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.
Process Management
Start an application with PM2 and keep it running in the background.
pm2 start app.jsLoad Balancing
Enable load balancing by starting multiple instances of the application across all CPUs.
pm2 start app.js -i maxMonitoring
Monitor all processes launched with PM2 using a terminal-based dashboard.
pm2 monitLogging
Display logs of all processes in real-time, or target specific processes.
pm2 logsStartup Script
Generate a startup script to resurrect PM2 and all processes on server reboot.
pm2 startupUpdate Processes
Reload all processes in the cluster without downtime.
pm2 reload allForever is a simple CLI tool for ensuring that a given script runs continuously (i.e., forever). It is similar to PM2 but lacks some of its advanced features like application monitoring and load balancing.
Nodemon is a utility that monitors for any changes in your source and automatically restarts your server. It is often used in development environments, unlike PM2 which is tailored for production use.
StrongLoop Process Manager (strong-pm) is a production process manager for Node.js applications with features like remote deployment and performance monitoring. It is part of the StrongLoop suite, which is now owned by IBM.
Supervisor is a client/server system that allows its users to monitor and control a number of processes on UNIX-like operating systems. It is not specifically designed for Node.js and is more general-purpose.
pm2 is a process manager for Node apps with a builtin load-balancer.
pm2 is perfect when you need to spread your stateless NodeJS code accross all CPUs available on a server, to keep all processes alive forever and to 0s reload them.
Tested with Node v0.11, v0.10, v0.8 (https://travis-ci.org/Unitech/pm2). Compatible with CoffeeScript. Works on Linux & MacOS.
Master : 
Development : 
We gonna release a very nice product, a dashboard to monitor every part of your NodeJS applications. Here are some links :
We are also looking for AngularJS developers and designers contact us at contact AT unitech DOT io
Thanks in advance and we hope that you like pm2 !
pm2 startup centosnpm install pm2@latest -g
$ npm install pm2@latest -g # Install pm2 command line globally
$ pm2 start app.js -i 4 # Daemonize pm2 and Start 4 clustered instances of app.js
# You can also pass the 'max' params to start
# the right numbers of processes depending of CPUs
$ pm2 start app.js --name my-api # Name process
$ pm2 start app.js --no-daemon # Doesn't exit process
$ pm2 list # Display all processes status
$ pm2 list -m # Serious display
$ pm2 monit # Monitor all processes
$ pm2 logs # Display all processes logs in streaming
$ pm2 flush # Empty all log file
$ pm2 stop all # Stop all processes
$ pm2 restart all # Restart all processes
$ pm2 reload all # Will 0s downtime reload (for NETWORKED processes)
$ pm2 stop 0 # Stop specific process id
$ pm2 restart 0 # Restart specific process id
$ pm2 delete 0 # Will remove process from pm2 list
$ pm2 delete all # Will remove all processes from pm2 list
$ pm2 ping # Ensure pm2 dameon has been launched
$ pm2 startup ubuntu # Generate init script for ubuntu to keep processes alive on restart
# ubuntu/centos
$ pm2 web # Launch Health computer API endpoint (http://localhost:9615)
$ pm2 dump # Backup current processes managed by pm2
$ pm2 resurrect # Restore backup
$ pm2 sendSignal SIGUSR2 signal.js # Send system signal to script
For other nature scripts :
$ pm2 start echo.php
$ pm2 start echo.py
$ pm2 start echo.sh
$ pm2 start echo.rb
$ pm2 start echo.pl
$ pm2 start app.js -i max # Will start maximum processes depending on available CPUs
$ pm2 start app.js -i 3 # Will start 3 processes
$ pm2 start app.js -x # Start app.js in fork mode instead of cluster
$ pm2 start app.js -x -- -a 23 # Start app.js in fork mode and pass arguments (-a 23)
$ pm2 start app.js --name serverone # Start a process an name it as server one
# you can now stop the process by doing
# pm2 stop serverone
$ pm2 start app.json # Start processes with options declared in app.json
# Go to chapter Multi process JSON declaration for more
$ pm2 start app.js -i max -- -a 23 # Pass arguments after -- to app.js
$ pm2 start app.js -i max -e err.log -o out.log # Will start and generate a configuration file
You can also execute app in other languages (the fork mode):
$ pm2 start my-bash-script.sh -x --interpreter bash
$ pm2 start my-python-script.py -x --interpreter python
By default every logs (error and out), pids files, dump, pm2 logs are located in ~/.pm2/
.pm2/
├── dump.pm2
├── custom_options.sh
├── pm2.log
├── pm2.pid
├── logs
└── pids
This feature permits to reload code without losing in process connections. Works for apps in cluster_mode (the default mode) that uses sockets (express or other).
