MetricReader and MetricExporter can determine default aggregation by …

…instrument (#4472)

* MetricReader and MetricExporter can determine default aggregation by instrument

* Add since annotations

docs/apidiffs/current_vs_latest/opentelemetry-sdk-metrics.txt

@@ -1,2 +1,20 @@
 Comparing source compatibility of  against 
-No changes.
++++  NEW INTERFACE: PUBLIC(+) ABSTRACT(+) io.opentelemetry.sdk.metrics.export.DefaultAggregationSelector  (not serializable)
+	+++  CLASS FILE FORMAT VERSION: 52.0 <- n.a.
+	+++  NEW SUPERCLASS: java.lang.Object
+	+++  NEW METHOD: PUBLIC(+) STATIC(+) io.opentelemetry.sdk.metrics.export.DefaultAggregationSelector getDefault()
+	+++  NEW METHOD: PUBLIC(+) ABSTRACT(+) io.opentelemetry.sdk.metrics.Aggregation getDefaultAggregation(io.opentelemetry.sdk.metrics.InstrumentType)
+	+++  NEW ANNOTATION: java.lang.FunctionalInterface
+**** MODIFIED INTERFACE: PUBLIC ABSTRACT io.opentelemetry.sdk.metrics.export.MetricExporter  (not serializable)
+	===  CLASS FILE FORMAT VERSION: 52.0 <- 52.0
+	+++  NEW INTERFACE: io.opentelemetry.sdk.metrics.export.DefaultAggregationSelector
+	+++* NEW METHOD: PUBLIC(+) io.opentelemetry.sdk.metrics.Aggregation getDefaultAggregation(io.opentelemetry.sdk.metrics.InstrumentType)
+**** MODIFIED INTERFACE: PUBLIC ABSTRACT io.opentelemetry.sdk.metrics.export.MetricReader  (not serializable)
+	===  CLASS FILE FORMAT VERSION: 52.0 <- 52.0
+	+++  NEW INTERFACE: io.opentelemetry.sdk.metrics.export.DefaultAggregationSelector
+	+++* NEW METHOD: PUBLIC(+) io.opentelemetry.sdk.metrics.Aggregation getDefaultAggregation(io.opentelemetry.sdk.metrics.InstrumentType)
+***  MODIFIED CLASS: PUBLIC FINAL io.opentelemetry.sdk.metrics.export.PeriodicMetricReader  (not serializable)
+	===  CLASS FILE FORMAT VERSION: 52.0 <- 52.0
+	===* UNCHANGED INTERFACE: io.opentelemetry.sdk.metrics.export.MetricReader
+	+++  NEW INTERFACE: io.opentelemetry.sdk.metrics.export.DefaultAggregationSelector
+	+++  NEW METHOD: PUBLIC(+) io.opentelemetry.sdk.metrics.Aggregation getDefaultAggregation(io.opentelemetry.sdk.metrics.InstrumentType)

sdk-extensions/autoconfigure/src/test/java/io/opentelemetry/sdk/autoconfigure/AutoConfiguredOpenTelemetrySdkTest.java

@@ -223,6 +223,7 @@ void builder_addPropertiesSupplier() {
   void builder_addMeterProviderCustomizer() {
     Mockito.lenient().when(metricReader.shutdown()).thenReturn(CompletableResultCode.ofSuccess());
     when(metricReader.forceFlush()).thenReturn(CompletableResultCode.ofSuccess());
+    when(metricReader.getDefaultAggregation(any())).thenCallRealMethod();
 
     SdkMeterProvider sdkMeterProvider =
         builder

sdk-extensions/metric-incubator/src/test/java/io/opentelemetry/sdk/viewconfig/ViewConfigTest.java

