Re: Automating Failover Resync & Re-Attach in pgpool2

Hi,

Thank you for your question.

> While working with PostgreSQL failover scenarios, I noticed that the process of re-attaching a standby node 
> after a failover can be somewhat manual and prone to delays, especially in production environments.

After a failover, the standby nodes can be automatically attached to the new primary by setting "follow_primary_command".

    https://www.pgpool.net/docs/latest/en/html/runtime-config-failover.html#RUNTIME-CONFIG-FAILOVER-SETTINGS

You can also automatically reattach a failed standby node by setting "auto_failback = on".

    https://www.pgpool.net/docs/latest/ja/html/runtime-config-failover.html#GUC-AUTO-FAILBACK

---
Bo Peng <pengbo@sraoss.co.jp>
SRA OSS K.K.
TEL: 03-5979-2701 FAX: 03-5979-2702
Mobile: 080-7752-0749
URL: https://www.sraoss.co.jp/


________________________________________
差出人: VASUKI M <vasukim1992002@gmail.com>
送信: 2025 年 10 月 10 日 (金曜日) 21:17
宛先: 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>
件名: Automating Failover Resync & Re-Attach in pgpool2




Dear PostgreSQL and Pgpool Communities,
While working with PostgreSQL failover scenarios, I noticed that the process of re-attaching a standby node after a failover can be somewhat manual and prone to delays, especially in production 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 reduce downtime and simplify management of failover nodes in high-availability setups.
Automatically resynchronize after failover
Reduce downtime and ensure quicker recovery
Minimize manual operations and errors
Maintain consistent cluster state with less administrative overhead
I believe that integrating such an automated resync and re-attach feature into Pgpool-II could be very valuable for PostgreSQL users, potentially as an enhancement in a future release.
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