respawn

Spawn a process and restart it if it crashes

respawn

Spawn a process and restart it if it crashes.

npm install respawn

It is easy to use

var respawn = require('respawn')
 
var monitor = respawn(['node', 'server.js'], {
  env: {ENV_VAR:'test'}, // set env vars 
  cwd: '.',              // set cwd 
  maxRestarts:10,        // how many restarts are allowed within 60s 
                         // or -1 for infinite restarts 
  sleep:1000,            // time to sleep between restarts, 
  kill:30000,            // wait 30s before force killing after stopping 
  stdio: [...]           // forward stdio options 
})
 
monitor.start() // spawn and watch 

Optionally you can specify the command to to spawn in the option map as command: [...]

  • monitor.start() Starts the monitor

  • monitor.stop(cb) Stops the monitor (kills the process if its running with SIGTERM)

  • monitor.status Get the current monitor status. Available values are running, stopping, stopped, crashed and sleeping

  • monitor.on('start') The monitor has started

  • monitor.on('stop') The monitor has fully stopped and the process is killed

  • monitor.on('crash') The monitor has crashed (too many restarts or spawn error).

  • monitor.on('sleep') monitor is sleeping

  • monitor.on('spawn', process) New child process has been spawned

  • monitor.on('exit', code, signal) child process has exited

  • monitor.on('stdout', data) child process stdout has emitted data

  • monitor.on('stderr', data) child process stderr has emitted data

  • monitor.on('warn', err) child process has emitted an error

To do graceful restart simply have your app stop gracefully when receiving SIGTERM and do

// graceful restart (do not wait for old process to die) 
monitor.stop()
monitor.start()
 
// hard restart (wait for old process to die) 
monitor.stop(function() {
  monitor.start()
})

MIT