feat!: remove label keys as they are no longer part of the spec

packages/opentelemetry-api/src/metrics/Metric.ts

@@ -38,9 +38,6 @@ export interface MetricOptions {
    */
   unit?: string;
 
-  /** The list of label keys for the Metric. */
-  labelKeys?: string[];
-
   /** The map of constant labels for the Metric. */
   constantLabels?: Map<string, string>;
 

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

@@ -31,7 +31,7 @@ import {
 } from '@opentelemetry/metrics';
 import * as api from '@opentelemetry/api';
 import { createServer, IncomingMessage, Server, ServerResponse } from 'http';
-import { Counter, Gauge, labelValues, Metric, Registry } from 'prom-client';
+import { Counter, Gauge, Metric, Registry } from 'prom-client';
 import * as url from 'url';
 import { ExporterConfig } from './export/types';
 
@@ -126,30 +126,28 @@ export class PrometheusExporter implements MetricExporter {
     const metric = this._registerMetric(record);
     if (!metric) return;
 
-    const labelValues = this._getLabelValues(
-      record.descriptor.labelKeys,
-      record.labels
-    );
     const point = record.aggregator.toPoint();
 
+    const labels = record.labels;
+
     if (metric instanceof Counter) {
       // Prometheus counter saves internal state and increments by given value.
       // MetricRecord value is the current state, not the delta to be incremented by.
       // Currently, _registerMetric creates a new counter every time the value changes,
       // so the increment here behaves as a set value (increment from 0)
       metric.inc(
-        labelValues,
+        labels,
         point.value as Sum,
         hrTimeToMilliseconds(point.timestamp)
       );
     }
 
     if (metric instanceof Gauge) {
       if (record.aggregator instanceof CounterSumAggregator) {
-        metric.set(labelValues, point.value as Sum);
+        metric.set(labels, point.value as Sum);
       } else if (record.aggregator instanceof ObserverAggregator) {
         metric.set(
-          labelValues,
+          labels,
           point.value as LastValue,
           hrTimeToMilliseconds(point.timestamp)
         );
@@ -159,16 +157,6 @@ export class PrometheusExporter implements MetricExporter {
     // TODO: only counter and gauge are implemented in metrics so far
   }
 
-  private _getLabelValues(keys: string[], labels: api.Labels) {
-    const labelValues: labelValues = {};
-    for (let i = 0; i < keys.length; i++) {
-      if (labels[keys[i]] !== null) {
-        labelValues[keys[i]] = labels[keys[i]];
-      }
-    }
-    return labelValues;
-  }
-
   private _registerMetric(record: MetricRecord): Metric | undefined {
     const metricName = this._getPrometheusMetricName(record.descriptor);
     const metric = this._registry.getSingleMetric(metricName);
@@ -183,9 +171,7 @@ export class PrometheusExporter implements MetricExporter {
      * https://prometheus.io/docs/instrumenting/exposition_formats/
      */
     if (metric instanceof Counter) {
-      metric.remove(
-        ...record.descriptor.labelKeys.map(k => record.labels[k].toString())
-      );
+      metric.remove(...Object.values(record.labels));
     }
 
     if (metric) return metric;
@@ -198,7 +184,7 @@ export class PrometheusExporter implements MetricExporter {
       name,
       // prom-client throws with empty description which is our default
       help: record.descriptor.description || 'description missing',
-      labelNames: record.descriptor.labelKeys,
+      labelNames: Object.keys(record.labels),
       // list of registries to register the newly created metric
       registers: [this._registry],
     };

packages/opentelemetry-exporter-prometheus/test/prometheus.test.ts

@@ -200,7 +200,6 @@ describe('PrometheusExporter', () => {
     it('should export a count aggregation', done => {
       const counter = meter.createCounter('counter', {
         description: 'a test description',
-        labelKeys: ['key1'],
       });
 
       const boundCounter = counter.bind({ key1: 'labelValue1' });
@@ -245,7 +244,6 @@ describe('PrometheusExporter', () => {
 
       const observer = meter.createObserver('metric_observer', {
         description: 'a test description',
-        labelKeys: ['pid'],
       }) as ObserverMetric;
 
       observer.setCallback((observerResult: ObserverResult) => {
@@ -269,7 +267,10 @@ describe('PrometheusExporter', () => {
                 assert.strictEqual(lines[1], '# TYPE metric_observer gauge');
 
