topic Determine Total CPU Utilization in Operating System - HP-UX

Determine Total CPU Utilization

MikeL_4 — Thu, 22 May 2014 12:55:42 GMT

We are running on HP-UX 11.31 itanium server, and CA's monitor keeps alerting on High CPU usage 95+%

However when we go into glance it is showing in the 30% range...

Glance 11.00.044 05:45:53 tmopdb01 ia64 Current Avg High
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CPU Util S SU U | 30% 32% 53%

So I guess the question is what command gives a true "Total CPU Percentage" ???

Also noticed in glace that although it is showing at a current 30% usage level, there is a line that also

shows an oracle process at 95% utilization

Top CPU user: PID 4452, oracletmop 95.3% cpu util
Active CPUs: 16

Do you know why this would show a difference like this ???

Re: Determine Total CPU Utilization

Patrick Wallek — Thu, 22 May 2014 13:49:37 GMT

It is entirely possible that one Oracle process could be using 95% of a single CPU, but overall your TOTAL (meaning ALL 16 CPUs in the system) usage is just 30%.

Re: Determine Total CPU Utilization

Bill Hassell — Sat, 24 May 2014 00:20:49 GMT

You'll have to ask CA what their report means. As is true for any computer, CPU usage is only meaningful when there is exactly one processor installed. With 16 processors, you will need 16 copies of Oracle running at the same time to reach 100% system PU usage. One process running at 100% on your system doesn't affect the other processes at all.

The question is: Is there a problem with Oracle? Is it normal for Oracle to use almost 100% CPU? Is the 100% CPU usage lasting for hours or days at a time? You'll have to ask your DBA whether this is normal.

CPU usage can be very tricky to report. A multithreaded application can show much more than 100% (like 150% or 200%) since all the threads are normally accumulated with the main program.