PM2 Complete Guide for Node.js Applications

Install PM2

npm install -g pm2

Verify Installation

pm2 --version

Start Application

pm2 start app.js

pm2 start server.js

Start Application With Name

pm2 start app.js --name backend-api

View Running Processes

pm2 list

Restart Application

pm2 restart backend-api

Stop Application

pm2 stop backend-api

Delete Application

pm2 delete backend-api

Monitor Logs

pm2 logs

pm2 logs backend-api

Real-Time Monitoring

pm2 monit

Enable Startup On Server Reboot

pm2 startup

pm2 save

This ensures applications automatically start after reboot.

Ecosystem File Example-1

module.exports = {
  apps: [
    {
      name: "backend-api",
      script: "./server.js",
      instances: 2,
      exec_mode: "cluster",
      watch: false,
      autorestart: true,
      max_memory_restart: "500M",
      env: {
        NODE_ENV: "production",
        PORT: 3000
      }
    }
  ]
};

Start Using Ecosystem File

pm2 start ecosystem.config.js

Reload Zero Downtime

pm2 reload ecosystem.config.js

Fork Mode Example

Fork mode runs a single instance of your application. This is ideal for development environments, small websites, internal tools, or applications with low traffic.

pm2 start server.js --name backend-api

Cluster Mode Example

Cluster mode allows PM2 to use multiple CPU cores. This improves performance, scalability, and application availability for production workloads.

pm2 start server.js -i max --name backend-api

The max option automatically uses all available CPU cores.

Useful PM2 Commands

pm2 show backend-api

pm2 flush

pm2 restart all

pm2 stop all

npm install pm2@latest -g && pm2 update

pm2 scale backend-api 8