Re: Quorum commit for multiple synchronous replication.

Noah Misch <noah@leadboat.com>

From: Noah Misch <noah@leadboat.com>
To: Fujii Masao <masao.fujii@gmail.com>
Cc: Michael Paquier <michael.paquier@gmail.com>, Masahiko Sawada <sawada.mshk@gmail.com>, Kyotaro HORIGUCHI <horiguchi.kyotaro@lab.ntt.co.jp>, Amit Kapila <amit.kapila16@gmail.com>, Robert Haas <robertmhaas@gmail.com>, Petr Jelinek <petr@2ndquadrant.com>, Vik Fearing <vik@2ndquadrant.fr>, Simon Riggs <simon@2ndquadrant.com>, Josh Berkus <josh@agliodbs.com>, PostgreSQL-development <pgsql-hackers@postgresql.org>
Date: 2017-04-19T03:34:35Z
Lists: pgsql-hackers
On Sun, Apr 16, 2017 at 07:25:28PM +0900, Fujii Masao wrote:
> On Sun, Apr 16, 2017 at 1:19 PM, Noah Misch <noah@leadboat.com> wrote:
> > On Fri, Apr 14, 2017 at 11:58:23PM -0400, Noah Misch wrote:
> >> On Wed, Apr 05, 2017 at 09:51:02PM -0400, Noah Misch wrote:
> >> > On Thu, Apr 06, 2017 at 12:48:56AM +0900, Fujii Masao wrote:
> >>
> >> > > > On Mon, Dec 19, 2016 at 09:49:58PM +0900, Fujii Masao wrote:
> >> > > >> (3)
> >> > > >> The priority value is assigned to each standby listed in s_s_names
> >> > > >> even in quorum commit though those priority values are not used at all.
> >> > > >> Users can see those priority values in pg_stat_replication.
> >> > > >> Isn't this confusing? If yes, it might be better to always assign 1 as
> >> > > >> the priority, for example.

> >> This PostgreSQL 10 open item is past due for your status update.  Kindly send
> >> a status update within 24 hours, and include a date for your subsequent status
> >> update.  Refer to the policy on open item ownership:
> >> https://www.postgresql.org/message-id/20170404140717.GA2675809%40tornado.leadboat.com

> >> > Since you do want (3) to change, please own it like any other open item,
> >> > including the mandatory status updates.
> >>
> >> Likewise.
> 
> As I told firstly this is not a bug. There are some proposals for better design
> of priority column in pg_stat_replication, but we've not reached the consensus
> yet. So I think that it's better to move this open item to "Design Decisions to
> Recheck Mid-Beta" section so that we can hear more opinions.

I'm reading that some people want to report NULL priority, some people want to
report a constant 1 priority, and nobody wants the current behavior.  Is that
an accurate summary?


Commits

Same data as JSON: GET /api/v1/messages/:b64id/commits the thread's linked commits as JSON, with link sources. API reference →
  1. Set the priorities of all quorum synchronous standbys to 1.

  2. Improve documentation and comment for quorum-based sync replication.