Server randomly lags... I suspect it's either Apache or PHP

My server starts to lag randomly, no apparent cause for it, just starts to lag until the only thing that would bring it back to life is a restart.
Like I said, it's random, it could happens 2 or 3 times in a day, or once every 2 or 3 days.
I'm not sure what might be causing it but I'd gladly pay to anyone that can deal with it and find me a solution.

Here's a screen cap of the daily process log from this afternoon while the server was having one of these episodes.

 

That's not really the right log to show us, since that's a full day average.
Its probably apache creating too many threads, and than leaking all over the place.

 

Thanks for your reply, zzbomb. What would you say is the right log to look at?

 

Would this make more sense? Here's the Apache log for today

http://www.mediafire/?fwr0cljavddg292

HTML:

 

I would suggest turning KeepAlive off, as your server seems to be fairly busy. You have hit the max clients in your Apache settings, 256 (256 requests currently being processed, 0 idle workers). Try first with the keep alive change, then, if needed, you can change the max clients variable to a larger number, but, you should not have to do that.

Chris

 

Thanks a bunch for the advice, Chris. That seems to have helped a LOT, I'll keep my fingers crossed

 

No problem at all, good luck!