Re: walsender & parallelism

On 01/06/17 06:06, Andres Freund wrote:
> On 2017-05-31 23:51:08 -0400, Peter Eisentraut wrote:
>> I think the easiest and safest thing to do now is to just prevent
>> parallel plans in the walsender. See attached patch. This prevents the
>> hang in the select_parallel tests run under your new test setup.
>
> I'm not quite sure I can buy this. The lack of wired up signals has
> more problems than just hurting parallelism. In fact, the USR1 thing
> seems like something that we actually should backpatch, rather than
> defer to v11. I think there's some fair arguments to be made that we
> shouldn't do the refactoring right now - although I'm not sure about it
> - but just not fixing the bugs seems like a bad plan.
>

I think the signal handling needs to be fixed. It does not have to be
done via large refactoring, but signals should be handled properly (= we
need to share SIGHUP/SIGUSR1 handling between postgres.c and walsender.c).

The rest can wait for PG11.

--
Petr Jelinek http://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Training & Services