Failsafe RetryPolicy instrumentation added

instrumentation/failsafe-3.0/library/src/main/java/io/opentelemetry/instrumentation/failsafe/v3_0/FailsafeTelemetry.java

@@ -13,18 +13,25 @@
 
 import dev.failsafe.CircuitBreaker;
 import dev.failsafe.CircuitBreakerConfig;
+import dev.failsafe.RetryPolicy;
+import dev.failsafe.RetryPolicyConfig;
 import io.opentelemetry.api.OpenTelemetry;
 import io.opentelemetry.api.common.AttributeKey;
 import io.opentelemetry.api.common.Attributes;
 import io.opentelemetry.api.metrics.LongCounter;
+import io.opentelemetry.api.metrics.LongHistogram;
 import io.opentelemetry.api.metrics.Meter;
+import java.util.stream.Collectors;
+import java.util.stream.LongStream;
 
 /** Entrypoint for instrumenting Failsafe components. */
 public final class FailsafeTelemetry {
   private static final String INSTRUMENTATION_NAME = "io.opentelemetry.failsafe-3.0";
 
   private static final AttributeKey<String> CIRCUIT_BREAKER_NAME =
       AttributeKey.stringKey("failsafe.circuit_breaker.name");
+  private static final AttributeKey<String> RETRY_POLICY_NAME =
+      AttributeKey.stringKey("failsafe.retry_policy.name");
 
   /** Returns a new {@link FailsafeTelemetry} configured with the given {@link OpenTelemetry}. */
   public static FailsafeTelemetry create(OpenTelemetry openTelemetry) {
@@ -70,4 +77,44 @@ public <R> CircuitBreaker<R> createCircuitBreaker(
         .onClose(buildInstrumentedCloseListener(userConfig, stateChangesCounter, attributes))
         .build();
   }
+
+  /**
+   * Returns an instrumented {@link RetryPolicy} by given values.
+   *
+   * @param delegate user configured {@link RetryPolicy} to be instrumented
+   * @param retryPolicyName identifier of given {@link RetryPolicy}
+   * @param <R> {@link RetryPolicy}'s result type
+   * @return instrumented {@link RetryPolicy}
+   */
+  public <R> RetryPolicy<R> createRetryPolicy(RetryPolicy<R> delegate, String retryPolicyName) {
+    RetryPolicyConfig<R> userConfig = delegate.getConfig();
+    Meter meter = openTelemetry.getMeter(INSTRUMENTATION_NAME);
+    LongCounter executionCounter =
+        meter
+            .counterBuilder("failsafe.retry_policy.execution.count")
+            .setDescription(
+                "Count of execution events processed by the retry policy. "
+                    + "Each event represents one complete execution flow (initial attempt + any retries). "
+                    + "This metric does not count individual retry attempts - it counts each time the policy is invoked.")
+            .build();
+    LongHistogram attemptsHistogram =
+        meter
+            .histogramBuilder("failsafe.retry_policy.attempts")
+            .setDescription("Histogram of number of attempts for each execution.")
+            .ofLongs()
+            .setExplicitBucketBoundariesAdvice(
+                LongStream.range(1, userConfig.getMaxAttempts() + 1)
+                    .boxed()
+                    .collect(Collectors.toList()))
+            .build();
+    Attributes attributes = Attributes.of(RETRY_POLICY_NAME, retryPolicyName);
+    return RetryPolicy.builder(userConfig)
+        .onFailure(
+            RetryPolicyEventListenerBuilders.buildInstrumentedFailureListener(
+                userConfig, executionCounter, attemptsHistogram, attributes))
+        .onSuccess(
+            RetryPolicyEventListenerBuilders.buildInstrumentedSuccessListener(
+                userConfig, executionCounter, attemptsHistogram, attributes))
+        .build();
+  }
 }

instrumentation/failsafe-3.0/library/src/main/java/io/opentelemetry/instrumentation/failsafe/v3_0/RetryPolicyEventListenerBuilders.java

@@ -0,0 +1,53 @@
+/*
+ * Copyright The OpenTelemetry Authors
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+package io.opentelemetry.instrumentation.failsafe.v3_0;
+
+import static io.opentelemetry.api.common.AttributeKey.stringKey;
+
+import dev.failsafe.RetryPolicyConfig;
+import dev.failsafe.event.EventListener;
+import dev.failsafe.event.ExecutionCompletedEvent;
+import io.opentelemetry.api.common.AttributeKey;
+import io.opentelemetry.api.common.Attributes;
+import io.opentelemetry.api.metrics.LongCounter;
+import io.opentelemetry.api.metrics.LongHistogram;
+
+final class RetryPolicyEventListenerBuilders {
+  private static final AttributeKey<String> OUTCOME_KEY =
+      stringKey("failsafe.retry_policy.outcome");
+
+  private RetryPolicyEventListenerBuilders() {}
+
+  static <R> EventListener<ExecutionCompletedEvent<R>> buildInstrumentedFailureListener(
+      RetryPolicyConfig<R> userConfig,
+      LongCounter executionCounter,
+      LongHistogram attemptsHistogram,
+      Attributes commonAttributes) {
+    Attributes attributes = commonAttributes.toBuilder().put(OUTCOME_KEY, "failure").build();
+    return e -> {
+      executionCounter.add(1, attributes);
+      attemptsHistogram.record(e.getAttemptCount(), attributes);
+      if (userConfig.getFailureListener() != null) {
+        userConfig.getFailureListener().accept(e);
+      }
+    };
+  }
+
+  static <R> EventListener<ExecutionCompletedEvent<R>> buildInstrumentedSuccessListener(
+      RetryPolicyConfig<R> userConfig,
+      LongCounter executionCounter,
+      LongHistogram attemptsHistogram,
+      Attributes commonAttributes) {
+    Attributes attributes = commonAttributes.toBuilder().put(OUTCOME_KEY, "success").build();
+    return e -> {
+      executionCounter.add(1, attributes);
+      attemptsHistogram.record(e.getAttemptCount(), attributes);
+      if (userConfig.getFailureListener() != null) {
+        userConfig.getFailureListener().accept(e);
+      }
+    };
+  }
+}

instrumentation/failsafe-3.0/library/src/test/java/io/opentelemetry/instrumentation/failsafe/v3_0/FailsafeTelemetryTest.java

