Re: Proposal: PCP command for watchdog leader switchover (TODO: "Pgpool-II leader node switchover")

Hi Tatsuo,
That helps and it will solve the problem partially.
Still, there are places where we need to failover to a specific node, like during the physical server restart with kernel patching or updating the pgpool configs etc.

Regards,

Dibyandu Roy

________________________________
From: Tatsuo Ishii <ishii(at)postgresql(dot)org>
Sent: Wednesday, September 9, 2026 9:38 AM
To: Roy, Dibyandu <dibyandu(dot)roy(at)intel(dot)com>
Cc: pgpool-hackers(at)lists(dot)postgresql(dot)org <pgpool-hackers(at)lists(dot)postgresql(dot)org>
Subject: Re: Proposal: PCP command for watchdog leader switchover (TODO: "Pgpool-II leader node switchover")

> A concrete example from our environment. We run three Pgpool-II nodes
> with watchdog, and three PostgreSQL nodes managed by Patroni. Normally
> node1 is both the watchdog leader and the PostgreSQL primary, which is
> our preferred configuration because it is the lowest latency path for
> write traffic.
>
> During a routine SSL certificate rotation we shut down Pgpool-II on
> node3, then on node1. node2 is then the only node left, so it becomes
> the leader. We restart Pgpool-II on node1 and node3, and both come back
> as standbys. There is no way to hand leadership back to node1, so the
> watchdog leader is now stranded on node2 while the PostgreSQL primary
> is still node1.

Pgpool-II 4.8 (supposed to be released by the end of this year) will
allow to reload SSL certificates without restarting pgpool.
https://git.postgresql.org/gitweb/?p=pgpool2.git;a=commit;h=931a37e7f63fe514e989d427e1b0c2b7f4344c0d

Does this help?

Regards,
--
Tatsuo Ishii
SRA OSS K.K.
English: http://www.sraoss.co.jp/index_en/
Japanese:http://www.sraoss.co.jp