Question about HP-UX 11.11 and CPU's

[Miguel Ustariz]

Hi guys:
Enviroment: HP rp5470 with 2 CPU's, hp-ux 11.11 and Oracle 9.2 or 10g.
I see with top that oracle use only one processor and the other is idle always.
Need I install some OS patch or reconfigure some kernel parameter in order to use both CPU wit Oracle ?. Somebody in an Oracle partner said me that exist an OS patch to do this. It is true ?

Thanks a lot...

[Bill Hassell]

No patch is necessary. If only one program is consuming CPU cycles, then only one CPU will be used. Only if multiple programs all need processors at the same time will more CPUs be used. As far as Oracle configyrations, you do have to tell Oracle how many processors to use (and Oracle will charge you extra for the additional CPUs) so it can initiate multiple process threads. That will increase the use of other CPUs.

[Wim Rombauts]

I vagely remember a patch about programs running on a single CPU on a multiple-CPU system, but I don't know if this was for 11.11 or 11.00 or even 10.20.
What is the latest gold-patchbundle that you have installed on your system ?
Oracle RDBMS software itself doesn't care about the number of CPU's. Even if you have a single-CPU license, you can run on 32 CPU's. Just hope that Oracle doesn't find out :-)
At the other side, what is your database parameter setting for CPU-count ?
Do you ave PRM running (process resource manager) ?

[T G Manikandan]

Though not sure about the 10g release

As far I know for the past years installing and configuring Oracle,Oracle does not find a way of restricting itself from using all the processors on the machine.


For ex.you buy a oracle license for a 2 CPU and use it for 4 CPU still oracle would use all the 4 processors but it would be illegal according to licensing agreements.

Just check as whether the Oracle application is restricted with tools like PRM(Process Resource Manager)

[T G Manikandan]

CPU_COUNT parameter is automatically determined by Oracle.

Do not change that..

I would advise you to use parallel query options for utilizing both the processors.

[Miguel Ustariz]

OK. We are talking about Oracle Application Server 10G (9.0.xx). No PRM installed. I do not know if tha application are use parallel query option.

[rick jones · Accepted solution]

You can likely use Glance to see if the process is single or multi-threaded. If single treaded, there isn't much more to do.

If multi-threaded, there still may not be much more to do :) In broad handwaving terms, it can be more efficient to run one CPU at 80% utilization than two CPUs at 40% each, even though it looks slightly odd.

While you are looking at things in Glance, you might make sure that other things are not a bottleneck - like disc I/O.

[Miguel Ustariz]

I followed your sugestion and all OK