[EventEngine] Enable the EventEngine DNS Resolver on Posix (#35573)

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Closes #35573

COPYBARA_INTEGRATE_REVIEW=https://github.com/grpc/grpc/pull/35573 from yijiem:enable-oss-ee-dns-posix-real 1df91d1d84
PiperOrigin-RevId: 609193851

bazel/experiments.bzl

@@ -204,9 +204,6 @@ EXPERIMENTS = {
         "dbg": {
         },
         "off": {
-            "cancel_ares_query_test": [
-                "event_engine_dns",
-            ],
             "compression_test": [
                 "v3_compression_filter",
             ],
@@ -244,9 +241,6 @@ EXPERIMENTS = {
             "logging_test": [
                 "promise_based_server_call",
             ],
-            "resolver_component_tests_runner_invoker": [
-                "event_engine_dns",
-            ],
             "resource_quota_test": [
                 "free_large_allocator",
                 "unconstrained_max_quota_buffer_size",
@@ -257,6 +251,9 @@ EXPERIMENTS = {
             ],
         },
         "on": {
+            "cancel_ares_query_test": [
+                "event_engine_dns",
+            ],
             "core_end2end_test": [
                 "event_engine_listener",
             ],
@@ -276,6 +273,9 @@ EXPERIMENTS = {
                 "round_robin_delegate_to_pick_first",
                 "wrr_delegate_to_pick_first",
             ],
+            "resolver_component_tests_runner_invoker": [
+                "event_engine_dns",
+            ],
             "surface_registered_method_lookup": [
                 "registered_method_lookup_in_transport",
             ],

src/core/lib/experiments/experiments.cc

@@ -719,7 +719,7 @@ const ExperimentMetadata g_experiment_metadata[] = {
     {"event_engine_client", description_event_engine_client,
      additional_constraints_event_engine_client, nullptr, 0, false, true},
     {"event_engine_dns", description_event_engine_dns,
-     additional_constraints_event_engine_dns, nullptr, 0, false, false},
+     additional_constraints_event_engine_dns, nullptr, 0, true, false},
     {"event_engine_listener", description_event_engine_listener,
      additional_constraints_event_engine_listener, nullptr, 0, true, true},
     {"free_large_allocator", description_free_large_allocator,

src/core/lib/experiments/experiments.h

@@ -194,7 +194,8 @@ inline bool IsCanaryClientPrivacyEnabled() { return false; }
 inline bool IsClientIdlenessEnabled() { return true; }
 inline bool IsClientPrivacyEnabled() { return false; }
 inline bool IsEventEngineClientEnabled() { return false; }
-inline bool IsEventEngineDnsEnabled() { return false; }
+#define GRPC_EXPERIMENT_IS_INCLUDED_EVENT_ENGINE_DNS
+inline bool IsEventEngineDnsEnabled() { return true; }
 #define GRPC_EXPERIMENT_IS_INCLUDED_EVENT_ENGINE_LISTENER
 inline bool IsEventEngineListenerEnabled() { return true; }
 inline bool IsFreeLargeAllocatorEnabled() { return false; }

src/core/lib/experiments/rollouts.yaml

@@ -69,7 +69,7 @@
   default:
     # not tested on iOS at all
     ios: broken
-    posix: false
+    posix: true
     # TODO(yijiem): resolve when the WindowsEventEngine DNS Resolver is
     # implemented
     windows: broken

