In the world of JavaScript and TypeScript development, two frameworks have gained significant traction for building scalable and efficient web applications: Next.js for React applications with server-side rendering capabilities and NestJS for building efficient, reliable, and scalable server-side applications. When it comes to deploying these applications in a production environment, stability, performance, and ease of management are paramount. This is where PM2, a powerful process manager for Node.js applications, comes into play. In this guide, we'll dive deep into why PM2 is an excellent choice for managing Next.js and NestJS applications in production and provide a step-by-step tutorial on how to set it up.

Why Choose PM2 for Your Production Server?

PM2 is a process manager that helps developers manage and keep their applications online 24/7. Here are some reasons why PM2 is a great choice for your Next.js and NestJS applications:

1. Process Management

PM2 ensures that your applications are always running. If an application crashes due to an unexpected error, PM2 automatically restarts it, minimizing downtime.

2. Load Balancing

With PM2, you can easily scale your application across multiple instances, enabling load balancing that improves application performance and reliability under heavy load conditions.

3. Monitoring and Logging

Monitoring application performance and logging are crucial in a production environment. PM2 provides out-of-the-box support for monitoring key metrics such as CPU and memory usage, and it manages logs, making troubleshooting and performance tuning more accessible.

4. Zero Downtime Deployments

PM2 supports hot reloading and zero-downtime deployments, allowing you to update your applications without any service interruption, which is crucial for maintaining a good user experience.

5. Environment Management

With PM2, you can easily manage environment variables for your applications, ensuring that your production, development, and other environments are correctly configured and separated.

Setting Up PM2 with Next.js and NestJS

To harness the full power of PM2 for managing your Next.js and NestJS applications, follow the steps below. This tutorial assumes you have Node.js and npm installed on your production server.

Step 1: Install PM2

First, install PM2 globally on your server using npm:

npm install pm2 -g

Step 2: Configure Your Applications

For PM2 to manage your applications, you need to create a configuration file, typically named ecosystem.config.js. This file tells PM2 how to start your applications, along with any specific settings you want to apply.

Next.js Configuration

For a Next.js application, your configuration might look something like this:

// ecosystem.config.js
module.exports = {
  apps : [{
    name: "next-app",
    script: "npm",
    args: "start",
    cwd: "/path/to/your/nextjs/app",
    watch: true,
    env: {
      NODE_ENV: "production",
    }
  }]
};

This configuration tells PM2 to start your Next.js application using npm start, watch for file changes, and set the NODE_ENV environment variable to production.

NestJS Configuration

For a NestJS application, the configuration will be slightly different, targeting the compiled JavaScript file:

// ecosystem.config.js
module.exports = {
  apps : [{
    name: "nestjs-app",
    script: "./dist/main.js",
    cwd: "/path/to/your/nestjs/app",
    watch: true,
    env: {
      NODE_ENV: "production",
    }
  }]
};

This configuration specifies the entry point of your built NestJS application and similarly sets the environment to production.

Step 3: Start Your Applications with PM2

With your ecosystem.config.js file ready, you can now start your applications using PM2:

pm2 start ecosystem.config.js

PM2 will start both your Next.js and NestJS applications as daemon processes, ensuring they are kept alive indefinitely.

Step 4: Monitoring and Managing Your Applications

PM2 provides a suite of commands to help you monitor and manage your applications:

• List all running applications: pm2 list
• Monitor CPU and memory usage: pm2 monit
• View logs in real-time: pm2 logs
• Stop an application: pm2 stop <app_name>
• Restart an application: pm2 restart <app_name>

Conclusion

Using PM2 to manage your Next.js and NestJS applications in a production environment offers numerous benefits, from ensuring high availability to facilitating zero-downtime deployments. By following the steps outlined in this guide, you can set up PM2 to take care of your application processes, allowing you to focus on developing great applications without worrying about their stability and performance in production.

Remember, every application and environment is different, so you might need to adjust the configurations and commands based on your specific requirements. Happy coding!