On Tue, 2010-10-05 at 09:56 -0500, Kevin Grittner wrote:
> Simon Riggs <simon@2ndQuadrant.com> wrote:
>
> > Is it a common use case that people have more than 3 separate
> > servers for one application, which is where the difference shows
> > itself.
>
> I don't know how common it is, but we replicate circuit court data
> to two machines each at two sites. That way a disaster which took
> out one building would leave us with the ability to run from the
> other building and still take a machine out of the production mix
> for scheduled maintenance or to survive a single-server failure at
> the other site. Of course, there's no way we would make that
> replication synchronous, and we're replicating from dozens of source
> machines -- so I don't know if you can even count our configuration.
>
> Still, the fact that we're replicating to two machines each at two
> sites and that is the same example which came to mind for Robert,
> suggests that perhaps it isn't *that* bizarre.
Hoping that you mean "bizarre" as "less common". I don't find Robert's
example in any way strange and respect his viewpoint.
I am looking for ways to simplify the specification so that we aren't
burdened with a level of complexity we can avoid in the majority if
cases. If we only need complex configuration to support a small minority
of cases, then I'd say we don't need that (yet). Adding that support
later will make it clearer what the additional cost/benefit is.
-- Simon Riggs www.2ndQuadrant.comPostgreSQL Development, 24x7 Support, Training and Services