What can consistently consume 100% of resources once a day on VDS?

Question

Highload

I'm looking for the reason for eating resources by an incomprehensible script or application on Centos. Stably every day at 12 am, 100% CPU load starts, lasts about 8 minutes, this time, as I understand it, depends on the size of the database. At the same time, htop gives out 100% loading of the mysqld process. cron is disabled. Removed Munin, installed Fail2ban, so I don't know if these applications could inherit after themselves. Actually the question is how and by what logs you can find out the application that makes the database strain. The apache, nginx logs do not give any information. What is responsible for autoloading applications in Centos besides Cron? I also don't see any applications running at the same time in htop.
I watched running processes in phpmyadmin, also no crime.
I changed the time to 23.59 with the date command, the processor did not load at 00.00, as a result, I synchronized the time with vmware vsphere again. I don't know where else to look.

Answer 1

Accidentally stumbled upon this old question of mine and remembered how I solved the problem. In general, I had my own VDS and several sites on another hosting. One of the sites was transferred from hosting to VDS, but after the transfer from the hoster, I forgot to disable wget in the panel. I had a database update script there once a day with various settings specific to the former host (file paths, etc.), and so on. stood the site address, it responded safely, but the script on the new VDS tried to find the old file paths and other nonsense from the muscle. In general, the conclusion is that when transferring sites, you need to monitor everything, even the settings of the "former" server.

Answer 2

Maybe a backup? Is the base itself big?
Read at your leisure ruhayload , very entertaining and productive.