OpenTelemetry Node SDK

This module provides automated instrumentation and tracing for Node.js applications.

For manual instrumentation see the @opentelemetry/sdk-trace-base package.

Note: Much of OpenTelemetry JS documentation is written assuming the compiled application is run as CommonJS. For more details on ECMAScript Modules vs CommonJS, refer to esm-support.

How auto instrumentation works

This package exposes a NodeTracerProvider. For loading instrumentations please use registerInstrumentations function from opentelemetry-instrumentation

OpenTelemetry comes with a growing number of instrumentation plugins for well known modules (see supported modules) and an API to create custom instrumentation (see the instrumentation developer guide).

Please note: This module does not bundle any plugins. They need to be installed separately.

This is done by wrapping all tracing-relevant functions.

This instrumentation code will automatically

• extract a trace-context identifier from inbound requests to allow distributed tracing (if applicable)
• make sure that this current trace-context is propagated while the transaction traverses an application (see context document in @opentelemetry/api for an in-depth explanation)
• add this trace-context identifier to outbound requests to allow continuing the distributed trace on the next hop (if applicable)
• create and end spans

Creating custom spans on top of auto-instrumentation

Additionally to automated instrumentation, NodeTracerProvider exposes the same API as @opentelemetry/sdk-trace-base, allowing creating custom spans if needed.

Installation

npm install --save @opentelemetry/api
npm install --save @opentelemetry/sdk-trace-node

# Install instrumentation plugins
npm install --save @opentelemetry/instrumentation-http
# and for example one additional
npm install --save @opentelemetry/instrumentation-graphql

Usage

The following code will configure the NodeTracerProvider to instrument http (and any other installed supported modules) using @opentelemetry/plugin-http.

const { registerInstrumentations } = require('@opentelemetry/instrumentation');
const { NodeTracerProvider } = require('@opentelemetry/sdk-trace-node');

// Create and configure NodeTracerProvider
const provider = new NodeTracerProvider();

// Initialize the provider
provider.register();

// register and load instrumentation and old plugins - old plugins will be loaded automatically as previously
// but instrumentations needs to be added
registerInstrumentations({
});

// Your application code - http will automatically be instrumented if
// @opentelemetry/plugin-http is present
const http = require('http');

Instrumentation configuration

In the following example:

• the express instrumentation is enabled
• the http instrumentation has a custom config for a requestHook

const { registerInstrumentations } = require('@opentelemetry/instrumentation');
const { HttpInstrumentation } = require('@opentelemetry/instrumentation-http');
const { ExpressInstrumentation } = require('@opentelemetry/instrumentation-express');

const provider = new NodeTracerProvider();
provider.register();

// register and load instrumentation and old plugins - old plugins will be loaded automatically as previously
// but instrumentations needs to be added
registerInstrumentations({
  instrumentations: [
    new ExpressInstrumentation(),
    new HttpInstrumentation({
        requestHook: (span, request) => {
          span.setAttribute("custom request hook attribute", "request");
        },
    }),
  ],
});

Examples

See how to automatically instrument http and gRPC / grpc-js using node-sdk.

Useful links

• For more information on OpenTelemetry, visit: https://opentelemetry.io/
• For more about OpenTelemetry JavaScript: https://github.com/open-telemetry/opentelemetry-js
• For help or feedback on this project, join us in GitHub Discussions

License

Apache 2.0 - See LICENSE for more information.