Spawn a process and restart it if it crashes
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 varscwd: '.' // set cwdmaxRestarts:10 // how many restarts are allowed within 60s// or -1 for infinite restartssleep:1000 // time to sleep between restarts,kill:30000 // wait 30s before force killing after stoppingstdio: // forward stdio optionsmonitorstart // spawn and watch
Optionally you can specify the command to to spawn in the option map as
sleep is an array of numbers it will use the value at the position of the current number of restarts as the timeout value. If the number of restarts exceed the length of the array it will use the last value in the array until it hits the maxRestarts.
sleep: [1000, 60000, 60000, 12000, 1000] will wait 1000ms before retrying, then it will wait 60000 before the next retry and so forth.
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
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)monitorstopmonitorstart// hard restart (wait for old process to die)monitorstopmonitorstart