Once in a while, our server starts lagging. It always start around 6:00 ( GMT + 1) in the morning and ends around 3 till 4 hours later.
We have munin installed and we see a peak in CPU utilization and in the MySQL throughput. Below are some screenshots from munin.
Currently, we got no clue anymore how to find out what is causing this peak. It first looked like it happened every tuesday, but today the problem also arose.
We got a slight feeling it's something in MySQL since the throughput is so high. We checked if we had some cronjobs running and checked the slow logs query. None of them gave us an answer to what is causing this.
So, our question is how we can find out what the exact problem is. Or is there some sort of MySQL optimalization what is causing this?
We are currently running an Ubuntu 12.04.1 server
Thanks for your help!