Re: Failover to another site Full DR.

From: David Barbour <>
Date: Thu, 29 Jan 2009 11:50:06 -0500
Message-ID: <>


Your question has a number of different levels of complexity involved which undoubtedly is the reason you haven't received any replies to this despite the fact it's entirely possible and many of us in this community probably have automatic failover set up for databases and applications.

Much depends on your business requirements for an application. Also there's the question as to what type of failure for which you are planning. And whether or not the application is housed on the same server as the database server, whether or not you're using application servers, whether or not you have interfaces that need to connect to the database/application and just a whole host of other things.

So database failover has to be taken as part of a larger context. In it's 'simplest' form, Oracle supports Transparent Application Failover (TAF) which allows a standby or RAC Node to accept connections from a failed instance. It's much more seamless in RAC than with Dataguard, but it works pretty well.

There are a number of Metalink articles that address the configuration(s) required for TAF, as well as sections in both the Dataguard and RAC Guides avilable from OTN.

I know this isn't much help, but if you're already shipping logs from the Primary to the Standby, AND the application(s) and application server(s) - if any - are not on the datbase server AND the application is merely connecting to the database (watch out for java) AND your only concern is database failover then it should be fairly easy to configure TAF. in this case, the IP range is immaterial (which is actually true only true 80% of the time).

On Thu, Jan 29, 2009 at 4:39 AM, Howard Latham <>wrote:

> Oracle 11 - Redhat Linux 64bit
> How do you failover over in dataguard/(AKA Log shipping) to another
> site with a completely different IP range.?
> Where does a users url get redirected ? and what about ip addresses /
> host names on their pcs?
> It seems to me there is going to be a single point of failure whatever you
> do.
> And has anybody written a manual that enables a non dba to do a
> failover ? ( I'm guessing not!)
> --
> Howard A. Latham
> --

Received on Thu Jan 29 2009 - 10:50:06 CST

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