googleapis · sushanb · Mar 3, 2026 · Mar 1, 2026 · Mar 2, 2026 · Mar 2, 2026
@@ -84,10 +84,7 @@ public void run() {
     LoadBalancingStrategy lbPolicy = lbPolicyRef.get();
 
     for (BigtableChannelObserver info : channelInsights) {
-      TransportType transportType =
-          info.isAltsChannel()
-              ? TransportType.TRANSPORT_TYPE_DIRECT_ACCESS
-              : TransportType.TRANSPORT_TYPE_CLOUD_PATH;
+      TransportType transportType = info.getTransportType();
 
       long currentOutstandingUnaryRpcs = info.getOutstandingUnaryRpcs();
       long currentOutstandingStreamingRpcs = info.getOutstandingStreamingRpcs();

@@ -88,6 +88,11 @@ public static class SidebandData {
     private static final CallOptions.Key<SidebandData> KEY =
         CallOptions.Key.create("bigtable-sideband");
 
+    @Nullable
+    public static SidebandData from(CallOptions callOptions) {
+      return callOptions.getOption(KEY);
+    }
+
     private static final Metadata.Key<String> SERVER_TIMING_HEADER_KEY =
         Metadata.Key.of("server-timing", Metadata.ASCII_STRING_MARSHALLER);
     private static final Pattern SERVER_TIMING_HEADER_PATTERN =

@@ -16,6 +16,7 @@
 package com.google.cloud.bigtable.gaxx.grpc;
 
 import com.google.api.core.InternalApi;
+import com.google.bigtable.v2.PeerInfo;
 
 /** Provides observability about a single channel in the channel pool. */
 @InternalApi
@@ -32,5 +33,5 @@ public interface BigtableChannelObserver {
   /** Get the current number of successful requests since the last observed period */
   long getAndResetSuccessCount();
 
-  boolean isAltsChannel();
+  PeerInfo.TransportType getTransportType();
 }
@@ -17,6 +17,8 @@
 
 import com.google.api.core.InternalApi;
 import com.google.api.gax.grpc.ChannelFactory;
+import com.google.bigtable.v2.PeerInfo;
+import com.google.cloud.bigtable.data.v2.stub.MetadataExtractorInterceptor;
 import com.google.cloud.bigtable.gaxx.grpc.ChannelPoolHealthChecker.ProbeResult;
 import com.google.common.annotations.VisibleForTesting;
 import com.google.common.base.Preconditions;
@@ -34,6 +36,7 @@
 import java.time.Clock;
 import java.util.ArrayList;
 import java.util.List;
+import java.util.Optional;
 import java.util.Random;
 import java.util.concurrent.CancellationException;
 import java.util.concurrent.ConcurrentLinkedQueue;
@@ -543,9 +546,8 @@ static class Entry implements BigtableChannelObserver {
      * outstanding RPCs has to happen when the ClientCall is closed or the ClientCall failed to
      * start.
      */
-    @VisibleForTesting final AtomicReference<Boolean> isAltsHolder = new AtomicReference<>(null);
-
     @VisibleForTesting final AtomicInteger errorCount = new AtomicInteger(0);
+
     @VisibleForTesting final AtomicInteger successCount = new AtomicInteger(0);
     @VisibleForTesting final AtomicInteger outstandingUnaryRpcs = new AtomicInteger(0);
 
@@ -554,6 +556,10 @@ static class Entry implements BigtableChannelObserver {
     private final AtomicInteger maxOutstandingUnaryRpcs = new AtomicInteger();
     private final AtomicInteger maxOutstandingStreamingRpcs = new AtomicInteger();
 
+    /** this contains the PeerInfo field of the most recent rpc on this channel entry. */
+    @VisibleForTesting
+    volatile PeerInfo.TransportType transportType = PeerInfo.TransportType.TRANSPORT_TYPE_UNKNOWN;
+
     /** Queue storing the last 5 minutes of probe results */
     @VisibleForTesting
     final ConcurrentLinkedQueue<ProbeResult> probeHistory = new ConcurrentLinkedQueue<>();
@@ -576,10 +582,18 @@ static class Entry implements BigtableChannelObserver {
       this.channel = channel;
     }
 
