Re: RAC and Data Guard Configuration Question
- From: Dan Norris <dannorris@xxxxxxxxxxxxx>
- To: chris.dunscombe@xxxxxxxxxxxxxxxx
- Date: Wed, 07 May 2008 08:18:05 -0500
Chris,
As Martin pointed out, for the "normal" case where DR is just performing
recovery, only one instance will be used to apply all redo. However, the
case you should be more concerned about is what happens when you
actually activate the DR site and try to run production there. If your
production workload requires 4 or 5 nodes in your current 6-node
production site, then trying to place that workload on 3 nodes will
result in a complete outage and negate any DR benefits you were trying
to achieve. In fact, it's almost worse since you'll be trying to run on
the DR site, failing, and likely will be troubleshooting the resulting
issues on the DR site. Meanwhile, no one is working on trying to get the
primary production site back up and running.
In no case would I consider running two instances on the DR servers
since that will probably just make things worse by carving up each
server's resources (CPU, RAM, I/O) for two instances. I don't think I'd
worry about instance naming since all applications should connect via
services (where service_name <> instance_name) anyway. I would use the
same service names on the DR site as I have on production, though.
Shouldn't be a requirement, just might make things easier.
GL!
Dan
Chris Dunscombe wrote:
<snip>
On the DR site we only have 3 nodes, we'd like 6 but 3 is all that we're going
to get.
The question is should we configure DR to have 1 instance per node (same as
production) but this leaves only a total of 3 instances and hence 3 redundant
UNDO tablespaces etc or have 2 instances per node?
Also is it best practice to have the instance names on DR the same as in
production.
Any experiences, advice, "best practice" etc. for this is most welcome.
--
//www.freelists.org/webpage/oracle-l
Other related posts:
