OpenTelemetry Node.js Runtime Metrics Instrumentation

This module provides automatic metric instrumentation that exposes measurements from the Performance measurement APIs (i.e. perf_hooks). While currently it is limited to metrics, it may be modified to produce other signals in the future.

Supported Versions

• Node.js >=14.10

Example

npm install --save @opentelemetry/sdk-node @opentelemetry/exporter-prometheus
npm install --save @opentelemetry/instrumentation-runtime-node

import { NodeSDK } from '@opentelemetry/sdk-node';
import { PrometheusExporter } from '@opentelemetry/exporter-prometheus';
import { RuntimeNodeInstrumentation } from '@opentelemetry/instrumentation-runtime-node';

const prometheusExporter = new PrometheusExporter({
  port: 9464,
  startServer: true
});

const sdk = new NodeSDK({
  metricReader: prometheusExporter,
  instrumentations: [new RuntimeNodeInstrumentation({
    monitoringPrecision: 5000,
  })],
});

sdk.start()

NodeSDK is the full OpenTelemetry SDK for Node.js that is a layer of abstraction on top of the @opentelemetry/sdk-metrics and @opentelemetry/sdk-trace-* packages. By specifying metricReader, it will initialize the metrics SDK and creates a MeterProvider. @opentelemetry/exporter-prometheus will output metrics collected by registered instrumentation on a /metrics endpoint.

Go to localhost:9464/metrics, and you should see:

# HELP nodejs_performance_event_loop_utilization Event loop utilization
# UNIT nodejs_performance_event_loop_utilization 1
# TYPE nodejs_performance_event_loop_utilization gauge
nodejs_performance_event_loop_utilization 0.010140079547955264

> Metrics will only be exported after it has collected two ELU readings (at least approximately RuntimeNodeInstrumentationConfig.monitoringPrecision milliseconds after initialization). Otherwise, you may see: > > txt > # no registered metrics >

Options

RuntimeNodeInstrumentation's constructor accepts the following options:

Useful links

• For more information on OpenTelemetry, visit:
• For more about OpenTelemetry JavaScript:
• For help or feedback on this project, join us in GitHub Discussions

License

Apache 2.0 - See LICENSE for more information.