OpenTelemetry Example PubSub App

This is an example app that uses the New Relic agent in the OpenTelemetry bridge mode to instrument GCP Pub/Sub.

Example App Setup

Setup GCP PubSub

In the PubSub Getting Started guide, follow the steps in the "Before you begin" and "Create a topic and subscription" sections. my-topic is the default topic name and my-sub is the default subscription name (matches the guide), but this can be changed in env-p.sample and env-s.sample respectively.

Run Example

Requirements:

• Node.js >= 20.6.0

npm install
cp env-p.sample .env-p # Publisher env vars
cp env-s.sample .env-s # Subscriber env vars
# Fill out `NEW_RELIC_LICENSE_KEY` in .env-p and .env-s
npm run subscribe # Start subscriber
npm run publish # Run publisher a few times

Instrumenting your Application

If you already have a GCP Pub/Sub application that you would like to instrument with our agent's OpenTelemetry bridge, here are the steps that you need to do:

1. Install newrelic normally. Please refer to our installation docs if you need help.
2. In your newrelic.js file, enable OpenTelemetry bridge w/ traces. inside exports.config:

   exports.config = {
        // ...
        opentelemetry_bridge: {
            enabled: true,
            traces: {
                enabled: true,
            }
        },
        // ...
   }

3. In every file that instantiates the PubSub class, give it the config of enableOpenTelemetryTracing:true.

   const { PubSub } = require('@google-cloud/pubsub')
   const pubsubClient = new PubSub({ enableOpenTelemetryTracing: true })

4. Wrap the code that publishes messages in a background transaction. This is not necessary for the subscriber.

   const newrelic = require('newrelic')
   // ...
   newrelic.startBackgroundTransaction('transaction name', async function handleTransaction() {
        const txn = newrelic.getTransaction()
        await publishMessage() // replace with your function
        txn.end()
   })