Re: Any-one know how to eliminate PLANNED downtime with Oracle RAC?
Date: Thu, 27 Nov 2008 16:21:36 +0200
Of course there may be issues that do not allow for this solution. This is true for every general idea.
I just want to point that there is no bi-directional replication. First the application works on server1 and replicate to server 2. Then the application works on server 2 and replicate to server 1.
The idea of building bi-directional replication is that is helps to return to the original server.
Niall Litchfield wrote:
> 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
> <mailto: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.
>> On Tue, Nov 25, 2008 at 5:05 PM, Yechiel Adar
>> <adar666_at_inter.net.il <mailto: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 Berger http://berxblog.blogspot.com
>>>> 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"
>>>> 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