Node.js Monitoring in Production (Step-by-Step with PM2 & Custom Metrics)

Are you struggling with slow Node.js performance in production? Monitoring is the key to uncovering hidden performance issues, avoiding downtime, and keeping your app fast and reliable. In this guide, you’ll learn exactly how to set up Node.js monitoring—step by step—with real examples and tools like Watchlog.

Node.js Monitoring in Production (Step-by-Step with PM2 & Custom Metrics)

🚀 Why Node.js Monitoring Matters in Production

Node.js is powerful, but also sensitive to issues like:

  • Memory leaks
  • Blocking the event loop
  • Slow database queries
  • High error rates

Without proper monitoring, these issues silently degrade performance. Real-time monitoring helps you:

✅ Detect anomalies early

✅ Improve response times

✅ Scale your app confidently

📊 Step 1: Define What You Need to Monitor

Before installing any tool, identify the critical metrics you want to track:

  • CPU & Memory Usage – Detect leaks or bottlenecks
  • Event Loop Lag – Ensure asynchronous operations stay fast
  • API Latency & Throughput – Monitor user experience
  • Error Rates – Discover hidden bugs
  • Database Performance – Identify slow queries
  • Custom Business Metrics – Track logins, payments, or failures

⚙️ Step 2: Install a Node.js Monitoring Agent

Use the Watchlog agent to begin collecting real-time metrics from your server:

sudo apiKey="your-api-key" server="your-server" bash -c "$(curl -L https://watchlog.io/ubuntu/watchlog-script.sh)"

This lightweight agent starts collecting CPU, memory, latency, and more—without affecting your app’s performance.

📦 Step 3: Monitor PM2 Processes (If You Use PM2)

PM2 is a popular process manager. With Watchlog’s PM2 integration, you can track:

  • Live status of each app
  • CPU & memory usage per process
  • Automatic metric forwarding to Watchlog

How to set it up:

git clone [email protected]:watchlogserver/watchlog-pm2.git
cd watchlog-pm2
npm install
pm2 start watchlog-pm2

Then log into your Watchlog panel and verify the metrics are displayed.

📐 Step 4: Track Custom Application Events

Want to track business-level metrics like "failed logins" or "checkout clicks"? Use watchlog-metric:

npm install watchlog-metric

Example:

const watchlog = require("watchlog-metric");


watchlog.increment("api_requests");
watchlog.increment("failed_logins", 3);

🚨 Step 5: Set Up Real-Time Alerts

Avoid surprises with proactive alerts. With Watchlog you can:

  • ✅ Get Slack or Email alerts
  • ✅ Integrate Webhooks for auto-responses
  • ✅ Define thresholds for custom business rules

📁 Step 6: Analyze Logs for Root Cause

Centralized logging makes debugging easier. Use tools like Winston or Watchlog’s built-in logging.

Example using Winston:

const winston = require("winston");
const logger = winston.createLogger({
  level: "info",
  transports: [
    new winston.transports.Console(),
    new winston.transports.File({ filename: "error.log", level: "error" })
  ]
});

📉 Step 7: Visualize Performance in Dashboards

Numbers mean nothing if you can’t see them. Watchlog’s dashboard helps you:

  • Track resource usage in real-time
  • Analyze API performance and bottlenecks
  • View error and anomaly trends
  • Compare historical metrics over time

🔄 Step 8: Automate Performance Optimization

Once you collect enough data, start optimizing:

  • 🔍 Identify slow queries
  • 🧠 Add smart caching
  • 🚦 Scale services with traffic
  • ✂️ Refactor performance bottlenecks

✅ Final Thoughts: Start Monitoring Node.js Today

Production issues are inevitable—but they don’t have to be painful. With proper Node.js monitoring, you gain full control over your application’s health and performance.

💡 Start using Watchlog today and gain real-time insights into your Node.js app.

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