Ian Turner wrote:
>
> Hi,
>
> I'm currently involved in a evaluation of an application that uses of Oracle
> RAC to scale horizontally.
>
> At full production volumes the supplier is recommending a 12-node database
> cluster - using 2CPU commodity servers. Although the transaction rates are
> likely to be low, probably only:
> - 1 update transaction (consisting of perhaps 10 updates/inserts) per
> second.
> - 10 queries/sec
> on average during the day with more queries and less updates overnight .
> Peak volumes are unlikely to be significantly higher.
>
> In the application architecture of the product some application components
> are hosted on the database server. This provides a standard building block
> to scale the application - so the vendor says.
>
> Normally I would expect to separate the application tier from the database
> tier, and believe that a single database server (4CPU's perhaps) would
> easily be able to handle this kind of transaction load. But with this
> shared server the vendor recommends scaling is by adding these combined
> application/database server's into the cluster.
>
> My understanding is that Oracle RAC would typically be deployed with < 5
> nodes. So I'm looking to identify any real world examples of RAC clusters
> and the transaction rates/numbers of nodes.
>
> I would also be interested to know if there are:
> - any recommendations as to the maximum number of nodes in a RAC cluster
> - any RAC design principles that we should ensure the vendor has followed
> - areas we could/should monitor when performing an assessment of the
> application.
> - ways of predicting RAC performance as additional nodes are added (we are
> unlikely to be able to test the application with 12 nodes so will have to
> factor this up from fewer nodes).
>
> Any other comments on the general stability of the Oracle RAC platform in
> real world production environments would also be appreciated.
>
> regards
>
> Ian
One very simple issue will be the license cost for a 12-node
RAC....ouch!
--
Connor McDonald
Co-author: "Mastering Oracle PL/SQL - Practical Solutions"
Co-author: "Oracle Insight - Tales of the OakTable"
web: http://www.oracledba.co.uk
web: http://www.oaktable.net
email: connor_mcdonald_at_yahoo.com
"GIVE a man a fish and he will eat for a day. But TEACH him how to fish,
and...he will sit in a boat and drink beer all day"
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Received on Wed Apr 20 2005 - 06:25:27 CDT
