Why can Apache restart every 15 minutes?

Question

linux

Hello,
On a server with centos 7 and ispmanager, Apache began to fall every 15 minutes, after which it reboots itself.
In the logs we see the following messages:

[Thu Apr 19 16:10:32.384758 2018] [mpm_prefork:notice] [pid 23180] AH00170: caught SIGWINCH, shutting down gracefully
Thu Apr 19 16:15:01.533158 2018] [mpm_prefork:notice] [pid 23615] AH00170: caught SIGWINCH, shutting down gracefully

Before that, we tried to install Docker on the server, but we are not sure if it is related to the problem.
Can you please tell me what could be causing this?
Thank you!

Answer 1

The whole thing turned out to be monitoring services from ispmanager, for some reason it started to fail and Apache killed every check. I solved it by turning it off :-/

Answer 2

Raise the debug level and watch the apache error log, you can also catch a whitefish when rotating the logs.

Answer 3

See logs. Lots of options. I had this with the maxrequestsperchild directive