@@ -20,7 +20,7 @@
 import io.opentelemetry.sdk.metrics.SdkMeterProviderBuilder;
 import io.opentelemetry.sdk.metrics.View;
 import io.opentelemetry.sdk.metrics.internal.view.AttributesProcessor;
-import io.opentelemetry.sdk.metrics.internal.view.ViewRegistryBuilder;
+import io.opentelemetry.sdk.metrics.internal.view.RegisteredView;
 import java.io.FileInputStream;
 import java.io.FileNotFoundException;
 import java.io.InputStream;
@@ -40,9 +40,7 @@ void registerViews_FullConfig() {
     ViewConfig.registerViews(builder, resourceFileInputStream("full-config.yaml"));
 
     assertThat(builder)
-        .extracting(
-            "viewRegistryBuilder", as(InstanceOfAssertFactories.type(ViewRegistryBuilder.class)))
-        .extracting("orderedViews", as(InstanceOfAssertFactories.list(Object.class)))
+        .extracting("registeredViews", as(InstanceOfAssertFactories.list(RegisteredView.class)))
         .hasSize(2);
   }
 

sdk/all/src/test/java/io/opentelemetry/sdk/OpenTelemetrySdkTest.java

@@ -8,6 +8,7 @@
 import static org.assertj.core.api.Assertions.assertThat;
 import static org.assertj.core.api.Assertions.assertThatThrownBy;
 import static org.assertj.core.api.InstanceOfAssertFactories.type;
+import static org.mockito.ArgumentMatchers.any;
 import static org.mockito.Mockito.mock;
 import static org.mockito.Mockito.when;
 
@@ -42,6 +43,7 @@
 @ExtendWith(MockitoExtension.class)
 class OpenTelemetrySdkTest {
 
+  @Mock private MetricExporter metricExporter;
   @Mock private SdkTracerProvider tracerProvider;
   @Mock private SdkMeterProvider meterProvider;
   @Mock private SdkLogEmitterProvider logEmitterProvider;
@@ -185,11 +187,12 @@ void getMeter() {
 
   @Test
   void meterBuilder() {
+    when(metricExporter.getDefaultAggregation(any())).thenCallRealMethod();
     OpenTelemetrySdk openTelemetry =
         OpenTelemetrySdk.builder()
             .setMeterProvider(
                 SdkMeterProvider.builder()
-                    .registerMetricReader(PeriodicMetricReader.create(mock(MetricExporter.class)))
+                    .registerMetricReader(PeriodicMetricReader.create(metricExporter))
                     .build())
             .build();
     assertThat(openTelemetry.meterBuilder("instr"))
@@ -198,11 +201,12 @@ void meterBuilder() {
 
