Re: Any-one know how to eliminate PLANNED downtime with Oracle RAC?

From: Yechiel Adar <>
Date: Tue, 25 Nov 2008 18:05:06 +0200
Message-id: <>

I was in a stream class today and the lecturer mentioned just this thing. Create a second database and create bi-directional streams between the two.

1) bring the application down for a minute or two.
2) change the application to access the second server.
3) bring down the first database.
4) bring up the application. It will start to put updates in the queues 
in the second database.
5) upgrade the first database.
6) bring up the first database and wait for the apply process to catch up.
7) bring down the application for a minute or two.
8) point the application to the first database.
9) start up the application.

Upgrade completed with only a few minutes down time.

Need EE for streams and works best in

Adar Yechiel
Rechovot, Israel

Martin Berger wrote:
> Hi Keith,
> I have to second Carels and Michaels meanings. Your desire is highly
> complex and multi dimensional. So you will not get any straight
> forward answer.
> In one of my prior lives I had to promote and support Multi Master
> Replication. If someone uses this wise, he can achieve a zero-downtime
> environment.
> But be warned: You need a tremendous engineering work and still really
> good skilled operational DBAs with enough time to take care of.
> I have never checked, wether or not streams can provide the same
> functionality. Maybe it's worth checking.
> just some ideas, might they help,
> Martin
> --
> Martin Berger
>> Hi, I'm working with a customer running a critical web site on a
>> 10gR2 RAC backend DB - they support hundreds of thousands of
>> simultaneous connections at the "quietest" time.
>> They have expressed a desire for NO downtime during ANY changes to
>> Oracle, particularly the application of Oracle patches and Oracle
>> upgrades (both minor and major), etc.
>> Any thoughts? Who's "been there done that"?

Received on Tue Nov 25 2008 - 10:05:06 CST

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