NodeJS Open Standards

OpenTracing

OpenTracing support is included in the dd-trace package.

const tracer = require('dd-trace').init()
const opentracing = require('opentracing')

opentracing.initGlobalTracer(tracer)

The tracer can now be used like in any other OpenTracing application.

The following tags are available to override Datadog specific options:

• service.name: The service name to be used for the span. The service name from the tracer will be used if this is not provided.
• resource.name: The resource name to be used for the span. The operation name will be used if this is not provided.
• span.type: The span type to be used for the span. Will fallback to custom if not provided.

See opentracing.io for OpenTracing NodeJS usage.

OpenTelemetry

OpenTelemetry support is available by using the opentelemetry-exporter-datadog package to export traces from OpenTelemetry to Datadog.

Installation

To install:

npm install --save opentelemetry-exporter-datadog

Usage

Install the Datadog processor and exporter in your application and configure the options. Then use the OpenTelemetry interfaces to produce traces and other information:

const opentelemetry = require('@opentelemetry/api');
const { BasicTracerProvider } = require('@opentelemetry/tracing');
const { DatadogSpanProcessor, DatadogExporter, DatadogProbabilitySampler, DatadogPropagator } = require('opentelemetry-exporter-datadog');

const provider = new BasicTracerProvider();

const exporterOptions = {
  serviceName: 'my-service', // optional
  agentUrl: 'http://localhost:8126', // optional
  tags: 'example_key:example_value,example_key_two:value_two', // optional
  env: 'production', // optional
  version: '1.0' // optional
};

const exporter = new DatadogExporter(exporterOptions);
const processor = new DatadogSpanProcessor(exporter);

provider.addSpanProcessor(processor);

// Next, add the Datadog Propagator for distributed tracing
provider.register({
  propagator: new DatadogPropagator()
});

const tracer = opentelemetry.trace.getTracer('example-basic-tracer-node');

// Create a span. A span must be closed.
const parentSpan = tracer.startSpan('main');

doWork(parentSpan);

setTimeout(() => {
  parentSpan.end();

  setTimeout(() => {
    processor.shutdown()
  },4000);
}, 5000);

function doWork(parent) {
  const span = tracer.startSpan('doWork', {
    parent,
  });

  // simulate some random work.
  for (let i = 0; i <= Math.floor(Math.random() * 40000000); i += 1) {
    // empty
  }
  // Set attributes to the span.
  span.setAttribute('key', 'value');
  setTimeout( () => {
    span.end();
  }, 1000)
}

Configuration options

The Datadog Agent URL and span tag values can be configured if necessary or desired based upon your environment and Agent location.

Datadog Agent URL

By default, the OpenTelemetry Datadog Exporter transmits traces to http://localhost:8126. Send traces to a different URL by configuring the following environment variables:

• DD_TRACE_AGENT_URL: The <host>:<port> where Datadog Agent listens for traces. For example, agent-host:8126.

You can override these values at the trace exporter level:

// Configure the datadog trace agent url
new DatadogExporter({agentUrl: 'http://dd-agent:8126'});

Tagging

Configure the application to automatically tag your Datadog exported traces by setting the following environment variables:

• DD_ENV: Your application environment, for example, production, staging.
• DD_SERVICE: Your application’s default service name, for example, billing-api.
• DD_VERSION: Your application version, for example, 2.5, 202003181415, or 1.3-alpha.
• DD_TAGS: Custom tags in value pairs, separated by commas, for example, layer:api,team:intake.
• If DD_ENV, DD_SERVICE, or DD_VERSION is set, it will override any corresponding env, service, or version tag defined in DD_TAGS.
• If DD_ENV, DD_SERVICE and DD_VERSION are not set, you can configure environment, service, and version by using corresponding tags in DD_TAGS.

Tag values can also be overridden at the trace exporter level. This lets you set values on a per-application basis, so you can have multiple applications reporting for different environments on the same host:

new DatadogExporter({
  serviceName: 'my-service', // optional
  agentUrl: 'http://localhost:8126', // optional
  tags: 'example_key:example_value,example_key_two:value_two', // optional
  env: 'production', // optional
  version: '1.1' // optional
});

Tags that are set directly on individual spans supersede conflicting tags defined at the application level.

OpenTelemetry links

• See npm or github for more OpenTelemetry NodeJS Datadog Exporter usage.