feat: add WIP metrics SDK (#2601)

Co-authored-by: Georg Pirklbauer <georg.pirklbauer@dynatrace.com>

experimental/packages/opentelemetry-exporter-metrics-otlp-grpc/tsconfig.json

@@ -20,9 +20,6 @@
     },
     {
       "path": "../opentelemetry-exporter-trace-otlp-http"
-    },
-    {
-      "path": "../opentelemetry-sdk-metrics-base"
     }
   ]
 }

experimental/packages/opentelemetry-exporter-metrics-otlp-http/tsconfig.esm.json

@@ -14,9 +14,6 @@
     },
     {
       "path": "../opentelemetry-exporter-trace-otlp-http/tsconfig.esm.json"
-    },
-    {
-      "path": "../opentelemetry-sdk-metrics-base/tsconfig.esm.json"
     }
   ]
 }

experimental/packages/opentelemetry-exporter-metrics-otlp-http/tsconfig.json

@@ -14,9 +14,6 @@
     },
     {
       "path": "../opentelemetry-exporter-trace-otlp-http"
-    },
-    {
-      "path": "../opentelemetry-sdk-metrics-base"
     }
   ]
 }

experimental/packages/opentelemetry-exporter-metrics-otlp-proto/tsconfig.json

@@ -20,9 +20,6 @@
     },
     {
       "path": "../opentelemetry-exporter-trace-otlp-proto"
-    },
-    {
-      "path": "../opentelemetry-sdk-metrics-base"
     }
   ]
 }

experimental/packages/opentelemetry-exporter-prometheus/tsconfig.json

@@ -11,9 +11,6 @@
   "references": [
     {
       "path": "../opentelemetry-api-metrics"
-    },
-    {
-      "path": "../opentelemetry-sdk-metrics-base"
     }
   ]
 }

experimental/packages/opentelemetry-sdk-metrics-base/package.json

@@ -1,6 +1,6 @@
 {
   "name": "@opentelemetry/sdk-metrics-base-wip",
-  "version": "0.26.0",
+  "version": "0.27.0",
   "private": true,
   "description": "Work in progress OpenTelemetry metrics SDK",
   "main": "build/src/index.js",
@@ -64,7 +64,7 @@
     "@opentelemetry/api": "^1.0.0"
   },
   "dependencies": {
-    "@opentelemetry/api-metrics": "0.26.0",
+    "@opentelemetry/api-metrics": "0.27.0",
     "@opentelemetry/core": "1.0.0",
     "@opentelemetry/resources": "1.0.0",
     "lodash.merge": "^4.6.2"

experimental/packages/opentelemetry-sdk-metrics-base/src/Aggregation.ts

@@ -0,0 +1,25 @@
+/*
+ * Copyright The OpenTelemetry Authors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+import { Measurement } from './Measurement';
+
+// https://github.com/open-telemetry/opentelemetry-specification/blob/main/specification/metrics/sdk.md#aggregation
+
+export interface Aggregator {
+    aggregate(measurement: Measurement): void;
+}
+
+// TODO define actual aggregator classes

