PM2 best tools for running multiple instance nodejs applications

Sometimes we need to run more than one instance in one server and need to manage automaticly these instances for example I need to run socket cluster in 8 instance and when one of these instance down automaticly restart.

For solve this problem you can use PM2.

PM2 is a production process manager for Node. js applications with a built-in load balancer. It allows you to keep applications alive forever, to reload them without downtime and to facilitate common system admin tasks.

Pm2

For more detail you can use pm2 documentation:

PM2 - Home

PM2 is a daemon process manager that will help you manage and keep your application online 24/7.

Install PM2

You can use code below for install node js package but before run this command you must install nodejs

npm install pm2 -g

FEATURES

A Complete feature set for production environment, built with a worldwide community of developers and enterprises.

BEHAVIOR CONFIGURATION

SOURCE MAP SUPPORT

CONTAINER INTEGRATION

WATCH & RELOAD

LOG MANAGEMENT

MONITORING

MODULE SYSTEM

MAX MEMORY RELOAD

CLUSTER MODE

HOT RELOAD

DEVELOPMENT WORKFLOW

STARTUP SCRIPTS

DEPLOYMENT WORKFLOW

PAAS COMPATIBLE

KEYMETRICS MONITORING

API

Run node js with PM2

After install package you can run your node js application with code below.

pm2 start app.js

This package have a lot of senarios for run node js application we can write some of them

If you like to know more senarios you can follow documents.

For Node.js applications, PM2 includes an automatic load balancer that will share all HTTP[s]/Websocket/TCP/UDP connections between each spawned processes.

To start an application in Cluster mode:

$ pm2 start app.js -i max

Ecosystem File

You can also create a configuration file, called Ecosystem File, to manage multiple applications. To generate an Ecosystem file:

$ pm2 ecosystem

This will generate an ecosystem.config.js file:

module.exports = {
  apps : [{
    name: "app",
    script: "./app.js",
    env: {
      NODE_ENV: "development",
    },
    env_production: {
      NODE_ENV: "production",
    }
  }, {
     name: 'worker',
     script: 'worker.js'
  }]
}