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help / color / mirror / Atom feedFrom: Alexander Korotkov <akorotkov@postgresql.org>
To: pgsql-committers@lists.postgresql.org
Subject: pgsql: Use WAIT FOR LSN in PostgreSQL::Test::Cluster::wait_for_catchup(
Date: Mon, 05 Jan 2026 17:56:31 +0000
Message-ID: <E1vcoog-004gON-2L@gemulon.postgresql.org> (raw)
Use WAIT FOR LSN in PostgreSQL::Test::Cluster::wait_for_catchup()
When the standby is passed as a PostgreSQL::Test::Cluster instance,
use the WAIT FOR LSN command on the standby server to implement
wait_for_catchup() for replay, write, and flush modes. This is more
efficient than polling pg_stat_replication on the upstream, as the
WAIT FOR LSN command uses a latch-based wakeup mechanism.
The optimization applies when:
- The standby is passed as a Cluster object (not just a name string)
- The mode is 'replay', 'write', or 'flush' (not 'sent')
- The standby is in recovery
For 'sent' mode, when the standby is passed as a string (e.g., a
subscription name for logical replication), or when the standby has
been promoted, the function falls back to the original polling-based
approach using pg_stat_replication on the upstream.
Discussion: https://postgr.es/m/CABPTF7UiArgW-sXj9CNwRzUhYOQrevLzkYcgBydmX5oDes1sjg%40mail.gmail.com
Author: Xuneng Zhou <xunengzhou@gmail.com>
Reviewed-by: Alexander Korotkov <aekorotkov@gmail.com>
Reviewed-by: Chao Li <li.evan.chao@gmail.com>
Reviewed-by: Alvaro Herrera <alvherre@kurilemu.de>
Branch
------
master
Details
-------
https://git.postgresql.org/pg/commitdiff/f30848cb05d4d63e1a5a2d6a9d72604f3b63370d
Modified Files
--------------
src/test/perl/PostgreSQL/Test/Cluster.pm | 59 +++++++++++++++++++++++++++++++-
1 file changed, 58 insertions(+), 1 deletion(-)
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To: pgsql-committers@postgresql.org
Cc: akorotkov@postgresql.org, pgsql-committers@lists.postgresql.org
Subject: Re: pgsql: Use WAIT FOR LSN in PostgreSQL::Test::Cluster::wait_for_catchup(
In-Reply-To: <E1vcoog-004gON-2L@gemulon.postgresql.org>
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