Add HTTPClientMetrics (#3598)

* Add HTTPClientMetrics

* Update instrumentation-api/src/main/java/io/opentelemetry/instrumentation/api/instrumenter/http/HttpClientMetrics.java

Co-authored-by: Trask Stalnaker <trask.stalnaker@gmail.com>

Co-authored-by: Trask Stalnaker <trask.stalnaker@gmail.com>

instrumentation-api/src/main/java/io/opentelemetry/instrumentation/api/instrumenter/http/HttpClientMetrics.java

@@ -0,0 +1,119 @@
+/*
+ * Copyright The OpenTelemetry Authors
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+package io.opentelemetry.instrumentation.api.instrumenter.http;
+
+import com.google.auto.value.AutoValue;
+import io.opentelemetry.api.common.Attributes;
+import io.opentelemetry.api.metrics.DoubleValueRecorder;
+import io.opentelemetry.api.metrics.Meter;
+import io.opentelemetry.api.metrics.common.Labels;
+import io.opentelemetry.api.metrics.common.LabelsBuilder;
+import io.opentelemetry.context.Context;
+import io.opentelemetry.context.ContextKey;
+import io.opentelemetry.instrumentation.api.annotations.UnstableApi;
+import io.opentelemetry.instrumentation.api.instrumenter.RequestListener;
+import io.opentelemetry.instrumentation.api.instrumenter.RequestMetrics;
+import java.util.concurrent.TimeUnit;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+/**
+ * {@link RequestListener} which keeps track of <a
+ * href="https://github.com/open-telemetry/opentelemetry-specification/blob/main/specification/metrics/semantic_conventions/http-metrics.md#http-client">HTTP
+ * client metrics</a>.
+ *
+ * <p>To use this class, you may need to add the {@code opentelemetry-api-metrics} artifact to your
+ * dependencies.
+ */
+@UnstableApi
+public final class HttpClientMetrics implements RequestListener {
+
+  private static final double NANOS_PER_MS = TimeUnit.MILLISECONDS.toNanos(1);
+
+  private static final ContextKey<State> HTTP_CLIENT_REQUEST_METRICS_STATE =
+      ContextKey.named("http-client-request-metrics-state");
+
+  private static final Logger logger = LoggerFactory.getLogger(HttpClientMetrics.class);
+
+  /**
+   * Returns a {@link RequestMetrics} which can be used to enable recording of {@link
+   * HttpClientMetrics} on an {@link
+   * io.opentelemetry.instrumentation.api.instrumenter.InstrumenterBuilder}.
+   */
+  @UnstableApi
+  public static RequestMetrics get() {
+    return HttpClientMetrics::new;
+  }
+
+  private final DoubleValueRecorder duration;
+
+  private HttpClientMetrics(Meter meter) {
+    duration =
+        meter
+            .doubleValueRecorderBuilder("http.client.duration")
+            .setUnit("milliseconds")
+            .setDescription("The duration of the outbound HTTP request")
+            .build();
+  }
+
+  @Override
+  public Context start(Context context, Attributes requestAttributes) {
+    long startTimeNanos = System.nanoTime();
+    Labels durationLabels = durationLabels(requestAttributes);
+
+    return context.with(
+        HTTP_CLIENT_REQUEST_METRICS_STATE,
+        new AutoValue_HttpClientMetrics_State(durationLabels, startTimeNanos));
+  }
+
+  @Override
+  public void end(Context context, Attributes responseAttributes) {
+    State state = context.get(HTTP_CLIENT_REQUEST_METRICS_STATE);
+    if (state == null) {
+      logger.debug(
+          "No state present when ending context {}. Cannot record HTTP request metrics.", context);
+      return;
+    }
+    duration.record(
+        (System.nanoTime() - state.startTimeNanos()) / NANOS_PER_MS, state.durationLabels());
+  }
+
+  private static Labels durationLabels(Attributes attributes) {
+    LabelsBuilder labels = Labels.builder();
+    attributes.forEach(
+        (key, value) -> {
+          switch (key.getKey()) {
+            case "http.method":
+            case "http.host":
+            case "http.scheme":
+            case "http.flavor":
+            case "http.server_name":
+            case "net.host.name":
+              if (value instanceof String) {
+                labels.put(key.getKey(), (String) value);
+              }
+              break;
+            case "http.status_code":
+            case "net.host.port":
+              if (value instanceof Long) {
+                labels.put(key.getKey(), Long.toString((long) value));
+              }
+              break;
+            default:
+              // fall through
+          }
+        });
+    return labels.build();
+  }
+
+  @AutoValue
+  abstract static class State {
+
+    abstract Labels durationLabels();
+
+    abstract long startTimeNanos();
+  }
+}

