Re: Best Practice
Date: Thu, 19 Jan 2012 11:10:34 +0000
Message-ID: <CAGdek=zi9H+8644iWVXKgFnKO-F4ZQQeqzv9hBpJmw7=CowBsQ_at_mail.gmail.com>
On Thu, Jan 19, 2012 at 10:08 AM, <Laimutis.Nedzinskas_at_seb.lt> wrote:
> We had an interesting case: a network failure between our DC's (data
> centers - one is used as primary and the other as standby as far as
> databases are concerned)
>
>
> In our case observer runs on standby DC. It decided to failover of course.
> The decision happened to be the correct one at least from admins point of
> view: the failover DC was still accessible to us, we could connect and
> restart what failed to failover, etc. End users could connect too.
It makes sens - if you use FSFO and primary database will loose connection to standby database and to observer it will shutdown automatically preventing environment from split brain when primary DC will be available again.
>
> You see: you need to consider what end customer functionality needs HA most
> and start from that. What's the purpose to have a failover if the DC is not
> accesible to the end users?
>
> If only isolated db/db server failure is concerned then you can run your
> observer on just a standby server. It will do the job: primary goes down,
> observer is running on standby, standby fails ower.
>
Is is possible to run observer in same place where are your end users ? It that case observer will see exactly same situation like your users.
regards,
-- Marcin Przepiorowski http://oracleprof.blogspot.com -- http://www.freelists.org/webpage/oracle-lReceived on Thu Jan 19 2012 - 05:10:34 CST