From: Amit Kapila <akapila@postgresql.org>
To: pgsql-committers@lists.postgresql.org
Subject: pgsql: Fix a deadlock during ALTER SUBSCRIPTION ... DROP PUBLICATION.
Date: Fri, 01 Aug 2025 08:11:43 +0000
Message-ID: <E1uhkre-000A46-2B@gemulon.postgresql.org> (raw)
Fix a deadlock during ALTER SUBSCRIPTION ... DROP PUBLICATION.
A deadlock can occur when the DDL command and the apply worker acquire
catalog locks in different orders while dropping replication origins.
The issue is rare in PG16 and higher branches because, in most cases, the
tablesync worker performs the origin drop in those branches, and its
locking sequence does not conflict with DDL operations.
This patch ensures consistent lock acquisition to prevent such deadlocks.
As per buildfarm.
Reported-by: Alexander Lakhin <exclusion@gmail.com>
Author: Ajin Cherian <itsajin@gmail.com>
Reviewed-by: Hayato Kuroda <kuroda.hayato@fujitsu.com>
Reviewed-by: vignesh C <vignesh21@gmail.com>
Reviewed-by: Amit Kapila <amit.kapila16@gmail.com>
Backpatch-through: 14, where it was introduced
Discussion: https://postgr.es/m/bab95e12-6cc5-4ebb-80a8-3e41956aa297@gmail.com
Branch
------
REL_15_STABLE
Details
-------
https://git.postgresql.org/pg/commitdiff/434d2d147b589206c58b4cdae366f353fe63f4eb
Modified Files
--------------
src/backend/catalog/pg_subscription.c | 33 +++++++++++++++++++++++++----
src/backend/replication/logical/tablesync.c | 27 ++++++++++++++++++++---
src/include/catalog/pg_subscription_rel.h | 2 ++
3 files changed, 55 insertions(+), 7 deletions(-)
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To: pgsql-committers@postgresql.org
Cc: akapila@postgresql.org, pgsql-committers@lists.postgresql.org
Subject: Re: pgsql: Fix a deadlock during ALTER SUBSCRIPTION ... DROP PUBLICATION.
In-Reply-To: <E1uhkre-000A46-2B@gemulon.postgresql.org>
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