fix(sdk-metrics-base): misbehaving aggregation temporality selector tolerance

CHANGELOG.md

@@ -6,7 +6,6 @@ All notable changes to this project will be documented in this file.
 
 ### :boom: Breaking Change
 
-* feat(metrics): metric readers and exporters now select aggregation temporality based on instrument type [#2902](https://github.com/open-telemetry/opentelemetry-js/pull/2902) @seemk
 * chore: remove unused InstrumentationConfig#path [#2944](https://github.com/open-telemetry/opentelemetry-js/pull/2944) @flarna
 
 ### :rocket: (Enhancement)

experimental/CHANGELOG.md

@@ -6,11 +6,13 @@ All notable changes to experimental packages in this project will be documented
 
 ### :boom: Breaking Change
 
+* feat(metrics): metric readers and exporters now select aggregation temporality based on instrument type #2902 @seemk
 * refactor(metrics-sdk): rename InstrumentationLibrary -> InstrumentationScope #2959 @pichlermarc
 
 ### :rocket: (Enhancement)
 
 * feat(exporters): update proto version and use otlp-transformer #2929 @pichlermarc
+* fix(sdk-metrics-base): misbehaving aggregation temporality selector tolerance #2958 @legendecas
 
 ### :bug: (Bug Fix)
 

experimental/packages/opentelemetry-sdk-metrics-base/src/state/TemporalMetricProcessor.ts

@@ -35,6 +35,10 @@ interface LastReportedHistory<T> {
    * The timestamp the data was reported.
    */
   collectionTime: HrTime;
+  /**
+   * The AggregationTemporality used to aggregate reports.
+   */
+  aggregationTemporality: AggregationTemporality;
 }
 
 /**
@@ -69,19 +73,20 @@ export class TemporalMetricProcessor<T> {
     sdkStartTime: HrTime,
     collectionTime: HrTime,
   ): Maybe<MetricData> {
-    const aggregationTemporality = collector.selectAggregationTemporality(instrumentDescriptor.type);
     // In case it's our first collection, default to start timestamp (see below for explanation).
     let lastCollectionTime = sdkStartTime;
 
     this._stashAccumulations(collectors, currentAccumulations);
     const unreportedAccumulations = this._getMergedUnreportedAccumulations(collector);
 
     let result = unreportedAccumulations;
+    let aggregationTemporality: AggregationTemporality;
     // Check our last report time.
     if (this._reportHistory.has(collector)) {
       // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
       const last = this._reportHistory.get(collector)!;
       lastCollectionTime = last.collectionTime;
+      aggregationTemporality = last.aggregationTemporality;
 
       // Use aggregation temporality + instrument to determine if we do a merge or a diff of
       // previous. We have the following four scenarios:
@@ -95,12 +100,16 @@ export class TemporalMetricProcessor<T> {
         // for the next cumulative measurement.
         result = TemporalMetricProcessor.merge(last.accumulations, unreportedAccumulations, this._aggregator);
       }
+    } else {
+      // Call into user code to select aggregation temporality for the instrument.
+      aggregationTemporality = collector.selectAggregationTemporality(instrumentDescriptor.type);
     }
 
     // Update last reported (cumulative) accumulation.
     this._reportHistory.set(collector, {
       accumulations: result,
       collectionTime,
+      aggregationTemporality,
     });
 
     // Metric data time span is determined as:

experimental/packages/opentelemetry-sdk-metrics-base/test/state/TemporalMetricProcessor.test.ts

@@ -17,6 +17,7 @@
 import * as api from '@opentelemetry/api';
 import { hrTime } from '@opentelemetry/core';
 import * as assert from 'assert';
+import * as sinon from 'sinon';
 import { SumAggregator } from '../../src/aggregator';
 import { AggregationTemporality } from '../../src/export/AggregationTemporality';
 import { DataPointType } from '../../src/export/MetricData';
@@ -40,11 +41,17 @@ const cumulativeCollector1: MetricCollectorHandle = {
 const sdkStartTime = hrTime();
 
 describe('TemporalMetricProcessor', () => {
+  afterEach(() => {
+    sinon.restore();
+  });
+
   describe('buildMetrics', () => {
     describe('single delta collector', () => {
       const collectors = [ deltaCollector1 ];
 
       it('should build metrics', () => {
+        const spy = sinon.spy(deltaCollector1, 'selectAggregationTemporality');
+
         const aggregator = new SumAggregator();
         const deltaMetricStorage = new DeltaMetricProcessor(aggregator);
         const temporalMetricStorage = new TemporalMetricProcessor(aggregator);
@@ -59,7 +66,10 @@ describe('TemporalMetricProcessor', () => {
             sdkStartTime,
             hrTime());
 
-          assertMetricData(metric, DataPointType.SINGULAR);
+          assertMetricData(metric,
+            DataPointType.SINGULAR,
+            defaultInstrumentDescriptor,
+            AggregationTemporality.DELTA);
           assert.strictEqual(metric.dataPoints.length, 1);
           assertDataPoint(metric.dataPoints[0], {}, 1);
         }
@@ -74,7 +84,10 @@ describe('TemporalMetricProcessor', () => {
             sdkStartTime,
             hrTime());
 
-          assertMetricData(metric, DataPointType.SINGULAR);
+          assertMetricData(metric,
+            DataPointType.SINGULAR,
+            defaultInstrumentDescriptor,
+            AggregationTemporality.DELTA);
           assert.strictEqual(metric.dataPoints.length, 1);
           assertDataPoint(metric.dataPoints[0], {}, 2);
         }
@@ -88,9 +101,15 @@ describe('TemporalMetricProcessor', () => {
             sdkStartTime,
             hrTime());
 
