Re: Real World Experience of Oracle RAC and its ability to Scale

From: Kent Stroker <kent_at_strokermedia.com>
Date: Tue, 19 Apr 2005 19:10:46 -0700
Message-ID: <BE8B0836.AC6%kent@strokermedia.com>

As an ex-Oracle employee and one of the RAC specialists, I saw (and still see) a heck of a lot of RAC installations. There is no "typical", but there are certainly more 2 to 4 node installations out there than 12 nodes.

The most unsettling about this "vendor" that I see is that running the middle-tier and the database (especially RAC) on the same servers is a big problem.

I suspect this vendors product has not been design or optimized for the Oracle technical stack. Do yourself a favor and bring in some outside help with this one before letting any PO's out.

Unless there are some giant connection and analytics requirements, a 12-node cluster might be wrong in this case. I have seen simple 2 CPU, 2 node clusters handle giant jobs - the need for 12 nodes may very well be due to poor block contention schema design. Until you ask some questions and perhaps get some help, I'd put the brakes on this on.

If for no other reason than running the middle-tier and the database on the same hardware is just plain wrong; certainly will invalidate any perceived HA gains from RAC.

On 4/19/05 5:50 PM, in article
1113958253.931994.62960_at_g14g2000cwa.googlegroups.com, "hpuxrac" <johnbhurley_at_sbcglobal.net> wrote:

>> You are incorrect that RAC is typically deployed with less than 5

> nodes:
>
> Synonym for typical ... regular.
>
> What statistics can you show give evidence that RAC is typically
> deployed with more than 4 nodes? Possibly oracle has that information
> ... let's see you dig something up that we can authenticate. Proving a
>
> statement ... Tom Kyte does that regularly. So does Mr. Lewis. Other
> people just make up stuff.
>
> Maybe it's just an english language thing. Seeing 8+ node clusters
> doesn't mean they are in the majority or even close ... which would
> meet the definition of typical.
>
> The rest of what Mr. Morgan said appears correct except for the
> possibly wild speculation about block contention.
>
> Personally I would recommend vendor references that might include
> visits to current customers and on-site demonstrations with current
> customers of the application vendor application running in production.
> Have them explain their recommended architecture and pro's/con's ...
> and keep drilling for detail.
>
> Maybe it's just a lack of information or not enough information but
> something doesn't sound right so far.
>
Received on Tue Apr 19 2005 - 21:10:46 CDT