PM2 - production process manager for Node.js

original : https://github.com/Unitech/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 is constantly assailed by more than 300 tests.

Compatible with io.js and Node.js. Compatible with CoffeeScript. Works on Linux (stable) & MacOSx (stable) & Windows (bêta).

Install PM2

$ npm install pm2 -g

npm is a builtin CLI when you install Node.js - Installing Node.js or io.js with NVM

Start an application

$ pm2 start app.js

Main features

Process management

Once apps are started you can list and manage them easily:

Listing all running processes:

$ pm2 list

Managing your processes is straightforward:

$ pm2 stop     <app_name|id|all>
$ pm2 restart  <app_name|id|all>
$ pm2 delete   <app_name|id|all>

To have more details on a specific process:

$ pm2 describe 0

Monitoring

Monitoring all processes launched:

$ pm2 monit

Log facilities

Displaying logs of a specified process or all processes, in real time:

$ pm2 logs
$ pm2 logs big-api
$ pm2 flush          # Clear all the logs

Load balancing / 0s reload downtime

When an app is started with the -i option, the cluster mode is enabled.

Warning: It's still a beta feature. If you want to use the embed cluster module or reload with 0s downtime, we recommend the use of node#0.12.0+ node#0.11.16+ or io.js#1.0.2+. We do not support node#0.10.* cluster module anymore!

With the cluster mode, PM2 enables load balancing between each worker. Each HTTP/TCP/UDP request will be forwarded to one specific process at a time.

$ pm2 start app.js -i max  # Enable load-balancer and cluster features

$ pm2 reload all           # Reload all apps in 0s manner

Startup script generation

PM2 can generate and configure a startup script to keep PM2 and your processes alive at every server restart.

$ pm2 startup
# auto-detect platform
$ pm2 startup [platform]
# render startup-script for a specific platform, the [platform] could be one of:
#   ubuntu|centos|redhat|gentoo|systemd|darwin|amazon

For Centos worked example 

#sudo env PATH=$PATH:/usr/local/bin pm2 startup centos -u root

To save a process list just do:

$ pm2 save