PM2 is a General Purpose Process Manager and a Production Runtime for Node.js apps with a built-in Load Balancer.
Key features:
- Simple and efficient process management (start/stop/restart/delete/show/monit)
- Keep your application ALWAYS ONLINE with auto restarts and init system script generation
- Clusterize Node.js Applications without code change to increase performance and reliability
- Hot Reload Node.js Applications without extra configuration
Starting an application in production mode is as easy as:
$ pm2 start app.js
PM2 is constantly assailed by more than 1800 tests.
Official website: http://pm2.keymetrics.io/
Works on Linux (stable) & macOS (stable) & Windows (stable). All Node.js versions are supported starting Node.js 0.12.
$ npm install pm2 -g
npm is a builtin CLI when you install Node.js - Installing Node.js with NVM
You can start any application (Node.js, Python, Ruby, binaries in $PATH...) like that:
$ pm2 start app.js
Your app is now daemonized, monitored and kept alive forever.
Once applications are started you can manage them easily:
To list all running processes:
$ pm2 list
Managing processes is straightforward:
$ 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:
$ pm2 describe <id|app_name>
To monitor logs, custom metrics, process information:
$ pm2 monit
The Cluster mode is a special mode when starting a Node.js application, it starts multiple processes and load-balance HTTP/TCP/UDP queries between them. This increase overall performance (by a factor of x10 on 16 cores machines) and reliability (faster socket re-balancing in case of unhandled errors).
Starting a Node.js application in cluster mode that will leverage all CPUs available:
$ pm2 start api.js -i <processes>
<processes>
can be 'max'
, -1
(all cpu minus 1) or a specified number of instances to start.
Hot Reload
Hot Reload allows to update an application without any downtime:
$ pm2 reload all
Seamlessly supported by all major Node.js frameworks and any Node.js applications without any code change:
More informations about how PM2 make clustering easy
With the drop-in replacement command for node
, called pm2-runtime
, run your Node.js application in a proper production environment.
We also offer an officialy supported Docker image.
Using it is seamless:
FROM keymetrics/pm2:latest-alpine
[...]
CMD [ "pm2-runtime", "npm", "--", "start" ]
Read More about the dedicated integration
Monitor all processes launched straight from the command line:
$ pm2 monit
Once you deploy your application in production, you can monitor, debug and profile it externally with our SaaS Monitoring.
To start monitoring applications from the terminal:
$ pm2 register
To get more insights on how your application behave, plug custom metrics inside your code and monitor them with the pm2 monit
command:
In your project install pmx:
$ npm install pmx --save
Then plug a custom metric:
var Probe = require('pmx').probe();
var counter = 1;
var metric = Probe.metric({
name : 'Counter',
value : function() {
return counter;
}
});
setInterval(function() {
counter++;
}, 1000);
Then to see the metric type from in the terminal:
$ pm2 monitor
Metric, Counter, Histogram and Meters are available
Displaying logs of a specified process or all processes, in real time is easy:
$ pm2 logs ['all'|app_name|app_id] [--json] [--format] [--raw]
Standard, Raw, JSON and formated output are available.
Examples:
$ pm2 logs APP-NAME # Display APP-NAME logs
$ pm2 logs --json # JSON output
$ pm2 logs --format # Formated output
$ pm2 flush # Flush all logs
$ pm2 reloadLogs # Reload all logs
PM2 can generates and configure a startup script to keep PM2 and your processes alive at every server restart.
Supports init systems like: systemd (Ubuntu 16, CentOS, Arch), upstart (Ubuntu 14/12), launchd (MacOSx, Darwin), rc.d (FreeBSD).
# Auto detect init system + generate and setup PM2 boot at server startup
$ pm2 startup
# Manually specify the startup system
# Can be: systemd, upstart, launchd, rcd
$ pm2 startup [platform]
# Disable and remove PM2 boot at server startup
$ pm2 unstartup
To save/freeze a process list on reboot:
$ pm2 save
# General
$ npm install pm2 -g # Install PM2
$ pm2 start app.js # Start, Daemonize and auto-restart application (Node)
$ pm2 start app.py # Start, Daemonize and auto-restart application (Python)
$ pm2 start npm -- start # Start, Daemonize and auto-restart Node application
# Cluster Mode (Node.js only)
$ pm2 start app.js -i 4 # Start 4 instances of application in cluster mode
# it will load balance network queries to each app
$ pm2 reload all # Zero Second Downtime Reload
$ pm2 scale [app-name] 10 # Scale Cluster app to 10 process
# Process Monitoring
$ pm2 list # List all processes started with PM2
$ pm2 list --sort=<field> # Sort all processes started with PM2
$ pm2 monit # Display memory and cpu usage of each app
$ pm2 show [app-name] # Show all information about application
# Log management
$ pm2 logs # Display logs of all apps
$ pm2 logs [app-name] # Display logs for a specific app
$ pm2 logs --json # Logs in JSON format
$ pm2 flush
$ pm2 reloadLogs
# Process State Management
$ pm2 start app.js --name="api" # Start application and name it "api"
$ pm2 start app.js -- -a 34 # Start app and pass option "-a 34" as argument
$ pm2 start app.js --watch # Restart application on file change
$ pm2 start script.sh # Start bash script
$ pm2 start app.json # Start all applications declared in app.json
$ pm2 reset [app-name] # Reset all counters
$ pm2 stop all # Stop all apps
$ pm2 stop 0 # Stop process with id 0
$ pm2 restart all # Restart all apps
$ pm2 gracefulReload all # Gracefully reload all apps in cluster mode
$ pm2 delete all # Kill and delete all apps
$ pm2 delete 0 # Delete app with id 0
# Startup/Boot management
$ pm2 startup # Detect init system, generate and configure pm2 boot on startup
$ pm2 save # Save current process list
$ pm2 resurrect # Restore previously saved processes
$ pm2 unstartup # Disable and remove startup system
$ pm2 update # Save processes, kill PM2 and restore processes
$ pm2 generate # Generate a sample json configuration file
# Deployment
$ 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
# Module system
$ 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
Also check out the example folder to discover all features.
# Install latest PM2 version
$ npm install pm2@latest -g
# Save process list, exit old PM2 & restore all processes
$ pm2 update
PM2 updates are seamless
PM2 embeds a simple and powerful module system. Installing a module is straightforward:
$ pm2 install <module_name>
Here are some PM2 compatible modules (standalone Node.js applications managed by PM2):
pm2-logrotate auto rotate logs of PM2 and applications managed
pm2-webshell expose a fully capable terminal in browsers
pm2-server-monit monitor your server health
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
Thanks in advance and we hope that you like PM2!
- Application Declaration via JS files
- Watch & Restart
- PM2 API
- Deployment workflow
- PM2 on Heroku/Azure/App Engine
- PM2 auto completion
- Using PM2 in ElasticBeanStalk
- PM2 Tutorial Series
PM2 is made available under the terms of the GNU Affero General Public License 3.0 (AGPL 3.0). We can deliver other licenses, for more informations contact sales.