From: Amit Kapila <akapila@postgresql.org>
To: pgsql-committers@lists.postgresql.org
Subject: pgsql: Fix duplicate transaction replay during pg_createsubscriber.
Date: Thu, 24 Jul 2025 09:20:48 +0000
Message-ID: <E1ues88-000UeW-05@gemulon.postgresql.org> (raw)
Fix duplicate transaction replay during pg_createsubscriber.
Previously, the tool could replay the same transaction twice, once during
recovery, then again during replication after the subscriber was set up.
This occurred because the same recovery_target_lsn was used both to
finalize recovery and to start replication. If
recovery_target_inclusive = true, the transaction at that LSN would be
applied during recovery and then sent again by the publisher leading to
duplication.
To prevent this, we now set recovery_target_inclusive = false. This
ensures the transaction at recovery_target_lsn is not reapplied during
recovery, avoiding duplication when replication begins.
Bug #18897
Reported-by: Zane Duffield <duffieldzane@gmail.com>
Author: Shlok Kyal <shlok.kyal.oss@gmail.com>
Reviewed-by: vignesh C <vignesh21@gmail.com>
Reviewed-by: Amit Kapila <amit.kapila16@gmail.com>
Backpatch-through: 17, where it was introduced
Discussion: https://postgr.es/m/18897-d3db67535860dddb@postgresql.org
Branch
------
REL_18_STABLE
Details
-------
https://git.postgresql.org/pg/commitdiff/33f74b806ce3facfc0deb1412ed85d19a44c0553
Modified Files
--------------
src/bin/pg_basebackup/pg_createsubscriber.c | 11 ++++++++++-
1 file changed, 10 insertions(+), 1 deletion(-)
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Reply to all the recipients using the --to and --cc options:
reply via email
To: pgsql-committers@postgresql.org
Cc: akapila@postgresql.org, pgsql-committers@lists.postgresql.org
Subject: Re: pgsql: Fix duplicate transaction replay during pg_createsubscriber.
In-Reply-To: <E1ues88-000UeW-05@gemulon.postgresql.org>
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
This inbox is served by DDX for PostgreSQL; see mirroring instructions
for how to clone and mirror all data and code used for this inbox