Horton

RE: Conflict detection for update_deleted in logical replication

Zhijie Hou (Fujitsu) <houzj.fnst@fujitsu.com>

View thread View on postgr.es
From: "Zhijie Hou (Fujitsu)" <houzj.fnst@fujitsu.com>
To: shveta malik <shveta.malik@gmail.com>
Cc: Amit Kapila <amit.kapila16@gmail.com>, "Hayato Kuroda (Fujitsu)" <kuroda.hayato@fujitsu.com>, pgsql-hackers <pgsql-hackers@postgresql.org>, vignesh C <vignesh21@gmail.com>, Nisha Moond <nisha.moond412@gmail.com>, Dilip Kumar <dilipbalaut@gmail.com>, Masahiko Sawada <sawada.mshk@gmail.com>
Date: 2025-07-31T10:18:53Z
Lists: pgsql-hackers 
On Thursday, July 31, 2025 5:26 PM shveta malik <shveta.malik@gmail.com> wrote:
> 
> On Tue, Jul 29, 2025 at 10:51 AM Zhijie Hou (Fujitsu) <houzj.fnst@fujitsu.com>
> wrote:
> >
> >
> > This is the V54 patch set, with only patch 0001 updated to address the
> > latest comments.
> >
> 
> Thanks for the patch.
> 
> While performing tests on the latest patch, I found an assert in tablesync
> worker in FindDeletedTupleInLocalRel (see
> Assert(TransactionIdIsValid(oldestxmin))). Logs at [1].
> 
> It seems table sync worker is trying to apply changes and going to
> update-deleted conflict detection patch but is not able to find
> MyLogicalRepWorker->oldest_nonremovable_xid as this xid is set only
> for apply-worker.

Thanks for reporting. I have fixed it by referring to conflict detection slot's
xmin instead of the leader worker's oldest_nonremovable_xid. This should
be safe because the slot.xmin is always valid.

Best Regards,
Hou zj

Commits

  1. Fix intermittent BF failures in 035_conflicts.

  2. Resume conflict-relevant data retention automatically.

  3. Fix intermittent test failure introduced in 6456c6e2c4.

  4. Fix Coverity issue reported in commit a850be2fe.

  5. Add test to prevent premature removal of conflict-relevant data.

  6. Post-commit review fixes for 228c370868.

  7. Add max_retention_duration option to subscriptions.

  8. Detect and report update_deleted conflicts.

  9. Preserve conflict-relevant data during logical replication.

  10. Integrate FullTransactionIds deeper into two-phase code

  11. Improve checks for GUC recovery_target_timeline

  12. Prevent excessive delays before launching new logrep workers.

  13. Keep WAL segments by slot's last saved restart LSN

  14. Rework some code handling pg_subscription data in psql and pg_dump

  15. Use generateClonedIndexStmt to propagate CREATE INDEX to partitions.