@@ -15,11 +15,8 @@
  */
 package com.google.cloud.bigtable.data.v2.stub.metrics;
 
-import com.google.common.base.Stopwatch;
-import io.grpc.Attributes;
 import io.grpc.ClientStreamTracer;
 import io.grpc.Metadata;
-import java.util.concurrent.TimeUnit;
 
 /**
  * Records the time a request is enqueued in a grpc channel queue. This a bridge between gRPC stream
@@ -28,21 +25,15 @@
  */
 class BigtableGrpcStreamTracer extends ClientStreamTracer {
 
-  private final Stopwatch stopwatch = Stopwatch.createUnstarted();
   private final BigtableTracer tracer;
 
   public BigtableGrpcStreamTracer(BigtableTracer tracer) {
     this.tracer = tracer;
   }
 
-  @Override
-  public void streamCreated(Attributes transportAttrs, Metadata headers) {
-    stopwatch.start();
-  }
-
   @Override
   public void outboundMessageSent(int seqNo, long optionalWireSize, long optionalUncompressedSize) {
-    tracer.grpcChannelQueuedLatencies(stopwatch.elapsed(TimeUnit.NANOSECONDS));
+    tracer.grpcMessageSent();
   }
 
   static class Factory extends ClientStreamTracer.Factory {
 
@@ -83,7 +83,14 @@ public void setLocations(String zone, String cluster) {
     // noop
   }
 
+  @Deprecated
+  /** @deprecated {@link #grpcMessageSent()} is called instead. */
   public void grpcChannelQueuedLatencies(long queuedTimeMs) {
     // noop
   }
+
+  /** Called when the message is sent on a grpc channel. */
+  public void grpcMessageSent() {
+    // noop
+  }
 }
@@ -263,8 +263,8 @@ public void batchRequestThrottled(long throttledTimeNanos) {
   }
 
   @Override
-  public void grpcChannelQueuedLatencies(long queuedTimeNanos) {
-    totalClientBlockingTime.addAndGet(queuedTimeNanos);
+  public void grpcMessageSent() {
+    totalClientBlockingTime.addAndGet(attemptTimer.elapsed(TimeUnit.NANOSECONDS));
   }
 
   @Override
 
@@ -225,4 +225,11 @@ public void grpcChannelQueuedLatencies(long queuedTimeMs) {
       tracer.grpcChannelQueuedLatencies(queuedTimeMs);
     }
   }
+
+  @Override
+  public void grpcMessageSent() {
+    for (BigtableTracer tracer : bigtableTracers) {
+      tracer.grpcMessageSent();
+    }
+  }
 }
@@ -692,9 +692,8 @@ public void testQueuedOnChannelUnaryLatencies() {
             .put(CLIENT_NAME_KEY, CLIENT_NAME)
             .build();
 
-    long expected = CHANNEL_BLOCKING_LATENCY * 2 / 3;
     long actual = getAggregatedValue(clientLatency, attributes);
-    assertThat(actual).isAtLeast(expected);
+    assertThat(actual).isAtLeast(CHANNEL_BLOCKING_LATENCY);
   }
 
   @Test
 
@@ -258,4 +258,11 @@ public void testRequestBlockedOnChannel() {
     verify(child3, times(1)).grpcChannelQueuedLatencies(5L);
     verify(child4, times(1)).grpcChannelQueuedLatencies(5L);
   }
+
+  @Test
+  public void testGrpcMessageSent() {
+    compositeTracer.grpcMessageSent();
+    verify(child3, times(1)).grpcMessageSent();
+    verify(child4, times(1)).grpcMessageSent();
+  }
 }
Original file line number	Diff line number	Diff line change
`@@ -83,7 +83,14 @@ public void setLocations(String zone, String cluster) {`
`83`	`83`	`// noop`
`84`	`84`	`}`
`85`	`85`
	`86`	`+ @Deprecated`
	`87`	`+ /** @deprecated {@link #grpcMessageSent()} is called instead. */`
`86`	`88`	`public void grpcChannelQueuedLatencies(long queuedTimeMs) {`
`87`	`89`	`// noop`
`88`	`90`	`}`
	`91`	`+`
	`92`	`+ /** Called when the message is sent on a grpc channel. */`
	`93`	`+ public void grpcMessageSent() {`
	`94`	`+ // noop`
	`95`	`+ }`
`89`	`96`	`}`
Original file line number	Diff line number	Diff line change
`@@ -263,8 +263,8 @@ public void batchRequestThrottled(long throttledTimeNanos) {`
`263`	`263`	`}`
`264`	`264`
`265`	`265`	`@Override`
`266`		`- public void grpcChannelQueuedLatencies(long queuedTimeNanos) {`
`267`		`- totalClientBlockingTime.addAndGet(queuedTimeNanos);`
	`266`	`+ public void grpcMessageSent() {`
	`267`	`+ totalClientBlockingTime.addAndGet(attemptTimer.elapsed(TimeUnit.NANOSECONDS));`
`268`	`268`	`}`
`269`	`269`
`270`	`270`	`@Override`
Original file line number	Diff line number	Diff line change
`@@ -225,4 +225,11 @@ public void grpcChannelQueuedLatencies(long queuedTimeMs) {`
`225`	`225`	`tracer.grpcChannelQueuedLatencies(queuedTimeMs);`
`226`	`226`	`}`
`227`	`227`	`}`
	`228`	`+`
	`229`	`+ @Override`
	`230`	`+ public void grpcMessageSent() {`
	`231`	`+ for (BigtableTracer tracer : bigtableTracers) {`
	`232`	`+ tracer.grpcMessageSent();`
	`233`	`+ }`
	`234`	`+ }`
`228`	`235`	`}`
Original file line number	Diff line number	Diff line change
`@@ -692,9 +692,8 @@ public void testQueuedOnChannelUnaryLatencies() {`
`692`	`692`	`.put(CLIENT_NAME_KEY, CLIENT_NAME)`
`693`	`693`	`.build();`
`694`	`694`
`695`		`- long expected = CHANNEL_BLOCKING_LATENCY * 2 / 3;`
`696`	`695`	`long actual = getAggregatedValue(clientLatency, attributes);`
`697`		`- assertThat(actual).isAtLeast(expected);`
	`696`	`+ assertThat(actual).isAtLeast(CHANNEL_BLOCKING_LATENCY);`
`698`	`697`	`}`
`699`	`698`
`700`	`699`	`@Test`
Original file line number	Diff line number	Diff line change
`@@ -258,4 +258,11 @@ public void testRequestBlockedOnChannel() {`
`258`	`258`	`verify(child3, times(1)).grpcChannelQueuedLatencies(5L);`
`259`	`259`	`verify(child4, times(1)).grpcChannelQueuedLatencies(5L);`
`260`	`260`	`}`
	`261`	`+`
	`262`	`+ @Test`
	`263`	`+ public void testGrpcMessageSent() {`
	`264`	`+ compositeTracer.grpcMessageSent();`
	`265`	`+ verify(child3, times(1)).grpcMessageSent();`
	`266`	`+ verify(child4, times(1)).grpcMessageSent();`
	`267`	`+ }`
`261`	`268`	`}`