Re: Setup two listeners on a machine

bdbafh wrote:
> On Dec 27, 8:35 pm, "EdStevens" <quetico_..._at_yahoo.com> wrote:
> > RA wrote:
> > > Hi,
> >
> > > I have a question on Listener process.
> >
> > > I have two listeners (L1 and L2) and two databases(DB1 and DB2) on one
> > > machine.
> >
> > > L1 and L2 are using the port 1521 and 1522.
> >
> > > My question is,
> >
> > > How do I set up failover for L1 and L2, meaning if L1 crashes, my
> > > user connections should automatically connect to L2.
> >
> > > A sample code would be great.
> >
> > > Thanks a bunch
> > > januWhy two listeners? One listener can serve as many databases as you
> > have on the server, even different version databases.
> >
> > Working with Oracle since v7.3, I can only remember one listener
> > 'crash'.
> >
> > Assuming you still think you need two listeners for high-availability,
> > you set up the 'failover' in your tnsnames. See chapter 6 of the Net
> > Services Reference.
>
> Ed,
>
> There is a case where different version listeners are required. I
> believe that it has to do with differences in Oracle Net and SQL*Net
> such that pre-8.1.7 and 10g databases and listeners are not compatible.
>
> Jared posted about this on the oracle-l a couple of weeks back.
>
> -bdbafh

Yes, I believe that if you are going to mix pre-8.1.7 and anythng later, you'd need two listeners. But if that's what's driving the requirement for two listeners, I'd presume you'd route requests for the old database to the old listener and the new database to the new listener. Like this:

8.x client --> 8.x listener --> 8.x database 10.x client --> 10.x listener --> 10.x database

Now, what happens when your scenario of a failed listener happens? Say it's the 8.x listener. Now you want to route the 8.x clients through the 10.x listener? Or vice versa? Either way, if your failover scenario works, you've just proved you don't really need two listeners to handle the multi-version installation. Received on Thu Dec 28 2006 - 13:36:11 CST