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Re: What does an app need to do to work with RAC

From: Anand Rao <>
Date: Mon, 29 Jan 2007 20:11:44 +0530
Message-ID: <>


allow me to recommend,

Chapter 16 - Developing Applications for RAC Oracle Real Application Clusters Handbook - K Gopalakrishnan

KG and i have documented some, if not all the reasons for an application not to work or scale on RAC. Note that the brief chapter is a discussion from a scalability / performance perspective and not necessarily from an operational / functional view, as your question seems to hint.

there is a need to define what you mean by "might not work on RAC"

  1. application won't start? are you are referring to a complete breakdown of the application / database?
  2. application "hangs" or doesn't respond after startup and connecting to database?
  3. transactions don't complete "on time"?

and so on...

if you are able to describe your apprehensions clearly, then you might get some more clues and answers.

As Anjo very rightly and accurately mentioned, contention is your biggest problem. The way in which your application accesses the data is a key factor and this is also what Tim has said very correctly in the orafaq forum.

Mladen does have a point. unless you know what each software module does inside the Oracle kernel, you may not find much use with x$kcbsw. Oracle Support might help you with that, if not the evangelists in this forum.

hope that helps,

best regards

On 29/01/07, Boris Dali <> wrote:
> John,
> For what it's worth I asked a somewhat related
> question back in 2002 and found Tim and Cary's replies
> very informative. I think they are still relevant.
> Here's the link:
> Thanks,
> Boris Dali.
> --- John Hallas <> wrote:
> > I will show my ignorance here and ask for what
> > reasons an application
> > might not work with RAC when more than one instance
> > is added.
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Received on Mon Jan 29 2007 - 08:41:44 CST

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