Re: 10g with HACMP (no RAC)?

From: Uwe Weber <uwe.weber_at_teleos-web.de>
Date: Sun, 07 Sep 2008 22:16:13 +0200
Message-ID: <6iir2qFqqc7dU1@mid.individual.net>


> Do we need to install any extra Oracle software (e.g clusterware)?

No, afaik Oracle Clusterware and HACMP do the same things, i. e. defining and monitoring of cluster ressources. IIRC you can build a failover cluster with Clusterware as well as with HACMP. Only IBM support will be lacking. Since IBM and SAP are aggresively marketing DB/2, support for Oracle on AIX gets worse every day.

> You mention the redo logs: I assume you refer to the online redo here,
> since starting the database on the second node should presumably be, in
> effect, the same thing as recovering from instance failure. That's
> right, isn't it?

Yes, it is. If HACMP decides that the active node has gone missing, it varies on the shared vgs, mounts the shared filesystems and sets an IP alias with the cluster's ip on the "public" interface of the standby node. It then executes all the application startup scripts which you have configured into the Ressource Group (RG). One of these scripts should start your Oracle instance, which will do an instance recovery. Or at least this is the case with a node failure.

In case of a RG move your scripts should shutdown the instance on the activie side and restart it on the other node.

Of course you have to do all the error checking in the scripts yourself and take care of every possible situation that could go wrong with db shutdown or startup.

Regards,
uwe     Received on Sun Sep 07 2008 - 15:16:13 CDT

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