instrumentation-api/src/test/java/io/opentelemetry/instrumentation/api/instrumenter/http/HttpClientMetricsTest.java

@@ -0,0 +1,93 @@
+/*
+ * Copyright The OpenTelemetry Authors
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+package io.opentelemetry.instrumentation.api.instrumenter.http;
+
+import static io.opentelemetry.api.common.AttributeKey.stringKey;
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.assertj.core.api.Assertions.entry;
+
+import io.opentelemetry.api.common.Attributes;
+import io.opentelemetry.context.Context;
+import io.opentelemetry.instrumentation.api.instrumenter.RequestListener;
+import io.opentelemetry.sdk.metrics.SdkMeterProvider;
+import io.opentelemetry.sdk.metrics.data.DoubleSummaryPointData;
+import io.opentelemetry.sdk.metrics.data.MetricData;
+import java.util.Collection;
+import org.junit.jupiter.api.Test;
+
+class HttpClientMetricsTest {
+
+  @Test
+  void collectsMetrics() {
+    SdkMeterProvider meterProvider = SdkMeterProvider.builder().build();
+
+    RequestListener listener = HttpClientMetrics.get().create(meterProvider.get("test"));
+
+    Attributes requestAttributes =
+        Attributes.builder()
+            .put("http.method", "GET")
+            .put("http.host", "host")
+            .put("http.scheme", "https")
+            .put("net.host.name", "localhost")
+            .put("net.host.port", 1234)
+            .put("rpc.service", "unused")
+            .put("rpc.method", "unused")
+            .build();
+
+    // Currently ignored.
+    Attributes responseAttributes =
+        Attributes.builder()
+            .put("http.flavor", "2.0")
+            .put("http.server_name", "server")
+            .put("http.status_code", 200)
+            .build();
+
+    Context context1 = listener.start(Context.current(), requestAttributes);
+
+    Collection<MetricData> metrics = meterProvider.collectAllMetrics();
+    assertThat(metrics).isEmpty();
+
+    Context context2 = listener.start(Context.current(), requestAttributes);
+
+    metrics = meterProvider.collectAllMetrics();
+    assertThat(metrics).isEmpty();
+
+    listener.end(context1, responseAttributes);
+
+    metrics = meterProvider.collectAllMetrics();
+    assertThat(metrics).hasSize(1);
+    assertThat(metrics)
+        .anySatisfy(
+            metric -> {
+              assertThat(metric.getName()).isEqualTo("http.client.duration");
+              assertThat(metric.getDoubleSummaryData().getPoints()).hasSize(1);
+              DoubleSummaryPointData data =
+                  metric.getDoubleSummaryData().getPoints().stream().findFirst().get();
+              assertThat(data.getAttributes().asMap())
+                  .containsOnly(
+                      entry(stringKey("http.host"), "host"),
+                      entry(stringKey("http.method"), "GET"),
+                      entry(stringKey("http.scheme"), "https"),
+                      entry(stringKey("net.host.name"), "localhost"),
+                      entry(stringKey("net.host.port"), "1234"));
+              assertThat(data.getPercentileValues()).isNotEmpty();
+            });
+
+    listener.end(context2, responseAttributes);
+
+    metrics = meterProvider.collectAllMetrics();
+    assertThat(metrics).hasSize(1);
+    assertThat(metrics)
+        .anySatisfy(
+            metric -> {
+              assertThat(metric.getName()).isEqualTo("http.client.duration");
+              assertThat(metric.getDoubleSummaryData().getPoints()).hasSize(1);
+              DoubleSummaryPointData data =
+                  metric.getDoubleSummaryData().getPoints().stream().findFirst().get();
+              assertThat(data.getPercentileValues()).isNotEmpty();
+            });
+  }
+}