$ pm2 reload all
$ pm2 reload my-api
Thanks to TruongSinh Tran-Nguyen https://github.com/truongsinh
$ pm2 gracefulReload all
Instead of just processing remaining connections, gracefulReload will also send a shutdown message to your process, so you can close all database/socket.io/* connections and be sure that your process will properly exit.
process.on('message', function(msg) {
if (msg == 'shutdown') {
// Your process is going to be reloaded
// Close all database/socket.io/* connections
console.log('Closing all connections...');
setTimeout(function() {
console.log('Finished closing connections');
// You can exit to faster the process or it will be
// automatically killed after 4000ms.
// You can override the timeout by modifying PM2_GRACEFUL_TIMEOUT
process.exit(0);
}, 1500);
}
});
var http = require('http');
http.createServer(function(req, res) {
res.writeHead(200);
res.end('hey');
}).listen(8000, function() {
console.log('listening');
});
$ pm2 start my_app.coffee
That's all !
## Enabling Harmony ES6You can enable Harmony ES6 by setting PM2_NODE_OPTIONS='--harmony' environment variable option when you start pm2 (pm2 should not be already daemonized).
To pass this option by default, you can edit ~/.pm2/custom_options.sh and add :
export PM2_NODE_OPTIONS='--harmony'
Then :
$ pm2 dump
$ pm2 exit
$ pm2 resurrect
If ES6 has been enabled you should see this message at the beggining of each pm2 commands :
● ES6 mode
The default mode of PM2 consists of wrapping the code of your node app into the Node Cluster module. It's called the cluster mode. There is also a more classical way to execute your app, like node-forever does, called the fork mode.
In fork mode almost all options are the same as the cluster mode. But no reload, gracefulReload.
By using the fork mode you will lose core features of PM2 like the automatic clusterization of your code over all CPUs available and the 0s reload.
So use it if you only need a forever-like behaviour.
Here is how to start your app in fork :
$ pm2 start app.js -x # Will start your app.js in fork mode
$ pm2 list # You will see that on the row "mode" it's written "fork"
You can also exec scripts in other languages :
$ pm2 start my-bash-script.sh -x --interpreter bash
$ pm2 start my-python-script.py -x --interpreter python
Just try the tests before using PM2 on your production server
$ git clone https://github.com/Unitech/pm2.git
$ cd pm2
$ npm install # Or do NODE_ENV=development npm install if some packages are missing
$ npm test
If a test is broken please report us issues here Also make sure you have all dependencies needed. For Ubuntu :
$ sudo apt-get install build-essential
$ wget -qO- https://raw.github.com/creationix/nvm/master/install.sh | sh
$ nvm install v0.11.9
$ nvm use v0.11.9
$ nvm alias default v0.11.9
List infos about all processes managed by pm2. It shows also how many times a process has been restarted because of an unhandled exception.
Monitor CPU and memory usage of every node process (and also clustered processes) managed by pm2.
PM2 provides an automatic way to keep Node processes alive on server restart. On exit it will dump the process list and their environment and will resurrect them on startup.
