High CPU peak every 30 minutes

[Petar]

Hi,

I have strange problem with one mine WHM server.
I have about 300 accounts on this VPS server with 64GB of RAM and 12 CPU cores.
Monitoring notify me every 30 minutes about high CPU load on WHM server.
That also showing my graph from monitoring below.


If I check running process during the peak, I can see there is a lot of litespeed php process and MySQL also from almost all users from the server.
I checked access logs during the peak and I can see there is wordpress cron php. If I check open connection with netstat I can see there is almost all connections going from localhost.
That mean something run wp cron on almost all wordpress installation there, but I can't figure out what run it, because if I check users cron list there is maybe dozen with cron setup.
I suspect on woordpress toolkit but I didn't found in documentation that I can disable any wordpress toolkit crons.

Maybe someone knows how can I disable this execution every 30 minutes?

P.S. I checked all systemc cron including crontab, cron.d, cron.hourly.

Thank you in advanced.

 

[cPRex]

Hey there! If you have confirmed this is caused by the wp-cron tool, can you try the details here to see if that helps?

https://support.cpanel.net/hc/en-us/articles/1500002781621-How-To-Set-Up-a-Regular-Run-of-wp-cron-php-with-WordPress-Toolkit

 

[Petar]

Yes, thank you on this, I already saw that. But I don't want to go over 300 accounts and disable wp-cron on every account.
On this server I have only WP instalation. Does wordpress toolkit have some global cron which run this that I can disable widely on server?

 

[cPRex]

Actually, that link would do the opposite - it sets up WordPress Toolkit to enable wp-cron to run at the time of your choosing, instead of the more random run that happens when users visit the site. Based off that information you're seeing, the issue either is not with wp-cron, or that one site is taking up a large amount of resources every half hour.

Are there any root-level crons setup on the machine? You could check that with "crontab -e" on the command line and "*/30 * * * * /path/of/command" would be an example of something that runs every thirty minutes.

 

[Petar]

All that about system cron I already checked as I mention and there is no one which can be related with this.
Also, I tailed cron log in that time to check, and no one which can cause this.

P.S. I checked all systemc cron including crontab, cron.d, cron.hourly.

or that one site is taking up a large amount of resources every half hour.

No, because I have cloudlinux with limited LVE packages, and because in that 30 minutes interval I have process in process list for almost all user accounts. All that process is active 1-2 minutes till finish and that every 30 minutes.

 

[cPRex]

You're always welcome to submit a ticket to our team so we can take a look at the machine directly. Since it consistently happens every half hour, we should be able to catch something.

 

[Petar]

Thank you, I will.

 

[cPRex]

If you can do that, please post the ticket number here so I can follow along.

 

[Petar]

I submitted ticket, #94504062
Thank you.

 

[cPRex]

Thanks for that - I see they recommended a service monitoring tool, so let us know if you find anything with that!

 

[Petar]

Hi, just update.
Script didn't find anything more than what I already saw.
Support can't help me, I need to find a solution.

 

[cPRex]

If that tool did not find anything helpful, it's time to reach out to a system administrator. We have a list of admins that advertise their services here:

System Administration Services

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although I can't recommend anyone in particular for you.