Re: Slony v. DBMirror

On May 5, 2005, at 10:35 AM, Peter Wilson wrote:

> I couldn't get it to work - and having tried another couple of
> solutions I settled on DBMirror which comes with Postgres in the
> 'contrib' directory.
>
>

I've had no issues setting up slony. I've even had it running in a 6
node cluster with no issues.
Did you try asking any folks on the mailling list about your issue?
All I've you say here is it didn't like your pk.

> + nether do automatic switch-over
>
>

Slony has the ability to promote a slave to being a master and then
other slaves will switch over. This functionality is not automatic
because a decision like that should be made by a human. Who decides
if a machine is down? It can become a very tricky problem.

> All slony seems to offer is a different configuration system and
> the ability to automatically propogate configuration changes. It
> seems this could be added to DBmirror pretty easily so why a whole
> new project?
>
>

One of the biggest things for Slony is that you can install slony,
set things up and it will bring the slave(s) "up to speed". You
don't need to do an initial data dump (I think you still need to load
the schema on the slaves, but not the data). That is a BIG win for
us folks who can't take a machine down while pg_dump runs (and while
it is restored on hte slave)

--
Jeff Trout <jeff(at)jefftrout(dot)com>
http://www.jefftrout.com/
http://www.stuarthamm.net/