It uses System V init script compatible with Ubuntu/CentOS/Redhat (maybe it works on other sys but not 100% sure).
$ pm2 startup ubuntu # then follow the command instruction
$ pm2 startup centos # will use chkconfig instead of updaterc.d
$ pm2 startup redhat # not very stable for redhat
Init script generated are located in /etc/init.d/pm2-init.sh.
The -u username option permits to specify which user has to start the process at startup.
NOTE that this user must have access to npm, apps and node ! So the best way is to log with this user su -l www, then do pm2 startup -u www.
Internally it uses sudo -u $USER.
Display logs in streaming of all processes, without having to do a tail -f or something else. You can also pass [name|id] as parameter to stream only the log of a specified process.
PM2 can disserve an API endpoint to monitor processes and computer health (cpu usage, memory, network interfaces...)
pm2 web
You can edit these options by editing the file ~/.pm2/custom_options.sh
These variables can be customized :
DAEMON_BIND_HOST : process.env.PM2_BIND_ADDR || 'localhost',
DAEMON_RPC_PORT : process.env.PM2_RPC_PORT || 6666, // RPC commands
DAEMON_PUB_PORT : process.env.PM2_PUB_PORT || 6667, // Realtime events
DEBUG : process.env.PM2_DEBUG || false,
WEB_INTERFACE : process.env.PM2_API_PORT || 9615,
GRACEFUL_TIMEOUT : parseInt(process.env.PM2_GRACEFUL_TIMEOUT) || 4000,
PM2_NODE_OPTIONS : ''
processes.json :
[{
"name" : "echo",
"script" : "./examples/args.js",
"args" : "['--toto=heya coco', '-d', '1']",
"env": {
"NODE_ENV": "production",
"AWESOME_SERVICE_API_TOKEN": "xxx"
}
}
,{
"name" : "api",
"script" : "./examples/child.js",
"instances" : "4",
"error_file" : "./examples/child-err.log",
"out_file" : "./examples/child-out.log",
"pid_file" : "./examples/child.pid",
"exec_mode" : "cluster_mode",
"port" : 9005
},{
"min_uptime" : "100",
"name" : "auto-kill",
"exec_mode" : "fork_mode",
"script" : "./examples/killfast.js"
}]
Then with the cli :
$ pm2 start processes.json
$ pm2 stop processes.json
$ pm2 delete processes.json
$ pm2 restart processes.json
Fork PM2 and to hack it it's pretty simple :
$ pm2 kill # kill the current pm2
$ git clone my_pm2_fork.git
$ cd pm2/
$ DEBUG=* PM2_DEBUG=true./bin/pm2 start xxx.js
Everytime you do a modification on the code you have to restart pm2, so just do a ./bin/pm2 kill before
starting an app or something else.
You have to restart it because the code is daemonized on the memory.
$ npm install git://github.com/Unitech/pm2#development -g
sudo update-rc.d -f pm2-init.sh removeFirst, install the lastest pm2 version :
$ npm install -g pm2@latest
$ pm2 start index.js -x # start my app in fork mode
For more informations about this issue : #74
Cannot read property 'getsockname' of undefinedWhen using the cluster mode (by default) you can't use ports from 0 to 1024. If you really need to exec in this range use the fork mode with the -x parameter.
By using the fork mode you will lose core features of PM2 like the automatic clusterization of your code over all CPUs available and the 0s reload.
npm test
Thanks to Devo.ps and Wiredcraft for their knowledge and expertise.
Files in lib/ are made available under the terms of the GNU Affero General Public License (AGPL). pm2-interface is made under the terms of the Apache V2 license.
0.7.2
FAQs
Production process manager for Node.JS applications with a built-in load balancer.
The npm package pm2 receives a total of 1,910,388 weekly downloads. As such, pm2 popularity was classified as popular.
We found that pm2 demonstrated a healthy version release cadence and project activity because the last version was released less than a year ago. It has 1 open source maintainer collaborating on the project.
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