   @Test
   void meterBuilder_ViaProvider() {
+    when(metricExporter.getDefaultAggregation(any())).thenCallRealMethod();
     OpenTelemetrySdk openTelemetry =
         OpenTelemetrySdk.builder()
             .setMeterProvider(
                 SdkMeterProvider.builder()
-                    .registerMetricReader(PeriodicMetricReader.create(mock(MetricExporter.class)))
+                    .registerMetricReader(PeriodicMetricReader.create(metricExporter))
                     .build())
             .build();
     assertThat(openTelemetry.getMeterProvider().meterBuilder("instr"))
@@ -225,16 +229,17 @@ void getMeterProvider() {
   // Demonstrates how clear or confusing is SDK configuration
   @Test
   void fullOpenTelemetrySdkConfigurationDemo() {
+    when(metricExporter.getDefaultAggregation(any())).thenCallRealMethod();
     OpenTelemetrySdk.builder()
         .setMeterProvider(
             SdkMeterProvider.builder()
                 .setResource(Resource.empty())
                 .setClock(mock(Clock.class))
                 .registerMetricReader(
-                    PeriodicMetricReader.builder(mock(MetricExporter.class))
+                    PeriodicMetricReader.builder(metricExporter)
                         .setInterval(Duration.ofSeconds(10))
                         .build())
-                .registerMetricReader(PeriodicMetricReader.create(mock(MetricExporter.class)))
+                .registerMetricReader(PeriodicMetricReader.create(metricExporter))
                 .registerView(
                     InstrumentSelector.builder().setName("name").build(),
                     View.builder().setName("new-name").build())
@@ -261,10 +266,11 @@ void fullOpenTelemetrySdkConfigurationDemo() {
   // Demonstrates how clear or confusing is SDK configuration
   @Test
   void trivialOpenTelemetrySdkConfigurationDemo() {
+    when(metricExporter.getDefaultAggregation(any())).thenCallRealMethod();
     OpenTelemetrySdk.builder()
         .setMeterProvider(
             SdkMeterProvider.builder()
-                .registerMetricReader(PeriodicMetricReader.create(mock(MetricExporter.class)))
+                .registerMetricReader(PeriodicMetricReader.create(metricExporter))
                 .build())
         .setTracerProvider(
             SdkTracerProvider.builder()
@@ -278,10 +284,11 @@ void trivialOpenTelemetrySdkConfigurationDemo() {
   // Demonstrates how clear or confusing is SDK configuration
   @Test
   void minimalOpenTelemetrySdkConfigurationDemo() {
+    when(metricExporter.getDefaultAggregation(any())).thenCallRealMethod();
     OpenTelemetrySdk.builder()
         .setMeterProvider(
             SdkMeterProvider.builder()
-                .registerMetricReader(PeriodicMetricReader.create(mock(MetricExporter.class)))
+                .registerMetricReader(PeriodicMetricReader.create(metricExporter))
                 .build())
         .setTracerProvider(
             SdkTracerProvider.builder()
@@ -294,7 +301,7 @@ void minimalOpenTelemetrySdkConfigurationDemo() {
     OpenTelemetrySdk.builder()
         .setMeterProvider(
             SdkMeterProvider.builder()
-                .registerMetricReader(PeriodicMetricReader.create(mock(MetricExporter.class)))
+                .registerMetricReader(PeriodicMetricReader.create(metricExporter))
                 .registerView(
                     InstrumentSelector.builder().setType(InstrumentType.COUNTER).build(),
                     View.builder().setAggregation(Aggregation.explicitBucketHistogram()).build())
@@ -313,7 +320,7 @@ void minimalOpenTelemetrySdkConfigurationDemo() {
   void stringRepresentation() {
     SpanExporter spanExporter = mock(SpanExporter.class);
     when(spanExporter.toString()).thenReturn("MockSpanExporter{}");
-    MetricExporter metricExporter = mock(MetricExporter.class);
+    when(metricExporter.getDefaultAggregation(any())).thenCallRealMethod();
     when(metricExporter.toString()).thenReturn("MockMetricExporter{}");
     Resource resource =
         Resource.builder().put(AttributeKey.stringKey("service.name"), "otel-test").build();

sdk/metrics/src/main/java/io/opentelemetry/sdk/metrics/AbstractInstrumentBuilder.java

@@ -104,8 +104,7 @@ final CallbackRegistration registerLongAsynchronousInstrument(
 
   final SdkObservableMeasurement buildObservableMeasurement(
       InstrumentType type, InstrumentValueType valueType) {
-    InstrumentDescriptor descriptor = makeDescriptor(type, valueType);
-    return meterSharedState.registerObservableMeasurement(descriptor, meterProviderSharedState);
+    return meterSharedState.registerObservableMeasurement(makeDescriptor(type, valueType));
   }
 
   @FunctionalInterface

sdk/metrics/src/main/java/io/opentelemetry/sdk/metrics/SdkMeterProvider.java

@@ -19,6 +19,7 @@
 import io.opentelemetry.sdk.metrics.internal.export.MetricProducer;
 import io.opentelemetry.sdk.metrics.internal.export.RegisteredReader;
 import io.opentelemetry.sdk.metrics.internal.state.MeterProviderSharedState;
+import io.opentelemetry.sdk.metrics.internal.view.RegisteredView;
 import io.opentelemetry.sdk.metrics.internal.view.ViewRegistry;
 import io.opentelemetry.sdk.resources.Resource;
 import java.io.Closeable;
@@ -40,6 +41,7 @@ public final class SdkMeterProvider implements MeterProvider, Closeable {
   private static final Logger LOGGER = Logger.getLogger(SdkMeterProvider.class.getName());
   static final String DEFAULT_METER_NAME = "unknown";
 
+  private final List<RegisteredView> registeredViews;
   private final List<RegisteredReader> registeredReaders;
   private final MeterProviderSharedState sharedState;
   private final ComponentRegistry<SdkMeter> registry;
@@ -51,16 +53,21 @@ public static SdkMeterProviderBuilder builder() {
   }
 
