Re: Standalone synchronous master

Bruce Momjian <bruce@momjian.us>

From: Bruce Momjian <bruce@momjian.us>
To: Heikki Linnakangas <hlinnakangas@vmware.com>
Cc: Simon Riggs <simon@2ndQuadrant.com>, Rajeev rastogi <rajeev.rastogi@huawei.com>, "pgsql-hackers@postgresql.org" <pgsql-hackers@postgresql.org>
Date: 2014-01-08T21:08:10Z
Lists: pgsql-hackers
On Wed, Jan  8, 2014 at 10:46:51PM +0200, Heikki Linnakangas wrote:
> On 01/08/2014 10:27 PM, Bruce Momjian wrote:
> >On Wed, Jan  8, 2014 at 05:39:23PM +0000, Simon Riggs wrote:
> >>On 8 January 2014 09:07, Heikki Linnakangas <hlinnakangas@vmware.com> wrote:
> >>
> >>>I'm going to say right off the bat that I think the whole notion to
> >>>automatically disable synchronous replication when the standby goes down is
> >>>completely bonkers.
> >>
> >>Agreed
> >>
> >>We had this discussion across 3 months and we don't want it again.
> >>This should not have been added as a TODO item.
> >
> >I am glad Heikki and Simon agree, but I don't.  ;-)
> >
> >The way that I understand it is that you might want durability, but
> >might not want to sacrifice availability.  Phrased that way, it makes
> >sense, and notifying the administrator seems the appropriate action.
> 
> They want to have the cake and eat it too. But they're not actually
> getting that. What they actually get is extra latency when things
> work, with no gain in durability.

They are getting guaranteed durability until they get a notification ---
that seems valuable.  When they get the notification, they can
reevaluate if they want that tradeoff.

-- 
  Bruce Momjian  <bruce@momjian.us>        http://momjian.us
  EnterpriseDB                             http://enterprisedb.com

  + Everyone has their own god. +