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Re: RAC Failover testing

From: Anand Rao <>
Date: Mon, 28 Aug 2006 09:20:30 +0530
Message-ID: <>

Hi Anurag,

Which exact version of 9i is it? i have had nightmares with various versions for a simple TAF test with no load balancing, broken connection, etc.

TAF should and will work when configured properly on 9.2 and above. it worked in 9i R1 also with patches. there is a good note on Metalink for configuring TAF, if you haven't seen it, please do read it.

you have to have remote_listener parameter set correctly. the configuration has to be correct on both client and server.

it shouldn't matter if it is shutdown immediate/abort. from a user's perspective its all the same. but, it works fine with shutdown abort but not shutdown immediate.

you say that you connect to the "first node". well, did you use MYDB as the connect string or did you use the individual instance connect string?


On 27/08/06, Andrey Kriushin <> wrote:
> Hi,
> Couple of comments.
> 1. (ENABLE=BROKEN) is used to request KeepAlive feature for TCP/IP
> socket. It might be useful if Oracle's standard DCD (Dead Connection
> Detection) is not working properly. I've used that option several times
> up to 9i inclusive together with OS KeepAlive settings (decreasing the
> check interval from usual 2 hour default). It actually helped shadow
> process to terminate when the client loses connection (well known
> session killing problem). I've even written an article some 6 years ago.
> Anyway, this has nothing in common with the ORA-01089, as your client
> had successfully recognized lost connection and then occasionally tried
> to reconnect to the same server. Which is legal as long as you provided
> two addresses and allow LOAD_BALANCE. Well, one may expect more
> intellectual behaviour from TAF (not try the address just faulted), but
> that is another question.
> 2. Some warning about failed over sessions, especially when TYPE=SELECT.
> Don't forget, that specific session setting won't be restored after
> successful failover. For example, if you'd change NLS_DATE_FORMAT from
> instance default value via ALTER SESSION before your SELECT with DATE
> datatype and managed to fetch some rows before the failure, than you'll
> be surprised with the rest of results after failover. :-)
> I would not recommend to use "out of the box" TAF if you need really
> "available" application. Take this as a demo of possibilities and go for
> There is similar chapter in JDBC documentation.
> Andrey
> Anurag Verma wrote:
> >
> > Why this is happening, as I am using (ENABLE=BROKEN) and (TYPE=SELECT)
> > options???
> >
> --

All I need to make a comedy is a park, a policeman and a pretty girl -
Charlie Chaplin

Received on Sun Aug 27 2006 - 22:50:30 CDT

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