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RE: RAC - Is it wise/ok/possible to run multiple databases across the same cluster?

From: Mark W. Farnham <mwf_at_rsiz.com>
Date: Mon, 30 Apr 2007 19:06:49 -0400
Message-ID: <00d901c78b7c$3ca52550$1100a8c0@rsiz.com>


IF you've got the shared disks for all the databases "zoned" for access by all the hosts (machines) and sufficient interconnect bandwidth amongst the machines, then it is really just a question of gracefully starting and stopping the relevant instances of the databases on the various machines.  

Automating all this to dynamically adapt to load spikes would be one of the many conflicting definitions of "grid." Doing it "by hand" at predefined workshifts should be reasonably manageable. You *might* want to avoid actually shutting down the non-prime-shift instances on C & D and just make it impossible to open a session on them if memory is not an issue on the C & D hosts. That depends on issues like pre-warming the cache, "kept" lookup tables and packages, etc. versus the resource cost of keeping the idle instances up and checking them for blocks (which should approach zero cost as the length of idleness increases).  

Don't confuse my statement that it should be possible with the idea that this is the best architecture for a given system.  

Regards,  

mwf  


From: oracle-l-bounce_at_freelists.org [mailto:oracle-l-bounce_at_freelists.org] On Behalf Of Ethan Post
Sent: Monday, April 30, 2007 3:52 PM
To: Kerber, Andrew W.
Cc: oracle-l
Subject: Re: RAC - Is it wise/ok/possible to run multiple databases across the same cluster?  

OK, I had heard that perhaps there are issues because of the interconnect uses UDP. The goal would is to for example allow say 3 databases access to machines A & B during the day, while another database has exclusive access to C & D, then at night allow one of the first three databases to access A, B, C & D.

On 4/30/07, Kerber, Andrew W. <Andrew.Kerber_at_umb.com> wrote:

None that are different than any other requirements. You don't even have to cluster all the instances.  

-----Original Message-----
From: oracle-l-bounce_at_freelists.org [mailto: <mailto:oracle-l-bounce_at_freelists.org> oracle-l-bounce_at_freelists.org] On Behalf Of Ethan Post
Sent: Monday, April 30, 2007 2:19 PM
To: oracle-l
Subject: RAC - Is it wise/ok/possible to run multiple databases across the same cluster?  

Are there any technical limitations in regards to running multiple databases across the same set of servers in the same cluster

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Received on Mon Apr 30 2007 - 18:06:49 CDT

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