Pm2: What's the difference between **reload** and **gracefulReload**?

[andrei-cocorean]

Hi, I was wondering why there are 2 commands for reloading. For my server I have a shutdown function to wait for all connections to close:

const server = http.createServer(reqListener)
server.listen()

function shutdown () {
  server.close(() => {
    console.log('server closed')
    process.exit()
  })
}

The cluster mode docs say that I should listen for a shutdown message:

process.on('message', msg => {
  if (msg === 'shutdown') {
    shutdown()
  }
})

and then exec $ pm2 gracefulReload app in the console.

But I can also listen for SIGINT process.on('SIGINT', shutdown) and then do $ pm2 reload app in the console.

As far as I can tell both approaches do the same thing. Am I missing some case covered by gracefulReload?

pm2 v1.0.2
node v4.4.0

[soyuka]

Reload will fallback to restart after a specified delay (GRACEFUL_LISTEN_TIMEOUT see here). After this delay, it'll force the script to restart even if it hasn't finished to process leftovers.

If you want to know more, please take a look at the Reload code source.

[dytsai]

I believe the problem here is the documentation. It suggests listening to SIGINT at the link http://pm2.keymetrics.io/docs/usage/signals-clean-restart for graceful reload but mentions process "shutdown" message here at http://pm2.keymetrics.io/docs/usage/pm2-doc-single-page. SIGINT is sent whenever app is stopped/restarted/deleted/reloaded/gracefulReloaded but shutdown message is only sent when doing graceful reload, which by default will wait for 8000ms before sending SIGINT to the process.

[andrei-cocorean]

Thanks for the clarification. It seems like the shutdown message covers just a single use case, while catching SIGINT covers all. I expect any cleanup code to be executed whenever the server shuts down, regardless if it's part of a reload or a stop. Is there any reason to use gracefulReload at all?

[Unitech]

Patch available on [email protected] (main):

$ npm install pm2 -g
$ pm2 update