chore: Composite Tracer

README.md

@@ -50,20 +50,20 @@ If you are using Maven without the BOM, add this to your dependencies:
 If you are using Gradle 5.x or later, add this to your dependencies:
 
 ```Groovy
-implementation platform('com.google.cloud:libraries-bom:26.40.0')
+implementation platform('com.google.cloud:libraries-bom:26.41.0')
 
 implementation 'com.google.cloud:google-cloud-spanner'
 ```
 If you are using Gradle without BOM, add this to your dependencies:
 
 ```Groovy
-implementation 'com.google.cloud:google-cloud-spanner:6.68.1'
+implementation 'com.google.cloud:google-cloud-spanner:6.69.0'
 ```
 
 If you are using SBT, add this to your dependencies:
 
 ```Scala
-libraryDependencies += "com.google.cloud" % "google-cloud-spanner" % "6.68.1"
+libraryDependencies += "com.google.cloud" % "google-cloud-spanner" % "6.69.0"
 ```
 <!-- {x-version-update-end} -->
 
@@ -687,7 +687,7 @@ Java is a registered trademark of Oracle and/or its affiliates.
 [kokoro-badge-link-5]: http://storage.googleapis.com/cloud-devrel-public/java/badges/java-spanner/java11.html
 [stability-image]: https://img.shields.io/badge/stability-stable-green
 [maven-version-image]: https://img.shields.io/maven-central/v/com.google.cloud/google-cloud-spanner.svg
-[maven-version-link]: https://central.sonatype.com/artifact/com.google.cloud/google-cloud-spanner/6.68.1
+[maven-version-link]: https://central.sonatype.com/artifact/com.google.cloud/google-cloud-spanner/6.69.0
 [authentication]: https://github.com/googleapis/google-cloud-java#authentication
 [auth-scopes]: https://developers.google.com/identity/protocols/oauth2/scopes
 [predefined-iam-roles]: https://cloud.google.com/iam/docs/understanding-roles#predefined_roles

google-cloud-spanner/src/main/java/com/google/cloud/spanner/CompositeTracer.java

@@ -0,0 +1,174 @@
+/*
+ * Copyright 2024 Google LLC
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *       http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.google.cloud.spanner;
+
+import com.google.api.core.InternalApi;
+import com.google.api.gax.tracing.ApiTracer;
+import com.google.api.gax.tracing.BaseApiTracer;
+import com.google.api.gax.tracing.MetricsTracer;
+import com.google.common.collect.ImmutableList;
+import java.util.ArrayList;
+import java.util.List;
+import org.threeten.bp.Duration;
+
+@InternalApi
+public class CompositeTracer extends BaseApiTracer {
+  private final List<ApiTracer> children;
+
+  public CompositeTracer(List<ApiTracer> children) {
+    this.children = ImmutableList.copyOf(children);
+  }
+
+  @Override
+  public Scope inScope() {
+    final List<Scope> childScopes = new ArrayList<>(children.size());
+
+    for (ApiTracer child : children) {
+      childScopes.add(child.inScope());
+    }
+
+    return new Scope() {
+      @Override
+      public void close() {
+        for (Scope childScope : childScopes) {
+          childScope.close();
+        }
+      }
+    };
+  }
+
+  @Override
+  public void operationSucceeded() {
+    for (ApiTracer child : children) {
+      child.operationSucceeded();
+    }
+  }
+
+  @Override
+  public void operationCancelled() {
+    for (ApiTracer child : children) {
+      child.operationCancelled();
+    }
+  }
+
+  @Override
+  public void operationFailed(Throwable error) {
+    for (ApiTracer child : children) {
+      child.operationFailed(error);
+    }
+  }
+
+  @Override
+  public void connectionSelected(String id) {
+    for (ApiTracer child : children) {
+      child.connectionSelected(id);
+    }
+  }
+
+  @Override
+  public void attemptStarted(int attemptNumber) {
+    for (ApiTracer child : children) {
+      child.attemptStarted(null, attemptNumber);
+    }
+  }
+
+  @Override
+  public void attemptStarted(Object request, int attemptNumber) {
+    for (ApiTracer child : children) {
+      child.attemptStarted(request, attemptNumber);
+    }
+  }
+
+  @Override
+  public void attemptSucceeded() {
+    for (ApiTracer child : children) {
+      child.attemptSucceeded();
+    }
+  }
+
+  @Override
+  public void attemptCancelled() {
+    for (ApiTracer child : children) {
+      child.attemptCancelled();
+    }
+  }
+
+  @Override
+  public void attemptFailed(Throwable error, Duration delay) {
+    for (ApiTracer child : children) {
+      child.attemptFailed(error, delay);
+    }
+  }
+
+  @Override
+  public void attemptFailedRetriesExhausted(Throwable error) {
+    for (ApiTracer child : children) {
+      child.attemptFailedRetriesExhausted(error);
+    }
+  }
+
+  @Override
+  public void attemptPermanentFailure(Throwable error) {
+    for (ApiTracer child : children) {
+      child.attemptPermanentFailure(error);
+    }
+  }
+
+  @Override
+  public void lroStartFailed(Throwable error) {
+    for (ApiTracer child : children) {
+      child.lroStartFailed(error);
+    }
+  }
+
+  @Override
+  public void lroStartSucceeded() {
+    for (ApiTracer child : children) {
+      child.lroStartSucceeded();
+    }
+  }
+
+  @Override
+  public void responseReceived() {
+    for (ApiTracer child : children) {
+      child.responseReceived();
+    }
+  }
+
+  @Override
+  public void requestSent() {
+    for (ApiTracer child : children) {
+      child.requestSent();
+    }
+  }
+
+  @Override
+  public void batchRequestSent(long elementCount, long requestSize) {
+    for (ApiTracer child : children) {
+      child.batchRequestSent(elementCount, requestSize);
+    }
+  }
+
+  public void addAttributes(String key, String value) {
+    for (ApiTracer child : children) {
+      if (child instanceof MetricsTracer) {
+        MetricsTracer metricsTracer = (MetricsTracer) child;
+        metricsTracer.addAttributes(key, value);
+      }
+    }
+  };
+}

