We have a pretty standard LAMP stack (Ubuntu 12.04 - Apache2 - MySQL - PHP), on a dedicated server with a large hosting provider.
Since a couple of days we are experiencing slow web performance from time to time (requests would succeed but would sometimes take up to 10-15 seconds).
I have tried to check the server usage with the top
command, but nothing seems to indicate anything unusual or excessive usage (cpu usage would lie between 10-30%).
Tasks: 268 total, 2 running, 266 sleeping, 0 stopped, 0 zombie
Cpu(s): 4.2%us, 2.8%sy, 0.0%ni, 80.3%id, 11.3%wa, 0.0%hi, 1.4%si, 0.0%st
Mem: 8070300k total, 7779400k used, 290900k free, 66648k buffers
Swap: 0k total, 0k used, 0k free, 2799188k cached
Does anybody have an idea what other stats I could check and in which direction I should continue searching?