-    void checkAndSetIsAlts(ClientCall<?, ?> call) {
-      // TODO(populate ALTS holder)
-      boolean result = false;
-      isAltsHolder.compareAndSet(null, result);
+    void setTransportType(CallOptions callOptions) {
+      MetadataExtractorInterceptor.SidebandData sidebandData =
+          MetadataExtractorInterceptor.SidebandData.from(callOptions);
+
+      // Set to the specific transport type if present, otherwise default to UNKNOWN
+      // we could check the Status and set it to unknown, but we might have PeerInfo with some non
+      // OK Status
+      transportType =
+          Optional.ofNullable(sidebandData)
+              .map(MetadataExtractorInterceptor.SidebandData::getPeerInfo)
+              .map(PeerInfo::getTransportType)
+              .orElse(PeerInfo.TransportType.TRANSPORT_TYPE_UNKNOWN);
     }
 
     ManagedChannel getManagedChannel() {
@@ -683,9 +697,8 @@ public long getAndResetSuccessCount() {
     }
 
     @Override
-    public boolean isAltsChannel() {
-      Boolean val = isAltsHolder.get();
-      return val != null && val;
+    public PeerInfo.TransportType getTransportType() {
+      return transportType;
     }
 
     void incrementErrorCount() {
@@ -717,7 +730,7 @@ public <RequestT, ResponseT> ClientCall<RequestT, ResponseT> newCall(
           methodDescriptor.getType() == MethodDescriptor.MethodType.SERVER_STREAMING;
       Entry entry = getRetainedEntry(index, isStreaming);
       return new ReleasingClientCall<>(
-          entry.channel.newCall(methodDescriptor, callOptions), entry, isStreaming);
+          entry.channel.newCall(methodDescriptor, callOptions), entry, isStreaming, callOptions);
     }
   }
 
@@ -726,13 +739,19 @@ static class ReleasingClientCall<ReqT, RespT> extends SimpleForwardingClientCall
     @Nullable private CancellationException cancellationException;
     final Entry entry;
     private final boolean isStreaming;
+    private final CallOptions callOptions;
     private final AtomicBoolean wasClosed = new AtomicBoolean();
     private final AtomicBoolean wasReleased = new AtomicBoolean();
 
-    public ReleasingClientCall(ClientCall<ReqT, RespT> delegate, Entry entry, boolean isStreaming) {
+    public ReleasingClientCall(
+        ClientCall<ReqT, RespT> delegate,
+        Entry entry,
+        boolean isStreaming,
+        CallOptions callOptions) {
       super(delegate);
       this.entry = entry;
       this.isStreaming = isStreaming;
+      this.callOptions = callOptions;
     }
 
     @Override
@@ -741,10 +760,14 @@ public void start(Listener<RespT> responseListener, Metadata headers) {
         throw new IllegalStateException("Call is already cancelled", cancellationException);
       }
       try {
-        entry.checkAndSetIsAlts(delegate());
-
         super.start(
             new SimpleForwardingClientCallListener<RespT>(responseListener) {
+              @Override
+              public void onHeaders(Metadata headers) {
+                super.onHeaders(headers);
+                entry.setTransportType(callOptions);
+              }
+
               @Override
               public void onClose(Status status, Metadata trailers) {
                 if (!wasClosed.compareAndSet(false, true)) {

@@ -20,6 +20,7 @@
 import static org.mockito.ArgumentMatchers.anyLong;
 import static org.mockito.Mockito.when;
 
+import com.google.bigtable.v2.PeerInfo;
 import com.google.cloud.bigtable.data.v2.internal.api.InstanceName;
 import com.google.cloud.bigtable.data.v2.internal.csm.MetricRegistry;
 import com.google.cloud.bigtable.data.v2.internal.csm.attributes.ClientInfo;
@@ -56,6 +57,9 @@
 
