@pyroscope/nodejs v0.3.7

Pyroscope nodejs package

Enhance your Node.js application’s performance with our Node.js Profiler. Seamlessly integrated with Pyroscope, it provides real-time insights into your application’s operation, helping you identify and resolve performance bottlenecks. This integration is key for Node.js developers aiming to boost efficiency, reduce latency, and maintain optimal application performance.

For more detailed information, please refer to our documentation page on using the Node.js language SDK

Configuration

Modes

Pyroscope supports two main operation modes:

• Push mode
• Pull mode

Push mode means the package itself uploads profile data to a pyroscope server, when pull mode means you provide pyroscope server with an endponts to scrape profile data

NodeJS Pyroscope module supports collecting cpu, wall-time and heap. More details you may find here

Push mode

Usage is differs for first you need to import and init pyroscope module. Module is available for both CommonJS and ESM variants, so you can use it the way it fits your project.

Javascript

const Pyroscope = require('@pyroscope/nodejs');

Pyroscope.init({serverAddress: 'http://pyroscope:4040', appName: 'nodejs'});
Pyroscope.start();

Typescript:

import Pyroscope from '@pyroscope/nodejs';

Pyroscope.init({serverAddress: 'http://pyroscope:4040', appName: 'nodejs'});
Pyroscope.start();

Both params appName and serverAddress are mandatory. Once you init you may startCpuProfiling(), startWallProfiling() and/or startHeapProfiling(). start() starts both memory and CPU profiling

Dynamic tags

You may assign certain labels to certain parts of your code by using wrapper function tagWrapper(tags: Record<string, string | number | undefined>, fn: Function). Please note that this only available for cpu profiling.

...

app.get('/scooter', function scooterSearchHandler(req, res) {
  Pyroscope.tagWrapper({'vehicle':'scooter'}, () =>
    genericSearchHandler(0.1)(req, res)
  );
});

Pull Mode

In order to enable pull mode you need to implement follwing endpoints:

• /debug/pprof/profile -- for wall-time profiling
• /debug/pprof/heap -- for heap profiling

You may implement your own enpoints with Pyroscope API, like in the example:

Pyroscope.init()

app.get('/debug/pprof/profile', async function handler(req, res) {
  console.log('Collecting Cpu for', req.query.seconds);
  try {
    const p = await Pyroscope.collectCpu(req.query.seconds);
    res.send(p);
  } catch (e) {
    console.error('Error collecting cpu', e);
    res.sendStatus(500);
  }
});

Parameter appName is mandatory in pull mode.

Pull Mode

In order to enable pull mode you need to implement follwing endpoints:

• /debug/pprof/profile -- for wall-time profiling
• /debug/pprof/heap -- for heap profiling

You may implement your own enpoints with Pyroscope API, like in the example:

app.get('/debug/pprof/profile', async function handler(req, res) {
  console.log('Collecting Cpu for', req.query.seconds);
  try {
    const p = await Pyroscope.collectCpu(req.query.seconds);
    res.send(p);
  } catch (e) {
    console.error('Error collecting cpu', e);
    res.sendStatus(500);
  }
});

or you may use express middleware.

import Pyroscope from '@pyroscope/nodejs'

Pyroscope.init()
const app = express()
app.use(Pyroscope.expressMiddleware());

then you also need to configure your pyroscope server by providing config file

---
log-level: debug
scrape-configs:
  - job-name: testing            # any name
    enabled-profiles: [cpu, mem] # cpu and mem for cpu and heap
    static-configs:
      - application: rideshare
        spy-name: nodespy        # make pyroscope know it's node profiles
        targets:
          - localhost:3000       # address of your scrape target
        labels:
          env: dev               # labels

Debugging

Use DEBUG env var set to pyroscope to enable debugging messages. Otherwise all messages will be suppressed.

DEBUG=pyroscope node index.js

API

Configuration

init(c : PyroscopeConfig)

Configuration options

interface PyroscopeConfig {
    serverAddress?: string;                // Server address for push mode
    appName?: string;                      // Application name
    tags?: Record<string, any>;            // Static tags
    sourceMapper?: SourceMapper;           // Source maps
    basicAuthUser?: string;                // Grafana Cloud Authentification
    basicAuthPassword?: string;            // Grafana Cloud Authentification
}

Both serverAddress and appName are mandatory for push mode.

CPU Profiling

// Start collecting for 10s and push to server
Pyroscope.startCpuProfiling()
Pyroscope.stopCpuProfiling()

// Or do it manually
Pyroscope.collectCpu(seconds?:number);

Wall Profiling

// Start collecting for 10s and push to server
Pyroscope.startWallProfiling()
Pyroscope.stopWallProfiling()

// Or do it manually
Pyroscope.collectWall(seconds?:number);

Heap Profiling

// Start heap profiling and upload to server
Pyroscope.startHeapProfiling()
Pyroscope.stopHeapProfiling()

// Or do it manually
Pyroscope.startHeapCollecting()
Pyroscope.collectHeap();
Pyroscope.stopHeapCollecting()