src/core/lib/experiments/experiments.yaml b/src/core/lib/experiments/experiments.yaml
@@ -51,11 +51,6 @@
   owner: roth@google.com
   test_tags: []
   allow_in_fuzzing_config: false
-- name: call_tracer_transport_fix
-  description: Use the correct call tracer in transport
-  expiry: 2025/06/01
-  owner: yashkt@google.com
-  test_tags: []
 - name: callv3_client_auth_filter
   description: Use the CallV3 client auth filter.
   expiry: 2025/06/01
diff --git a/src/core/lib/experiments/rollouts.yaml b/src/core/lib/experiments/rollouts.yaml
@@ -44,8 +44,6 @@
   default: true
 - name: call_tracer_in_transport
   default: true
-- name: call_tracer_transport_fix
-  default: true
 - name: chaotic_good_framing_layer
   default: true
 - name: error_flatten
diff --git a/test/cpp/ext/filters/census/stats_plugin_end2end_test.cc b/test/cpp/ext/filters/census/stats_plugin_end2end_test.cc
@@ -813,10 +813,7 @@ TEST_F(StatsPluginEnd2EndTest, TestMetadataSizeAnnotations) {
   traces_recorder_->StopRecording();
   // Check presence of metadata size annotations in client span.
   auto sent_span_data = GetSpanByName(
-      recorded_spans,
-      absl::StrCat(
-          grpc_core::IsCallTracerTransportFixEnabled() ? "Attempt." : "Sent.",
-          client_method_name_));
+      recorded_spans, absl::StrCat("Attempt.", client_method_name_));
   ASSERT_NE(sent_span_data, recorded_spans.end());
   EXPECT_TRUE(IsAnnotationPresent(
       sent_span_data,
@@ -856,10 +853,7 @@ TEST_F(StatsPluginEnd2EndTest, TestHttpAnnotations) {
   auto recorded_spans = traces_recorder_->GetAndClearSpans(3);
   traces_recorder_->StopRecording();
   auto client_span_data = GetSpanByName(
-      recorded_spans,
-      absl::StrCat(
-          grpc_core::IsCallTracerTransportFixEnabled() ? "Attempt." : "Sent.",
-          client_method_name_));
+      recorded_spans, absl::StrCat("Attempt.", client_method_name_));
   ASSERT_NE(client_span_data, recorded_spans.end());
   EXPECT_TRUE(IsAnnotationPresent(client_span_data,
                                   "HttpAnnotation type: Start time: .* "
