Re: RAC newbie question

From: jason arneil <>
Date: Tue, 7 Oct 2008 17:01:46 +0100
Message-ID: <>

Hello Yavor,

2008/10/7 Yavor Ivanov <>

> Hello, Dan
> Yes, I see I did not explain myself to clearly... I haven't done 10g
> -> 11g RAC upgrades, but as far as I remember, 9i to 10g RAC upgrade
> requires downtime for the whole cluster during the upgrade (or "migration",
> on Oracle terms) of the clusterware. Are you sure it is possible to make
> rolling upgrade from 10g to 11g (or 11 to 12...) of the clusterware without
> downtime?

I have done an Oracle Clusterware rolling upgrade from to it worked as advertised without whole cluster downtime. I Wrote it up




> I'm not talking about the possibility to use the standby database to
> minimize downtime.
> Regards,
> Yavor Ivanov
> Oracle Certified Master
> -----Original Message-----
> From: Dan Norris []
> Sent: Tuesday, October 07, 2008 4:35 PM
> To: Yavor Ivanov
> Cc:; Mercadante, Thomas F (LABOR);
> Subject: Re: RAC newbie question
> Yavor,
> I'm not sure I am clear on your recommendation. You said you'd use a
> single 9-node cluster too, but then seem to bring up topics that appear
> to suggest that a single cluster is a Bad Thing.
> To clarify, there is no planned downtime I can foresee that would affect
> the entire cluster. Clusterware upgrades are rolling. New ORACLE_HOMEs
> would just be added (no downtime) along side the existing ORACLE_HOMEs
> so that some databases could run on a newer version. Assuming all
> databases are either multi-instance or single-instance but could afford
> a short failover outage, no applications should have any extended
> outages. Obviously, if a database patch/upgrade is required then those
> databases would have planned outages to apply the patches (if the patch
> isn't rolling upgradable too). Of course, this is no different than if
> you were in 3, 3-node clusters.
> In short, I can't find any reason to "break up" the nodes into multiple
> clusters. I'd put all of them in a single cluster which I think will
> ultimately increase the overall availability of the total environment.
> Dan
> Yavor Ivanov wrote:
> > Usualy I would go with single 9-node cluster too. Same reasons.
> But there are some more things to consider here.
> >
> > Think about cluster upgrades. If you have one cluster to upgrade,
> this sounds like single downtime window. But what if one database needs a
> newer version (and newer clusterware), and the other cannot afford downtime
> at that moment? This is something rare, but it's not bad to think of it.
> >
> > Also, some influences may come from your backup / DR strategy.
> But this goes too deep, and gives too little value.
> >
> > But as I've said, I'd usually go to 9-node with every app running
> on different nodes.
> >
> > Regards,
> > Yavor Ivanov
> > Oracle Certified Master
> >
> --
-- -- --
Received on Tue Oct 07 2008 - 11:01:46 CDT

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