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New Pleskian
I recently decided to add some text message notifications to a Node.js server app, for when a particular update was discovered. While I was at it, I figured it would be a good idea to add a server start-up and shutdown notifications too. This led to a few of unpleasant discoveries:
1) Roughly every 24 hours my server (not the entire Plesk server, just this one Node.js server app) was restarting for no good reason, between 3:30-4:30 AM.
2) There was no graceful detection of a shutdown before each restart, so it appears that the Node.js app was being killed outright, not sent SIGINT or SIGTERM, which I was listening for.
3) Even using the Plesk control panel, where you can request an app restart, a graceful restart doesn't occur. Your Node.js app is simply unceremoniously killed.
The once-per-24-hour restart, after some investigation, is apparently triggered by Apache log rotation. Why simple log rotation should cause this is another mystery to be solved.
In the meantime, I want to know if there's a way to make sure GRACEFUL shutdowns happen, whether they happen because Apache is stopping or shutting down, or because the "Restart App" button is pressed.
I look for shutdowns by monitoring these signals:
Is there a different signal I should check for?
Is the process shutdown mercilessly with a SIGKILL instead?
If so, can I change that, perhaps with some sort of delay to give a graceful shutdown some time to occur?
1) Roughly every 24 hours my server (not the entire Plesk server, just this one Node.js server app) was restarting for no good reason, between 3:30-4:30 AM.
2) There was no graceful detection of a shutdown before each restart, so it appears that the Node.js app was being killed outright, not sent SIGINT or SIGTERM, which I was listening for.
3) Even using the Plesk control panel, where you can request an app restart, a graceful restart doesn't occur. Your Node.js app is simply unceremoniously killed.
The once-per-24-hour restart, after some investigation, is apparently triggered by Apache log rotation. Why simple log rotation should cause this is another mystery to be solved.
In the meantime, I want to know if there's a way to make sure GRACEFUL shutdowns happen, whether they happen because Apache is stopping or shutting down, or because the "Restart App" button is pressed.
I look for shutdowns by monitoring these signals:
JavaScript:
process.on('SIGINT', shutdown);
process.on('SIGTERM', shutdown);
process.on('SIGUSR2', shutdown);Is there a different signal I should check for?
Is the process shutdown mercilessly with a SIGKILL instead?
If so, can I change that, perhaps with some sort of delay to give a graceful shutdown some time to occur?
