Question

I’m currently designing a graph system for a website that shows current CPU usage, you can see my work in progress here – http://nereus.rikkuness.net/admin/cpu2.php

It’s working exactly as I want it to at the moment, but the problem is the way that I am polling for CPU usage is currently

sar 1 | sed -n '5p' | awk '{ print $8; }'

Which works fine but it takes around a second or so to reply with CPU usage which is making the graph not update as I would expect it to in the browser.

Any help on a command that will give me the same information but much faster would be massively appreciated.

Many thanks,

Steve

Answer 1

You can simply use sar 0. This will return an immediate result instead of waiting for a 1 second interval like you do with sar 1.\

Note that this will only return a single point in time value, so you might need to use javascript to track the previous values (i.e. add new value to array and pop old value off).