MySQL is eating up about 80% of my CPU for no reason as far as I can see. Right now this server is rarely used, more of a test site I set up that will eventually be a used for production once I fix small problems like this. I run 3 instances of MySQL but it seems that my first instance is taking up all the CPU. When I turn off the first instance and leave the other two on everything runs fine.
I tried Show Processlist and no statements are being run besides "Sleep" and the query "Show Processlist" (obviously) at the time it's using up all this CPU.
my.cnf is basic. I did not optimize or change any MySQL settings. Do you think this would cause such strange behavior?
The machine is running Linux Centos 5.7 64 bit and MySQL 5.0.95.