instrumentation/apache-httpasyncclient-4.1/javaagent/src/main/java/io/opentelemetry/javaagent/instrumentation/apachehttpasyncclient/ApacheHttpAsyncClientSingletons.java

@@ -10,6 +10,7 @@ import io.opentelemetry.instrumentation.api.instrumenter.Instrumenter;
 import io.opentelemetry.instrumentation.api.instrumenter.SpanNameExtractor;
 import io.opentelemetry.instrumentation.api.instrumenter.SpanStatusExtractor;
 import io.opentelemetry.instrumentation.api.instrumenter.http.HttpAttributesExtractor;
+import io.opentelemetry.instrumentation.api.instrumenter.http.HttpClientMetrics;
 import io.opentelemetry.instrumentation.api.instrumenter.http.HttpSpanNameExtractor;
 import io.opentelemetry.instrumentation.api.instrumenter.http.HttpSpanStatusExtractor;
 import io.opentelemetry.javaagent.instrumentation.api.instrumenter.PeerServiceAttributesExtractor;
@@ -37,6 +38,7 @@ public final class ApacheHttpAsyncClientSingletons {
             .addAttributesExtractor(httpAttributesExtractor)
             .addAttributesExtractor(netAttributesExtractor)
             .addAttributesExtractor(PeerServiceAttributesExtractor.create(netAttributesExtractor))
+            .addRequestMetrics(HttpClientMetrics.get())
             .newClientInstrumenter(new HttpHeaderSetter());
   }
 

instrumentation/apache-httpclient/apache-httpclient-2.0/javaagent/src/main/java/io/opentelemetry/javaagent/instrumentation/apachehttpclient/v2_0/ApacheHttpClientSingletons.java

@@ -10,6 +10,7 @@ import io.opentelemetry.instrumentation.api.instrumenter.Instrumenter;
 import io.opentelemetry.instrumentation.api.instrumenter.SpanNameExtractor;
 import io.opentelemetry.instrumentation.api.instrumenter.SpanStatusExtractor;
 import io.opentelemetry.instrumentation.api.instrumenter.http.HttpAttributesExtractor;
+import io.opentelemetry.instrumentation.api.instrumenter.http.HttpClientMetrics;
 import io.opentelemetry.instrumentation.api.instrumenter.http.HttpSpanNameExtractor;
 import io.opentelemetry.instrumentation.api.instrumenter.http.HttpSpanStatusExtractor;
 import io.opentelemetry.javaagent.instrumentation.api.instrumenter.PeerServiceAttributesExtractor;
@@ -37,6 +38,7 @@ public final class ApacheHttpClientSingletons {
             .addAttributesExtractor(httpAttributesExtractor)
             .addAttributesExtractor(netAttributesExtractor)
             .addAttributesExtractor(PeerServiceAttributesExtractor.create(netAttributesExtractor))
+            .addRequestMetrics(HttpClientMetrics.get())
             .newClientInstrumenter(new HttpHeaderSetter());
   }
 

instrumentation/apache-httpclient/apache-httpclient-4.0/javaagent/src/main/java/io/opentelemetry/javaagent/instrumentation/apachehttpclient/v4_0/ApacheHttpClientSingletons.java

