Deploy Node.js App on VPS with PM2 Process Manager

Running node app.js directly on a VPS has a critical flaw — the app stops when you close the terminal, and won't restart if it crashes. PM2 (Process Manager 2) solves all of these problems: auto-restart, cluster mode, log management, and startup scripts all in one tool.

1. What is PM2 and Why Use It

PM2 is the most popular Production Process Manager for Node.js with these key features:

2. Prerequisites

• VPS with Ubuntu 20.04/22.04/24.04 (or Debian)
• Node.js ≥ 16 LTS installed
• npm or yarn
• Non-root user (recommended)

3. Install Node.js via NVM

# Install nvm
curl -o- https://raw.githubusercontent.com/nvm-sh/nvm/v0.39.7/install.sh | bash
source ~/.bashrc

# Install Node.js LTS
nvm install --lts
nvm use --lts

# Verify installation
node -v
npm -v

4. Install PM2

npm install -g pm2
pm2 -v

5. Start Your App with PM2

# Basic start
pm2 start app.js

# Start with a name (recommended)
pm2 start app.js --name "myapp"

# Start with arguments
pm2 start app.js --name "myapp" -- --port 3000

# Check status
pm2 status

# View logs
pm2 logs myapp

6. Use ecosystem.config.js for Configuration

// ecosystem.config.js
module.exports = {
  apps: [{
    name: 'myapp',
    script: './app.js',
    instances: 'max',        // cluster mode — use all CPU cores
    exec_mode: 'cluster',
    watch: false,
    max_memory_restart: '500M',
    env: {
      NODE_ENV: 'production',
      PORT: 3000
    },
    error_file: './logs/err.log',
    out_file: './logs/out.log',
    log_date_format: 'YYYY-MM-DD HH:mm:ss'
  }]
};

# Start from config file
pm2 start ecosystem.config.js

# Zero-downtime reload
pm2 reload ecosystem.config.js

7. Cluster Mode — Boost Performance

Node.js is single-threaded. Cluster Mode allows PM2 to use multiple CPU cores:

# Use all CPU cores
pm2 start app.js -i max

# Use 4 cores
pm2 start app.js -i 4

# Zero-downtime reload
pm2 reload myapp

8. Startup Script — Run on Reboot

# Generate startup script (copy and run the output command with sudo)
pm2 startup

# After starting your apps, save the state
pm2 save

9. Log Management

# View all logs
pm2 logs

# View specific app logs
pm2 logs myapp --lines 100

# Clear logs
pm2 flush

# Install automatic log rotation
pm2 install pm2-logrotate

10. Monitoring and Basic Commands

# Real-time dashboard
pm2 monit

# List all processes
pm2 list

# Detailed app info
pm2 show myapp

# Restart / Stop / Delete
pm2 restart myapp
pm2 stop myapp
pm2 delete myapp

# Restart all
pm2 restart all

11. Nginx Reverse Proxy Setup

# /etc/nginx/sites-available/myapp
server {
    listen 80;
    server_name yourdomain.com;

    location / {
        proxy_pass http://localhost:3000;
        proxy_http_version 1.1;
        proxy_set_header Upgrade $http_upgrade;
        proxy_set_header Connection 'upgrade';
        proxy_set_header Host $host;
        proxy_set_header X-Real-IP $remote_addr;
        proxy_cache_bypass $http_upgrade;
    }
}

sudo ln -s /etc/nginx/sites-available/myapp /etc/nginx/sites-enabled/
sudo nginx -t
sudo systemctl reload nginx

12. Zero-Downtime Deployment

# Pull new code
git pull origin main

# Install dependencies
npm install --production

# Zero-downtime reload (Cluster Mode)
pm2 reload myapp

# Or restart if not using Cluster Mode
pm2 restart myapp

Summary

PM2 is an essential tool for deploying Node.js in production on a VPS. The core workflow is: install PM2 → start app with ecosystem config → enable Cluster Mode → set up startup script → add Nginx reverse proxy. For a reliable VPS to run your Node.js apps, check out AsiaGB VPS with SSD storage, 99% uptime, and dedicated support.