Re: Account DB CPU vs OS CPU
- From: Christo Kutrovsky <kutrovsky.oracle@xxxxxxxxx>
- To: exriscer@xxxxxxxxx
- Date: Thu, 24 Sep 2009 14:34:41 -0400
How did you measure CPU usage over the period of time ?
I can't tell you for sure, but here's a few thinking points.
- dbwriter and other background processes - are these accounted in DB CPU ?
- LMS processes - are these accounted in DB CPU ?
- listener, clusterware, process initialization - those are not accounted for
--
Christo Kutrovsky
Senior Consultant
The Pythian Group
On Thu, Sep 24, 2009 at 1:07 AM, LS Cheng <exriscer@xxxxxxxxx> wrote:
> By the way I understand that when doing I/O CPU is not accounted by Oracle,
> so it might be a the cause of such observation?
>
>
> Thanks
>
> --
> LSC
>
>
> On Thu, Sep 24, 2009 at 6:55 AM, LS Cheng <exriscer@xxxxxxxxx> wrote:
>>
>> Hi
>>
>> I have a 4 nodes RAC running on Solaris 10 each with 5 quadcore CPU (or
>> Dual with Threading not sure). Shows 20 CPU in psrinfo.
>>
>> A few days ago we were running with two nodes only and one node during
>> peak time was consuming an average of 95% CPU. There are 15 instances per
>> node so I obtained DB CPU from time model for each instance during the peak
>> time (one hour), added them up and got around 45000 seconds. Considering 20
>> CPU there should be around 72000 seconds CPU so from Oracle point of view
>> 62.5% of CPU was being used in average but from OS point of view 95%.
>>
>> There arent any more application running except Patrol agent and Grid
>> agent, so how trustie is DB CPU statistic?
>>
>>
>> Thanks!
>>
>> --
>> LSC
>>
>
>
--
Christo Kutrovsky
Senior DBA
The Pythian Group - www.pythian.com
I blog at http://www.pythian.com/blogs/
--
//www.freelists.org/webpage/oracle-l
Other related posts:
