pm2
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Production process manager for Node.JS applications with a built-in load balancer.
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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.
Starting an application in production mode is as easy as:
```bash
pm2 start app.js
```
PM2 is constantly assailed by [more than 1000 tests](https://travis-ci.org/Unitech/pm2).
Official website: [http://pm2.keymetrics.io/](http://pm2.keymetrics.io/)
Works on Linux (stable) & MacOSx (stable) & Windows (stable).
[](https://nodei.co/npm/pm2/)
# Install PM2
```bash
npm install pm2 -g
```
*npm is a builtin CLI when you install Node.js - [Installing Node.js with NVM](https://keymetrics.io/2015/02/03/installing-node-js-and-io-js-with-nvm/)*
# Start an application
```bash
pm2 start app.js
```
Your app is now put in background, monitored and kept alive forever.
[More about Process Management](http://pm2.keymetrics.io/docs/usage/quick-start/#cheat-sheet)
# Update PM2
```bash
Install latest pm2 version
npm install pm2 -g
Save process list, exit old PM2 & restore all processes
pm2 update
```
*PM2 updates are seamless*
# Main features
## Commands overview
```bash
npm install pm2 -g # Install PM2
pm2 start app.js # Start, Daemonize and auto-restart application
pm2 start app.js -i 4 # Start 4 instances of application in cluster mode
# it will load balance network queries to each app
pm2 start app.js --name="api" # Start application and name it "api"
pm2 start app.js --watch # Restart application on file change
pm2 start script.sh # Start bash script
pm2 start npm -- start # Start, Daemonize and auto-restart Node application
pm2 list # List all processes started with PM2
pm2 monit # Display memory and cpu usage of each app
pm2 show [app-name] # Show all informations about application
pm2 logs # Display logs of all apps
pm2 logs [app-name] # Display logs for a specific app
pm2 flush
pm2 stop all # Stop all apps
pm2 stop 0 # Stop process with id 0
pm2 restart all # Restart all apps
pm2 reload all # Reload all apps in cluster mode
pm2 gracefulReload all # Graceful reload all apps in cluster mode
pm2 delete all # Kill and delete all apps
pm2 delete 0 # Delete app with id 0
pm2 scale api 10 # Scale app with name api to 10 instances
pm2 reset [app-name] # Reset number of restart for [app-name]
pm2 startup # Generate a startup script to respawn PM2 on boot
pm2 save # Save current process list
pm2 resurrect # Restore previously save processes
pm2 update # Save processes, kill PM2 and restore processes
pm2 generate # Generate a sample json configuration file
pm2 deploy app.json prod setup # Setup "prod" remote server
pm2 deploy app.json prod # Update "prod" remote server
pm2 deploy app.json prod revert 2 # Revert "prod" remote server by 2
pm2 module:generate [name] # Generate sample module with name [name]
pm2 install pm2-logrotate # Install module (here a log rotation system)
pm2 uninstall pm2-logrotate # Uninstall module
pm2 publish # Increment version, git push and npm publish
```
## Different ways of starting processes
```bash
pm2 start app.js --watch # Restart application on file change
pm2 start script.sh # Start bash script
pm2 start app.js -- -a 34 # Start app and pass option -a 34
pm2 start app.json # Start all applications declared in app.json
pm2 start my-python-script.py --interpreter python
```
## Process management
Once apps are started you can list and manage them easily:

Listing all running processes:
```bash
pm2 list
```
Managing your processes is straightforward:
```bash
pm2 stop <app_name|id|'all'|json_conf>
pm2 restart <app_name|id|'all'|json_conf>
pm2 delete <app_name|id|'all'|json_conf>
```
To have more details on a specific process:
```bash
pm2 describe <id|app_name>
```
[More about Process Management](http://pm2.keymetrics.io/docs/usage/quick-start/#cheat-sheet)
## Load balancing / 0s reload downtime
When an app is started with the -i <worker number> option, the **cluster** mode is enabled.
Supported by all major Node.js frameworks and any Node.js applications

