Re: data guard fast start failover

From: Alex Gorbachev <>
Date: Mon, 19 Jan 2009 09:58:29 +1100
Message-Id: <>

Thanks Mark,

What about Data Guard now? You have a connection to the each node in RAC but how you handle connections to standby? On one project I'm working on now, with RAC on primary and RAC on standby, we plan to setup multi-pool controlling underlying pools for each instance on primary *AND* standby. Theoretically, WebLogic multi- pool with load balancing will not send transactions to the "broken" pools but in the past we didn't have good experience with that. Another issue is the failover time - VIP's are not taken over by standby on role switch and, of course, connection timeout takes long time so if it's 60 seconds for you, is your OS setting for tcp_timeout 60 seconds?

Anybody attempted to do automation of VIP management integrating it with Observer and FSFO?


On 19/01/2009, at 9:17 AM, Mark Strickland wrote:

> I'll find out more from our WebLogic SME, but we're using WebLogic
> multi-pools (multi-datasources?), ie each server running WebLogic
> has three connection pools -- one for each of the RAC instances.
> The connections do re-connect automatically after failover. We're
> finding that it takes 60-90 seconds for failover and reconnect. I
> believe that we are using WebLogic XA transactions but I'll verify.
> -Mark
> On Sun, Jan 18, 2009 at 1:49 PM, Alex Gorbachev <>
> wrote:
> Hi Mark,
> Could you elaborate on WebLogic config you are using for RAC?
> - Is it configured using WebLogic multi-datasources?
> - Do you use WebLogic XA transactions? Does WebLogic datasource re-
> tries transaction on reconnect?
> - What are the patched you mentioned (perhaps, you have the
> reference to the WebLogic support docs)?
> Cheers,
> Alex
> On 17/01/2009, at 8:52 AM, Mark Strickland wrote:
>> We've been testing FSF with and my co-DBA discovered a bug
>> that can cause a split-brain to occur. I don't remember the exact
>> circumstances, but the fix is in which is driving us to
>> apply that patchset. Our FSF testing with has been going
>> very well. If you use WebLogic, it will handle a failover but it
>> requires a patch depending on what version you use. I've been
>> doing new builds with RAC and Data Guard with FSF for a
>> new customer. No issues so far.
>> Mark
>> Seattle, WA
>> On Thu, Jan 15, 2009 at 11:27 PM, <> wrote:
>> Hi all
>> Anyone's using data guard fast-start failover ?
>> What are the experiences ?
>> What about split brain?
>> Does it interfere heavily with normal database activities?
>> Any other comments?
>> Thank you in advance,
>> Laimis N
>> --


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Received on Sun Jan 18 2009 - 16:58:29 CST

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