experimental/packages/opentelemetry-sdk-metrics-base/src/Instruments.ts

@@ -0,0 +1,70 @@
+/*
+ * Copyright The OpenTelemetry Authors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+import * as api from '@opentelemetry/api';
+import * as metrics from '@opentelemetry/api-metrics';
+import { Meter } from './Meter';
+
+// https://github.com/open-telemetry/opentelemetry-specification/blob/main/specification/metrics/api.md#instrument
+
+export enum InstrumentType {
+    COUNTER = 'COUNTER',
+    HISTOGRAM = 'HISTOGRAM',
+    UP_DOWN_COUNTER = 'UP_DOWN_COUNTER',
+    OBSERVABLE_COUNTER = 'OBSERVABLE_COUNTER',
+    OBSERVABLE_GAUGE = 'OBSERVABLE_GAUGE',
+    OBSERVABLE_UP_DOWN_COUNTER = 'OBSERVABLE_UP_DOWN_COUNTER',
+}
+
+export class SyncInstrument {
+    constructor(private _meter: Meter, private _name: string) { }
+
+    getName(): string {
+        return this._name;
+    }
+
+
+    aggregate(value: number, attributes: metrics.Attributes = {}, ctx: api.Context = api.context.active()) {
+        this._meter.aggregate(this, {
+            value,
+            attributes,
+            context: ctx,
+        });
+    }
+}
+
+export class UpDownCounter extends SyncInstrument implements metrics.Counter {
+    add(value: number, attributes?: metrics.Attributes, ctx?: api.Context): void {
+        this.aggregate(value, attributes, ctx);
+    }
+}
+
+export class Counter extends SyncInstrument implements metrics.Counter {
+    add(value: number, attributes?: metrics.Attributes, ctx?: api.Context): void {
+        if (value < 0) {
+            api.diag.warn(`negative value provided to counter ${this.getName()}: ${value}`);
+            return;
+        }
+
+        this.aggregate(value, attributes, ctx);
+    }
+}
+
+export class Histogram extends SyncInstrument implements metrics.Histogram {
+    record(value: number, attributes?: metrics.Attributes, ctx?: api.Context): void {
+        this.aggregate(value, attributes, ctx);
+    }
+}

experimental/packages/opentelemetry-sdk-metrics-base/src/Measurement.ts

@@ -0,0 +1,27 @@
+/*
+ * Copyright The OpenTelemetry Authors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+import * as api from '@opentelemetry/api'
+import { Attributes } from '@opentelemetry/api-metrics'
+
+// https://github.com/open-telemetry/opentelemetry-specification/blob/main/specification/metrics/api.md#measurement
+
+export type Measurement = {
+    value: number;
+    // TODO use common attributes
+    attributes: Attributes
+    context?: api.Context;
+}

experimental/packages/opentelemetry-sdk-metrics-base/src/Meter.ts

@@ -0,0 +1,65 @@
+/*
+ * Copyright The OpenTelemetry Authors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+import * as metrics from '@opentelemetry/api-metrics';
+import { InstrumentationLibrary } from '@opentelemetry/core';
+import { Counter, Histogram, UpDownCounter } from './Instruments';
+import { Measurement } from './Measurement';
+import { MeterProvider } from './MeterProvider';
+
+// https://github.com/open-telemetry/opentelemetry-specification/blob/main/specification/metrics/api.md#meter
+
+export class Meter implements metrics.Meter {
+    // instrumentation library required by spec to be on meter
+    // spec requires provider config changes to apply to previously created meters, achieved by holding a reference to the provider
+    constructor(private _provider: MeterProvider, private _instrumentationLibrary: InstrumentationLibrary, private _schemaUrl?: string) { }
+
+    /** this exists just to prevent ts errors from unused variables and may be removed */
+    getSchemaUrl(): string | undefined {
+        return this._schemaUrl;
+    }
+
+    /** this exists just to prevent ts errors from unused variables and may be removed */
+    getInstrumentationLibrary(): InstrumentationLibrary {
+        return this._instrumentationLibrary;
+    }
+
+    createHistogram(_name: string, _options?: metrics.MetricOptions): Histogram {
+        return new Histogram(this, _name);
+    }
+
+    createCounter(_name: string, _options?: metrics.MetricOptions): metrics.Counter {
+        return new Counter(this, _name);
+    }
+
+    createUpDownCounter(_name: string, _options?: metrics.MetricOptions): metrics.UpDownCounter {
+        return new UpDownCounter(this, _name);
+    }
+
+    createObservableGauge(_name: string, _options?: metrics.MetricOptions, _callback?: (observableResult: metrics.ObservableResult) => void): metrics.ObservableBase {
+        throw new Error('Method not implemented.');
+    }
+    createObservableCounter(_name: string, _options?: metrics.MetricOptions, _callback?: (observableResult: metrics.ObservableResult) => void): metrics.ObservableBase {
+        throw new Error('Method not implemented.');
+    }
+    createObservableUpDownCounter(_name: string, _options?: metrics.MetricOptions, _callback?: (observableResult: metrics.ObservableResult) => void): metrics.ObservableBase {
+        throw new Error('Method not implemented.');
+    }
+
+    public aggregate(metric: unknown, measurement: Measurement) {
+        this._provider.aggregate(this, metric, measurement);
+    }
+}