PM2 Quick Start

PM2 Tutorial

@(Node)[Load Balance|Process Manager]

[TOC]

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Introduction to PM2

PM2 is a process manager for Node applications with load balancing.
PM2 is perfect when you want your standalone code to utilize all CPUs on all servers, and keep processes alive forever, with 0 seconds of reload . It is very suitable for IaaS structure, but don't use it for PaaS solution (solution for Paas will be developed later).

Remark

   · SaaS、PaaS和IaaS是云服务模式。
   · SaaS 软件即服务，例如Google的 Gmail 邮箱服务.面向应用型用户.
   · PaaS 平台即服务.例如Google的GAE,面向开发型用户
   · IaaS  基础架构即服务,例如亚马逊的AWS，IaaS对于不知道新推出的应用程序/网站会有多成功的创业公司来说非常有用

Main features:

• Built-in load balancing (using the Node cluster cluster module)
• Background process
• 0 seconds downtime and reloading, I understand that it means that no downtime is required during maintenance and upgrades.
• Startup scripts with Ubuntu and CentOS
• Stop unstable processes (avoid infinite loops)
• console detection
• Provide HTTP API
• Remote control and real-time interface API (Nodejs module, allows interaction with PM2 process manager)
• Tested Nodejs v0.11 v0.10 v0.8 version, compatible with CoffeeScript, based on Linux and MacOS.

Install

    npm install -g pm2

usage

$ npm install pm2 -g     # 命令行安装 pm2 
$ pm2 start app.js -i 4  #后台运行pm2，启动4个app.js 
                                # 也可以把'max' 参数传递给 start
                                # 正确的进程数目依赖于Cpu的核心数目
$ pm2 start app.js --name my-api # 命名进程
$ pm2 list               # 显示所有进程状态
$ pm2 monit              # 监视所有进程
$ pm2 logs               #  显示所有进程日志
$ pm2 stop all           # 停止所有进程
$ pm2 restart all        # 重启所有进程
$ pm2 reload all         # 0秒停机重载进程 (用于 NETWORKED 进程)
$ pm2 stop 0             # 停止指定的进程
$ pm2 restart 0          # 重启指定的进程
$ pm2 startup            # 产生 init 脚本 保持进程活着
$ pm2 web                # 运行健壮的 computer API endpoint (http://localhost:9615)
$ pm2 delete 0           # 杀死指定的进程
$ pm2 delete all         # 杀死全部进程

Different ways to run a process:

$ pm2 start app.js -i max  # 根据有效CPU数目启动最大进程数目
$ pm2 start app.js -i 3      # 启动3个进程
$ pm2 start app.js -x        #用fork模式启动 app.js 而不是使用 cluster
$ pm2 start app.js -x -- -a 23   # 用fork模式启动 app.js 并且传递参数 (-a 23)
$ pm2 start app.js --name serverone  # 启动一个进程并把它命名为 serverone
$ pm2 stop serverone       # 停止 serverone 进程
$ pm2 start app.json        # 启动进程, 在 app.json里设置选项
$ pm2 start app.js -i max -- -a 23                   #在--之后给 app.js 传递参数
$ pm2 start app.js -i max -e err.log -o out.log  # 启动 并 生成一个配置文件
                                                 # 你也可以执行用其他语言编写的app  ( fork 模式):
$ pm2 start my-bash-script.sh    -x --interpreter bash
$ pm2 start my-python-script.py -x --interpreter python

0 seconds downtime and reload:

This feature allows you to reload code without losing the request connection.

Notice:

• Can only be used for web applications
• Running on Node 0.11.x version
• Runs in cluster mode (default mode)

$ pm2 reload all

CoffeeScript:

$ pm2 start my_app.coffee #这就是全部

PM2 Product Level Services

Just test on your server

$ git clone https://github.com/Unitech/pm2.git
$ cd pm2
$ npm install # 或者 npm install --dev ，如果devDependencies 没有安装
$ npm test

pm2 list

Lists all process information managed by pm2, and also shows how many times a process will be started because of unhandled exceptions.

pm2 list 

pm2 monit

Monitor the CPU and memory usage of each node process.