@@ -11,12 +11,20 @@
 import dev.failsafe.CircuitBreaker;
 import dev.failsafe.CircuitBreakerOpenException;
 import dev.failsafe.Failsafe;
+import dev.failsafe.RetryPolicy;
 import io.opentelemetry.api.common.Attributes;
 import io.opentelemetry.instrumentation.testing.junit.InstrumentationExtension;
 import io.opentelemetry.instrumentation.testing.junit.LibraryInstrumentationExtension;
+import io.opentelemetry.sdk.metrics.data.HistogramData;
+import io.opentelemetry.sdk.metrics.data.HistogramPointData;
+import io.opentelemetry.sdk.metrics.data.LongPointData;
+import io.opentelemetry.sdk.metrics.data.SumData;
 import io.opentelemetry.sdk.testing.assertj.LongPointAssert;
 import java.time.Duration;
+import java.util.Arrays;
+import java.util.Collection;
 import java.util.Objects;
+import java.util.concurrent.atomic.AtomicInteger;
 import java.util.function.Consumer;
 import org.junit.jupiter.api.Test;
 import org.junit.jupiter.api.extension.RegisterExtension;
@@ -80,6 +88,82 @@ void captureCircuitBreakerMetrics() {
                                     1, "failsafe.circuit_breaker.state", "closed"))));
   }
 
+  @Test
+  void captureRetryPolicyMetrics() {
+    // given
+    RetryPolicy<Object> userRetryPolicy =
+        dev.failsafe.RetryPolicy.builder()
+            .handleResultIf(Objects::isNull)
+            .withMaxAttempts(3)
+            .build();
+    FailsafeTelemetry failsafeTelemetry = FailsafeTelemetry.create(testing.getOpenTelemetry());
+    RetryPolicy<Object> instrumentedRetryPolicy =
+        failsafeTelemetry.createRetryPolicy(userRetryPolicy, "testing");
+
+    // when
+    for (int i = 0; i <= 3; i++) {
+      int temp = i;
+      AtomicInteger retry = new AtomicInteger(0);
+      Failsafe.with(instrumentedRetryPolicy)
+          .get(
+              () -> {
+                if (retry.get() < temp) {
+                  retry.incrementAndGet();
+                  return null;
+                } else {
+                  return new Object();
+                }
+              });
+    }
+
+    // then
+    testing.waitAndAssertMetrics("io.opentelemetry.failsafe-3.0");
+    assertThat(testing.metrics().size()).isEqualTo(2);
+
+    SumData<LongPointData> executionCountMetric =
+        testing.metrics().stream()
+            .filter(m -> m.getName().equals("failsafe.retry_policy.execution.count"))
+            .findFirst()
+            .get()
+            .getLongSumData();
+    assertThat(executionCountMetric.getPoints().size()).isEqualTo(2);
+    assertThat(executionCountMetric.getPoints())
+        .anyMatch(
+            p ->
+                p.getAttributes().equals(buildExpectedRetryPolicyAttributes("failure"))
+                    && p.getValue() == 1);
+    assertThat(executionCountMetric.getPoints())
+        .anyMatch(
+            p ->
+                p.getAttributes().equals(buildExpectedRetryPolicyAttributes("success"))
+                    && p.getValue() == 3);
+
+    HistogramData attemptsMetric =
+        testing.metrics().stream()
+            .filter(m -> m.getName().equals("failsafe.retry_policy.attempts"))
+            .findFirst()
+            .get()
+            .getHistogramData();
+    Collection<HistogramPointData> pointData = attemptsMetric.getPoints();
+    assertThat(pointData).hasSize(2);
+    assertThat(pointData)
+        .anyMatch(
+            p ->
+                p.getCount() == 3
+                    && p.getMin() == 1
+                    && p.getMax() == 3
+                    && p.getAttributes().equals(buildExpectedRetryPolicyAttributes("success"))
+                    && Arrays.equals(p.getCounts().toArray(), new Long[] {1L, 1L, 1L, 0L}));
+    assertThat(pointData)
+        .anyMatch(
+            p ->
+                p.getCount() == 1
+                    && p.getMin() == 3
+                    && p.getMax() == 3
+                    && p.getAttributes().equals(buildExpectedRetryPolicyAttributes("failure"))
+                    && Arrays.equals(p.getCounts().toArray(), new Long[] {0L, 0L, 1L, 0L}));
+  }
+
   private static Consumer<LongPointAssert> buildCircuitBreakerAssertion(
       long expectedValue, String expectedAttributeKey, String expectedAttributeValue) {
     return longSumAssert ->
@@ -94,4 +178,11 @@ private static Consumer<LongPointAssert> buildCircuitBreakerAssertion(
                             .build(),
                         attributes));
   }
+
+  private static Attributes buildExpectedRetryPolicyAttributes(String expectedOutcome) {
+    return Attributes.builder()
+        .put("failsafe.retry_policy.name", "testing")
+        .put("failsafe.retry_policy.outcome", expectedOutcome)
+        .build();
+  }
 }