Fix: suggested changes

Author: AgraVator

api/src/main/java/io/grpc/NameResolver.java

@@ -561,9 +561,7 @@ public Builder toBuilder() {
       builder.setOverrideAuthority(overrideAuthority);
       builder.setMetricRecorder(metricRecorder);
       builder.setNameResolverRegistry(nameResolverRegistry);
-      if (channelConfigurator != null) {
-        builder.setChildChannelConfigurator(channelConfigurator);
-      }
+      builder.setChildChannelConfigurator(channelConfigurator);
       builder.customArgs = cloneCustomArgs(customArgs);
       return builder;
     }

xds/src/main/java/io/grpc/xds/GrpcXdsTransportFactory.java

@@ -185,6 +185,7 @@ public XdsStreamingCall(
                     .setType(MethodDescriptor.MethodType.BIDI_STREAMING)
                     .setRequestMarshaller(reqMarshaller)
                     .setResponseMarshaller(respMarshaller)
+                    .setSampledToLocalTracing(true)
                     .build(),
                 CallOptions.DEFAULT.withCallCredentials(
                     callCredentials)); // TODO(zivy): support waitForReady

xds/src/main/java/io/grpc/xds/client/XdsTransportFactory.java

@@ -31,6 +31,12 @@ public interface XdsTransportFactory {
    * Represents transport for xDS communication (e.g., a gRPC channel).
    */
   interface XdsTransport {
+    /**
+     * Creates a bidirectional streaming call.
+     *
+     * @param fullMethodName should be a constant/literal string so that metric recorders
+     *     like OpenTelemetry can record the exact method name.
+     */
     <ReqT, RespT> StreamingCall<ReqT, RespT> createStreamingCall(
          String fullMethodName, MethodDescriptor.Marshaller<ReqT> reqMarshaller,
          MethodDescriptor.Marshaller<RespT> respMarshaller);

xds/src/test/java/io/grpc/xds/FakeControlPlaneXdsIntegrationTest.java

@@ -73,7 +73,8 @@
 import java.net.InetSocketAddress;
 import java.util.Arrays;
 import java.util.List;
-import java.util.concurrent.atomic.AtomicInteger;
+import java.util.concurrent.CountDownLatch;
+import java.util.concurrent.TimeUnit;
 import org.junit.Before;
 import org.junit.Rule;
 import org.junit.Test;
@@ -427,25 +428,20 @@ public void childChannelConfigurator_passesMetricSinkToServer_E2E() throws Excep
   }
 
   private static final class CountingMetricSink extends NoopMetricSink {
-    private final AtomicInteger count =
-        new AtomicInteger();
+    private final CountDownLatch latch = new CountDownLatch(1);
 
     @Override
     public void addLongCounter(
         LongCounterMetricInstrument metricInstrument,
         long value,
         List<String> requiredLabelValues,
         List<String> optionalLabelValues) {
-      count.incrementAndGet();
+      latch.countDown();
     }
 
     public void awaitCall() throws InterruptedException {
-      long start = System.currentTimeMillis();
-      while (count.get() == 0) {
-        if (System.currentTimeMillis() - start > 5000) {
-          throw new AssertionError("Timed out waiting for metric sink call");
-        }
-        Thread.sleep(50);
+      if (!latch.await(5, TimeUnit.SECONDS)) {
+        throw new AssertionError("Timed out waiting for metric sink call");
       }
     }
   }

xds/src/test/java/io/grpc/xds/FakeControlPlaneXdsOtelIntegrationTest.java

@@ -35,6 +35,7 @@
 import io.opentelemetry.sdk.metrics.data.MetricData;
 import io.opentelemetry.sdk.testing.exporter.InMemoryMetricReader;
 import java.util.Arrays;
+import java.util.concurrent.TimeUnit;
 import org.junit.Before;
 import org.junit.Rule;
 import org.junit.Test;
@@ -118,22 +119,22 @@ public void configureChannelBuilder(ManagedChannelBuilder<?> builder) {
         SimpleServiceGrpc.newBlockingStub(channel);
     blockingStub.unaryRpc(SimpleRequest.getDefaultInstance());
 
+    // Shut down the channel to complete the RPC cycle.
+    channel.shutdownNow();
+    channel.awaitTermination(5, TimeUnit.SECONDS);
+
     // Verify that OpenTelemetry metrics specifically from the xDS Control Plane ADS stream
-    // successfully propagated, method name is recorded as 'other' because dynamic descriptors
-    // are not sampled to local tracing by default.
-    boolean foundXdsMetrics = false;
-    for (int i = 0; i < 50; i++) {
-      for (MetricData metric : metricReader.collectAllMetrics()) {
-        if (metric.toString().contains("grpc.client.") && metric.toString().contains("other")) {
-          foundXdsMetrics = true;
+    // successfully propagated, with the exact stream method name preserved.
+    boolean foundTargetMethod = false;
+    for (MetricData metric : metricReader.collectAllMetrics()) {
+      String name = metric.getName();
+      if ("grpc.client.attempt.started".equals(name) || "grpc.client.call.duration".equals(name)) {
+        if (metric.toString().contains("envoy.service.discovery.v3.AggregatedDiscoveryService")) {
+          foundTargetMethod = true;
           break;
         }
       }
-      if (foundXdsMetrics) {
-        break;
-      }
-      Thread.sleep(100);
     }
-    assertThat(foundXdsMetrics).isTrue();
+    assertThat(foundTargetMethod).isTrue();
   }
 }