Re: RAC and scalability

From: DA Morgan <>
Date: Tue, 08 Apr 2008 08:45:41 -0700
Message-ID: <>

hpuxrac wrote:
> On Apr 7, 6:52 am, Andrea <> wrote:

>> Hi all,
>> i've need some advise for resolve my doubt on RAC, because i have to
>> sizing RAC environment in my business.
>> Have been shows me two different solutions of RAC:
>> 1)  One node of Bl680c (until 4 CPU quad Core)
>> 2)  Two node of Bl480c (only 2 CPU quad Core)
>> The type of choice is a valuate for future scalability, first solution
>> support vertical scalability (2 to 4 CPU) instead of second solution
>> where scalability is only for horizontal (add a nodes).
>> First solution is correct sure but is more expensive and i would like
>> to know if his cost is justifiable, more cpu are effective benefit?
>> thanks for your info
>> bye
>> Andrew

> I would start by recommending that you read "You probably don't need
> RAC" by Moans Nogood.
> That pretty much gives you most of the critical things to think about.
> RAC certainly has overhead that causes scalability problems for some
> applications your mileage may vary. Generic testing of hardware that
> doesn't really test out how well your applications scale out in RAC is
> an exercise in wasting time.
> An excellent point that Moans makes is that the very act of trying to
> get high availability ( implementing RAC ) often causes lower
> availability. Does this site and company have the critical mass of
> experienced people necessary to support RAC? The questions that you
> are asking make me think "not so much".
> Try locating that paper by Moans and do your homework ... that is my
> recommendation.

Amazing how much easier it might be for the OP to find the paper you refer to it you didn't spend so much time trying to act like you are part of the "in" crowd.

The gentleman's name is Mogens Norgaard and this will actually help the OP find the paper.

PS: Please go right ahead and complain about my signature block if it it is cathartic.

Daniel A. Morgan
Oracle Ace Director & Instructor
University of Washington (replace x with u to respond)
Puget Sound Oracle Users Group
Received on Tue Apr 08 2008 - 10:45:41 CDT

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