Re: Single transaction in the tablesync worker?

On Mon, Jan 25, 2021 at 8:03 AM Peter Smith <smithpb2250(at)gmail(dot)com> wrote:
>
> Hi Amit.
>
> PSA the v19 patch for the Tablesync Solution1.
>

I see one race condition in this patch where we try to drop the origin
via apply process and DropSubscription. I think it can lead to the
error "cache lookup failed for replication origin with oid %u". The
same problem can happen via exposed API pg_replication_origin_drop but
probably because this is not used concurrently so nobody faced this
issue. I think for the matter of this patch we can try to suppress
such an error either via try..catch, or by adding missing_ok argument
to replorigin_drop API, or we can just add to comments that such a
race exists. Additionally, we should try to start a new thread for the
existence of this problem in pg_replication_origin_drop. What do you
think?

--
With Regards,
Amit Kapila.