Convert histogram measurements to double before passing recording exe…

…mplar reservoir
open-telemetry · Nov 28, 2023 · ff5595a · ff5595a
1 parent c57ca65
commit ff5595a
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Showing 7 changed files with 286 additions and 6 deletions.
diff --git a/...trics/src/main/java/io/opentelemetry/sdk/metrics/internal/exemplar/ExemplarReservoir.java b/...trics/src/main/java/io/opentelemetry/sdk/metrics/internal/exemplar/ExemplarReservoir.java
@@ -8,6 +8,7 @@
 import io.opentelemetry.api.common.Attributes;
 import io.opentelemetry.context.Context;
 import io.opentelemetry.sdk.common.Clock;
+import io.opentelemetry.sdk.metrics.Aggregation;
 import io.opentelemetry.sdk.metrics.data.DoubleExemplarData;
 import io.opentelemetry.sdk.metrics.data.ExemplarData;
 import io.opentelemetry.sdk.metrics.data.LongExemplarData;
@@ -25,6 +26,19 @@
  */
 public interface ExemplarReservoir<T extends ExemplarData> {
 
+  /**
+   * Wraps a {@link ExemplarReservoir}, casting calls to {@link
+   * ExemplarReservoir#offerLongMeasurement(long, Attributes, Context)} to {@link
+   * ExemplarReservoir#offerDoubleMeasurement(double, Attributes, Context)} such that {@link
+   * ExemplarReservoir#collectAndReset(Attributes)} only returns {@link DoubleExemplarData}.
+   *
+   * <p>This is used for {@link Aggregation#explicitBucketHistogram()} and {@link
+   * Aggregation#base2ExponentialBucketHistogram()} which only support double measurements.
+   */
+  static <T extends ExemplarData> ExemplarReservoir<T> longToDouble(ExemplarReservoir<T> delegate) {
+    return new LongToDoubleExemplarReservoir<>(delegate);
+  }
+
   /** Wraps a {@link ExemplarReservoir} with a measurement pre-filter. */
   static <T extends ExemplarData> ExemplarReservoir<T> filtered(
       ExemplarFilter filter, ExemplarReservoir<T> original) {

diff --git a/...in/java/io/opentelemetry/sdk/metrics/internal/exemplar/LongToDoubleExemplarReservoir.java b/...in/java/io/opentelemetry/sdk/metrics/internal/exemplar/LongToDoubleExemplarReservoir.java
@@ -0,0 +1,35 @@
+/*
+ * Copyright The OpenTelemetry Authors
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+package io.opentelemetry.sdk.metrics.internal.exemplar;
+
+import io.opentelemetry.api.common.Attributes;
+import io.opentelemetry.context.Context;
+import io.opentelemetry.sdk.metrics.data.ExemplarData;
+import java.util.List;
+
+class LongToDoubleExemplarReservoir<T extends ExemplarData> implements ExemplarReservoir<T> {
+
+  private final ExemplarReservoir<T> delegate;
+
+  LongToDoubleExemplarReservoir(ExemplarReservoir<T> delegate) {
+    this.delegate = delegate;
+  }
+
+  @Override
+  public void offerDoubleMeasurement(double value, Attributes attributes, Context context) {
+    delegate.offerDoubleMeasurement(value, attributes, context);
+  }
+
+  @Override
+  public void offerLongMeasurement(long value, Attributes attributes, Context context) {
+    offerDoubleMeasurement((double) value, attributes, context);
+  }
+
+  @Override
+  public List<T> collectAndReset(Attributes pointAttributes) {
+    return delegate.collectAndReset(pointAttributes);
+  }
+}
diff --git a/...java/io/opentelemetry/sdk/metrics/internal/view/Base2ExponentialHistogramAggregation.java b/...java/io/opentelemetry/sdk/metrics/internal/view/Base2ExponentialHistogramAggregation.java
@@ -72,10 +72,11 @@ public <T extends PointData, U extends ExemplarData> Aggregator<T, U> createAggr
             () ->
                 ExemplarReservoir.filtered(
                     exemplarFilter,
-                    ExemplarReservoir.doubleFixedSizeReservoir(
-                        Clock.getDefault(),
-                        Runtime.getRuntime().availableProcessors(),
-                        RandomSupplier.platformDefault())),
+                    ExemplarReservoir.longToDouble(
+                        ExemplarReservoir.doubleFixedSizeReservoir(
+                            Clock.getDefault(),
+                            Runtime.getRuntime().availableProcessors(),
+                            RandomSupplier.platformDefault()))),
             maxBuckets,
             maxScale);
   }

