chore: refactoring host metrics, aligning with semantic conventions

examples/host-metrics/node.js

@@ -1,17 +1,24 @@
 'use strict';
 
 const { HostMetrics } = require('@opentelemetry/host-metrics');
-const { PrometheusExporter } = require('@opentelemetry/exporter-prometheus');
+// const { PrometheusExporter } = require('@opentelemetry/exporter-prometheus');
 const { MeterProvider } = require('@opentelemetry/metrics');
+const { CollectorMetricExporter } = require('@opentelemetry/exporter-collector');
+const exporter = new CollectorMetricExporter({
+  headers: {},
+  serviceName: 'test-host-metrics',
+  // url: '',
+});
 
-const exporter = new PrometheusExporter(
-  {
-    startServer: true,
-  },
-  () => {
-    console.log('prometheus scrape endpoint: http://localhost:9464/metrics');
-  },
-);
+// for testing purposes if you don't want to use CollectorMetricExporter
+// const exporter = new PrometheusExporter(
+//   {
+//     startServer: true,
+//   },
+//   () => {
+//     console.log('prometheus scrape endpoint: http://localhost:9464/metrics');
+//   },
+// );
 
 const meterProvider = new MeterProvider({
   exporter,
@@ -20,3 +27,8 @@ const meterProvider = new MeterProvider({
 
 const hostMetrics = new HostMetrics({ meterProvider, name: 'example-host-metrics' });
 hostMetrics.start();
+
+// keep running
+(function wait () {
+   setTimeout(wait, 1000);
+})();

examples/host-metrics/package.json

@@ -26,10 +26,11 @@
     "url": "https://github.com/open-telemetry/opentelemetry-js/issues"
   },
   "dependencies": {
-    "@opentelemetry/api": "^0.12.0",
-    "@opentelemetry/core": "^0.12.0",
-    "@opentelemetry/exporter-prometheus": "^0.12.0",
-    "@opentelemetry/metrics": "^0.12.0",
+    "@opentelemetry/api": "^0.13.0",
+    "@opentelemetry/core": "^0.13.0",
+    "@opentelemetry/exporter-prometheus": "^0.13.0",
+    "@opentelemetry/exporter-collector": "^0.13.0",
+    "@opentelemetry/metrics": "^0.13.0",
     "@opentelemetry/host-metrics": "^0.11.0"
   },
   "homepage": "https://github.com/open-telemetry/opentelemetry-js#readme"

packages/opentelemetry-host-metrics/package.json

@@ -61,9 +61,9 @@
     "typescript": "3.9.7"
   },
   "dependencies": {
-    "@opentelemetry/api": "^0.12.0",
-    "@opentelemetry/core": "^0.12.0",
-    "@opentelemetry/metrics": "^0.12.0",
-    "systeminformation": "^4.27.10"
+    "@opentelemetry/api": "^0.13.0",
+    "@opentelemetry/core": "^0.13.0",
+    "@opentelemetry/metrics": "^0.13.0",
+    "systeminformation": "^4.31.0"
   }
 }

