fix(bigtable): Use a different t4t7 latencies for directpath

google-cloud-bigtable/src/main/java/com/google/cloud/bigtable/data/v2/internal/csm/tracers/BigtableGrpcStreamTracer.java

@@ -36,6 +36,16 @@ public void outboundMessageSent(int seqNo, long optionalWireSize, long optionalU
     tracer.grpcMessageSent();
   }
 
+  @Override
+  public void outboundHeaders() {
+    tracer.grpcHeadersSent();
+  }
+
+  @Override
+  public void inboundHeaders() {
+    tracer.grpcHeadersReceived();
+  }
+
   static class Factory extends ClientStreamTracer.Factory {
 
     private final BigtableTracer tracer;

google-cloud-bigtable/src/main/java/com/google/cloud/bigtable/data/v2/internal/csm/tracers/BuiltinMetricsTracer.java

@@ -87,6 +87,7 @@ class BuiltinMetricsTracer extends BigtableTracer {
   private volatile Duration remainingDeadlineAtAttemptStart = Duration.ZERO;
 
   private volatile MetadataExtractorInterceptor.SidebandData sidebandData = new SidebandData();
+  private volatile Optional<Stopwatch> faket4t7 = Optional.empty();
 
   BuiltinMetricsTracer(
       MetricRegistry.RecorderRegistry recorder, ClientInfo clientInfo, MethodInfo methodInfo) {
@@ -263,6 +264,16 @@ public void grpcMessageSent() {
     grpcMessageSentDelay.set(attemptTimer.elapsed(TimeUnit.NANOSECONDS));
   }
 
+  @Override
+  public void grpcHeadersSent() {
+    faket4t7 = Optional.of(Stopwatch.createStarted());
+  }
+
+  @Override
+  public void grpcHeadersReceived() {
+    faket4t7.ifPresent(Stopwatch::stop);
+  }
+
   @Override
   public void setTotalTimeoutDuration(java.time.Duration totalTimeoutDuration) {
     // This method is called by BigtableTracerStreamingCallable and
@@ -386,7 +397,8 @@ private void recordAttemptCompletion(@Nullable Throwable throwable) {
           code,
           Comparators.max(remainingDeadlineAtAttemptStart, Duration.ZERO));
     }
-
+    // if we don't have t4t7 latency from gfe, we use dur between initial metadata sent and initial
+    // metadata recv
     if (sidebandData.getGfeTiming() != null) {
       recorder.serverLatency.record(
           clientInfo,
@@ -395,6 +407,16 @@ private void recordAttemptCompletion(@Nullable Throwable throwable) {
           sidebandData.getClusterInfo(),
           code,
           sidebandData.getGfeTiming());
+    } else {
+      faket4t7.ifPresent(
+          stopwatch ->
+              recorder.serverLatency.record(
+                  clientInfo,
+                  tableId,
+                  methodInfo,
+                  sidebandData.getClusterInfo(),
+                  code,
+                  stopwatch.elapsed()));
     }
 
     boolean seenServer =

google-cloud-bigtable/src/main/java/com/google/cloud/bigtable/data/v2/internal/csm/tracers/CompositeTracer.java

@@ -241,6 +241,20 @@ public void grpcMessageSent() {
     }
   }
 
+  @Override
+  public void grpcHeadersSent() {
+    for (BigtableTracer tracer : bigtableTracers) {
+      tracer.grpcHeadersSent();
+    }
+  }
+
+  @Override
+  public void grpcHeadersReceived() {
+    for (BigtableTracer tracer : bigtableTracers) {
+      tracer.grpcHeadersReceived();
+    }
+  }
+
   @Override
   public void setTotalTimeoutDuration(java.time.Duration totalTimeoutDuration) {
     for (BigtableTracer tracer : bigtableTracers) {

google-cloud-bigtable/src/main/java/com/google/cloud/bigtable/data/v2/stub/metrics/BigtableTracer.java

@@ -89,6 +89,16 @@ public void grpcMessageSent() {
     // noop
   }
 
+  /** Called when the header is sent on a grpc channel. */
+  public void grpcHeadersSent() {
+    // noop
+  }
+
+  /** Called when the header is received on a grpc channel. */
+  public void grpcHeadersReceived() {
+    // noop
+  }
+
   /**
    * Record the operation timeout from user settings for calculating remaining deadline. Currently,
    * it's called in BuiltinMetricsTracer on attempt start from {@link BigtableTracerUnaryCallable}

google-cloud-bigtable/src/test/java/com/google/cloud/bigtable/data/v2/internal/csm/tracers/CompositeTracerTest.java

@@ -271,4 +271,18 @@ public void testGrpcMessageSent() {
     verify(child3, times(1)).grpcMessageSent();
     verify(child4, times(1)).grpcMessageSent();
   }
+
+  @Test
+  public void testGrpcHeadersSent() {
+    compositeTracer.grpcHeadersSent();
+    verify(child3, times(1)).grpcHeadersSent();
+    verify(child4, times(1)).grpcHeadersSent();
+  }
+
+  @Test
+  public void testGrpcHeadersReceived() {
+    compositeTracer.grpcHeadersReceived();
+    verify(child3, times(1)).grpcHeadersReceived();
+    verify(child4, times(1)).grpcHeadersReceived();
+  }
 }