Hi.

I'm on Ubuntu 18.04 with Apache2.4.34 and php.7.2. Limesurvey Version 3.17.3+190429.

I don't know if this is neccecary a problem with Limesurvey itself because it runs fine on our ubuntu server but there has been some problem ever since we installed it.

The inital problem happend everyday at midnight when apache2 does a graceful restart (i think as part of logrotate). This caused endless segmentation faults in the error.log:

[Thu Jul 11 03:27:03.153546 2019] [core:notice] [pid 25564] AH00051: child pid 26562 exit signal Segmentation fault (11), possible coredump in /etc/$
[Thu Jul 11 03:27:03.153673 2019] [core:error] [pid 25564] AH00546: no record of generation 0 of exiting child 26562

I fixed this by changing graceful reload to restart in my logrotate configuration. The problem was gone for a while but suddendly appeared again a few days ago. This time it seems to happen at seemingly random times. 6AM, 2AM, 11AM...

Is there anything in Limesurvey that can cause this? I don't know what you need to debug this issue so I can try to provide anything if you ask.

oledole wrote: Is there anything in Limesurvey that can cause this?

From your description I see no relation with LimeSurvey.

You will need to investigate on OS and Apache Level.

I'm not much into Ubuntu but Ubuntu 18.04.2 LTS (Bionic Beaver) seems not to offer Apache2.4.34 as a package.

I see apache2 2.4.29 as the last version offered as part of the distribution.
launchpad.net/ubuntu/bionic/+package/apache2