-          assertMetricData(metric, DataPointType.SINGULAR);
+          assertMetricData(metric,
+            DataPointType.SINGULAR,
+            defaultInstrumentDescriptor,
+            AggregationTemporality.DELTA);
           assert.strictEqual(metric.dataPoints.length, 0);
         }
+
+        // selectAggregationTemporality should be called only once.
+        assert.strictEqual(spy.callCount, 1);
       });
     });
 
@@ -112,7 +131,10 @@ describe('TemporalMetricProcessor', () => {
             sdkStartTime,
             hrTime());
 
-          assertMetricData(metric, DataPointType.SINGULAR);
+          assertMetricData(metric,
+            DataPointType.SINGULAR,
+            defaultInstrumentDescriptor,
+            AggregationTemporality.DELTA);
           assert.strictEqual(metric.dataPoints.length, 1);
           assertDataPoint(metric.dataPoints[0], {}, 1);
         }
@@ -126,7 +148,10 @@ describe('TemporalMetricProcessor', () => {
             sdkStartTime,
             hrTime());
 
-          assertMetricData(metric, DataPointType.SINGULAR);
+          assertMetricData(metric,
+            DataPointType.SINGULAR,
+            defaultInstrumentDescriptor,
+            AggregationTemporality.DELTA);
           assert.strictEqual(metric.dataPoints.length, 1);
           assertDataPoint(metric.dataPoints[0], {}, 1);
         }
@@ -136,6 +161,8 @@ describe('TemporalMetricProcessor', () => {
     describe('single cumulative collector', () => {
       const collectors = [ cumulativeCollector1 ];
       it('should build metrics', () => {
+        const spy = sinon.spy(cumulativeCollector1, 'selectAggregationTemporality');
+
         const aggregator = new SumAggregator();
         const deltaMetricStorage = new DeltaMetricProcessor(aggregator);
         const temporalMetricStorage = new TemporalMetricProcessor(aggregator);
@@ -150,7 +177,10 @@ describe('TemporalMetricProcessor', () => {
             sdkStartTime,
             hrTime());
 
-          assertMetricData(metric, DataPointType.SINGULAR);
+          assertMetricData(metric,
+            DataPointType.SINGULAR,
+            defaultInstrumentDescriptor,
+            AggregationTemporality.CUMULATIVE);
           assert.strictEqual(metric.dataPoints.length, 1);
           assertDataPoint(metric.dataPoints[0], {}, 1);
         }
@@ -165,10 +195,16 @@ describe('TemporalMetricProcessor', () => {
             sdkStartTime,
             hrTime());
 
-          assertMetricData(metric, DataPointType.SINGULAR);
+          assertMetricData(metric,
+            DataPointType.SINGULAR,
+            defaultInstrumentDescriptor,
+            AggregationTemporality.CUMULATIVE);
           assert.strictEqual(metric.dataPoints.length, 1);
           assertDataPoint(metric.dataPoints[0], {}, 3);
         }
+
+        // selectAggregationTemporality should be called only once.
+        assert.strictEqual(spy.callCount, 1);
       });
     });
 
@@ -189,7 +225,10 @@ describe('TemporalMetricProcessor', () => {
             sdkStartTime,
             hrTime());
 
-          assertMetricData(metric, DataPointType.SINGULAR);
+          assertMetricData(metric,
+            DataPointType.SINGULAR,
+            defaultInstrumentDescriptor,
+            AggregationTemporality.CUMULATIVE);
           assert.strictEqual(metric.dataPoints.length, 1);
           assertDataPoint(metric.dataPoints[0], {}, 1);
         }
@@ -204,7 +243,10 @@ describe('TemporalMetricProcessor', () => {
             sdkStartTime,
             hrTime());
 
-          assertMetricData(metric, DataPointType.SINGULAR);
+          assertMetricData(metric,
+            DataPointType.SINGULAR,
+            defaultInstrumentDescriptor,
+            AggregationTemporality.DELTA);
           assert.strictEqual(metric.dataPoints.length, 1);
           assertDataPoint(metric.dataPoints[0], {}, 3);
         }
@@ -217,7 +259,10 @@ describe('TemporalMetricProcessor', () => {
             sdkStartTime,
             hrTime());
 
-          assertMetricData(metric, DataPointType.SINGULAR);
+          assertMetricData(metric,
+            DataPointType.SINGULAR,
+            defaultInstrumentDescriptor,
+            AggregationTemporality.CUMULATIVE);
           assert.strictEqual(metric.dataPoints.length, 1);
           assertDataPoint(metric.dataPoints[0], {}, 3);
         }

experimental/packages/opentelemetry-sdk-metrics-base/test/util.ts

@@ -29,6 +29,7 @@ import { Measurement } from '../src/Measurement';
 import { isNotNullish } from '../src/utils';
 import { HrTime } from '@opentelemetry/api';
 import { Histogram } from '../src/aggregator/types';
+import { AggregationTemporality } from '../src/export/AggregationTemporality';
 
 export const defaultResource = new Resource({
   resourceKey: 'my-resource',
@@ -71,6 +72,7 @@ export function assertMetricData(
   actual: unknown,
   dataPointType?: DataPointType,
   instrumentDescriptor: Partial<InstrumentDescriptor> | null = defaultInstrumentDescriptor,
+  aggregationTemporality?: AggregationTemporality,
 ): asserts actual is MetricData {
   const it = actual as MetricData;
   if (instrumentDescriptor != null) {
@@ -81,6 +83,9 @@ export function assertMetricData(
   } else {
     assert(isNotNullish(DataPointType[it.dataPointType]));
   }
+  if (aggregationTemporality != null) {
+    assert.strictEqual(aggregationTemporality, it.aggregationTemporality);
+  }
   assert(Array.isArray(it.dataPoints));
 }