Hello i current have a LAMP Stack running on Ubuntu 14.04, and there is something wrong going one, for apparently no reason my CPU usage is being boosted to 100% which is causing all my websites to go down.

http://i.imgur.com/38nDIOB.png

When this happen, i reboot my server and everything goes back to normal, my question is how can i find what is causing my CPU usage to go up so fast?

Thanks is advance for any help!