Re: 10g RAC and defined services performance problem

From: Andrew Kerber <andrew.kerber_at_gmail.com>
Date: Thu, 11 Sep 2008 15:30:15 -0500
Message-ID: <ad3aa4c90809111330q589af98dred71c545303cd02d@mail.gmail.com>


This is very much a shot in the dark, but look closely at your library hit ratio. A common cause of high cpu is non-reusable sql

On Thu, Sep 11, 2008 at 10:07 AM, Crisler, Jon <Jon.Crisler_at_usi.com> wrote:

> Good question- in fact we did do that- each service runs the same
> application, but accesses different schemas; this way a particular schema
> would be located on one node. In previous tests the cluster seemed to work
> quite well, but now that they are live we are getting high cpu
> utilization. We have all the normal tricks in place for performance
> tuning- large SGA, fast disks, gige RAC interconnect with bonding etc.
> Since I have not been told about the time periods that it tends to choke I
> have not been able to do much with AWR etc but I am trying to get that info.
>
>
> ------------------------------
>
> *From:* Andrew Kerber [mailto:andrew.kerber_at_gmail.com]
> *Sent:* Thursday, September 11, 2008 10:57 AM
> *To:* Crisler, Jon
> *Cc:* oracle-l; oracle-rac_at_freelists.org
> *Subject:* Re: 10g RAC and defined services performance problem
>
>
>
> I cant think of any reason why the services per-se could be the problem.
> However, it is not that unusual for applications not to scale well across
> multiple nodes. Did you do any analysis to try and partition the workload
> across the nodes so that each node would access a different subset of data?
>
> On Thu, Sep 11, 2008 at 9:51 AM, Crisler, Jon <Jon.Crisler_at_usi.com> wrote:
>
> We have a 3-node 10.2.0.3 RAC Server on Red Hat 4, and have defined about
> 20 additional services with preferred nodes set to 1 specific node, with
> available nodes set for the other 2 nodes. Workload is divided evenly with
> about 7 services on each node. Has anybody run into specific problems with
> performance when using a lot of services, as opposed to having the
> application just connect to the main db load-balanced service ?
>
>
>
> This particular application has a reputation from the developers of not
> scaling well across RAC nodes, and we have recently been advised of a lot of
> performance problems that I am now starting to investigate, but I want to
> get some opinions on the wisdom of using many different services rather than
> just a few or one.
>
>
>
>
> --
> Andrew W. Kerber
>
> 'If at first you dont succeed, dont take up skydiving.'
>

-- 
Andrew W. Kerber

'If at first you dont succeed, dont take up skydiving.'

--
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Received on Thu Sep 11 2008 - 15:30:15 CDT

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