Re: Perform streaming logical transactions by background workers and parallel apply

On Fri, May 5, 2023 at 9:14 AM Zhijie Hou (Fujitsu)
<houzj(dot)fnst(at)fujitsu(dot)com> wrote:
>
> On Wednesday, May 3, 2023 3:17 PM Amit Kapila <amit(dot)kapila16(at)gmail(dot)com> wrote:
> >
>
> Attach another patch to fix the problem that pa_shutdown will access invalid
> MyLogicalRepWorker. I personally want to avoid introducing new static variable,
> so I only reorder the callback registration in this version.
>
> When testing this, I notice a rare case that the leader is possible to receive
> the worker termination message after the leader stops the parallel worker. This
> is unnecessary and have a risk that the leader would try to access the detached
> memory queue. This is more likely to happen and sometimes cause the failure in
> regression tests after the registration reorder patch because the dsm is
> detached earlier after applying the patch.
>

I think it is only possible for the leader apply can worker to try to
receive the error message from an error queue after your 0002 patch.
Because another place already detached from the queue before stopping
the parallel apply workers. So, I combined both the patches and
changed a few comments and a commit message. Let me know what you
think of the attached.

--
With Regards,
Amit Kapila.