diff --git a/...n/java/io/opentelemetry/sdk/metrics/internal/view/ExplicitBucketHistogramAggregation.java b/...n/java/io/opentelemetry/sdk/metrics/internal/view/ExplicitBucketHistogramAggregation.java
@@ -57,8 +57,9 @@ public <T extends PointData, U extends ExemplarData> Aggregator<T, U> createAggr
             () ->
                 ExemplarReservoir.filtered(
                     exemplarFilter,
-                    ExemplarReservoir.histogramBucketReservoir(
-                        Clock.getDefault(), bucketBoundaries)));
+                    ExemplarReservoir.longToDouble(
+                        ExemplarReservoir.histogramBucketReservoir(
+                            Clock.getDefault(), bucketBoundaries))));
   }
 
   @Override

diff --git a/sdk/metrics/src/test/java/io/opentelemetry/sdk/metrics/SdkDoubleHistogramTest.java b/sdk/metrics/src/test/java/io/opentelemetry/sdk/metrics/SdkDoubleHistogramTest.java
@@ -14,12 +14,16 @@
 import io.opentelemetry.api.common.Attributes;
 import io.opentelemetry.api.metrics.DoubleHistogram;
 import io.opentelemetry.api.metrics.Meter;
+import io.opentelemetry.api.trace.Span;
+import io.opentelemetry.api.trace.Tracer;
+import io.opentelemetry.context.Scope;
 import io.opentelemetry.internal.testing.slf4j.SuppressLogger;
 import io.opentelemetry.sdk.common.InstrumentationScopeInfo;
 import io.opentelemetry.sdk.metrics.internal.state.DefaultSynchronousMetricStorage;
 import io.opentelemetry.sdk.resources.Resource;
 import io.opentelemetry.sdk.testing.exporter.InMemoryMetricReader;
 import io.opentelemetry.sdk.testing.time.TestClock;
+import io.opentelemetry.sdk.trace.SdkTracerProvider;
 import java.time.Duration;
 import java.util.Arrays;
 import java.util.Collections;
@@ -275,6 +279,97 @@ void doubleHistogramRecord_NaN() {
     assertThat(sdkMeterReader.collectAllMetrics()).hasSize(0);
   }
 
+  @Test
+  void collectMetrics_ExemplarsWithExponentialHistogram() {
+    InMemoryMetricReader reader = InMemoryMetricReader.create();
+    SdkMeterProvider sdkMeterProvider =
+        SdkMeterProvider.builder()
+            .setClock(testClock)
+            .setResource(RESOURCE)
+            .registerView(
+                InstrumentSelector.builder().setType(InstrumentType.HISTOGRAM).build(),
+                View.builder()
+                    .setAggregation(Aggregation.base2ExponentialBucketHistogram())
+                    .setAttributeFilter(Collections.emptySet())
+                    .build())
+            .registerMetricReader(reader)
+            .build();
+    Meter sdkMeter = sdkMeterProvider.get(getClass().getName());
+    DoubleHistogram histogram = sdkMeter.histogramBuilder("testHistogram").build();
+
+    SdkTracerProvider tracerProvider = SdkTracerProvider.builder().build();
+    Tracer tracer = tracerProvider.get("foo");
+
+    Span span = tracer.spanBuilder("span").startSpan();
+    try (Scope unused = span.makeCurrent()) {
+      histogram.record(10, Attributes.builder().put("key", "value").build());
+    }
+
+    assertThat(reader.collectAllMetrics())
+        .satisfiesExactly(
+            metric ->
+                assertThat(metric)
+                    .hasExponentialHistogramSatisfying(
+                        exponentialHistogram ->
+                            exponentialHistogram.hasPointsSatisfying(
+                                point ->
+                                    point
+                                        .hasSum(10.0)
+                                        .hasAttributes(Attributes.empty())
+                                        .hasExemplarsSatisfying(
+                                            exemplar ->
+                                                exemplar
+                                                    .hasValue(10.0)
+                                                    .hasFilteredAttributes(
+                                                        Attributes.builder()
+                                                            .put("key", "value")
+                                                            .build())))));
+  }
+
+  @Test
+  void collectMetrics_ExemplarsWithExplicitBucketHistogram() {
+    InMemoryMetricReader reader = InMemoryMetricReader.create();
+    SdkMeterProvider sdkMeterProvider =
+        SdkMeterProvider.builder()
+            .setClock(testClock)
+            .setResource(RESOURCE)
+            .registerView(
+                InstrumentSelector.builder().setName("*").build(),
+                View.builder().setAttributeFilter(Collections.emptySet()).build())
+            .registerMetricReader(reader)
+            .build();
+    Meter sdkMeter = sdkMeterProvider.get(getClass().getName());
+    DoubleHistogram histogram = sdkMeter.histogramBuilder("testHistogram").build();
+
+    SdkTracerProvider tracerProvider = SdkTracerProvider.builder().build();
+    Tracer tracer = tracerProvider.get("foo");
+
+    Span span = tracer.spanBuilder("span").startSpan();
+    try (Scope unused = span.makeCurrent()) {
+      histogram.record(10, Attributes.builder().put("key", "value").build());
+    }
+
+    assertThat(reader.collectAllMetrics())
+        .satisfiesExactly(
+            metric ->
+                assertThat(metric)
+                    .hasHistogramSatisfying(
+                        explicitHistogram ->
+                            explicitHistogram.hasPointsSatisfying(
+                                point ->
+                                    point
+                                        .hasSum(10)
+                                        .hasAttributes(Attributes.empty())
+                                        .hasExemplarsSatisfying(
+                                            exemplar ->
+                                                exemplar
+                                                    .hasValue(10.0)
+                                                    .hasFilteredAttributes(
+                                                        Attributes.builder()
+                                                            .put("key", "value")
+                                                            .build())))));
+  }
+
   @Test
   void stressTest() {
     DoubleHistogram doubleHistogram = sdkMeter.histogramBuilder("testHistogram").build();

