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

I guess some of the cynicism comes from the following issues that might bite such an approach.

1. Unsupported datatypes.
2. Schemas that can't do bi-directional replication - for example Oracle Apps/PeopleSoft etc
3. apps where reconfiguring database location takes more than 'just a few minutes'.

Using bi-directional replication to reduce downtime is a pretty nice idea, but somewhat complex in practice and subject to all sorts of customer specific caveats.

On Thu, Nov 27, 2008 at 11:50 AM, Yechiel Adar <adar666_at_inter.net.il> wrote:

> He is one of the most respected guys in the Israel oracle community.
>
> Adar Yechiel
> Rechovot, Israel
>
>
>
> LS Cheng wrote:
>
> Was the lecturer a pure lecturer or lecturer/consultant?
>
> Academic stuffs sounds very good always but us we live in real worlds and
> work with real applications.
>
>
> Regards
> --
> LSC
>
>
> On Tue, Nov 25, 2008 at 5:05 PM, Yechiel Adar <adar666_at_inter.net.il>wrote:
>
>> 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 10.2.0.4.
>>
>> 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 http://berxblog.blogspot.com
>>
>>
>> Hi, I'm working with a customer running a critical web site on a 10gR2RAC 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"?
>>
>>
>>
>>
>

-- 
Niall Litchfield
Oracle DBA
http://www.orawin.info

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