Re: DataGuard failover/switchover questions

From: Jurijs Velikanovs <j.velikanovs_at_gmail.com>
Date: Sun, 27 May 2007 00:33:52 +0300
Message-ID: <d6f0def50705261433q56e3d478sfdc5cbc9984f8b23@mail.gmail.com>

Regarding switchover and client connections I believe it is questions form Oracle Net / Network configuration area.

It would depend on how your system setup and configuration (used client versions etc).

If to consider Oracle Net configuration then you might try to

Part A
Define Service in your listener.ora and have Production instance as you primary instance for your service (clients redirected to your Production by default).

Part B
If switchover happened then you manually (or by script) reconfigure your listener to have Standby Instance as your primary for the Service.

Part C
In order to ensure an availability of the primary listener (in case Primary site goes down) you could have second listener configured on Standby server. Clients would have something like

     (FAILOVER=on)
     (ADDRESS = (PROTOCOL = TCP)(HOST = primary)(PORT = 1527))
     (ADDRESS = (PROTOCOL = TCP)(HOST = secondary)(PORT = 1527))

entries in tnsnames.ora files.

Another slightly simpler conf would be to have separate listeners on both sides serving the same service name. In case of switchover you just shutdown the listener process on primary mode keeping client's configuration (Part C). Clients would automatically recognize Primary site unavailability and connects to secondary site.

This something that came to my mind as first ideas. Sure others will advice more proper solutions from their experience.

PS IMHO noviceoracledba_at_digistar.com - would be more appropriate anyway :)

Jurijs

>
> On 5/26/07, Oracle <oracle_at_digistar.com> wrote:
> >
> > On May 26, 2007, at 4:34 PM, Jurijs Velikanovs wrote:
> >
> > > Dear Mr. Oracle,
> > >
> > > IMHO: With that modest email address I would expect you give me
> > > answers.
> > > I bet you would get answers to your questions quicker if try to send
> > > those question from email like noviceoracledba_at_pleasehelpme.net
> > >
> > > It doesn't cost to tray, does it? ;)
> > > Just my 0.02$,
> > > Jurijs
> > >
> > > PS Sorry wasn't able to resist from send this email :-)
> > >
> >
> > SIgh... I guess you didn't try putting digistar.com (the domain name
> > for my email address) in your browser to see where that led you? :-)
> > Perhaps your email client doesn't show the domain name... I use a
> > different email address for different mailing lists, etc. - it makes
> > it easier to change addresses when the spammers find it (only one
> > list to change instead of 50 subscriptions tied to one account).
> >
> >
> >
> > With that said - when I switchover to the standby, what is the
> > recommended method to point clients to the new primary? As it stands
> > now, when the primary becomes a standby I can still connect to the
> > standby but because the database is not open (physical standby) only
> > views are accessible.
> >
> >
> > thanks
> >
>
>
> --
> Yury
> +371 29268222 (+2 GMT)
> ============================================
> http://otn.oracle.com/ocm/jvelikanovs.html
>

-- 
Yury
+371 29268222 (+2 GMT)
============================================
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Received on Sat May 26 2007 - 16:33:52 CDT