Hi all,
Apologies if I’m posting this in the wrong forum.
I'm having a problem with excessive CPU usage occurring about every hour, sometimes a few times in a row (e.g. 5:56, 6:04, 6:08 and then 7:01).
I have Limesurvey version 2.67.2+170719, installed with Installatron. I'm currently using PHP 5.6; when the problem first occurred I was using PHP 7.1.
I was wondering whether anyone knows if and how Limesurvey might be causing such peaks in cpu usage?
Many thanks

dirk999 wrote: I'm having a problem with excessive CPU usage occurring about every hour, sometimes a few times in a row (e.g. 5:56, 6:04, 6:08 and then 7:01).

Since LimeSurvey is only running when triggering a php-page you might just disable access to LimeSurvey scripts to see if the peaks are gone. You would need to wait till you no longer have a running, active survey.
Depending on your OS I would check cron jobs (Linux,OSX) or task scheduler (Windows). There might is a hourly job running.

Thanks Jelo, seems sensible to look into cronjobs, I’ve asked my internet provider if they can check whether something’s still running that I’m not aware of. I was curious though whether there might be some sort of process that Limesurvey triggers at regular intervals (I’m afraid I can’t currently interrupt Limesurvey due to a running survey...)

dirk999 wrote: … might be some sort of process that Limesurvey triggers at regular intervals…

LimeSurvey CAN NOT trigger something at regular interval, because server didn't add CRON itself …

jelo already answer on this part : if it's really every hour at same minutes : i's a cron job set by you or your hoster.

Thanks for the clarification!

DenisChenu wrote: if it's really every hour at same minutes : i's a cron job set by you or your hoster.

You get the same behavior if someone is monitoring the survey installation from a external site. E.g. Screenscraping the surveylist. So checking for cron jobs AND checking logfiles of webaccess might show the source of CPU peak. Depending on the server setup (hardware virtualization, RAID-Controller or filesystem check routines) might be worth a look too. What kind of hosting is used? Shared hosting, virtual server, dedicated server?
If you have access to the shell you can use tools like htop, iftop and iotop to watch the activities on the server a bit closer.

Thanks for the further suggestions jelo! I currently have a survey running, when it's finished I'm going to dig a little deeper.