   SdkMeterProvider(
-      List<RegisteredReader> registeredReaders,
+      List<RegisteredView> registeredViews,
+      List<MetricReader> metricReaders,
       Clock clock,
       Resource resource,
-      ViewRegistry viewRegistry,
       ExemplarFilter exemplarFilter) {
     long startEpochNanos = clock.now();
-    this.registeredReaders = registeredReaders;
+    this.registeredViews = registeredViews;
+    this.registeredReaders =
+        metricReaders.stream()
+            .map(
+                reader ->
+                    RegisteredReader.create(reader, ViewRegistry.create(reader, registeredViews)))
+            .collect(toList());
     this.sharedState =
-        MeterProviderSharedState.create(
-            clock, resource, viewRegistry, exemplarFilter, startEpochNanos);
+        MeterProviderSharedState.create(clock, resource, exemplarFilter, startEpochNanos);
     this.registry =
         new ComponentRegistry<>(
             instrumentationLibraryInfo ->
@@ -144,7 +151,7 @@ public String toString() {
         + ", metricReaders="
         + registeredReaders.stream().map(RegisteredReader::getReader).collect(toList())
         + ", views="
-        + sharedState.getViewRegistry().getViews()
+        + registeredViews
         + "}";
   }
 

sdk/metrics/src/main/java/io/opentelemetry/sdk/metrics/SdkMeterProviderBuilder.java

@@ -10,9 +10,7 @@
 import io.opentelemetry.sdk.metrics.internal.SdkMeterProviderUtil;
 import io.opentelemetry.sdk.metrics.internal.debug.SourceInfo;
 import io.opentelemetry.sdk.metrics.internal.exemplar.ExemplarFilter;
-import io.opentelemetry.sdk.metrics.internal.export.RegisteredReader;
-import io.opentelemetry.sdk.metrics.internal.view.ViewRegistry;
-import io.opentelemetry.sdk.metrics.internal.view.ViewRegistryBuilder;
+import io.opentelemetry.sdk.metrics.internal.view.RegisteredView;
 import io.opentelemetry.sdk.resources.Resource;
 import java.util.ArrayList;
 import java.util.List;
@@ -34,8 +32,8 @@ public final class SdkMeterProviderBuilder {
 
   private Clock clock = Clock.getDefault();
   private Resource resource = Resource.getDefault();
-  private final ViewRegistryBuilder viewRegistryBuilder = ViewRegistry.builder();
-  private final List<RegisteredReader> registeredReaders = new ArrayList<>();
+  private final List<MetricReader> metricReaders = new ArrayList<>();
+  private final List<RegisteredView> registeredViews = new ArrayList<>();
   private ExemplarFilter exemplarFilter = DEFAULT_EXEMPLAR_FILTER;
 
   SdkMeterProviderBuilder() {}
@@ -96,8 +94,9 @@ SdkMeterProviderBuilder setExemplarFilter(ExemplarFilter filter) {
   public SdkMeterProviderBuilder registerView(InstrumentSelector selector, View view) {
     Objects.requireNonNull(selector, "selector");
     Objects.requireNonNull(view, "view");
-    viewRegistryBuilder.addView(
-        selector, view, view.getAttributesProcessor(), SourceInfo.fromCurrentStack());
+    registeredViews.add(
+        RegisteredView.create(
+            selector, view, view.getAttributesProcessor(), SourceInfo.fromCurrentStack()));
     return this;
   }
 
@@ -107,13 +106,12 @@ public SdkMeterProviderBuilder registerView(InstrumentSelector selector, View vi
    * <p>Note: custom implementations of {@link MetricReader} are not currently supported.
    */
   public SdkMeterProviderBuilder registerMetricReader(MetricReader reader) {
-    registeredReaders.add(RegisteredReader.create(reader));
+    metricReaders.add(reader);
     return this;
   }
 
   /** Returns an {@link SdkMeterProvider} built with the configuration of this builder. */
   public SdkMeterProvider build() {
-    return new SdkMeterProvider(
-        registeredReaders, clock, resource, viewRegistryBuilder.build(), exemplarFilter);
+    return new SdkMeterProvider(registeredViews, metricReaders, clock, resource, exemplarFilter);
   }
 }

sdk/metrics/src/main/java/io/opentelemetry/sdk/metrics/export/DefaultAggregationSelector.java