test/core/end2end/tests/cancel_after_invoke.cc

@@ -23,6 +23,7 @@
 
 #include <grpc/status.h>
 
+#include "src/core/ext/transport/chttp2/transport/internal.h"
 #include "src/core/lib/gprpp/time.h"
 #include "test/core/end2end/end2end_tests.h"
 #include "test/core/end2end/tests/cancel_test_helpers.h"
@@ -36,6 +37,8 @@ const Duration kDeadlineTimeout = Duration::Seconds(2);
 void CancelAfterInvoke6(CoreEnd2endTest& test,
                         std::unique_ptr<CancellationMode> mode,
                         Duration timeout) {
+  test.InitClient(ChannelArgs());
+  test.InitServer(ChannelArgs().Set(GRPC_ARG_PING_TIMEOUT_MS, 5000));
   auto c = test.NewClientCall("/service/method").Timeout(timeout).Create();
   CoreEnd2endTest::IncomingStatusOnClient server_status;
   CoreEnd2endTest::IncomingMetadata server_initial_metadata;
@@ -57,6 +60,8 @@ void CancelAfterInvoke6(CoreEnd2endTest& test,
 void CancelAfterInvoke5(CoreEnd2endTest& test,
                         std::unique_ptr<CancellationMode> mode,
                         Duration timeout) {
+  test.InitClient(ChannelArgs());
+  test.InitServer(ChannelArgs().Set(GRPC_ARG_PING_TIMEOUT_MS, 5000));
   auto c = test.NewClientCall("/service/method").Timeout(timeout).Create();
   CoreEnd2endTest::IncomingStatusOnClient server_status;
   CoreEnd2endTest::IncomingMetadata server_initial_metadata;

test/core/end2end/tests/cancel_with_status.cc

@@ -24,6 +24,7 @@
 #include <grpc/support/alloc.h>
 #include <grpc/support/string_util.h>
 
+#include "src/core/ext/transport/chttp2/transport/internal.h"
 #include "src/core/lib/gprpp/time.h"
 #include "test/core/end2end/end2end_tests.h"
 
@@ -64,6 +65,8 @@ CORE_END2END_TEST(CoreEnd2endTest, CancelWithStatus2) {
 }
 
 CORE_END2END_TEST(CoreEnd2endTest, CancelWithStatus3) {
+  InitClient(ChannelArgs());
+  InitServer(ChannelArgs().Set(GRPC_ARG_PING_TIMEOUT_MS, 5000));
   auto c = NewClientCall("/foo").Timeout(Duration::Minutes(1)).Create();
   CoreEnd2endTest::IncomingMetadata server_initial_metadata;
   CoreEnd2endTest::IncomingStatusOnClient server_status;
@@ -83,6 +86,8 @@ CORE_END2END_TEST(CoreEnd2endTest, CancelWithStatus3) {
 }
 
 CORE_END2END_TEST(CoreEnd2endTest, CancelWithStatus4) {
+  InitClient(ChannelArgs());
+  InitServer(ChannelArgs().Set(GRPC_ARG_PING_TIMEOUT_MS, 5000));
   auto c = NewClientCall("/foo").Timeout(Duration::Minutes(1)).Create();
   CoreEnd2endTest::IncomingMetadata server_initial_metadata;
   CoreEnd2endTest::IncomingStatusOnClient server_status;

test/cpp/ext/filters/census/stats_plugin_end2end_test.cc

@@ -32,6 +32,7 @@
 #include <grpc++/grpc++.h>
 #include <grpcpp/opencensus.h>
 
+#include "src/core/lib/experiments/experiments.h"
 #include "src/cpp/ext/filters/census/context.h"
 #include "src/cpp/ext/filters/census/grpc_plugin.h"
 #include "src/cpp/ext/filters/census/open_census_call_tracer.h"
@@ -662,8 +663,14 @@ TEST_F(StatsPluginEnd2EndTest,
   auto sent_span_data =
       GetSpanByName(recorded_spans, absl::StrCat("Sent.", client_method_name_));
   ASSERT_NE(sent_span_data, recorded_spans.end());
-  EXPECT_TRUE(
-      IsAnnotationPresent(sent_span_data, "Delayed name resolution complete."));
+  // TODO(yijiem): the EventEngine DNS resolver might be faster in getting the
+  // result before TryCheckResolution and the call would not be queued:
+  // https://github.com/grpc/grpc/blob/master/src/core/ext/filters/client_channel/client_channel.cc#L2340.
+  // We could use a FakeResolver and introduce a delay to deflake this test.
+  if (!grpc_core::IsEventEngineDnsEnabled()) {
+    EXPECT_TRUE(IsAnnotationPresent(sent_span_data,
+                                    "Delayed name resolution complete."));
+  }
   // Check presence of trace annotation for removal from channel's pending
   // lb pick queue.
   auto attempt_span_data = GetSpanByName(