# Pm2

# Overview

In this article we will be going over handy how-to commands in configuring, deploying and troubleshooting your PM2 application. PM2 is a process manager for Node.js applications, it comes with many benefits with the overall benefit being it making sure your application runs continuously and is easily manageable.

Benefits include:

  • Keeps the application running due to auto-restarts
  • Managing of multiple applications
  • Monitoring
  • Easy viewing of logs
  • ...

# Installation

When defining Node.js in your deployment in my.turbostack.app pm2 will be installed by default by your node package manager :

image

# Deploying the application

  1. In case you migrated from another environment, and you want to start with a fresh deployment, make sure to clean out the node_modules directory:

    rm -rf node_modules

    It could be that during migration something is missing/corrupted/incompatible. Removing the directory ensures a flawless reinstallation.

  2. Check the important configuration files are present and changed accordingly if needed ( next.config.js and package.json)

  3. Install the dependencies, these will rebuild node_modules:

    npm install

  4. Build the application:

    npm run build

  5. Start the application with pm2:

    pm2 start npm --name <appname> -- start

  6. As a final step do not forget to save your running configuration:

    pm2 save

This will store the current process list so the application can be restarted automatically after a reboot of the server or any other disturbance causing the service to stop. Always do this whenever the running process list changes (e.g. when deleting/starting a new application, changing the app name, etcetera...)

  1. If this is the first-time setup it could be that you need to run:

    pm2 startup

This prepares pm2 to launch on system boot, afterwards, pm2 save will handle all running operations.

# Monitoring and troubleshooting the application

  • List all processes:

    pm2 ls

  • Opening a live monitoring dashboard:

    pm2 monit

    This will show

    • CPU and memory usage per application
    • Application status
    • Restart count
    • Real-time logs

  • Display metadata of an application:

    pm2 show <appname>

  • Check logs of an application:

    pm2 logs <appname>

    There are some helpful options with this command:

    • --lines n : show only last n liens
    • --err : show only errors
    • --out : show only output

  • Restart or reload an application:

    pm2 restart <appname>

    pm2 reload <appname>