pm2

PM2 is a Production Runtime and 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 facilitate common Devops tasks.

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: https://pm2.io/doc/

Works on Linux (stable) & macOS (stable) & Windows (stable). All Node.js versions are supported starting Node.js 4.X.

Installing PM2

$ npm install pm2 -g

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

Start an application

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.

More about Process Management

Container Support

With the drop-in replacement command for node, called pm2-runtime, run your Node.js application in a hardened production environment. Using it is seamless:

RUN npm install pm2 -g
CMD [ "pm2-runtime", "npm", "--", "start" ]

Read More about the dedicated integration

Managing Applications

Once applications are started you can manage them easily:

To list all running applications:

$ pm2 list

Managing apps 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 application:

$ pm2 describe <id|app_name>

To monitor logs, custom metrics, application information:

$ pm2 monit

More about Application Management

Cluster Mode: Node.js Load Balancing & Zero Downtime Reload

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.

Zero Downtime 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

Terminal Based Monitoring

Monitor all processes launched straight from the command line:

$ pm2 monit

Log Management

To consult logs just type the command:

$ pm2 logs

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

More about log management

Startup Hooks Generation

PM2 can generates and configure a Startup Script to keep PM2 and your processes alive at every server restart.

Init Systems Supported: systemd, upstart, launchd, rc.d

# Generate Startup Script
$ pm2 startup

# Freeze your process list across server restart
$ pm2 save

# Remove Startup Script
$ pm2 unstartup

More about Startup Hooks

Updating PM2

# Install latest PM2 version
$ npm install pm2@latest -g
# Save process list, exit old PM2 & restore all processes
$ pm2 update

PM2 updates are seamless

Ready to Scale? Go further with PM2 Plus!

$ pm2 plus

Once you scale you need to make sure that your application is running properly, without bugs, performance issues and without downtimes.

That's why we created PM2 Plus. It's a set of advanced features for both hardening the PM2 Runtime and monitoring applications in production.

With PM2 Plus you get:

• A Real-time Monitoring Web Interface
• Smart Exception Reporting
• Production Profiling for Memory and CPU
• PM2 Runtime High Availability Fallback

And much more like realtime logs, custom metrics, remote actions...

You can also create account via the app: here

PM2 Plus Features

Visual Memory Snapshots:

CPU FlameGraphs:

Multi Server Overview:

PM2 Plus: Expose Custom Metrics

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 pm2-io-pm:

$ npm install @pm2/io --save

Then plug a custom metric:

const io = require('@pm2/io');

let counter = 1;

const latency = io.metric({
   name    : 'Counter',
   value   : function() {
     return counter;
   }
});

setInterval(() => {
  counter++;
}, 1000);

PM2 Plus: Module system

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 automatically rotate logs and limit logs size
pm2-server-monit monitor the current server with more than 20+ metrics and 8 actions

CHANGELOG

CHANGELOG

Contributors

Contributors

License

PM2 is made available under the terms of the GNU Affero General Public License 3.0 (AGPL 3.0). For other licenses contact us.