topic Re: Oracle processes staying on one processor in Operating System - HP-UX

Oracle processes staying on one processor

Brent Barton — Fri, 30 Nov 2001 16:24:25 GMT

We migrated several Oracle instances from a K580 6-way to an N4000 4-way. Ever since the move we have noticed that most (if not all) of the Oracle processes want to run on CPU 0, and will wait for that CPU. Looking at Glance shows:

CPU 0 100% UTIL
CPU 1 2.7% UTIL
CPU 2 0.6% UTIL
CPU 3 1.9% UTIL

I found a post on Dutchworks that the DBA can instruct Oracle to use multiple processors, but I haven't found any evidence on how.
Any Ideas?

Thanks...

Re: Oracle processes staying on one processor

S.K. Chan — Fri, 30 Nov 2001 17:01:10 GMT

If the same Oracle version is able to run in multi-cpu mode in your K-class it should do the same for the N-class (HP-UX version the same ?).
Anyway we had this situation before on the L-class (11.0) and this 2 patches fixed our problem. Check with HP Response center first.
PHKL_18543 11.00 PM/VM/UFS/async/SCSI/IO/DMAPI/JFS perf patch
PHNE_25385 11.00 Streams PTY cumulative patch

Re: Oracle processes staying on one processor

Anthony deRito — Fri, 30 Nov 2001 18:36:41 GMT

Are you using PRM by any chance? The standard HP-UX job scheduler is very complicated and does its best based on loading and priority to maintain load balance between multiple processors. I did not know Oracle has this kind of control. But then again, I don't know much about Oracle. Check if PRM is being used.

Tony

Re: Oracle processes staying on one processor

Brent Barton — Fri, 30 Nov 2001 18:43:14 GMT

PRM is not installed. I am currently working with Response Center to discuss patches, etc. I will reply with their response.

Thanks

Re: Oracle processes staying on one processor

Wodisch — Fri, 30 Nov 2001 19:22:28 GMT

Hello Brent,

have you set the "init.ora" parameter "cpu_count" to the number of cpus you want to use for/by Oracle? The default is only one...

HTH,
Wodisch

Re: Oracle processes staying on one processor

Sanjay_6 — Fri, 30 Nov 2001 19:38:23 GMT

Hi Brent,

Try this link,

http://us-support2.external.hp.com/cki/bin/doc.pl/sid=902012d715d5312b79/screen=ckiDisplayDocument?docId=200000049809883

Hope this helps.

regds

Re: Oracle processes staying on one processor

Brent Barton — Thu, 13 Dec 2001 15:00:33 GMT

We run the security product SeOS by CA. After removing the product the load was then balanced across all 4 processors. I then reinstalled SeOS and the load was still balancing across all cpu's. So my guess is that the initial install of the security product was not clean.