 @RunWith(JUnit4.class)
 public class ChannelPoolMetricsTracerTest {
+  private static final String PROJECT_ID = "fake-project";
+  private static final String INSTANCE_ID = "fake-instance";
+  private static final String APP_PROFILE_ID = "fake-profile";
 
   @Rule public final MockitoRule mockito = MockitoJUnit.rule();
 
@@ -74,8 +78,8 @@ public void setUp() {
     metricReader = InMemoryMetricReader.create();
     ClientInfo clientInfo =
         ClientInfo.builder()
-            .setInstanceName(InstanceName.of("fake-project", "fake-instance"))
-            .setAppProfileId("fake-profile")
+            .setInstanceName(InstanceName.of(PROJECT_ID, INSTANCE_ID))
+            .setAppProfileId(APP_PROFILE_ID)
             .build();
     SdkMeterProvider meterProvider =
         SdkMeterProvider.builder().registerMetricReader(metricReader).build();
@@ -105,8 +109,10 @@ public void setUp() {
     when(mockInsight2.getOutstandingStreamingRpcs()).thenReturn(0);
     when(mockInsight2.getAndResetErrorCount()).thenReturn(0L);
     when(mockInsight2.getAndResetSuccessCount()).thenReturn(0L);
-    when(mockInsight1.isAltsChannel()).thenReturn(false);
-    when(mockInsight2.isAltsChannel()).thenReturn(false);
+    when(mockInsight1.getTransportType())
+        .thenReturn(PeerInfo.TransportType.TRANSPORT_TYPE_CLOUD_PATH);
+    when(mockInsight2.getTransportType())
+        .thenReturn(PeerInfo.TransportType.TRANSPORT_TYPE_CLOUD_PATH);
   }
 
   /** Helper to run the captured ChannelPoolMetricsTracer task. */
@@ -119,11 +125,24 @@ void runTrackerTask() {
   }
 
   private Attributes getExpectedErrorAttributes() {
-    return Attributes.builder().build();
+    return Attributes.builder()
+        .put(AttributeKey.stringKey("project_id"), PROJECT_ID)
+        .put(AttributeKey.stringKey("instance"), INSTANCE_ID)
+        .put(AttributeKey.stringKey("app_profile"), APP_PROFILE_ID)
+        .put(
+            AttributeKey.stringKey("client_name"),
+            "java-bigtable/" + com.google.cloud.bigtable.Version.VERSION)
+        .build();
   }
 
   private static Attributes getExpectedRpcAttributes(String lbPolicy, boolean streaming) {
     return Attributes.builder()
+        .put(AttributeKey.stringKey("project_id"), PROJECT_ID)
+        .put(AttributeKey.stringKey("instance"), INSTANCE_ID)
+        .put(AttributeKey.stringKey("app_profile"), APP_PROFILE_ID)
+        .put(
+            AttributeKey.stringKey("client_name"),
+            "java-bigtable/" + com.google.cloud.bigtable.Version.VERSION)
         .put(AttributeKey.stringKey("transport_type"), "cloudpath")
         .put(AttributeKey.stringKey("lb_policy"), lbPolicy)
         .put(AttributeKey.booleanKey("streaming"), streaming)
@@ -147,15 +166,6 @@ private static HistogramPointData getPointForStreaming(
             () -> new AssertionError("Missing HistogramPointData for streaming=" + streaming));
   }
 
-  /** Helper to create expected Attributes for assertions. */
-  private static Attributes getExpectedAttributes(String lbPolicy, boolean streaming) {
-    return Attributes.builder()
-        .put(AttributeKey.stringKey("transport_type"), "grpc")
-        .put(AttributeKey.stringKey("lb_policy"), lbPolicy)
-        .put(AttributeKey.booleanKey("streaming"), streaming)
-        .build();
-  }
-
   @Test
   public void testSingleRun() {
     // Arrange