Re: BUG #13657: Some kind of undetected deadlock between query and "startup process" on replica.

On Sat, Oct 24, 2015 at 4:16 PM, Maxim Boguk wrote:
> On Wed, Oct 21, 2015 at 4:42 AM, Michael Paquier wrote:
>> Maxim, did you get the occasion to test your setup with 9.4.5? It
>> seems that your environment is more likely to reproduce this deadlock.
>
>
> Sorry for late response, after upgrade to 9.4.5 this issue never happened
> anymore (zero occurrences during the last week).

Good to know. If you see any problems, feel free to report them on
this thread of course.

> Before all cases of deadlock happened during wal replay of 2 specific tables
> (and only them) of the database of few thousands. These tables are somewhat
> special in sense they have medium insert/delete load but most time they have
> zero alive tuples and size changes from 0 block to 1-2 block and back quite
> a lot.
> I suppose deadlock had been happened when replay process replaying
> truncation to zero pages after vacuum on the master db (but it's mostly
> theory with no good evidence).

By what was AccessExclusiveLock created on master? Did you run
TRUNCATE on those two relations from time to time?
--
Michael