Continuous profiling for Node.js

Continuous profiling on Upsun

Upsun Continuous Profiling is powered by Blackfire. It is available directly from the Console under the Profiling tab of your environments.

The Node.js continuous profiling is currently made across 3 dimensions:

• CPU Time: Time spent running on the CPU
• Wall-time: Elapsed time per function call
• Heap: Memory allocation and reserved space over time

The default sampling frequency is 100 Hz. This means the Node.js continuous profiler is collecting information 100 times per second.

Prerequisites

Upsun Continuous Profiler requires Node.js >= 16.0.0.

Installation

Get the Blackfire Continuous Profiler NodeJS library:

npm install @blackfireio/node-tracing

const Blackfire = require('@blackfireio/node-tracing');

NodeJS continuous profiler API

The NodeJS continuous profiler API has two functions:

function start(config) {}
function stop() {}

function start(config) {}

The start function starts the continuous profiler probe. It collects profiling information in the background and periodically uploads it to the Blackfire Agent until the stop function is called.

const Blackfire = require('@blackfireio/node-tracing');
Blackfire.start({
   appName: 'my-app'
});
// your application...
// If needed, you can stop profiling before cpuDuration
// Blackfire.stop();

The start function accepts an object as a parameter with the following keys:

• appName: name of the application

• durationMillis: time in milliseconds for which to collect profile (default: 45_000)

• cpuProfileRate: average sampling frequency in Hz. (default: 100)

• labels: Labels to add to the profile. (default: {})

• uploadTimeoutMillis: Timeout in milliseconds for the upload request (default: 10000)

function stop() {}

Stops the continuous profiling probe.

An example application

1. Get the Continuous Profiler NodeJS library

npm install express @blackfireio/node-tracing

2. Create index.js with the following code

const Blackfire = require('@blackfireio/node-tracing');
const express = require('express')
const crypto = require("crypto");
const app = express()
const port = 3000

app.get('/', (req, res) => {
   const salt = crypto.randomBytes(128).toString("base64");
   const hash = crypto.pbkdf2Sync("this is my password", salt, 10000, 512, "sha512");

   res.send('Hello World!');
})


app.listen(port, () => {
   console.log(`Example app listening on port ${port}`)
   Blackfire.start({appName: 'blackfire-example'});
})

3. Run the Node.js server

node index.js