On Tue, Nov 8, 2011 at 3:21 PM, Leonardo M. Ramé <l.rame at griensu.com> wrote:
> Hi, we have one application connected to a local PostgreSql server and
> we are facing the need to allow a remote site's users to use the
> application. As a point-to-point connection is really expensive, we're
> looking for other solutions, like replication.
>
> On each site ~25 clients are connected to the server doing reads and
> writes, and we would like to synchronize both servers, so, for example
> if a new record is added on Site1, in about 15minutes, that record must
> appear on Site2, and viceversa.
>
> Is this possible with Slony-I?.

Unfortunately, the "vice versa" part is not possible.

Slony-I is a *single* master to multiple subscribers replication
system; it does not try to address the multimaster problem.

What reasonably works is for site #1 to be the "master," and for that
data to appear reasonably quickly at site #2.

There are ways of approximating multimaster replication with Slony-I,
but it quickly gets pretty involved, and you need to effectively
design that into your application.