Re: Which HA Solution allows to have least downtime while having oracleupgrades/patches

Hans Forbrich wrote:
> Chandra,
>
> (Naively assuming you are serious about this question and not just trolling
> for the upcoming round of marketing hype ...)
>
> I'm not aware of any database solution (Oracle or other) that guarantees it
> will support rolling upgrades and rolling patches. Many solutions do
> attempt to keep the time to a minimum, and Oracle9i is certainly reducing
> the reasons why maintainance downtime is required. IMHO, like security,
> there will always be at least one additional situation that will require a
> complete outage.
>
> The answer, unfortunately, depends a lot on the applications you need to
> keep alive, the physical support infrastructure you are willing to support,
> the methods and policies you are willing to enforce, and finally the amount
> of money you are willing to throw at the solution.
>
> I encourage you to look at the OTN white papers and the discussion around
> MAA before digging into implementation details in the documentation. This
> will also help you understand the differences between HA and DR, and which
> Oracle features support the two situations best.
>
> The white papers are at
> http://otn.oracle.com/deploy/availability/content.html
>
>
>

Hi Hans,

Thanks a lot for the information. I have been going through the MAA document apart from others, it's a 198 page interesting document and I am still on it. I am really serious about getting some information which would help me to have a clear and concrete understanding of various HA/DR options/solutions and the best solution which can be used to provide minimum downtime for online applications (or any web related apps which can't afford extended downtime) using Oracle.

I also need some sanity check on this idea - whether or not it is practically possible or if I am missing/overlooking something?

Assuming that I have a two-node Multi-Master Replication setup which is presently on Oracle9i 9.2.0.1, can I do the following to patch from the present version to the latest. Or for that matter, say from Oracle8i to Oralce9i or from Oracle9i to OracleXXi.

1. Push all the transactions from the Node 2 to 1.
2. Disable the push job on Node 1.
3. Shutdown Node 2.
4. Patch Oracle on Node 2 and open it for use. Connections would be routed to Node 2 instead of 1 or from 1.
5. Push all the transactions from Node 1 to 2.
6. Disable the push job on Node 2.
7. Patch Oracle on Node 1 and so on......

As regards Upgrading from lower to higher version I am sure there would be restrictions stating that all the participating nodes should be on the same version of Oracle if not at least on the same patchset.

Any thoughts, ideas would be appreciated.

Thanks
CP Received on Sat Jun 21 2003 - 10:38:40 CDT