@@ -10,6 +10,7 @@ import io.opentelemetry.instrumentation.api.instrumenter.Instrumenter;
 import io.opentelemetry.instrumentation.api.instrumenter.SpanNameExtractor;
 import io.opentelemetry.instrumentation.api.instrumenter.SpanStatusExtractor;
 import io.opentelemetry.instrumentation.api.instrumenter.http.HttpAttributesExtractor;
+import io.opentelemetry.instrumentation.api.instrumenter.http.HttpClientMetrics;
 import io.opentelemetry.instrumentation.api.instrumenter.http.HttpSpanNameExtractor;
 import io.opentelemetry.instrumentation.api.instrumenter.http.HttpSpanStatusExtractor;
 import io.opentelemetry.javaagent.instrumentation.api.instrumenter.PeerServiceAttributesExtractor;
@@ -37,6 +38,7 @@ public final class ApacheHttpClientSingletons {
             .addAttributesExtractor(httpAttributesExtractor)
             .addAttributesExtractor(netAttributesExtractor)
             .addAttributesExtractor(PeerServiceAttributesExtractor.create(netAttributesExtractor))
+            .addRequestMetrics(HttpClientMetrics.get())
             .newClientInstrumenter(new HttpHeaderSetter());
   }
 

instrumentation/apache-httpclient/apache-httpclient-5.0/javaagent/src/main/java/io/opentelemetry/javaagent/instrumentation/apachehttpclient/v5_0/ApacheHttpClientSingletons.java

@@ -10,6 +10,7 @@ import io.opentelemetry.instrumentation.api.instrumenter.Instrumenter;
 import io.opentelemetry.instrumentation.api.instrumenter.SpanNameExtractor;
 import io.opentelemetry.instrumentation.api.instrumenter.SpanStatusExtractor;
 import io.opentelemetry.instrumentation.api.instrumenter.http.HttpAttributesExtractor;
+import io.opentelemetry.instrumentation.api.instrumenter.http.HttpClientMetrics;
 import io.opentelemetry.instrumentation.api.instrumenter.http.HttpSpanNameExtractor;
 import io.opentelemetry.instrumentation.api.instrumenter.http.HttpSpanStatusExtractor;
 import io.opentelemetry.javaagent.instrumentation.api.instrumenter.PeerServiceAttributesExtractor;
@@ -38,6 +39,7 @@ public final class ApacheHttpClientSingletons {
             .addAttributesExtractor(httpAttributesExtractor)
             .addAttributesExtractor(netAttributesExtractor)
             .addAttributesExtractor(PeerServiceAttributesExtractor.create(netAttributesExtractor))
+            .addRequestMetrics(HttpClientMetrics.get())
             .newClientInstrumenter(new HttpHeaderSetter());
   }
 

instrumentation/armeria-1.3/library/src/main/java/io/opentelemetry/instrumentation/armeria/v1_3/ArmeriaTracingBuilder.java

@@ -15,6 +15,7 @@ import io.opentelemetry.instrumentation.api.instrumenter.Instrumenter;
 import io.opentelemetry.instrumentation.api.instrumenter.InstrumenterBuilder;
 import io.opentelemetry.instrumentation.api.instrumenter.SpanNameExtractor;
 import io.opentelemetry.instrumentation.api.instrumenter.SpanStatusExtractor;
+import io.opentelemetry.instrumentation.api.instrumenter.http.HttpClientMetrics;
 import io.opentelemetry.instrumentation.api.instrumenter.http.HttpServerMetrics;
 import io.opentelemetry.instrumentation.api.instrumenter.http.HttpSpanNameExtractor;
 import io.opentelemetry.instrumentation.api.instrumenter.http.HttpSpanStatusExtractor;
@@ -84,6 +85,7 @@ public final class ArmeriaTracingBuilder {
                     .addAttributesExtractor(netAttributesExtractor)
                     .addAttributesExtractors(additionalExtractors));
 
+    clientInstrumenterBuilder.addRequestMetrics(HttpClientMetrics.get());
     serverInstrumenterBuilder.addRequestMetrics(HttpServerMetrics.get());
 
     return new ArmeriaTracing(

instrumentation/async-http-client/async-http-client-2.0/javaagent/src/main/java/io/opentelemetry/javaagent/instrumentation/asynchttpclient/v2_0/AsyncHttpClientSingletons.java

