[Pgpool-general] pgpool-II features doubts

[Jaume Sabater]

On Fri, Apr 24, 2009 at 4:35 PM, Pedro Silva <pedrovieirasilva at gmail.com> wrote:

> 1.I would like to understand if my current configuration is a really
> master-master configuration?

Sort of. It has a single point of entry, therefore it's not a
master-master (it's just master), but commits are done on both nodes
then returned to the client, therefore it's a synchronous cluster.

> 2. Load Balancing as it is activated will distribute my SELECT queries between
> my two backends.

Yes.

> 3. If I now setup online recovery it doesn't matter if backend1 one or backend2
> fails because recovery works from the one that is running, right?

Yes.

> 4. It is my understanding that recovery phase 1 will only finish when clients
> terminate their connections. Won't this be a problem due to the fact that web
> applications have normally a pool of connections that is kept between the
> database and the application? This way the connections will never end and phase
> 1 won't finish, right?

It means connections between clients and pgpool-II. pgpool-II will
keep those, but cut the ones between pgpool-II and PostgreSQL. Also,
pgpool-II will cut the latter and keep the first in a pool that will
be attended once the online recovery is done. Also,
connections/transactions will be drop after a timeout in case they
have not finished/closed by themselves.

-- 
Jaume Sabater
http://linuxsilo.net/

"Ubi sapientas ibi libertas"