Skip site navigation (1) Skip section navigation (2)

Re: Sync Rep Design

From: Robert Treat <rob(at)xzilla(dot)net>
To: Simon Riggs <simon(at)2ndquadrant(dot)com>
Cc: pgsql-hackers(at)postgresql(dot)org
Subject: Re: Sync Rep Design
Date: 2010-12-30 20:51:19
Message-ID: (view raw, whole thread or download thread mbox)
Lists: pgsql-hackers
On Thu, Dec 30, 2010 at 3:36 PM, Simon Riggs <simon(at)2ndquadrant(dot)com> wrote:
> On Thu, 2010-12-30 at 15:07 -0500, Robert Treat wrote:
> > > If more than one standby server specifies synchronous_replication,
> > then
> > > whichever standby replies first will release waiting commits.
> > I don't want you to think I am setting an expectation, but I'm curious
> > about the possibility of requiring more than 1 server to reply?
> I was initially interested in this myself, but after a long discussion
> on "quorum commit" it was decided to go with "first past post".
> That is easier to manage, requires one less parameter, performs better
> and doesn't really add that much additional confidence.

Yes, I think with a single master, you are probably right (been
dealing with more than my fair share of multi-master based nosql
solutions lately)

Still, one thing that has me concerned is that in the case of two
slaves, you don't know which one is the more up-to-date one if you
need to failover. It'd be nice if you could just guarantee they both
are, but in lieu of that, I guess whatever decision tree is being
used, it needs to look at current xlog location of any potential
failover targets.

> It was also discussed that we would have a plugin API, but I'm less sure
> about that now. Perhaps we can add that option in the future, but its
> not high on my list of things for this release.


Robert Treat

In response to


pgsql-hackers by date

Next:From: Jeff DavisDate: 2010-12-30 20:55:22
Subject: Re: Old git repo
Previous:From: Stefan KaltenbrunnerDate: 2010-12-30 20:42:23
Subject: Re: Sync Rep Design

Privacy Policy | About PostgreSQL
Copyright © 1996-2017 The PostgreSQL Global Development Group