Specify ...jvm.gc.duration buckets using advice API (#8436)

open-telemetry · May 15, 2023 · e8a22ed · e8a22ed
1 parent 0b774af
commit e8a22ed
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Showing 3 changed files with 35 additions and 16 deletions.
diff --git a/instrumentation/runtime-metrics/library/build.gradle.kts b/instrumentation/runtime-metrics/library/build.gradle.kts
@@ -4,6 +4,7 @@ plugins {
 
 dependencies {
   implementation(project(":instrumentation-api"))
+  implementation("io.opentelemetry:opentelemetry-extension-incubator")
 
   testImplementation("io.opentelemetry:opentelemetry-sdk-metrics")
   testImplementation(project(":testing-common"))

diff --git a/...brary/src/main/java/io/opentelemetry/instrumentation/runtimemetrics/GarbageCollector.java b/...brary/src/main/java/io/opentelemetry/instrumentation/runtimemetrics/GarbageCollector.java
@@ -5,15 +5,20 @@
 
 package io.opentelemetry.instrumentation.runtimemetrics;
 
+import static java.util.Collections.emptyList;
+
 import com.sun.management.GarbageCollectionNotificationInfo;
 import io.opentelemetry.api.OpenTelemetry;
 import io.opentelemetry.api.common.AttributeKey;
 import io.opentelemetry.api.common.Attributes;
-import io.opentelemetry.api.metrics.LongHistogram;
+import io.opentelemetry.api.metrics.DoubleHistogram;
+import io.opentelemetry.api.metrics.DoubleHistogramBuilder;
 import io.opentelemetry.api.metrics.Meter;
+import io.opentelemetry.extension.incubator.metrics.ExtendedDoubleHistogramBuilder;
 import java.lang.management.GarbageCollectorMXBean;
 import java.lang.management.ManagementFactory;
 import java.util.List;
+import java.util.concurrent.TimeUnit;
 import java.util.function.Function;
 import java.util.logging.Logger;
 import javax.management.Notification;
@@ -35,6 +40,8 @@ public final class GarbageCollector {
 
   private static final Logger logger = Logger.getLogger(GarbageCollector.class.getName());
 
+  private static final double MILLIS_PER_S = TimeUnit.SECONDS.toMillis(1);
+
   private static final AttributeKey<String> GC_KEY = AttributeKey.stringKey("gc");
   private static final AttributeKey<String> ACTION_KEY = AttributeKey.stringKey("action");
 
@@ -66,43 +73,52 @@ static void registerObservers(
       Function<Notification, GarbageCollectionNotificationInfo> notificationInfoExtractor) {
     Meter meter = RuntimeMetricsUtil.getMeter(openTelemetry);
 
-    LongHistogram gcTime =
+    DoubleHistogramBuilder gcDurationBuilder =
         meter
             .histogramBuilder("process.runtime.jvm.gc.duration")
             .setDescription("Duration of JVM garbage collection actions")
-            .setUnit("ms")
-            .ofLongs()
-            .build();
+            .setUnit("s");
+    setGcDurationBuckets(gcDurationBuilder);
+    DoubleHistogram gcDuration = gcDurationBuilder.build();
 
     for (GarbageCollectorMXBean gcBean : gcBeans) {
       if (!(gcBean instanceof NotificationEmitter)) {
         continue;
       }
       NotificationEmitter notificationEmitter = (NotificationEmitter) gcBean;
       notificationEmitter.addNotificationListener(
-          new GcNotificationListener(gcTime, notificationInfoExtractor), GC_FILTER, null);
+          new GcNotificationListener(gcDuration, notificationInfoExtractor), GC_FILTER, null);
+    }
+  }
+
+  private static void setGcDurationBuckets(DoubleHistogramBuilder builder) {
+    if (!(builder instanceof ExtendedDoubleHistogramBuilder)) {
+      // that shouldn't really happen
+      return;
     }
+    ((ExtendedDoubleHistogramBuilder) builder)
+        .setAdvice(advice -> advice.setExplicitBucketBoundaries(emptyList()));
   }
 
   private static final class GcNotificationListener implements NotificationListener {
 
-    private final LongHistogram gcTime;
+    private final DoubleHistogram gcDuration;
     private final Function<Notification, GarbageCollectionNotificationInfo>
         notificationInfoExtractor;
 
     private GcNotificationListener(
-        LongHistogram gcTime,
+        DoubleHistogram gcDuration,
         Function<Notification, GarbageCollectionNotificationInfo> notificationInfoExtractor) {
-      this.gcTime = gcTime;
+      this.gcDuration = gcDuration;
       this.notificationInfoExtractor = notificationInfoExtractor;
     }
 
     @Override
     public void handleNotification(Notification notification, Object unused) {
       GarbageCollectionNotificationInfo notificationInfo =
           notificationInfoExtractor.apply(notification);
-      gcTime.record(
-          notificationInfo.getGcInfo().getDuration(),
+      gcDuration.record(
+          notificationInfo.getGcInfo().getDuration() / MILLIS_PER_S,
           Attributes.of(
               GC_KEY, notificationInfo.getGcName(), ACTION_KEY, notificationInfo.getGcAction()));
     }

diff --git a/...y/src/test/java/io/opentelemetry/instrumentation/runtimemetrics/GarbageCollectorTest.java b/...y/src/test/java/io/opentelemetry/instrumentation/runtimemetrics/GarbageCollectorTest.java
@@ -72,28 +72,30 @@ void registerObservers() {
                     assertThat(metricData)
                         .hasInstrumentationScope(EXPECTED_SCOPE)
                         .hasDescription("Duration of JVM garbage collection actions")
-                        .hasUnit("ms")
+                        .hasUnit("s")
                         .hasHistogramSatisfying(
                             histogram ->
                                 histogram.hasPointsSatisfying(
                                     point ->
                                         point
                                             .hasCount(2)
-                                            .hasSum(22)
+                                            .hasSum(0.022)
                                             .hasAttributes(
                                                 Attributes.builder()
                                                     .put("gc", "G1 Young Generation")
                                                     .put("action", "end of minor GC")
-                                                    .build()),
+                                                    .build())
+                                            .hasBucketBoundaries(),
                                     point ->
                                         point
                                             .hasCount(1)
-                                            .hasSum(11)
+                                            .hasSum(0.011)
                                             .hasAttributes(
                                                 Attributes.builder()
                                                     .put("gc", "G1 Old Generation")
                                                     .put("action", "end of major GC")
-                                                    .build())))));
+                                                    .build())
+                                            .hasBucketBoundaries()))));
   }
 
   private static Notification createTestNotification(