Horton

Re: BUG #17255: Server crashes in index_delete_sort_cmp() due to race condition with vacuum

Peter Geoghegan <pg@bowt.ie>

View thread View on postgr.es
From: Peter Geoghegan <pg@bowt.ie>
To: Andres Freund <andres@anarazel.de>
Cc: Dmitry Dolgov <9erthalion6@gmail.com>, Alexander Lakhin <exclusion@gmail.com>, Matthias van de Meent <boekewurm+postgres@gmail.com>, PostgreSQL mailing lists <pgsql-bugs@lists.postgresql.org>, Mark Dilger <mark.dilger@enterprisedb.com>
Date: 2021-11-19T02:55:08Z
Lists: pgsql-bugs 
On Thu, Nov 18, 2021 at 4:36 PM Andres Freund <andres@anarazel.de> wrote:
> Attached is such an isolationtest. In an unmodified HEAD it ends up with

> without amcheck detecting corruption at that point:(.

The best way to teach amcheck to detect this kind of thing is bound to
be verification of HOT chains themselves:

https://www.postgresql.org/message-id/flat/CAH2-Wznphpd490o%2Bur_bi6-YmC47hRu3Qyxod72RLqC-Uvuhcg%40mail.gmail.com

It would also be nice to teach verify_nbtree.c to look out for the
presence of index tuples that shouldn't be there during heapallindexed
verification, but that's significantly harder.

--
Peter Geoghegan

Commits

  1. vacuumlazy.c: Standardize rel_pages terminology.

  2. vacuumlazy.c: document vistest and OldestXmin.

  3. heap pruning: Only call BufferGetBlockNumber() once.

  4. Fix possible HOT corruption when RECENTLY_DEAD changes to DEAD while pruning.

  5. Assert redirect pointers are sensible after heap_page_prune().

  6. Remove tupgone special case from vacuumlazy.c.

  7. Recycle nbtree pages deleted during same VACUUM.

  8. snapshot scalability: Don't compute global horizons while building snapshots.

  9. Refactor heap_page_prune so that instead of changing item states on-the-fly,