google-cloud-spanner/src/main/java/com/google/cloud/spanner/CompositeTracerFactory.java

@@ -0,0 +1,46 @@
+/*
+ * Copyright 2024 Google LLC
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *       http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.google.cloud.spanner;
+
+import com.google.api.core.InternalApi;
+import com.google.api.gax.tracing.ApiTracer;
+import com.google.api.gax.tracing.ApiTracerFactory;
+import com.google.api.gax.tracing.BaseApiTracerFactory;
+import com.google.api.gax.tracing.SpanName;
+import com.google.common.collect.ImmutableList;
+import java.util.ArrayList;
+import java.util.List;
+
+@InternalApi
+public class CompositeTracerFactory extends BaseApiTracerFactory {
+
+  private final List<ApiTracerFactory> apiTracerFactories;
+
+  public CompositeTracerFactory(List<ApiTracerFactory> apiTracerFactories) {
+    this.apiTracerFactories = ImmutableList.copyOf(apiTracerFactories);
+  }
+
+  @Override
+  public ApiTracer newTracer(ApiTracer parent, SpanName spanName, OperationType operationType) {
+    List<ApiTracer> children = new ArrayList<>(apiTracerFactories.size());
+
+    for (ApiTracerFactory factory : apiTracerFactories) {
+      children.add(factory.newTracer(parent, spanName, operationType));
+    }
+    return new CompositeTracer(children);
+  }
+}

google-cloud-spanner/src/main/java/com/google/cloud/spanner/SpannerOptions.java

@@ -72,7 +72,9 @@
 import java.io.IOException;
 import java.net.MalformedURLException;
 import java.net.URL;
+import java.util.ArrayList;
 import java.util.HashMap;
+import java.util.List;
 import java.util.Map;
 import java.util.Map.Entry;
 import java.util.Set;
@@ -1621,8 +1623,12 @@ public OpenTelemetry getOpenTelemetry() {
 
   @Override
   public ApiTracerFactory getApiTracerFactory() {
+    List<ApiTracerFactory> apiTracerFactories = new ArrayList();
     // Prefer any direct ApiTracerFactory that might have been set on the builder.
-    return MoreObjects.firstNonNull(super.getApiTracerFactory(), getDefaultApiTracerFactory());
+    apiTracerFactories.add(
+        MoreObjects.firstNonNull(super.getApiTracerFactory(), getDefaultApiTracerFactory()));
+
+    return new CompositeTracerFactory(apiTracerFactories);
   }
 
   private ApiTracerFactory getDefaultApiTracerFactory() {