feat(sdk-metrics): implement metric reader metrics

CHANGELOG.md

@@ -35,6 +35,7 @@ For notes on migrating to 2.x / 0.200.x see [the upgrade guide](doc/upgrade-to-2
 
 ### :rocket: Features
 
+* feat(sdk-metrics): implement metric reader metrics  [#6449](https://github.com/open-telemetry/opentelemetry-js/pull/6449) @anuraaga
 * feat(sdk-trace): implement span start/end metrics  [#6213](https://github.com/open-telemetry/opentelemetry-js/pull/6213) @anuraaga
 
 ### :bug: Bug Fixes

experimental/packages/opentelemetry-exporter-prometheus/src/PrometheusExporter.ts

@@ -14,6 +14,7 @@ import type { IncomingMessage, Server, ServerResponse } from 'http';
 import { createServer } from 'http';
 import type { ExporterConfig } from './export/types';
 import { PrometheusSerializer } from './PrometheusSerializer';
+import { OTEL_COMPONENT_TYPE_VALUE_PROMETHEUS_HTTP_TEXT_METRIC_EXPORTER } from './semconv';
 /** Node.js v8.x compat */
 import { URL } from 'url';
 
@@ -60,6 +61,8 @@ export class PrometheusExporter extends MetricReader {
       },
       aggregationTemporalitySelector: _instrumentType =>
         AggregationTemporality.CUMULATIVE,
+      otelComponentType:
+        OTEL_COMPONENT_TYPE_VALUE_PROMETHEUS_HTTP_TEXT_METRIC_EXPORTER,
       metricProducers: config.metricProducers,
     });
     this._host =

experimental/packages/opentelemetry-exporter-prometheus/src/semconv.ts

@@ -0,0 +1,20 @@
+/*
+ * Copyright The OpenTelemetry Authors
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+/*
+ * This file contains a copy of unstable semantic convention definitions
+ * used by this package.
+ * @see https://github.com/open-telemetry/opentelemetry-js/tree/main/semantic-conventions#unstable-semconv
+ */
+
+/**
+ * Enum value "prometheus_http_text_metric_exporter" for attribute {@link ATTR_OTEL_COMPONENT_TYPE}.
+ *
+ * Prometheus metric exporter over HTTP with the default text-based format
+ *
+ * @experimental This enum value is experimental and is subject to breaking changes in minor releases of `@opentelemetry/semantic-conventions`.
+ */
+export const OTEL_COMPONENT_TYPE_VALUE_PROMETHEUS_HTTP_TEXT_METRIC_EXPORTER =
+  'prometheus_http_text_metric_exporter' as const;

experimental/packages/opentelemetry-sdk-node/README.md

@@ -241,6 +241,7 @@ OTEL_NODE_EXPERIMENTAL_SDK_METRICS=true
 Currently a subset of the specified metrics are implemented. See the following
 linkes for details:
 
+- Metric reader metrics: [MetricReaderMetrics](../../../packages//sdk-metrics/src/export/MetricReaderMetrics.ts)
 - Span metrics: [TracerMetrics.ts](../../../packages/opentelemetry-sdk-trace-base/src/TracerMetrics.ts)
 
 ## Useful links

experimental/packages/opentelemetry-sdk-node/src/sdk.ts

@@ -312,6 +312,12 @@ export class NodeSDK {
             })
           );
 
+    // While SDK metrics are unstable, we require an opt-in.
+    // https://opentelemetry.io/docs/specs/semconv/otel/sdk-metrics/
+    const sdkMetricsEnabled = getBooleanFromEnv(
+      'OTEL_NODE_EXPERIMENTAL_SDK_METRICS'
+    );
+
     if (
       this._meterProviderConfig?.readers &&
       // only register if there is a reader, otherwise we waste compute/memory.
@@ -321,6 +327,7 @@ export class NodeSDK {
         resource: this._resource,
         views: this._meterProviderConfig?.views ?? [],
         readers: this._meterProviderConfig.readers,
+        sdkMetricsEnabled,
       });
 
       this._meterProvider = meterProvider;
@@ -340,11 +347,6 @@ export class NodeSDK {
 
     // Only register if there is a span processor
     if (spanProcessors.length > 0) {
-      // While SDK metrics are unstable, we require an opt-in.
-      // https://opentelemetry.io/docs/specs/semconv/otel/sdk-metrics/
-      const sdkMetricsEnabled = getBooleanFromEnv(
-        'OTEL_NODE_EXPERIMENTAL_SDK_METRICS'
-      );
       this._tracerProvider = new NodeTracerProvider({
         ...this._configuration,
         resource: this._resource,

experimental/packages/opentelemetry-sdk-node/test/sdk.test.ts

@@ -69,6 +69,7 @@ import { OTLPTraceExporter as OTLPGrpcTraceExporter } from '@opentelemetry/expor
 import { ZipkinExporter } from '@opentelemetry/exporter-zipkin';
 
 import { ATTR_HOST_NAME, ATTR_PROCESS_PID } from '../src/semconv';
+import { NOOP_HISTOGRAM_METRIC } from '../../../../api/src/metrics/NoopMeter';
 
 function assertDefaultContextManagerRegistered() {
   assert.ok(
@@ -408,7 +409,7 @@ describe('Node SDK', () => {
       await sdk.shutdown();
     });
 
