Re: [HACKERS] Quorum commit for multiple synchronous replication. - Mailing list pgsql-hackers

From Michael Paquier
Subject Re: [HACKERS] Quorum commit for multiple synchronous replication.
Date
Msg-id 20161216053821.GA17838@paquier.xyz
Whole thread Raw
In response to Re: [HACKERS] Quorum commit for multiple synchronous replication.  (Masahiko Sawada <sawada.mshk@gmail.com>)
List pgsql-hackers
On Thu, Dec 15, 2016 at 6:08 PM, Masahiko Sawada <sawada.mshk@gmail.com> wrote:
> Attached latest v12 patch.
> I changed behavior of "N (standby_list)" to use the priority method
> and incorporated some review comments so far. Please review it.

Some comments...

+    Another example of <varname>synchronous_standby_names</> for multiple
+    synchronous standby is:
Here standby takes an 's'.

+    candidates. The master server will wait for at least 2 replies from them.
+    <literal>s4</> is an asynchronous standby since its name is not in the list.
+   </para>
"will wait for replies from at least two of them".

+ * next-highest-priority standby. In quorum method, the all standbys
+ * appearing in the list are considered as a candidate for quorum commit.
"the all" is incorrect. I think you mean "all the" instead.

+ * NIL if no sync standby is connected. In quorum method, all standby
+ * priorities are same, that is 1. So this function returns the list of
This is not true. Standys have a priority number assigned. Though it does
not matter much for quorum groups, it gives an indication of their position
in the defined list.
#synchronous_standby_names = ''    # standby servers that provide sync rep-               # number of sync standbys and
comma-separatedlist of application_name+               # synchronization method, number of sync standbys+
#and comma-separated list of application_name                # from standby(s); '*' = all
 
The formulation is funny here: "sync rep synchronization method".

I think that Fujii-san has also some doc changes in his box. For anybody
picking up this patch next, it would be good to incorporate the things
I have noticed here.
-- 
Michael



pgsql-hackers by date:

Previous
From: Etsuro Fujita
Date:
Subject: Re: [HACKERS] postgres_fdw bug in 9.6
Next
From: Michael Paquier
Date:
Subject: Re: [HACKERS] Crash on promotion when recovery.conf is renamed