From: | Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> |
---|---|
To: | Kyotaro Horiguchi <horikyota(dot)ntt(at)gmail(dot)com> |
Cc: | masahiko(dot)sawada(at)2ndquadrant(dot)com, masao(dot)fujii(at)oss(dot)nttdata(dot)com, pgsql-hackers(at)lists(dot)postgresql(dot)org |
Subject: | Re: Race condition in SyncRepGetSyncStandbysPriority |
Date: | 2020-04-14 20:32:40 |
Message-ID: | 13059.1586896360@sss.pgh.pa.us |
Views: | Raw Message | Whole Thread | Download mbox | Resend email |
Thread: | |
Lists: | pgsql-hackers |
I wrote:
> It doesn't seem to me to be that hard to implement the desired
> semantics for synchronous_standby_names with inconsistent info.
> In FIRST mode you basically just need to take the N smallest
> priorities you see in the array, but without assuming there are no
> duplicates or holes. It might be a good idea to include ties at the
> end, that is if you see 1,2,2,4 or 1,3,3,4 and you want 2 sync
> standbys, include the first three of them in the calculation until
> the inconsistency is resolved. In ANY mode I don't see that
> inconsistent priorities matter at all.
Concretely, I think we ought to do the attached, or something pretty
close to it.
I'm not really happy about breaking ties based on walsnd_index,
but I see that there are several TAP test cases that fail if we
do something else. I'm inclined to think those tests are bogus ...
but I won't argue to change them right now.
regards, tom lane
Attachment | Content-Type | Size |
---|---|---|
syncrep-fixes-1.patch | text/x-diff | 23.0 KB |
From | Date | Subject | |
---|---|---|---|
Next Message | Andrew Dunstan | 2020-04-14 20:33:31 | Re: documenting the backup manifest file format |
Previous Message | Alvaro Herrera | 2020-04-14 20:11:00 | Re: documenting the backup manifest file format |