How bad/normal/good is this CPU usage?
Cpu0 : 14.4%us, 6.3%sy, 0.0%ni, 78.8%id, 0.0%wa, 0.0%hi, 0.5%si, 0.0%st Cpu1 : 88.3%us, 8.0%sy, 0.0%ni, 0.0%id, 0.0%wa, 0.0%hi, 3.7%si, 0.0%st
We get CPU usage alerts ranging between (80-88%) from a specific group of servers (that handles the most important parts of our application) every once in a while. I don't normally don't take actions on them because I see most of the usage is in the
%us space. I look at it as the sign of a healthy system working efficiently. I am in the process of composing an email to our team trying to explain when should we panic and when should we not on these CPU alerts? My questions are:
Is it fair to say that as long as
%sy are not too high, a CPU with a high usage in %us column indicates a healthy system than a crowded system.
Is it right in thinking that even 95% of CPU usage is not a problem with the server as long as it is at
If the server is at 88% CPU usage at
%us, am I right in thinking that most probably the tuning has to be done in the application? Again, this 88% usage is not affecting the performance, so is it better to leave it like that and accept the fact that our application is highly CPU bound?
This particular server runs on RHEL 6.5 and runs a
java process with more than 800 threads most times.