diff --git a/sdk/metrics/src/test/java/io/opentelemetry/sdk/metrics/SdkLongHistogramTest.java b/sdk/metrics/src/test/java/io/opentelemetry/sdk/metrics/SdkLongHistogramTest.java
@@ -14,11 +14,15 @@
 import io.opentelemetry.api.common.Attributes;
 import io.opentelemetry.api.metrics.LongHistogram;
 import io.opentelemetry.api.metrics.Meter;
+import io.opentelemetry.api.trace.Span;
+import io.opentelemetry.api.trace.Tracer;
+import io.opentelemetry.context.Scope;
 import io.opentelemetry.internal.testing.slf4j.SuppressLogger;
 import io.opentelemetry.sdk.common.InstrumentationScopeInfo;
 import io.opentelemetry.sdk.resources.Resource;
 import io.opentelemetry.sdk.testing.exporter.InMemoryMetricReader;
 import io.opentelemetry.sdk.testing.time.TestClock;
+import io.opentelemetry.sdk.trace.SdkTracerProvider;
 import java.time.Duration;
 import java.util.Arrays;
 import java.util.Collections;
@@ -435,6 +439,97 @@ void longHistogramRecord_NonNegativeCheck() {
         "Histograms can only record non-negative values. Instrument testHistogram has recorded a negative value.");
   }
 
