Re: relfrozenxid may disagree with row XIDs after 1ccc1e05ae

Melanie Plageman <melanieplageman@gmail.com>

From: Melanie Plageman <melanieplageman@gmail.com>

To: Bowen Shi <zxwsbg12138@gmail.com>

Cc: Robert Haas <robertmhaas@gmail.com>, Matthias van de Meent <boekewurm+postgres@gmail.com>, Noah Misch <noah@leadboat.com>, Peter Geoghegan <pg@bowt.ie>, Alexander Lakhin <exclusion@gmail.com>, PostgreSQL mailing lists <pgsql-bugs@lists.postgresql.org>, Andres Freund <andres@anarazel.de>

Date: 2024-05-15T13:26:57Z

Lists: pgsql-bugs

Commits

Same data as JSON: GET /api/v1/messages/:b64id/commits the thread's linked commits as JSON, with link sources. API reference →

Ensure vacuum removes all visibly dead tuples older than OldestXmin
- 06bf404cd07b 16.4 landed
- 45ce054c02b8 14.13 landed
- dc6354c67017 15.8 landed
Combine freezing and pruning steps in VACUUM
- 6dbb490261a6 17.0 cited
Handle non-chain tuples outside of heap_prune_chain()
- 6f47f6883151 17.0 cited
Fix false reports in pg_visibility
- e85662df44ff 17.0 cited
Remove retry loop in heap_page_prune().
- 1ccc1e05ae8f 17.0 cited
vacuumlazy.c: document vistest and OldestXmin.
- 73f6ec3d3c8d 15.0 cited
Deduplicate choice of horizon for a relation procarray.c.
- d9d8aa9bb9aa 15.0 cited
Remove tupgone special case from vacuumlazy.c.
- 8523492d4e34 14.0 cited
Simplify state managed by VACUUM.
- b4af70cb2103 14.0 cited
Recycle nbtree pages deleted during same VACUUM.
- 9dd963ae2534 14.0 cited
snapshot scalability: Don't compute global horizons while building snapshots.
- dc7420c2c927 14.0 cited
Raise error when affecting tuple moved into different partition.
- f16241bef7cc 11.0 cited

On Tue, May 14, 2024 at 10:43 PM Bowen Shi <zxwsbg12138@gmail.com> wrote:
>
>
>> On Wed, May 15, 2024 at 7:33 AM Melanie Plageman <melanieplageman@gmail.com> wrote:
>>
>>
>> Are you reproducing the hang locally with my repro? Or do you have
>> your own repro? How are you testing pg_terminate_backend() and seeing
>> that the InterruptHoldoffCount is 1?
>
>
> I noticed this problem occurring several times on PG16, but I didn't use your repro, and haven't found a way to reproduce the problem. Instead, I simply force the vacuum to enter a retry loop with the following code and found InterruptHoldoffCount is 1.

You saw this problem on PG16? Did you see vacuum hanging or you saw
some kind of incorrect relfrozenxid advancement? My repro does not
work for PG16, and I do not see how we could face this problem on
PG16. It would be very helpful if you have any more details.

- Melanie