packages/opentelemetry-host-metrics/src/BaseMetrics.ts

@@ -0,0 +1,125 @@
+/*
+ * 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/metrics';
+
+import { VERSION } from './version';
+
+/**
+ * Metrics Collector Configuration
+ */
+export interface MetricsCollectorConfig {
+  logger?: api.Logger;
+  // maximum timeout to wait for stats collection default is 500ms
+  maxTimeoutUpdateMS?: number;
+  // Meter Provider
+  meterProvider?: metrics.MeterProvider;
+  // Character to be used to join metrics - default is "."
+  metricNameSeparator?: string;
+  // Name of component
+  name: string;
+  // metric export endpoint
+  url?: string;
+}
+
+const DEFAULT_MAX_TIMEOUT_UPDATE_MS = 500;
+const DEFAULT_NAME = 'opentelemetry-host-metrics';
+const DEFAULT_METRIC_NAME_SEPARATOR = '.';
+
+// default label name to be used to store metric name
+const DEFAULT_KEY = 'name';
+
+/**
+ * Base Class for metrics
+ */
+export abstract class BaseMetrics {
+  protected _logger: api.Logger | undefined;
+  protected _maxTimeoutUpdateMS: number;
+  protected _meter: metrics.Meter;
+  private _name: string;
+  private _boundCounters: { [key: string]: api.BoundCounter } = {};
+  private _metricNameSeparator: string;
+
+  constructor(config: MetricsCollectorConfig) {
+    this._logger = config.logger || new api.NoopLogger();
+    this._name = config.name || DEFAULT_NAME;
+    this._maxTimeoutUpdateMS =
+      config.maxTimeoutUpdateMS || DEFAULT_MAX_TIMEOUT_UPDATE_MS;
+    this._metricNameSeparator =
+      config.metricNameSeparator || DEFAULT_METRIC_NAME_SEPARATOR;
+    const meterProvider =
+      config.meterProvider! || api.metrics.getMeterProvider();
+    if (!config.meterProvider) {
+      this._logger.warn('No meter provider, using default');
+    }
+    this._meter = meterProvider.getMeter(this._name, VERSION);
+  }
+
+  /**
+   * Creates a metric key name based on metric name and a key
+   * @param metricName
+   * @param key
+   */
+  protected _boundKey(metricName: string, key: string) {
+    if (!key) {
+      return metricName;
+    }
+    return `${metricName}${this._metricNameSeparator}${key}`;
+  }
+
+  /**
+   * Updates counter based on boundkey
+   * @param metricName
+   * @param key
+   * @param value
+   */
+  protected _counterUpdate(metricName: string, key: string, value = 0) {
+    const boundKey = this._boundKey(metricName, key);
+    this._boundCounters[boundKey].add(value);
+  }
+
+  /**
+   * @param metricName metric name - this will be added as label under name
+   *     "name"
+   * @param values values to be used to generate bound counters for each
+   * value prefixed with metricName
+   * @param description metric description
+   */
+  protected _createCounter(
+    metricName: string,
+    values: string[],
+    description?: string
+  ) {
+    const keys = values.map(key => this._boundKey(metricName, key));
+    const counter = this._meter.createCounter(metricName, {
+      description: description || metricName,
+    });
+    keys.forEach(key => {
+      this._boundCounters[key] = counter.bind({ [DEFAULT_KEY]: key });
+    });
+  }
+
+  /**
+   * Creates metrics
+   */
+  protected abstract _createMetrics(): void;
+
+  /**
+   * Starts collecting stats
+   */
+  public abstract start(): void;
+}

packages/opentelemetry-host-metrics/src/enum.ts

@@ -15,24 +15,28 @@
  */
 
 export enum METRIC_NAMES {
-  CPU = 'cpu',
-  NETWORK = 'net',
-  MEMORY = 'mem',
+  CPU_TIME = 'system.cpu.time',
+  CPU_UTILIZATION = 'system.cpu.utilization',
+  MEMORY_USAGE = 'system.memory.usage',
+  MEMORY_UTILIZATION = 'system.memory.utilization',
+  NETWORK_DROPPED = 'system.network.dropped',
+  NETWORK_ERRORS = 'system.network.errors',
+  NETWORK_IO = 'system.network.io',
 }
 
 export enum CPU_LABELS {
   USER = 'user',
-  SYSTEM = 'sys',
-  USAGE = 'usage',
-  TOTAL = 'total',
+  SYSTEM = 'system',
+  IDLE = 'idle',
 }
 
 export enum NETWORK_LABELS {
-  BYTES_SENT = 'bytesSent',
-  BYTES_RECEIVED = 'bytesRecv',
+  DEVICE = 'device',
+  RECEIVE = 'receive',
+  TRANSMIT = 'transmit',
 }
 
 export enum MEMORY_LABELS {
-  AVAILABLE = 'available',
-  TOTAL = 'total',
+  FREE = 'free',
+  USED = 'used',
 }

packages/opentelemetry-host-metrics/src/index.ts

@@ -14,5 +14,6 @@
  * limitations under the License.
  */
 
+export * from './BaseMetrics';
 export * from './metric';
 export * from './types';