Add histogram collection benchmark

sdk/metrics/src/jmh/java/io/opentelemetry/sdk/metrics/internal/aggregator/HistogramCollectBenchmark.java

@@ -0,0 +1,160 @@
+/*
+ * Copyright The OpenTelemetry Authors
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+package io.opentelemetry.sdk.metrics.internal.aggregator;
+
+import io.opentelemetry.api.common.Attributes;
+import io.opentelemetry.api.metrics.DoubleHistogram;
+import io.opentelemetry.sdk.common.CompletableResultCode;
+import io.opentelemetry.sdk.metrics.Aggregation;
+import io.opentelemetry.sdk.metrics.InstrumentType;
+import io.opentelemetry.sdk.metrics.SdkMeterProvider;
+import io.opentelemetry.sdk.metrics.SdkMeterProviderBuilder;
+import io.opentelemetry.sdk.metrics.data.AggregationTemporality;
+import io.opentelemetry.sdk.metrics.data.MetricData;
+import io.opentelemetry.sdk.metrics.export.MetricExporter;
+import io.opentelemetry.sdk.metrics.export.PeriodicMetricReader;
+import io.opentelemetry.sdk.metrics.internal.SdkMeterProviderUtil;
+import io.opentelemetry.sdk.metrics.internal.exemplar.ExemplarFilter;
+import io.opentelemetry.sdk.metrics.internal.view.ExponentialHistogramAggregation;
+import java.time.Duration;
+import java.util.ArrayList;
+import java.util.Collection;
+import java.util.List;
+import java.util.Random;
+import java.util.concurrent.TimeUnit;
+import org.openjdk.jmh.annotations.Benchmark;
+import org.openjdk.jmh.annotations.BenchmarkMode;
+import org.openjdk.jmh.annotations.Fork;
+import org.openjdk.jmh.annotations.Measurement;
+import org.openjdk.jmh.annotations.Mode;
+import org.openjdk.jmh.annotations.OutputTimeUnit;
+import org.openjdk.jmh.annotations.Param;
+import org.openjdk.jmh.annotations.Scope;
+import org.openjdk.jmh.annotations.Setup;
+import org.openjdk.jmh.annotations.State;
+import org.openjdk.jmh.annotations.TearDown;
+import org.openjdk.jmh.annotations.Threads;
+import org.openjdk.jmh.annotations.Warmup;
+
+/**
+ * Measures the collection path for various histogram aggregations. Should be used primarily to
+ * compare memory allocation rates.
+ */
+@BenchmarkMode(Mode.SingleShotTime)
+@OutputTimeUnit(TimeUnit.NANOSECONDS)
+@Measurement(iterations = 5, batchSize = 100)
+@Warmup(iterations = 2, batchSize = 10)
+@Fork(1)
+public class HistogramCollectBenchmark {
+
+  private static final int cardinality = 100;
+  private static final int measurementsPerSeries = 10_000;
+
+  @State(Scope.Benchmark)
+  public static class ThreadState {
+    @Param private AggregationTemporality aggregationTemporality;
+    @Param private AggregationGenerator aggregationGenerator;
+
+    private SdkMeterProvider sdkMeterProvider;
+    private DoubleHistogram histogram;
+    private Random random;
+    private List<Attributes> attributesList;
+
+    @Setup
+    public void setup() {
+      SdkMeterProviderBuilder builder =
+          SdkMeterProvider.builder()
+              .registerMetricReader(
+                  PeriodicMetricReader.builder(
+                          // Configure an exporter that configures the temporality and aggregation
+                          // for the test case, but otherwise drops the data on export
+                          new NoopMetricExporter(
+                              aggregationTemporality, aggregationGenerator.aggregation))
+                      // Effectively disable periodic reading so reading is only done on #flush()
+                      .setInterval(Duration.ofSeconds(Integer.MAX_VALUE))
+                      .build());
+      // Disable examplars
