Re: tough choices

From: Daniel Morgan <damorgan_at_x.washington.edu>
Date: Thu, 17 Jun 2004 22:39:48 -0700
Message-ID: <1087537216.808358@yasure>

Michael Austin wrote:

> Niall Litchfield wrote:
>

>> "Daniel Morgan" <damorgan_at_x.washington.edu> wrote in message
>> news:1087421232.498660_at_yasure...
>>
>>> The main consideration I would think would be the overhead of federating
>>> data for DB2. The more data the more difficult and time consuming and
>>> the fact that losing nodes with RAC is an inconvience ... with DB2 you
>>> have a lot more to worry about ... and mean time between failures goes
>>> down, not up, as you add nodes.
>>
>>
>>
>> I'd be impressed with a RAC 'scalability' solution that didn't have 
>> higher
>> downtime than an appropriately sized single node equivalent. More 
>> complexity
>> = less screwups is an equation with which I am unfamiliar :) The same of
>> course applies to IBM clustered solutions.
>>

>
> Daniel,
>
> If I understand the correct programming of a RAC application is to have
> a connection to multiple nodes in the cluster simultaneously and if
> there is a failure, the transaction continues unscathed on another node
> in the cluster. I have seen this demonstrated to be true. So, what this
> should mean is that even though you may have a node crash, your
> application AND database AND transactions will survive with no
> "downtime" experienced by the end user. The application and database is
> available 100% or as near 100% as you can get...
>
> According to Oracle marketing and technical folks (2 years ago), this
> really only worked as advertised on 2 platforms. Can you guess which
> ones they were??
>
> You mentioned that you have a multi-node Linux cluster using a NAS-head
> for disk access... Can you provide me a pointer to the details of the
> complete configuration? I am not opposed to learning new configurations
> and platforms. What do you see as it's weaknesses and strong-points.
>
> Michael Austin.

I have 8 HP DL360 dual proc servers running RedHat EL AS 3 update 2. They each NFS mount a NetApp F810 Filer Head with an 8GB RAM cache connected to a tray with 1.2TB of disk.

We use the Oracle TAF demo running on a workstation as the load and shutdown nodes by either pulling the power cord or doing a SHUTDOWN ABORT. Transactions seamlessly continue after less than one second.

The TAF demo can be downloaded from the PSOUG web site (http://www.psoug.org) along with a zip file with our configuration files for the demo.

-- 
Daniel Morgan
http://www.outreach.washington.edu/ext/certificates/oad/oad_crs.asp
http://www.outreach.washington.edu/ext/certificates/aoa/aoa_crs.asp
damorgan_at_x.washington.edu
(replace 'x' with a 'u' to reply)

Received on Fri Jun 18 2004 - 00:39:48 CDT