Modern application development requires effective error tracking and performance monitoring to enhance user experience. This article details how to integrate Sentry with Node.js applications for real-time error tracking and performance monitoring.
What is Sentry?
Sentry is a powerful tool for application error tracking and performance monitoring. It helps developers detect, track, and analyze errors in real-time, allowing for quick problem resolution and improved user experience.
Key Features of Sentry
- Error Tracking: Automatically detects and reports exceptions and errors in the code.
- Performance Monitoring: Monitors application performance in real-time and analyzes the causes of latency or performance degradation.
- Integration: Supports various programming languages and frameworks, easily integrating with tools like GitHub, Slack, Jira, and more.
- Notifications: Immediate notifications for errors or performance issues.
- Release Tracking: Tracks issues in specific releases.
Integrating Sentry with Node.js Applications
Next, we will explore step-by-step how to integrate Sentry with a Node.js application.
1. Install Sentry SDK
First, you need to install the `@sentry/node` package. Run the following command in the terminal:
npm install @sentry/node
2. Configure Sentry
Set up Sentry in the application’s entry file (e.g., `app.js` or `index.js`). The Sentry DSN (Data Source Name) can be found in your Sentry project settings.
const Sentry = require('@sentry/node');
const express = require('express');
const app = express();
// Initialize Sentry
Sentry.init({ dsn: 'YOUR_SENTRY_DSN' });
// Use Sentry request handler as the first middleware for all requests.
app.use(Sentry.Handlers.requestHandler());
// Example route
app.get('/', function mainHandler(req, res) {
throw new Error('Broke!');
});
// Use Sentry error handler as the error middleware.
app.use(Sentry.Handlers.errorHandler());
// Set up port and start server
app.listen(3000, () => {
console.log('Server running on port 3000');
});
3. Add Error Handler
Add Sentry’s error handler as the last error handler in your Express.js application. This handler automatically reports errors to Sentry.
// Send all errors to Sentry, then respond to the user
app.use(Sentry.Handlers.errorHandler());
// General error handler
app.use(function onError(err, req, res, next) {
// Additional error handling logic
res.statusCode = 500;
res.end(res.sentry + "\n");
});
Additional Configuration Options
Sentry offers various configuration options. Here are a few useful ones:
Environment
Set the environment (e.g., production, staging) in which the application is running.
Sentry.init({
dsn: 'YOUR_SENTRY_DSN',
environment: 'production'
});
Release
Set the release version to track issues in specific releases.
Sentry.init({
dsn: 'YOUR_SENTRY_DSN',
release: 'my-project-name@2.3.12'
});
Traces Sample Rate
Set the sampling rate for performance data.
Sentry.init({
dsn: 'YOUR_SENTRY_DSN',
tracesSampleRate: 1.0 // 100% sampling
});
Example
Here is a simple example of an Express.js application integrated with Sentry.
const Sentry = require('@sentry/node');
const express = require('express');
const app = express();
// Initialize Sentry
Sentry.init({ dsn: 'YOUR_SENTRY_DSN' });
// Use Sentry request handler for all requests
app.use(Sentry.Handlers.requestHandler());
// Example route
app.get('/', (req, res) => {
res.send('Hello, world!');
});
// Route that intentionally throws an error
app.get('/error', (req, res) => {
throw new Error('This is a test error!');
});
// Use Sentry error handler
app.use(Sentry.Handlers.errorHandler());
// Set up port and start server
app.listen(3000, () => {
console.log('Server running on port 3000');
});
In the example above, the `/error` route intentionally throws an error, which is automatically reported to Sentry.
Conclusion
Using Sentry, you can track errors and monitor the performance of your Node.js applications in real-time. This enhances user experience by allowing quick problem resolution. Follow this guide to easily integrate Sentry and improve the stability and performance of your applications.