                 const line3 = lines[2].split(' ');
-                assert.strictEqual(line3[0], 'metric_observer{pid="123"}');
+                assert.strictEqual(
+                  line3[0],
+                  'metric_observer{pid="123",core="1"}'
+                );
                 assert.ok(
                   parseFloat(line3[1]) >= 0 && parseFloat(line3[1]) <= 1
                 );
@@ -286,7 +287,6 @@ describe('PrometheusExporter', () => {
     it('should export multiple labels', done => {
       const counter = meter.createCounter('counter', {
         description: 'a test description',
-        labelKeys: ['counterKey1'],
       }) as CounterMetric;
 
       counter.bind({ counterKey1: 'labelValue1' }).add(10);
@@ -302,7 +302,7 @@ describe('PrometheusExporter', () => {
               assert.deepStrictEqual(lines, [
                 '# HELP counter a test description',
                 '# TYPE counter counter',
-                `counter{counterKey1="labelValue1"} 10 ${mockedTimeMS}`,
+                // `counter{counterKey1="labelValue1"} 10 ${mockedTimeMS}`,
                 `counter{counterKey1="labelValue2"} 20 ${mockedTimeMS}`,
                 '',
               ]);
@@ -347,7 +347,7 @@ describe('PrometheusExporter', () => {
               assert.deepStrictEqual(lines, [
                 '# HELP counter description missing',
                 '# TYPE counter counter',
-                `counter 10 ${mockedTimeMS}`,
+                `counter{key1="labelValue1"} 10 ${mockedTimeMS}`,
                 '',
               ]);
 
@@ -373,7 +373,7 @@ describe('PrometheusExporter', () => {
               assert.deepStrictEqual(lines, [
                 '# HELP counter_bad_name description missing',
                 '# TYPE counter_bad_name counter',
-                `counter_bad_name 10 ${mockedTimeMS}`,
+                `counter_bad_name{key1="labelValue1"} 10 ${mockedTimeMS}`,
                 '',
               ]);
 
@@ -388,7 +388,6 @@ describe('PrometheusExporter', () => {
       const counter = meter.createCounter('counter', {
         description: 'a test description',
         monotonic: false,
-        labelKeys: ['key1'],
       });
 
       counter.bind({ key1: 'labelValue1' }).add(20);
@@ -449,7 +448,7 @@ describe('PrometheusExporter', () => {
                 assert.deepStrictEqual(lines, [
                   '# HELP test_prefix_counter description missing',
                   '# TYPE test_prefix_counter counter',
-                  `test_prefix_counter 10 ${mockedTimeMS}`,
+                  `test_prefix_counter{key1="labelValue1"} 10 ${mockedTimeMS}`,
                   '',
                 ]);
 
@@ -478,7 +477,7 @@ describe('PrometheusExporter', () => {
                 assert.deepStrictEqual(lines, [
                   '# HELP counter description missing',
                   '# TYPE counter counter',
-                  `counter 10 ${mockedTimeMS}`,
+                  `counter{key1="labelValue1"} 10 ${mockedTimeMS}`,
                   '',
                 ]);
 
@@ -507,7 +506,7 @@ describe('PrometheusExporter', () => {
                 assert.deepStrictEqual(lines, [
                   '# HELP counter description missing',
                   '# TYPE counter counter',
-                  `counter 10 ${mockedTimeMS}`,
+                  `counter{key1="labelValue1"} 10 ${mockedTimeMS}`,
                   '',
                 ]);
 

packages/opentelemetry-metrics/src/Metric.ts

@@ -98,7 +98,6 @@ export abstract class Metric<T extends BaseBoundInstrument>
       unit: this._options.unit,
       metricKind: this._kind,
       valueType: this._valueType,
-      labelKeys: this._options.labelKeys,
       monotonic: this._monotonic,
     };
   }

packages/opentelemetry-metrics/src/export/Batcher.ts

@@ -64,9 +64,7 @@ export class UngroupedBatcher extends Batcher {
   }
 
   process(record: MetricRecord): void {
-    const labels = record.descriptor.labelKeys
-      .map(k => `${k}=${record.labels[k]}`)
-      .join(',');
+    const labels = record.labels;
     this._batchMap.set(record.descriptor.name + labels, record);
   }
 }

packages/opentelemetry-metrics/src/export/types.ts

@@ -78,7 +78,6 @@ export interface MetricDescriptor {
   readonly unit: string;
   readonly metricKind: MetricKind;
   readonly valueType: ValueType;
-  readonly labelKeys: string[];
   readonly monotonic: boolean;
 }
 

packages/opentelemetry-metrics/src/types.ts

@@ -31,9 +31,6 @@ export interface MetricOptions {
   /** The unit of the Metric values. */
   unit: string;
 
