Re: Quorum commit for multiple synchronous replication.

Masahiko Sawada <sawada.mshk@gmail.com>

From: Masahiko Sawada <sawada.mshk@gmail.com>
To: Josh Berkus <josh@berkus.org>
Cc: Robert Haas <robertmhaas@gmail.com>, Michael Paquier <michael.paquier@gmail.com>, Noah Misch <noah@leadboat.com>, Petr Jelinek <petr.jelinek@2ndquadrant.com>, Fujii Masao <masao.fujii@gmail.com>, Kyotaro HORIGUCHI <horiguchi.kyotaro@lab.ntt.co.jp>, Amit Kapila <amit.kapila16@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: 2017-08-29T07:25:55Z
Lists: pgsql-hackers
On Thu, Aug 24, 2017 at 4:27 PM, Masahiko Sawada <sawada.mshk@gmail.com> wrote:
> On Thu, Aug 24, 2017 at 3:11 AM, Josh Berkus <josh@berkus.org> wrote:
>> On 08/22/2017 11:04 PM, Masahiko Sawada wrote:
>>> WARNING:  what you did is ok, but you might have wanted to do something else
>>>
>>> First of all, whether or not that can properly be called a warning is
>>> highly debatable.  Also, if you do that sort of thing to your spouse
>>> and/or children, they call it "nagging".  I don't think users will
>>> like it any more than family members do.
>>
>> Realistically, we'll support the backwards-compatible syntax for 3-5
>> years.  Which is fine.
>>
>> I suggest that we just gradually deprecate the old syntax from the docs,
>> and then around Postgres 16 eliminate it.  I posit that that's better
>> than changing the meaning of the old syntax out from under people.
>>
>
> It seems to me that there is no folk who intently votes for making the
> quorum commit the default. There some folks suggest to keep backward
> compatibility in PG10 and gradually deprecate the old syntax. And only
> the issuing from docs can be possible in PG10.
>

According to the discussion so far, it seems to me that keeping
backward compatibility and issuing a warning in docs that old syntax
could be changed or removed in a future release is the most acceptable
way in PG10. There is no objection against that so far and I already
posted a patch to add a warning in docs[1]. I'll wait for the
committer's decision.

[1] https://www.postgresql.org/message-id/CAD21AoAe%2BoGSFi3bjZ%2BfW6Q%3DTK7avPdDCZLEr02zM_c-U0JsRA%40mail.gmail.com

Regards,

--
Masahiko Sawada
NIPPON TELEGRAPH AND TELEPHONE CORPORATION
NTT Open Source Software Center


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.