chore: PoC for App Centric metrics

gax-java/gax/src/main/java/com/google/api/gax/tracing/AppCentricMetricsRecorder.java

@@ -0,0 +1,90 @@
+/*
+ * Copyright 2024 Google LLC
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ *     * Neither the name of Google LLC nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+package com.google.api.gax.tracing;
+
+import com.google.api.core.BetaApi;
+import com.google.api.core.InternalApi;
+import com.google.api.gax.core.GaxProperties;
+import com.google.common.annotations.VisibleForTesting;
+import com.google.common.base.Preconditions;
+import io.opentelemetry.api.OpenTelemetry;
+import io.opentelemetry.api.common.Attributes;
+import io.opentelemetry.api.common.AttributesBuilder;
+import io.opentelemetry.api.metrics.DoubleHistogram;
+import io.opentelemetry.api.metrics.Meter;
+import java.util.Map;
+
+@BetaApi
+@InternalApi
+public class AppCentricMetricsRecorder implements MetricsRecorder {
+
+  public static final String GAX_METER_NAME = "gax-java";
+  private final DoubleHistogram requestDurationRecorder;
+  private final String serviceName;
+
+  public AppCentricMetricsRecorder(OpenTelemetry openTelemetry, String serviceName) {
+
+    Meter meter =
+        openTelemetry
+            .meterBuilder(GAX_METER_NAME)
+            .setInstrumentationVersion(GaxProperties.getGaxVersion())
+            .build();
+    this.serviceName = serviceName;
+    this.requestDurationRecorder =
+        meter
+            .histogramBuilder("gcp.client.request.duration")
+            .setDescription(
+                "Measures the total time taken for a logical client request (T3 span), including any retries, backoff, and pre/post-processing.")
+            .setUnit("s")
+            .build();
+  }
+
+  /**
+   * Record the latency for the entire operation. This is the latency for the entire RPC, including
+   * all the retry attempts
+   *
+   * @param operationLatency Operation Latency in ms
+   * @param attributes Map of the attributes to store
+   */
+  @Override
+  public void recordOperationLatency(double operationLatency, Map<String, String> attributes) {
+    requestDurationRecorder.record(operationLatency, toOtelAttributes(attributes));
+  }
+
+  @VisibleForTesting
+  Attributes toOtelAttributes(Map<String, String> attributes) {
+    Preconditions.checkNotNull(attributes, "Attributes map cannot be null");
+    AttributesBuilder attributesBuilder = Attributes.builder();
+    attributes.forEach(attributesBuilder::put);
+    attributesBuilder.put("gcp.client.service", serviceName);
+    return attributesBuilder.build();
+  }
+}

gax-java/gax/src/main/java/com/google/api/gax/tracing/MetricsTracer.java

@@ -55,9 +55,9 @@
 @BetaApi
 @InternalApi
 public class MetricsTracer implements ApiTracer {
-  public static final String METHOD_ATTRIBUTE = "method";
+  public static final String METHOD_ATTRIBUTE = "rpc.method";
   public static final String LANGUAGE_ATTRIBUTE = "language";
-  public static final String STATUS_ATTRIBUTE = "status";
+  public static final String STATUS_ATTRIBUTE = "grpc.status";
   public static final String DEFAULT_LANGUAGE = "Java";
   private static final String OPERATION_FINISHED_STATUS_MESSAGE =
       "Operation has already been completed";