+      SdkMeterProviderUtil.setExemplarFilter(builder, ExemplarFilter.neverSample());
+      sdkMeterProvider = builder.build();
+      histogram = sdkMeterProvider.get("meter").histogramBuilder("histogram").build();
+
+      random = new Random();
+      attributesList = new ArrayList<>(cardinality);
+      String last = "aaaaaaaaaaaaaaaaaaaaaaaaaa";
+      for (int i = 0; i < cardinality; i++) {
+        char[] chars = last.toCharArray();
+        chars[random.nextInt(last.length())] = (char) (random.nextInt(26) + 'a');
+        last = new String(chars);
+        attributesList.add(Attributes.builder().put("key", last).build());
+      }
+    }
+
+    @TearDown
+    public void tearDown() {
+      sdkMeterProvider.shutdown().join(10, TimeUnit.SECONDS);
+    }
+  }
+
+  @Benchmark
+  @Threads(value = 1)
+  public void recordAndCollect(ThreadState threadState) {
+    for (Attributes attributes : threadState.attributesList) {
+      for (int i = 0; i < measurementsPerSeries; i++) {
+        int value = threadState.random.nextInt(10_000);
+        threadState.histogram.record(value, attributes);
+      }
+    }
+    threadState.sdkMeterProvider.forceFlush().join(10, TimeUnit.SECONDS);
+  }
+
+  @SuppressWarnings("ImmutableEnumChecker")
+  public enum AggregationGenerator {
+    EXPLICIT_BUCKET_HISTOGRAM(Aggregation.explicitBucketHistogram()),
+    EXPONENTIAL_BUCKET_HISTOGRAM(ExponentialHistogramAggregation.getDefault());
+
+    private final Aggregation aggregation;
+
+    AggregationGenerator(Aggregation aggregation) {
+      this.aggregation = aggregation;
+    }
+  }
+
+  private static class NoopMetricExporter implements MetricExporter {
+    private final AggregationTemporality aggregationTemporality;
+    private final Aggregation aggregation;
+
+    private NoopMetricExporter(
+        AggregationTemporality aggregationTemporality, Aggregation aggregation) {
+      this.aggregationTemporality = aggregationTemporality;
+      this.aggregation = aggregation;
+    }
+
+    @Override
+    public CompletableResultCode export(Collection<MetricData> metrics) {
+      return CompletableResultCode.ofSuccess();
+    }
+
+    @Override
+    public CompletableResultCode flush() {
+      return CompletableResultCode.ofSuccess();
+    }
+
+    @Override
+    public CompletableResultCode shutdown() {
+      return CompletableResultCode.ofSuccess();
+    }
+
+    @Override
+    public Aggregation getDefaultAggregation(InstrumentType instrumentType) {
+      return aggregation;
+    }
+
+    @Override
+    public AggregationTemporality getAggregationTemporality(InstrumentType instrumentType) {
+      return aggregationTemporality;
+    }
+  }
+}

sdk/metrics/src/jmh/java/io/opentelemetry/sdk/metrics/internal/aggregator/HistogramValueGenerator.java

@@ -60,11 +60,9 @@ public double getAsDouble() {
   }
   /** Constructs a pool using explicit bucket histogram boundaries. */
   private static double[] explicitDefaultBucketPool() {
-    List<Double> fixedBoundaries = new ArrayList<Double>();
-    // Add minimal recording value.
-    fixedBoundaries.add(0.0);
-    // Add the bucket LE bucket boundaries (starts at 5).
-    fixedBoundaries.addAll(ExplicitBucketHistogramUtils.DEFAULT_HISTOGRAM_BUCKET_BOUNDARIES);
+    // Add the bucket LE bucket boundaries.
+    List<Double> fixedBoundaries =
+        new ArrayList<>(ExplicitBucketHistogramUtils.DEFAULT_HISTOGRAM_BUCKET_BOUNDARIES);
     // Add Double max value as our other extreme.
     fixedBoundaries.add(Double.MAX_VALUE);
     return ExplicitBucketHistogramUtils.createBoundaryArray(fixedBoundaries);