@@ -0,0 +1,33 @@
+/*
+ * Copyright The OpenTelemetry Authors
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+package io.opentelemetry.sdk.metrics.export;
+
+import io.opentelemetry.sdk.metrics.Aggregation;
+import io.opentelemetry.sdk.metrics.InstrumentType;
+
+/**
+ * A functional interface that selects default {@link Aggregation} based on {@link InstrumentType}.
+ *
+ * @since 1.16.0
+ */
+@FunctionalInterface
+public interface DefaultAggregationSelector {
+
+  /**
+   * The default implementation of {@link DefaultAggregationSelector} which returns the default
+   * aggregation for each instrument.
+   */
+  static DefaultAggregationSelector getDefault() {
+    return instrumentType -> Aggregation.defaultAggregation();
+  }
+
+  /**
+   * Return the default aggregation for the {@link InstrumentType}.
+   *
+   * <p>The default aggregation is used when an instrument does not match any views.
+   */
+  Aggregation getDefaultAggregation(InstrumentType instrumentType);
+}

sdk/metrics/src/main/java/io/opentelemetry/sdk/metrics/export/MetricExporter.java

@@ -6,6 +6,8 @@
 package io.opentelemetry.sdk.metrics.export;
 
 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.MetricData;
@@ -22,7 +24,19 @@
  *
  * @since 1.14.0
  */
-public interface MetricExporter extends AggregationTemporalitySelector, Closeable {
+public interface MetricExporter
+    extends AggregationTemporalitySelector, DefaultAggregationSelector, Closeable {
+
+  /**
+   * Return the default aggregation for the {@link InstrumentType}.
+   *
+   * @see DefaultAggregationSelector#getDefaultAggregation(InstrumentType)
+   * @since 1.16.0
+   */
+  @Override
+  default Aggregation getDefaultAggregation(InstrumentType instrumentType) {
+    return Aggregation.defaultAggregation();
+  }
 
   /**
    * Exports the {@code metrics}. The caller (i.e. {@link PeriodicMetricReader} will not call export

sdk/metrics/src/main/java/io/opentelemetry/sdk/metrics/export/MetricReader.java

@@ -6,6 +6,8 @@
 package io.opentelemetry.sdk.metrics.export;
 
 import io.opentelemetry.sdk.common.CompletableResultCode;
+import io.opentelemetry.sdk.metrics.Aggregation;
+import io.opentelemetry.sdk.metrics.InstrumentType;
 import io.opentelemetry.sdk.metrics.SdkMeterProvider;
 
 /**
@@ -16,7 +18,7 @@
  *
  * @since 1.14.0
  */
-public interface MetricReader extends AggregationTemporalitySelector {
+public interface MetricReader extends AggregationTemporalitySelector, DefaultAggregationSelector {
 
   /**
    * Called by {@link SdkMeterProvider} and supplies the {@link MetricReader} with a handle to
@@ -27,6 +29,17 @@ public interface MetricReader extends AggregationTemporalitySelector {
    */
   void register(CollectionRegistration registration);
 
+  /**
+   * Return the default aggregation for the {@link InstrumentType}.
+   *
+   * @see DefaultAggregationSelector#getDefaultAggregation(InstrumentType)
+   * @since 1.16.0
+   */
+  @Override
+  default Aggregation getDefaultAggregation(InstrumentType instrumentType) {
+    return Aggregation.defaultAggregation();
+  }
+
   /**
    * Read and export the metrics.
    *

sdk/metrics/src/main/java/io/opentelemetry/sdk/metrics/export/PeriodicMetricReader.java

@@ -6,6 +6,7 @@
 package io.opentelemetry.sdk.metrics.export;
 
 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;
@@ -68,6 +69,11 @@ public AggregationTemporality getAggregationTemporality(InstrumentType instrumen
     return exporter.getAggregationTemporality(instrumentType);
   }
 
+  @Override
+  public Aggregation getDefaultAggregation(InstrumentType instrumentType) {
+    return exporter.getDefaultAggregation(instrumentType);
+  }
+
   @Override
   public CompletableResultCode forceFlush() {
     return scheduled.doRun();