Re: Vacuum ERRORs out considering freezing dead tuples from before OldestXmin

On Mon, Jul 22, 2024 at 2:17 PM Melanie Plageman
<melanieplageman(at)gmail(dot)com> wrote:
>
> So, I've just gone through all the test failures on master and 17 for
> mamba, gull, mereswine, and copperhead. I wanted to confirm that the
> test was always failing for the same reason and also if it had any
> failures pre-TIDStore.
>
> We've only run tests with this commit on some of the back branches for
> some of these animals. Of those, I don't see any failures so far. So,
> it seems the test instability is just related to trying to get
> multiple passes of index vacuuming reliably with TIDStore.
>
> AFAICT, all the 32bit machine failures are timeouts waiting for the
> standby to catch up (mamba, gull, merswine). Unfortunately, the
> failures on copperhead (a 64 bit machine) are because we don't
> actually succeed in triggering a second vacuum pass. This would not be
> fixed by a longer timeout.
>
> Because of this, I'm inclined to revert the test on 17 and master to
> avoid distracting folks committing other work and seeing those animals
> go red.

Okay, I reverted this for now on 17 and master. Adding Sawada-san to
the thread to see if he has any ideas for a smaller two-round index
vacuum example.

- Melanie