From: Tom Lane <tgl@sss.pgh.pa.us>
To: Kyotaro Horiguchi <horikyota.ntt@gmail.com>
cc: bdrouvot@amazon.com, sawada.mshk@gmail.com, ashutosh.bapat.oss@gmail.com,
        pgsql-hackers@postgresql.org
Subject: Re: more descriptive message for process termination due to
 max_slot_wal_keep_size
In-reply-to: <20220908.134020.228552226800754222.horikyota.ntt@gmail.com>
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Comments: In-reply-to Kyotaro Horiguchi <horikyota.ntt@gmail.com>
	message dated "Thu, 08 Sep 2022 13:40:20 +0900"
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Date: Wed, 28 Sep 2022 16:30:37 -0400
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Kyotaro Horiguchi <horikyota.ntt@gmail.com> writes:
> Okay. the points you brought up above are sufficient grounds for not
> doing so.  Now they are in the following format.

> LOG: terminating process 16034 to release replication slot "rep1"
> because its restart_lsn 0/3158000 exceeds the limit by 15368192 bytes

This seems to me to be a pretty blatant violation of our first message
style guideline [1]:

    The primary message should be short, factual, and avoid reference to
    implementation details such as specific function names. “Short” means
    “should fit on one line under normal conditions”. Use a detail message
    if needed to keep the primary message short ...

I think you should leave the primary message alone and add a DETAIL,
as the first version of the patch did.

The existing "invalidating slot" message is already in violation
of this guideline, so splitting off a DETAIL from that seems
indicated as well.

			regards, tom lane

[1] https://www.postgresql.org/docs/devel/error-style-guide.html