Re: Configuring synchronous replication

On Fri, 2010-09-24 at 14:12 +0300, Heikki Linnakangas wrote:
> What I'm saying is that in a two standby situation, if 
> you're willing to continue operation as usual in the master even if
> the standby is down, you're not doing synchronous replication.

Oracle and I disagree with you on that point, but I am more interested
in behaviour than semantics.

If you have two standbys and one is down, please explain how data loss
has occurred.

>  Extending that to a two standby situation, my claim is that if you're
> willing to continue operation as usual in the master when both
> standbys are down, you're not doing synchronous replication. 

Agreed. 

But you still need to decide how you will act. I choose pragmatism in
that case. 

Others have voiced that they would like the database to shutdown or have
all sessions hang. I personally doubt their employers would feel the
same way. Arguing technical correctness would seem unlikely to allow a
DBA to keep his job if they stood and watched the app become
unavailable.

-- Simon Riggs           www.2ndQuadrant.comPostgreSQL Development, 24x7 Support, Training and Services