From: Bo Peng <pengbo@sraoss.co.jp>
To: VASUKI M <vasukim1992002@gmail.com>, "pgsql-bugs@lists.postgresql.org"
	<pgsql-bugs@lists.postgresql.org>
CC: "bharatdb@cdac.in" <bharatdb@cdac.in>,
	"pgpool-general@lists.postgresql.org" <pgpool-general@lists.postgresql.org>
Subject: Re: Automating Failover Resync & Re-Attach in pgpool2
Thread-Topic: Automating Failover Resync & Re-Attach in pgpool2
Thread-Index: AQHcOeKzDyufEV7HYUCNC9sQpuQ8I7TGASvP
Date: Fri, 17 Oct 2025 07:55:26 +0000
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Precedence: bulk

Hi,=0A=
=0A=
Thank you for your question.=0A=
=0A=
> While working with PostgreSQL failover scenarios, I noticed that the proc=
ess of re-attaching a standby node =0A=
> after a failover can be somewhat manual and prone to delays, especially i=
n production environments.=0A=
=0A=
After a failover, the standby nodes can be automatically attached to the ne=
w primary by setting "follow_primary_command".=0A=
=0A=
    https://www.pgpool.net/docs/latest/en/html/runtime-config-failover.html=
#RUNTIME-CONFIG-FAILOVER-SETTINGS=0A=
=0A=
You can also automatically reattach a failed standby node by setting "auto_=
failback =3D on".=0A=
=0A=
    https://www.pgpool.net/docs/latest/ja/html/runtime-config-failover.html=
#GUC-AUTO-FAILBACK=0A=
=0A=
---=0A=
Bo Peng <pengbo@sraoss.co.jp>=0A=
SRA OSS K.K.=0A=
TEL: 03-5979-2701 FAX: 03-5979-2702=0A=
Mobile: 080-7752-0749=0A=
URL: https://www.sraoss.co.jp/=0A=
=0A=
=0A=
________________________________________=0A=
=1B$B:9=3DP?M=1B(B: VASUKI M <vasukim1992002@gmail.com>=0A=
=1B$BAw?.=1B(B: 2025 =1B$BG/=1B(B 10 =1B$B7n=1B(B 10 =1B$BF|=1B(B (=1B$B6bM=
KF|=1B(B) 21:17=0A=
=1B$B08@h=1B(B: pgsql-bugs@lists.postgresql.org <pgsql-bugs@lists.postgresq=
l.org>=0A=
Cc: bharatdb@cdac.in <bharatdb@cdac.in>; pgpool-general@lists.postgresql.or=
g <pgpool-general@lists.postgresql.org>=0A=
=1B$B7oL>=1B(B: Automating Failover Resync & Re-Attach in pgpool2=0A=
=0A=
=0A=
=0A=
=0A=
Dear PostgreSQL and Pgpool Communities,=0A=
While working with PostgreSQL failover scenarios, I noticed that the proces=
s of re-attaching a standby node after a failover can be somewhat manual an=
d prone to delays, especially in production environments.=0A=
I explored automating this process using a combination of pg_rewind and WAL=
 replay, which allows a standby node to resynchronize and re-attach to the =
primary automatically after a failover. This could reduce downtime and simp=
lify management of failover nodes in high-availability setups.=0A=
Automatically resynchronize after failover=0A=
Reduce downtime and ensure quicker recovery=0A=
Minimize manual operations and errors=0A=
Maintain consistent cluster state with less administrative overhead=0A=
I believe that integrating such an automated resync and re-attach feature i=
nto Pgpool-II could be very valuable for PostgreSQL users, potentially as a=
n enhancement in a future release.=0A=
I wanted to share this idea with the community to get feedback, suggestions=
, or any pointers on existing work that may align with this. I am happy to =
contribute more details=0A=