On a fairly busy RHEL6 server I keep noticing on average following indications
CPU Usage : 2%.
CPU Load AVG: 0.4,0.2,0.1
Memory Usage: 1.3 out of 16 GB
This is the CPU this server has
Intel(R) Xeon(R) CPU E31240 @ 3.30GHz, 8 cores
Does this mean server is healthy and is not under heavy load? I would assume so but since this is always on a low end even with fairly heavy traffic I am just wondering if I could be overlooking something?
Not that I expect the server to bog down, we try to ensure we use minimal resources and serve the web pages as efficiently as possible but I just want to make sure I'm not taken for a surprise someday.
Best Answer
Numbers you have posted look just fine. But it is hard to tell what else is going under the hood. If the server is doing fine - meaning response times are in acceptable range, no spikes or so, everything is working as expected - then stick to the golden rule "if it's working, don't mess with it".
But if you want to do some studying, there is a great template from performance engineer Brendan Gregg that describes probably most possible bottlenecks in a Linux server and commands to monitor/reveal them.
I recommend going through the slides on that page as well.
It is important as well to have continous monitoring (using something like munin), as that is the only way to find problems occuring at odd times, or very sparsely and allows you to spot trends (future problems) as well.
Edit: oh, and don't forget logs (like i just did), always check logs.