High CPU and RAM usage, how to know what is the cause? : <p>I am maintaining a cloud server (ubuntu 14, webuzo) on Amazon (AWS).
Recently the usage of CPU and RAM are increasing high which cause the server going down.</p>

<p>i thought there is an attact to the server, then i try to modify the security from the AWS console. I block all the ports, except for accessing the control panel of my hosting panel which i set it to only accept from my ip address.</p>

<p>But still, the CPU and RAM usage is still high.</p>

<p>I guess this is not caused from the outside(attact/flood), but it comes from inside the server.</p>

<p>So the question is how to know or determine what is the cause?</p>

<p>Regards</p>
