Lately, my cpanel server is going on a strange behavior:

At peak access times, the number of processes (watching with TOP) goes very high, from 200 to 600, apache stops responding requests and the server load goes sky high, like 50, 80, 100.

Does anybody have a clue of what is happening ?

a problem like that could be many things. for any of us to help you, we'd need more info...

Can you cut and paste the screen after typeing "TOP" at the command line as root?

Have you looked at apache logs?

Try ps -aux as root when the load is high. This will give you a list of all the processes happening.

I've experienced it a couple time with different times, one possibility is a DOS attack.

Thanks.

i had the same problem and it was due to some guy spamming to an aol database from my server.

Check if your processes are related to exim, or the mailscanner (if installed) also check your mailqueue and if you have messages going to aol users.

Otherwise copy and paste the processes runing here.