**Warning**: If you want to use the embedded load balancer (cluster mode), we recommend the use of `node#0.12.0+` or `node#0.11.16+`. We do not support `node#0.10.*`'s cluster module anymore.
With the cluster mode, PM2 enables load balancing between multiple application to use all CPUs available in a server.
Each HTTP/TCP/UDP request will be forwarded to one specific process at a time.
```bash
pm2 start app.js -i 0 # Enable load-balancer and cluster features
pm2 reload all # Reload all apps in 0s manner
pm2 scale <app_name> <instance_number> # Increase / Decrease process number
```
[More informations about how PM2 make clustering easy](https://keymetrics.io/2015/03/26/pm2-clustering-made-easy/)
## CPU / Memory Monitoring

Monitoring all processes launched:
```bash
pm2 monit
```
## Log facilities

Displaying logs of a specified process or all processes, in real time:
`pm2 logs ['all'|'PM2'|app_name|app_id] [--err|--out] [--lines <n>] [--raw] [--timestamp [format]]`
Examples:
```bash
pm2 logs
pm2 logs WEB-API --err
pm2 logs all --raw
pm2 logs --lines 5
pm2 logs --timestamp "HH:mm:ss"
pm2 logs WEB-API --lines 0 --timestamp "HH:mm" --out
pm2 logs PM2 --timestamp
pm2 flush # Clear all the logs
```
[More about log management](http://pm2.keymetrics.io/docs/usage/log-management/)
## Startup script generation
PM2 can generate and configure a startup script to keep PM2 and your processes alive at every server restart. Execute the startup command only as the user to be running the PM2 daemon.
```bash
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
```
To save a process list just do:
```bash
pm2 save
```
[More about startup scripts](http://pm2.keymetrics.io/docs/usage/startup/)
# Module system
PM2 embeds a simple and powerful module system. Installing a module is straightforward:
```bash
pm2 install <module_name>
```
Here are some PM2 compatible modules (standalone Node.js applications managed by PM2):
[**pm2-logrotate**](https://github.com/pm2-hive/pm2-logrotate) auto rotate logs of PM2 and applications managed<br/>
[**pm2-webshell**](https://github.com/pm2-hive/pm2-webshell) expose a fully capable terminal in browsers<br/>
[**pm2-auto-pull**](https://github.com/pm2-hive/pm2-auto-pull) auto pull all applications managed by PM2<br/>
[How to write a module](http://pm2.keymetrics.io/docs/advanced/pm2-module-system/)
# Keymetrics monitoring
[](https://app.keymetrics.io/#/register)
If you manage your NodeJS app with PM2, Keymetrics makes it easy to monitor and manage apps across servers.
Feel free to try it:
[Discover the monitoring dashboard for PM2](https://app.keymetrics.io/#/register)
Thanks in advance and we hope that you like PM2!
# More about PM2
- [Watch & Restart](http://pm2.keymetrics.io/docs/usage/watch-and-restart/)
- [Application Declaration via JS files](http://pm2.keymetrics.io/docs/usage/application-declaration/)
- [PM2 API](http://pm2.keymetrics.io/docs/usage/pm2-api/)
- [Deploying workflow](http://pm2.keymetrics.io/docs/usage/deployment/)
- [PM2 and Heroku/Azure/App Engine](http://pm2.keymetrics.io/docs/usage/use-pm2-with-cloud-providers/)
- [PM2 auto completion](http://pm2.keymetrics.io/docs/usage/auto-completion/)
# CHANGELOG
[CHANGELOG](https://github.com/Unitech/PM2/blob/master/CHANGELOG.md)
# Contributors
[Contributors](http://pm2.keymetrics.io/hall-of-fame/)
# License
PM2 is made available under the terms of the GNU Affero General Public License 3.0 (AGPL 3.0).
If you use the PM2 API contact us to get a LGPL license.
[Contact us](https://keymetrics.io/contact/).
[](https://github.com/igrigorik/ga-beacon)