+  @Test
+  void collectMetrics_ExemplarsWithExponentialHistogram() {
+    InMemoryMetricReader reader = InMemoryMetricReader.create();
+    SdkMeterProvider sdkMeterProvider =
+        SdkMeterProvider.builder()
+            .setClock(testClock)
+            .setResource(RESOURCE)
+            .registerView(
+                InstrumentSelector.builder().setType(InstrumentType.HISTOGRAM).build(),
+                View.builder()
+                    .setAggregation(Aggregation.base2ExponentialBucketHistogram())
+                    .setAttributeFilter(Collections.emptySet())
+                    .build())
+            .registerMetricReader(reader)
+            .build();
+    Meter sdkMeter = sdkMeterProvider.get(getClass().getName());
+    LongHistogram histogram = sdkMeter.histogramBuilder("testHistogram").ofLongs().build();
+
+    SdkTracerProvider tracerProvider = SdkTracerProvider.builder().build();
+    Tracer tracer = tracerProvider.get("foo");
+
+    Span span = tracer.spanBuilder("span").startSpan();
+    try (Scope unused = span.makeCurrent()) {
+      histogram.record(10, Attributes.builder().put("key", "value").build());
+    }
+
+    assertThat(reader.collectAllMetrics())
+        .satisfiesExactly(
+            metric ->
+                assertThat(metric)
+                    .hasExponentialHistogramSatisfying(
+                        exponentialHistogram ->
+                            exponentialHistogram.hasPointsSatisfying(
+                                point ->
+                                    point
+                                        .hasSum(10.0)
+                                        .hasAttributes(Attributes.empty())
+                                        .hasExemplarsSatisfying(
+                                            exemplar ->
+                                                exemplar
+                                                    .hasValue(10.0)
+                                                    .hasFilteredAttributes(
+                                                        Attributes.builder()
+                                                            .put("key", "value")
+                                                            .build())))));
+  }
+
+  @Test
+  void collectMetrics_ExemplarsWithExplicitBucketHistogram() {
+    InMemoryMetricReader reader = InMemoryMetricReader.create();
+    SdkMeterProvider sdkMeterProvider =
+        SdkMeterProvider.builder()
+            .setClock(testClock)
+            .setResource(RESOURCE)
+            .registerView(
+                InstrumentSelector.builder().setName("*").build(),
+                View.builder().setAttributeFilter(Collections.emptySet()).build())
+            .registerMetricReader(reader)
+            .build();
+    Meter sdkMeter = sdkMeterProvider.get(getClass().getName());
+    LongHistogram histogram = sdkMeter.histogramBuilder("testHistogram").ofLongs().build();
+
+    SdkTracerProvider tracerProvider = SdkTracerProvider.builder().build();
+    Tracer tracer = tracerProvider.get("foo");
+
+    Span span = tracer.spanBuilder("span").startSpan();
+    try (Scope unused = span.makeCurrent()) {
+      histogram.record(10, Attributes.builder().put("key", "value").build());
+    }
+
+    assertThat(reader.collectAllMetrics())
+        .satisfiesExactly(
+            metric ->
+                assertThat(metric)
+                    .hasHistogramSatisfying(
+                        explicitHistogram ->
+                            explicitHistogram.hasPointsSatisfying(
+                                point ->
+                                    point
+                                        .hasSum(10)
+                                        .hasAttributes(Attributes.empty())
+                                        .hasExemplarsSatisfying(
+                                            exemplar ->
+                                                exemplar
+                                                    .hasValue(10.0)
+                                                    .hasFilteredAttributes(
+                                                        Attributes.builder()
+                                                            .put("key", "value")
+                                                            .build())))));
+  }
+
   @Test
   void stressTest() {
     LongHistogram longHistogram = sdkMeter.histogramBuilder("testHistogram").ofLongs().build();

diff --git a/...ava/io/opentelemetry/sdk/metrics/internal/exemplar/LongToDoubleExemplarReservoirTest.java b/...ava/io/opentelemetry/sdk/metrics/internal/exemplar/LongToDoubleExemplarReservoirTest.java
@@ -0,0 +1,39 @@
+/*
+ * Copyright The OpenTelemetry Authors
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+package io.opentelemetry.sdk.metrics.internal.exemplar;
+
+import static org.mockito.ArgumentMatchers.any;
+import static org.mockito.ArgumentMatchers.anyLong;
+import static org.mockito.Mockito.never;
+import static org.mockito.Mockito.verify;
+
+import io.opentelemetry.api.common.Attributes;
+import io.opentelemetry.context.Context;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.extension.ExtendWith;
+import org.mockito.Mock;
+import org.mockito.junit.jupiter.MockitoExtension;
+
+@ExtendWith(MockitoExtension.class)
+class LongToDoubleExemplarReservoirTest {
+  @Mock ExemplarReservoir<?> delegate;
+
+  @Test
+  void offerDoubleMeasurement() {
+    ExemplarReservoir<?> filtered = new LongToDoubleExemplarReservoir<>(delegate);
+    filtered.offerDoubleMeasurement(1.0, Attributes.empty(), Context.root());
+    verify(delegate).offerDoubleMeasurement(1.0, Attributes.empty(), Context.root());
+    verify(delegate, never()).offerLongMeasurement(anyLong(), any(), any());
+  }
+
+  @Test
+  void offerLongMeasurement() {
+    ExemplarReservoir<?> filtered = new LongToDoubleExemplarReservoir<>(delegate);
+    filtered.offerLongMeasurement(1L, Attributes.empty(), Context.root());
+    verify(delegate).offerDoubleMeasurement(1.0, Attributes.empty(), Context.root());
+    verify(delegate, never()).offerLongMeasurement(anyLong(), any(), any());
+  }
+}