Sometimes my website 'goes down' due to Mysql consuming all the resources, but I think it does not stop creating more httpd processes. Is that possible? If I restart apache, these processes disappear and I can see the CPU consumption by the mysql process go down slowly, and then the site is online again.
I'm having trouble finding the bottleneck anyway. The site has a lot of cronjobs (php scripts), and each one generates logs, which include the total execution time.
So my first thought was to try to find the script that took a lot of time, but that was not possible because it takes only one of them slowing the mysql server, to have all of them increasing their execution time.
Where can I learn how to find the bottlenecks?
Note: I'm on CentOS, apache 2, php 5.3, and mysql 5