Horton

Re: Conflict detection for update_deleted in logical replication

shveta malik <shveta.malik@gmail.com>

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From: shveta malik <shveta.malik@gmail.com>
To: "Zhijie Hou (Fujitsu)" <houzj.fnst@fujitsu.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>, shveta malik <shveta.malik@gmail.com>
Date: 2025-07-31T09:25:44Z
Lists: pgsql-hackers 
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.

[1]:
TRAP: failed Assert("TransactionIdIsValid(oldestxmin)"), File:
"worker.c", Line: 3237, PID: 96003
postgres: logical replication tablesync worker for subscription 16394
sync 16469 (ExceptionalCondition+0xbb)[0x619c4117031b]
postgres: logical replication tablesync worker for subscription 16394
sync 16469 (+0x65f4ca)[0x619c40ea94ca]
postgres: logical replication tablesync worker for subscription 16394
sync 16469 (+0x65fa23)[0x619c40ea9a23]
postgres: logical replication tablesync worker for subscription 16394
sync 16469 (+0x65e860)[0x619c40ea8860]
postgres: logical replication tablesync worker for subscription 16394
sync 16469 (apply_dispatch+0xa2)[0x619c40eaa725]
postgres: logical replication tablesync worker for subscription 16394
sync 16469 (+0x660db9)[0x619c40eaadb9]
postgres: logical replication tablesync worker for subscription 16394
sync 16469 (start_apply+0x81)[0x619c40eace64]
postgres: logical replication tablesync worker for subscription 16394
sync 16469 (+0x659f1f)[0x619c40ea3f1f]
postgres: logical replication tablesync worker for subscription 16394
sync 16469 (TablesyncWorkerMain+0x33)[0x619c40ea3f69]


thanks
Shveta

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.