topic Re: High CPU usage by Oracle processes in Operating System - HP-UX

High CPU usage by Oracle processes

fly_fisher — Fri, 07 Jun 2002 14:39:16 GMT

Hi you all,

I'm having a performance problem with a machine. The CPU is near 100%. After seeing what processes are the guilty ones I've seen they are some Oracle ones. I'm a newbie with Oracle. Here I send you the init.ora file. I'm afraid the DB is not well dimensioned. There are a lot of processes like:

oracle 28834 1 19 11:07:16 ? 0:00 oracleNMPROD (DESCRIPTION=(LOCAL=no)(ADDRESS=(PROTOCOL=BEQ))

they end very fast, but there are many of them each second.

So my question is, how could be reduced the CPU usage (if possible)?

Memory 512 MB
2 CPU's 450 MHZ
SO HPUX 11.0

Thank you very much for your help,
Regards.

Re: High CPU usage by Oracle processes

fly_fisher — Fri, 07 Jun 2002 14:41:47 GMT

I forgot to say it's Oracle 8.1.6

Thanks.

Re: High CPU usage by Oracle processes

Sanjay_6 — Fri, 07 Jun 2002 14:50:11 GMT

Hi Rafael,

Take a Look at this thread,

http://technet.oracle.com/doc/hp/server.804/A59371_01/ch3_opt.htm#8830

Hope this helps.

Regds

Re: High CPU usage by Oracle processes

A. Clay Stephenson — Fri, 07 Jun 2002 15:04:42 GMT

The very first thing to check is the value of the kernel tunable 'timeslice'. There has been a Tuned Parameter set for databases that wrongly set timeslice to 1 rather than 10.

Re: High CPU usage by Oracle processes

fly_fisher — Fri, 07 Jun 2002 15:24:25 GMT

Hi A.Clay,

timeslice is 10;

Thank you very much. I've seen in Glance that the CPU is being used mainly by these system calls:

System Call Name ID Count Rate CPU Time Cum CPU
--------------------------------------------------------------------------------
exit
1 446 91.0 0.62159 148.23025
fork 2 984 189.2 0.43792 107.06064

Re: High CPU usage by Oracle processes

MANOJ SRIVASTAVA — Fri, 07 Jun 2002 15:34:02 GMT

Hi Rafael

With the information you ahve provided , the first thing look like is that you ahve a lesser memory , can you porst a o/p of like sar 2 5 which shouls the CPU usage , also waht are the kernel parameters of HP UX . The best way to figure out would be know is really CPU used for more memory i/o , what is the swap size , mem utilization etc , physical , logical reads , etc .

A good palce to star would be to post the sar o/p , and also vmstat o/p .

If you are sure taht it is not the OS and the same is proeperly tuned then you amy look at the following :

http://web.singnet.com.sg/~petermag/tune.html

Manoj Srivastava

Re: High CPU usage by Oracle processes

Jim Butler — Fri, 07 Jun 2002 17:55:18 GMT

try metalink.oracle.com, and enter your oracle sid to set yourself up for some really good tech docs. With oracle, it could be just about anything. I posted my oracle kernel that I use here to support 3 SIDS on one of our oracle boxes here.

Are you running a listener process, and if so, are you communication with a webserver?
or
Are you running a stand alone OLTP system where you are serving terms to your users, etc.?