Re: Quorum commit for multiple synchronous replication.

On Sun, Dec 18, 2016 at 9:36 PM, Michael Paquier
<michael(dot)paquier(at)gmail(dot)com> wrote:
> On Fri, Dec 16, 2016 at 10:42 PM, Fujii Masao <masao(dot)fujii(at)gmail(dot)com> wrote:
>> Attached is the modified version of the patch. Barring objections, I will
>> commit this version.
>
> There is a whitespace:
> $ git diff master --check
> src/backend/replication/syncrep.c:39: trailing whitespace.
> + *

Okey, pushed the patch with this fix. Thanks!

Regarding this feature, there are some loose ends. We should work on
and complete them until the release.

(1)
Which synchronous replication method, priority or quorum, should be
chosen when neither FIRST nor ANY is specified in s_s_names? Right now,
a priority-based sync replication is chosen for keeping backward
compatibility. However some hackers argued to change this decision
so that a quorum commit is chosen because they think that most users
prefer to a quorum.

(2)
There will be still many source comments and documentations that
we need to update, for example, in high-availability.sgml. We need to
check and update them throughly.

(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.

Any other?

Regards,

--
Fujii Masao