Resolved Apache2 keeps restarting..

[Erjen]

My Apache2 service restarts just random. I tried a lot, following a lot of guides (configured graceful reload instead of restart, changed Apache restart interval etc, rebooted the server etc.).

But it just keeps restarting. Sometimes in 15 minutes, sometimes it takes an hour but at least every hour..
The error logs says just this: [mpm_prefork:notice] [pid 18192] AH00169: caught SIGTERM, shutting down
So something is triggering the restart. Memory usage etc. is just fine. And during restarts, no one is making changes in Plesk. It happens every hour, even at night.

Anyone an idea what is triggering it?

 

[Bitpalast]

This can be caused by a lot of things. One of the most frequent causes is resource overuse, e.g. too many httpd processes/instances running. I suggest to monitor the numberr of httpd instances, maybe it gives you an idea what is happening
# ps aux | grep sbin/httpd | grep -v grep | wc -l
If they are constantly increasing until the SIGTERM is monitored, you could try to use
# strace -p <pid>
to look into a process to see what it is doing to investige the issue further.

It could maybe help, too, to monitor what the top 20 (or another number) processes are doing, like
# watch "ps aux | sort -nrk 3,3 | head -n 20"
Maybe you have one or two that are constantly requiring a lot of CPU attention, then that's the point to look further.

 

[Erjen]

None of it was an issue, but thanks a lot for your time and response.
In the end, I configured Nginx as a reverse proxy. All problems gone now very strange but solved.