Re: Documentation for reasons to NOT use RAC?
From: Tim Gorman <tim_at_evdbt.com>
Date: Mon, 22 Feb 2010 09:06:40 -0700
Message-ID: <4B82AB90.1030500_at_evdbt.com>
RAC is good technology, but it is a niche solution, not a general-purpose solution. It is not high-availability -- look toward Data Guard for viable database high-availability. It is a database scalability solution, plain and simple. If you cannot scale by moving to a larger server, then RAC is a viable alternative. Once the justification of RAC as a high-availability solution is removed (as it should be), then the decision of how to scale becomes a matter of which platform you are using. If you are on Solaris or HP-UX or AIX, chances are good you can scale quite high within a single server, without using RAC. If you are on Windows or Linux, chances are good you might have to use RAC. Crude generalizations, yes - but I'm being terse. Cost enters into it, as many IT departments do not want to buy/lease "big iron", but the Oracle licensing for RAC generally more than offsets, not to mention the hidden costs of training (formal or OJT).
I'm an OPS/RAC DBA since 1994, and the common trajectory for OPS/RAC implementations made for the wrong reasons (i.e. H/A not scalability, general-purpose not special-purpose, etc) often resembles Napoleon's retreat from Moscow.
Still, it's great technology, can be a lot of fun, and looks great on the resume.
Guillermo Alan Bort wrote:
Date: Mon, 22 Feb 2010 09:06:40 -0700
Message-ID: <4B82AB90.1030500_at_evdbt.com>
First and foremost, before you jump into this, make sure that your mission-critical applications are "certified" supported on RAC, and which version of RAC -- after all, a "RAC cluster" is ipso facto one version. That could be illuminating and show-stopping.
RAC is good technology, but it is a niche solution, not a general-purpose solution. It is not high-availability -- look toward Data Guard for viable database high-availability. It is a database scalability solution, plain and simple. If you cannot scale by moving to a larger server, then RAC is a viable alternative. Once the justification of RAC as a high-availability solution is removed (as it should be), then the decision of how to scale becomes a matter of which platform you are using. If you are on Solaris or HP-UX or AIX, chances are good you can scale quite high within a single server, without using RAC. If you are on Windows or Linux, chances are good you might have to use RAC. Crude generalizations, yes - but I'm being terse. Cost enters into it, as many IT departments do not want to buy/lease "big iron", but the Oracle licensing for RAC generally more than offsets, not to mention the hidden costs of training (formal or OJT).
I'm an OPS/RAC DBA since 1994, and the common trajectory for OPS/RAC implementations made for the wrong reasons (i.e. H/A not scalability, general-purpose not special-purpose, etc) often resembles Napoleon's retreat from Moscow.
Still, it's great technology, can be a lot of fun, and looks great on the resume.
Tim Gorman consultant -> Evergreen Database Technologies, Inc. postal => P.O. Box 630791, Highlands Ranch CO 80163-0791 website => http://www.EvDBT.com/ email => Tim_at_EvDBT.com mobile => +1-303-885-4526 fax => +1-303-484-3608 Lost Data? => http://www.ora600.be/ for info about DUDE...
Guillermo Alan Bort wrote:
Just make sure you don't end up having to manage 50 pointless RACs... ;)-- http://www.freelists.org/webpage/oracle-l Received on Mon Feb 22 2010 - 10:06:40 CST
Alan.-
On Mon, Feb 22, 2010 at 1:18 PM, Goulet, Richard <Richard.Goulet_at_parexel.com> wrote:
Hemant,
That is quite true, but once you've voiced your concerns and
objections (as someone else recently pointed out) your off the hook.
Dick Goulet
Senior Oracle DBA/NA Team Lead
PAREXEL International
-----Original Message-----
From: Hemant K Chitale [mailto:hkchital_at_singnet.com.sg]
Sent: Monday, February 22, 2010 9:51 AM
To: Goulet, Richard
Cc: oracle-l_at_freelists.org
Subject: RE: Documentation for reasons to NOT use RAC?
Sometimes being politically correct can mean being professionally
lacking. Lacking in management's duty to protecting shareholders (or
citizen's) money.
At 10:35 PM Monday, Goulet, Richard wrote:
> Maybe the best argument for RAC is politics. .... It just makes
> your boss feel more secure.
>
>
>Dick Goulet
>Senior Oracle DBA/NA Team Lead
>PAREXEL International
>
Hemant K Chitale
http://hemantoracledba.blogspot.com
--
http://www.freelists.org/webpage/oracle-l