-    it('should register a meter provider to the tracer provider if both initialized and metrics enabled', async () => {
+    it('should configure components for SDK metrics if enabled', async () => {
       process.env.OTEL_NODE_EXPERIMENTAL_SDK_METRICS = 'true';
       const exporter = new ConsoleMetricExporter();
       const metricReader = new PeriodicExportingMetricReader({
@@ -418,7 +419,7 @@ describe('Node SDK', () => {
       });
 
       const sdk = new NodeSDK({
-        metricReader: metricReader,
+        metricReaders: [metricReader],
         traceExporter: new ConsoleSpanExporter(),
         autoDetectResources: false,
       });
@@ -436,11 +437,15 @@ describe('Node SDK', () => {
       );
 
       assert.ok(metrics.getMeterProvider() instanceof MeterProvider);
+      assert.notDeepEqual(
+        (metricReader as any)._metrics.collectionDuration,
+        NOOP_HISTOGRAM_METRIC
+      );
 
       await sdk.shutdown();
     });
 
-    it('should not register a meter provider to the tracer provider if both initialized but metrics disabled', async () => {
+    it('should not configure components for SDK metrics if disabled', async () => {
       const exporter = new ConsoleMetricExporter();
       const metricReader = new PeriodicExportingMetricReader({
         exporter: exporter,
@@ -449,7 +454,7 @@ describe('Node SDK', () => {
       });
 
       const sdk = new NodeSDK({
-        metricReader: metricReader,
+        metricReaders: [metricReader],
         traceExporter: new ConsoleSpanExporter(),
         autoDetectResources: false,
       });
@@ -465,6 +470,10 @@ describe('Node SDK', () => {
       assert.equal((tracerProvider as any)._config.meterProvider, undefined);
 
       assert.ok(metrics.getMeterProvider() instanceof MeterProvider);
+      assert.deepEqual(
+        (metricReader as any)._metrics.collectionDuration,
+        NOOP_HISTOGRAM_METRIC
+      );
 
       await sdk.shutdown();
     });

packages/opentelemetry-core/src/common/time.ts

@@ -110,6 +110,14 @@ export function hrTimeToNanoseconds(time: api.HrTime): number {
   return time[0] * SECOND_TO_NANOSECONDS + time[1];
 }
 
+/**
+ * Convert hrTime to microseconds.
+ * @param time
+ */
+export function hrTimeToMicroseconds(time: api.HrTime): number {
+  return time[0] * 1e6 + time[1] / 1e3;
+}
+
 /**
  * Convert hrTime to milliseconds.
  * @param time
@@ -119,13 +127,12 @@ export function hrTimeToMilliseconds(time: api.HrTime): number {
 }
 
 /**
- * Convert hrTime to microseconds.
+ * Convert hrTime to seconds.
  * @param time
  */
-export function hrTimeToMicroseconds(time: api.HrTime): number {
-  return time[0] * 1e6 + time[1] / 1e3;
+export function hrTimeToSeconds(time: api.HrTime): number {
+  return time[0] + time[1] / SECOND_TO_NANOSECONDS;
 }
-
 /**
  * check if time is HrTime
  * @param value

packages/opentelemetry-core/src/index.ts

@@ -20,6 +20,7 @@ export {
   hrTimeToMicroseconds,
   hrTimeToMilliseconds,
   hrTimeToNanoseconds,
+  hrTimeToSeconds,
   hrTimeToTimeStamp,
   isTimeInput,
   isTimeInputHrTime,

packages/opentelemetry-core/test/common/time.test.ts

@@ -13,8 +13,9 @@ import {
   timeInputToHrTime,
   hrTimeDuration,
   hrTimeToNanoseconds,
-  hrTimeToMilliseconds,
   hrTimeToMicroseconds,
+  hrTimeToMilliseconds,
+  hrTimeToSeconds,
   hrTimeToTimeStamp,
   isTimeInput,
   addHrTimes,
@@ -164,19 +165,27 @@ describe('time', () => {
     });
   });
 
+  describe('#hrTimeToMicroseconds', () => {
+    it('should return microseconds', () => {
+      const output = hrTimeToMicroseconds([1, 200000000]);
+      assert.deepStrictEqual(output, 1200000);
+    });
+  });
+
   describe('#hrTimeToMilliseconds', () => {
     it('should return milliseconds', () => {
       const output = hrTimeToMilliseconds([1, 200000000]);
       assert.deepStrictEqual(output, 1200);
     });
   });
 
