Date: Tue, 19 May 2026 21:55:52 +0900 (JST)
Message-Id: <20260519.215552.499378691092618823.ishii@postgresql.org>
To: emond.papegaaij@gmail.com
Cc: pgpool-hackers@lists.postgresql.org
Subject: Re: Primary node detection race at clean startup
From: Tatsuo Ishii <ishii@postgresql.org>
In-Reply-To: <20260519.214037.579991005061650329.ishii@postgresql.org>
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	<20260519.214037.579991005061650329.ishii@postgresql.org>
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Hi Emond,

>> Hi,
>> 
>> In our tests, we've found an issue that can cause all Pgpool nodes to
>> report an incorrect 'Role: standby':
>> Role                   : standby    ← stale, never updated on this node
>> Backend Role           : primary    ← actual SR-check result
>> 
>> This can happen if all nodes in a watchdog cluster start with a clean
>> state at the same time. If the first node is still trying to determine
>> the primary database, it's primary_node_id is -2. This value is then
>> synced to other nodes in the cluster, causing all nodes to report the
>> stale state indefinitely. Attached is a patch against 4.7 that should
>> fix this.
>> 
>> Note that this analysis was done by Claude Code and it also created
>> the patch. The failure on our CI was real though and I think the
>> explanation makes sense.
> 
> I have looked into the patch. Although I failed to reproduce the
> issue, I agree with you: the explanation makes sense. Also I have run
> the regression test and all test passed. I am going to push the patch
> to all supported branches.

Done.

Note that the credits section in the commit message is as follows:

Reported-by: Emond Papegaaij <emond.papegaaij@gmail.com>
Reported-by: Claude Code
Author: Tatsuo Ishii <ishii@postgresql.org>
Discussion: https://www.postgresql.org/message-id/CAGXsc%2BZmBoLs3Mz%3DG-Bdm4JJG%2BfH1NpHfR3qVJVwW4eBKWwStQ%40mail.gmail.com
Backpatch-through: v4.3

You are credited as a reporter, and Claude Code is also a reporter to
indicate that the report was created by AI. I credited myself as the
author. This is by following reasons:

1) AI cannot be the author.
2) The committer (me) is responsible for the commit.

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