What monitoring and analytics tools have you used in your projects?

In Node.js projects, the following tools are often used for monitoring and analytics:

• Prometheus + Grafana — for metrics collection and visualization. Prometheus collects metrics from applications, and Grafana creates dashboards.
• Elastic Stack (ELK) — Elasticsearch, Logstash, and Kibana for centralized logging and log analysis.
• New Relic, Datadog, AppDynamics — commercial solutions for application performance monitoring (APM), which allow tracking response times, errors, and load.
• Sentry — for real-time error and exception tracking.
• PM2 — a process manager for Node.js with built-in monitoring and logging.

Example of integrating Prometheus with Node.js:

const client = require('prom-client');
const express = require('express');
const app = express();

const collectDefaultMetrics = client.collectDefaultMetrics;
collectDefaultMetrics();

app.get('/metrics', async (req, res) => {
  res.set('Content-Type', client.register.contentType);
  res.end(await client.register.metrics());
});

app.listen(3000);

This endpoint allows Prometheus to collect metrics from your application.