-  describe('#hrTimeToMicroseconds', () => {
-    it('should return microseconds', () => {
-      const output = hrTimeToMicroseconds([1, 200000000]);
-      assert.deepStrictEqual(output, 1200000);
+  describe('#hrTimeToSeconds', () => {
+    it('should return seconds', () => {
+      const output = hrTimeToSeconds([1, 200000000]);
+      assert.deepStrictEqual(output, 1.2);
     });
   });
+
   describe('#isTimeInput', () => {
     it('should return true for a number', () => {
       assert.strictEqual(isTimeInput(12), true);

packages/sdk-metrics/src/MeterProvider.ts

@@ -26,6 +26,12 @@ export interface MeterProviderOptions {
   resource?: Resource;
   views?: ViewOptions[];
   readers?: IMetricReader[];
+
+  /**
+   * Whether to enable SDK metrics for this meter provider.
+   * @experimental This option is experimental and is subject to breaking changes in minor releases.
+   */
+  sdkMetricsEnabled?: boolean;
 }
 
 /**
@@ -50,6 +56,9 @@ export class MeterProvider implements IMeterProvider {
         const collector = new MetricCollector(this._sharedState, metricReader);
         metricReader.setMetricProducer(collector);
         this._sharedState.metricCollectors.push(collector);
+        if (options.sdkMetricsEnabled) {
+          metricReader.setMeterProvider?.(this);
+        }
       }
     }
   }

packages/sdk-metrics/src/export/MetricReader.ts

@@ -23,6 +23,9 @@ import {
 } from './AggregationSelector';
 import type { AggregationOption } from '../view/AggregationOption';
 import type { CardinalitySelector } from './CardinalitySelector';
+import { MetricReaderMetrics } from './MetricReaderMetrics';
+import { VERSION } from '../version';
+import { hrTime, hrTimeDuration, hrTimeToSeconds } from '@opentelemetry/core';
 
 export interface MetricReaderOptions {
   /**
@@ -54,6 +57,11 @@ export interface MetricReaderOptions {
    * @experimental
    */
   metricProducers?: MetricProducer[];
+  /**
+   * The component type used for reporting SDK metrics.
+   * @experimental This option is experimental and is subject to breaking changes in minor releases.
+   */
+  otelComponentType?: string;
 }
 
 /**
@@ -118,6 +126,12 @@ export interface IMetricReader {
    * @param options options with timeout.
    */
   forceFlush(options?: ForceFlushOptions): Promise<void>;
+
+  /**
+   * Sets the MeterProvider to use for reporting metrics for this reader.
+   * @experimental This option is experimental and is subject to breaking changes in minor releases.
+   */
+  setMeterProvider?(meterProvider: api.MeterProvider): void;
 }
 
 /**
@@ -132,9 +146,12 @@ export abstract class MetricReader implements IMetricReader {
   private _metricProducers: MetricProducer[];
   // MetricProducer used by this instance which produces metrics from the SDK
   private _sdkMetricProducer?: MetricProducer;
+  // Metrics about the MetricReader itself
+  private _metrics: MetricReaderMetrics;
   private readonly _aggregationTemporalitySelector: AggregationTemporalitySelector;
   private readonly _aggregationSelector: AggregationSelector;
   private readonly _cardinalitySelector?: CardinalitySelector;
+  private readonly _otelComponentType: string;
 
   constructor(options?: MetricReaderOptions) {
     this._aggregationSelector =
@@ -144,6 +161,12 @@ export abstract class MetricReader implements IMetricReader {
       DEFAULT_AGGREGATION_TEMPORALITY_SELECTOR;
     this._metricProducers = options?.metricProducers ?? [];
     this._cardinalitySelector = options?.cardinalitySelector;
+    this._otelComponentType =
+      options?.otelComponentType ?? this.constructor.name;
+    this._metrics = new MetricReaderMetrics(
+      this._otelComponentType,
+      api.createNoopMeter()
+    );
   }
 
   setMetricProducer(metricProducer: MetricProducer) {
@@ -156,6 +179,11 @@ export abstract class MetricReader implements IMetricReader {
     this.onInitialized();
   }
 
+  setMeterProvider(meterProvider: api.MeterProvider): void {
+    const meter = meterProvider.getMeter('@opentelemetry/sdk-metrics', VERSION);
+    this._metrics = new MetricReaderMetrics(this._otelComponentType, meter);
+  }
+
   selectAggregation(instrumentType: InstrumentType): AggregationOption {
     return this._aggregationSelector(instrumentType);
   }
@@ -207,6 +235,7 @@ export abstract class MetricReader implements IMetricReader {
       throw new Error('MetricReader is shutdown');
     }
 
+    const startTime = hrTime();
     const [sdkCollectionResults, ...additionalCollectionResults] =
       await Promise.all([
         this._sdkMetricProducer.collect({
@@ -218,11 +247,21 @@ export abstract class MetricReader implements IMetricReader {
           })
         ),
       ]);
+    const endTime = hrTime();
 
     // Merge the results, keeping the SDK's Resource
     const errors = sdkCollectionResults.errors.concat(
       additionalCollectionResults.flatMap(result => result.errors)
     );
+
+    const collectDuration = hrTimeToSeconds(hrTimeDuration(startTime, endTime));
+    this._metrics.recordCollection(
+      collectDuration,
+      errors.length > 0
+        ? ((errors[0] as Error).name ?? 'collect_error')
+        : undefined
+    );
+
     const resource = sdkCollectionResults.resourceMetrics.resource;
     const scopeMetrics =
       sdkCollectionResults.resourceMetrics.scopeMetrics.concat(