From: Bo Peng <pengbo@sraoss.co.jp>
To: VASUKI M <vasukim1992002@gmail.com>
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: AQHcOeKzDyufEV7HYUCNC9sQpuQ8I7TGBCuL
Date: Fri, 17 Oct 2025 08:00:15 +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=
Dear PostgreSQL and Pgpool Communities,While working with PostgreSQL failov=
er scenarios, I noticed that the process of re-attaching a standby node aft=
er a failover can be somewhat manual and prone to delays, especially in pro=
duction environments.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 red=
uce downtime and simplify management of failover nodes in high-availability=
 setups.Automatically resynchronize after failoverReduce downtime and ensur=
e quicker recoveryMinimize manual operations and errorsMaintain consistent =
cluster state with less administrative overheadI believe that integrating s=
uch an automated resync and re-attach feature into Pgpool-II could be very =
valuable for PostgreSQL users, potentially as an enhancement in a future re=
lease.I wanted to share this idea with the community to get feedback, sugge=
stions, or any pointers on existing work that may align with this. I am hap=
py to contribute more details=