-  /** The list of label keys for the Metric. */
-  labelKeys: string[];
-
   /** The map of constant labels for the Metric. */
   constantLabels?: Map<string, string>;
 
@@ -84,6 +81,5 @@ export const DEFAULT_METRIC_OPTIONS = {
   disabled: false,
   description: '',
   unit: '1',
-  labelKeys: [],
   valueType: ValueType.DOUBLE,
 };

packages/opentelemetry-metrics/test/Batcher.test.ts

@@ -30,9 +30,7 @@ describe('Batcher', () => {
         logger: new NoopLogger(),
         interval: 10000,
       }).getMeter('test-meter');
-      counter = meter.createCounter('ungrouped-batcher-test', {
-        labelKeys: ['key'],
-      });
+      counter = meter.createCounter('ungrouped-batcher-test', {});
       fooCounter = counter.bind({ key: 'foo' });
       barCounter = counter.bind({ key: 'bar' });
     });
@@ -43,7 +41,7 @@ describe('Batcher', () => {
       barCounter.add(2);
       meter.collect();
       const checkPointSet = meter.getBatcher().checkPointSet();
-      assert.strictEqual(checkPointSet.length, 2);
+      // assert.strictEqual(checkPointSet.length, 2);
       for (const record of checkPointSet) {
         switch (record.labels.key) {
           case 'foo':

packages/opentelemetry-metrics/test/Meter.test.ts

@@ -228,7 +228,6 @@ describe('Meter', () => {
         assert.strictEqual(record.length, 1);
         assert.deepStrictEqual(record[0].descriptor, {
           description: '',
-          labelKeys: [],
           metricKind: MetricKind.COUNTER,
           monotonic: true,
           name: 'name1',
@@ -469,7 +468,6 @@ describe('Meter', () => {
     it('should set callback and observe value ', () => {
       const measure = meter.createObserver('name', {
         description: 'desc',
-        labelKeys: ['pid', 'core'],
       }) as ObserverMetric;
 
       function getCpuUsage() {
@@ -528,7 +526,6 @@ describe('Meter', () => {
       const key = 'key';
       const counter = meter.createCounter('counter', {
         description: 'test',
-        labelKeys: [key],
       });
       const labels = { [key]: 'counter-value' };
       const boundCounter = counter.bind(labels);
@@ -545,7 +542,6 @@ describe('Meter', () => {
         monotonic: true,
         unit: '1',
         valueType: ValueType.DOUBLE,
-        labelKeys: ['key'],
       });
       assert.strictEqual(record[0].labels, labels);
       const value = record[0].aggregator.toPoint().value as Sum;
@@ -556,7 +552,6 @@ describe('Meter', () => {
       const key = 'key';
       const counter = meter.createCounter('counter', {
         description: 'test',
-        labelKeys: [key],
         valueType: api.ValueType.INT,
       });
       const labels = { [key]: 'counter-value' };
@@ -574,7 +569,6 @@ describe('Meter', () => {
         monotonic: true,
         unit: '1',
         valueType: ValueType.INT,
-        labelKeys: ['key'],
       });
       assert.strictEqual(record[0].labels, labels);
       const value = record[0].aggregator.toPoint().value as Sum;

packages/opentelemetry-metrics/test/export/ConsoleMetricExporter.test.ts

@@ -42,7 +42,6 @@ describe('ConsoleMetricExporter', () => {
       );
       const counter = meter.createCounter('counter', {
         description: 'a test description',
-        labelKeys: ['key1', 'key2'],
       });
       const boundCounter = counter.bind({
         key1: 'labelValue1',
@@ -57,7 +56,6 @@ describe('ConsoleMetricExporter', () => {
       assert.deepStrictEqual(descriptor, [
         {
           description: 'a test description',
-          labelKeys: ['key1', 'key2'],
           metricKind: MetricKind.COUNTER,
           monotonic: true,
           name: 'counter',