Re: Switching timeline over streaming replication

On Tue, Sep 25, 2012 at 11:01 AM, md@rpzdesign.com <md@rpzdesign.com> wrote:
> Amit:
>
> At some point, every master - slave replicator gets to the point where they
> need
> to start thinking about master-master replication.

Even in a master-master system, the ability to cleanly swap leaders
managing a member of the master-master cluster is very useful.  This
patch can make writing HA software for Postgres a lot less ridiculous.

> Instead of getting stuck in the weeds to finally realize that master-master
> is the ONLY way
> to go, many developers do not start out planning for master - master, but
> they should, out of habit.
>
> You can save yourself a lot of grief just be starting with master-master
> architecture.

I've seen more projects get stuck spinning their wheels on the one
Master-Master system to rule them all then succeed and move on.  It
doesn't help that master-master does not have a single definition, and
different properties are possible with different logical models, too,
so that pervades its way up to the language layer.

As-is, managing single-master HA Postgres is a huge pain without this
patch.  If there is work to be done on master-master, the logical
replication and event trigger work are probably more relevant, and I
know the authors of those projects are keen to make it more feasible
to experiment.

-- 
fdr