@@ -10,6 +10,7 @@ import io.opentelemetry.instrumentation.api.instrumenter.Instrumenter;
 import io.opentelemetry.instrumentation.api.instrumenter.SpanNameExtractor;
 import io.opentelemetry.instrumentation.api.instrumenter.SpanStatusExtractor;
 import io.opentelemetry.instrumentation.api.instrumenter.http.HttpAttributesExtractor;
+import io.opentelemetry.instrumentation.api.instrumenter.http.HttpClientMetrics;
 import io.opentelemetry.instrumentation.api.instrumenter.http.HttpSpanNameExtractor;
 import io.opentelemetry.instrumentation.api.instrumenter.http.HttpSpanStatusExtractor;
 import io.opentelemetry.javaagent.instrumentation.api.instrumenter.PeerServiceAttributesExtractor;
@@ -38,6 +39,7 @@ public final class AsyncHttpClientSingletons {
             .addAttributesExtractor(httpAttributesExtractor)
             .addAttributesExtractor(netAttributesExtractor)
             .addAttributesExtractor(PeerServiceAttributesExtractor.create(netAttributesExtractor))
+            .addRequestMetrics(HttpClientMetrics.get())
             .newClientInstrumenter(new HttpHeaderSetter());
   }
 

instrumentation/jetty-httpclient/jetty-httpclient-9.2/library/src/main/java/io/opentelemetry/instrumentation/jetty/httpclient/v9_2/internal/JettyClientInstrumenterBuilder.java

@@ -11,6 +11,7 @@ import io.opentelemetry.instrumentation.api.instrumenter.Instrumenter;
 import io.opentelemetry.instrumentation.api.instrumenter.SpanNameExtractor;
 import io.opentelemetry.instrumentation.api.instrumenter.SpanStatusExtractor;
 import io.opentelemetry.instrumentation.api.instrumenter.http.HttpAttributesExtractor;
+import io.opentelemetry.instrumentation.api.instrumenter.http.HttpClientMetrics;
 import io.opentelemetry.instrumentation.api.instrumenter.http.HttpSpanNameExtractor;
 import io.opentelemetry.instrumentation.api.instrumenter.http.HttpSpanStatusExtractor;
 import java.util.ArrayList;
@@ -54,6 +55,7 @@ public final class JettyClientInstrumenterBuilder {
             .addAttributesExtractor(httpAttributesExtractor)
             .addAttributesExtractor(netAttributesExtractor)
             .addAttributesExtractors(additionalExtractors)
+            .addRequestMetrics(HttpClientMetrics.get())
             .newClientInstrumenter(new HttpHeaderSetter());
     return instrumenter;
   }

instrumentation/okhttp/okhttp-3.0/library/src/main/java/io/opentelemetry/instrumentation/okhttp/v3_0/OkHttpTracingBuilder.java

@@ -10,6 +10,7 @@ import static io.opentelemetry.instrumentation.api.instrumenter.SpanKindExtracto
 import io.opentelemetry.api.OpenTelemetry;
 import io.opentelemetry.instrumentation.api.instrumenter.AttributesExtractor;
 import io.opentelemetry.instrumentation.api.instrumenter.Instrumenter;
+import io.opentelemetry.instrumentation.api.instrumenter.http.HttpClientMetrics;
 import io.opentelemetry.instrumentation.api.instrumenter.http.HttpSpanNameExtractor;
 import io.opentelemetry.instrumentation.api.instrumenter.http.HttpSpanStatusExtractor;
 import io.opentelemetry.instrumentation.okhttp.v3_0.internal.OkHttpNetAttributesExtractor;
@@ -54,6 +55,7 @@ public final class OkHttpTracingBuilder {
             .addAttributesExtractor(httpAttributesExtractor)
             .addAttributesExtractor(netAttributesExtractor)
             .addAttributesExtractors(additionalExtractors)
+            .addRequestMetrics(HttpClientMetrics.get())
             .newInstrumenter(alwaysClient());
     return new OkHttpTracing(instrumenter, openTelemetry.getPropagators());
   }