Re: Replication slot stats misgivings

On Wed, Apr 21, 2021 at 2:46 PM Masahiko Sawada <sawada(dot)mshk(at)gmail(dot)com> wrote:
>
> On Wed, Apr 21, 2021 at 3:09 PM Amit Kapila <amit(dot)kapila16(at)gmail(dot)com> wrote:
> >
> > On Tue, Apr 20, 2021 at 7:54 PM Masahiko Sawada <sawada(dot)mshk(at)gmail(dot)com> wrote:
> > >
> > >
> > > I've attached the patch. In addition to the test Vignesh prepared, I
> > > added one test for the message for creating a slot that checks if the
> > > statistics are initialized after re-creating the same name slot.
> > >
> >
> > I am not sure how much useful your new test is because you are testing
> > it for slot name for which we have removed the slot file. It is not
> > related to stat messages this patch is sending. I think we can leave
> > that for now.
>
> I might be missing something but I think the test is related to the
> message for creating a slot that initializes all counters. No? If
> there is no that message, we will end up getting old stats if a
> message for dropping slot gets lost (simulated by dropping slot file)
> and the same name slot is created.
>

The test is not waiting for a new slot creation message to reach the
stats collector. So, if the old slot data still exists in the file and
now when we read stats via backend, then won't there exists a chance
that old slot stats data still exists?

--
With Regards,
Amit Kapila.