Re: Clustering, mirroriing, or replication?

Jon Brisbin wrote:
> We're trying to figure out how we can implement a reasonably simple cluster
> of postgres servers on a private network at our store locations. The idea
> is to have a group of 2-6 PCs each be able to share data in a replicated
> manner. Having a separate database server is not an option due to the
> immense cost and logistics (we have over 800 stores), so we need to find a
> way to mirror or replicate data between all the nodes currently up and on
> the network. Some nodes might be not always be up, so we need a failover
> system. I'm testing to see if the dbmirror that comes with Postgres will
> work, but I haven't got it completely figured out yet.

I'm talking well out of my experience here, having never tried to set up
800 sets of desktop PCs as replicated shared DB servers, but I can't
believe it's more expensive to put servers in. In my experience, even a
cheap white-box dedicated server is more reliable than a PC being used
for desktop apps.

Assume each user kicks the power cable out of their PC once a year, that
means you'll be dealing with several failovers a day on average.

Assuming you can't get a server for each store (that'd be a minimum of
£400 * 800 = £320,000 in the UK), is there any networking between them?

--
Richard Huxton
Archonet Ltd