[Fedora-infrastructure-list] Database for Account System 2

[Curt Moore]

> There are two good projects, slony-i_ and pg-cluster, that support
> master-slave replication and multi-master replication respectively.  I
> haven't used either but Curt Moore mentioned he uses slony-i during one
> of the IRC meetings.

Yes, I use Slony-I in my production environment and like most other
complex software packages, it works quite well if it's configured
correctly.  As Toshio mentioned, Slony-I is a single master, multi-slave
architecture so write operations can only be performed to a master DB
and those changes then have to be replicated down to the slave servers.
There are provisions for promoting a slave to be the master server in
case the master crashes but they advise doing everything humanly
possible to ensure that this doesn't happen.

> 
> slony-i_ http://gborg.postgresql.org/project/slony1/projdisplay.php
> pg-cluster_ http://pgfoundry.org/projects/pgcluster/
> 

The last time I experimented with PGCluster, which is
multi-master/multi-slave, probably around Oct/Nov of 2005, I was using
PostgreSQL 8.0.1 and it wasn't that well supported at that time.  Its
architecture was also quite hardware intensive in order to avoid a SPOF,
which wouldn't have been a big deal to me if it had worked.  The project
has since progressed and I believe they have improved support for
Postgres 8.x so it may warrant further investigation in our discussions
for DB replication; I've just not had time to get around to testing the
updated versions in my environment.

-Curt