Date: Mon, 8 Jul 2024 17:04:01 -0700
From: Noah Misch <noah@leadboat.com>
To: Jacob Champion <jacob.champion@enterprisedb.com>
Cc: PostgreSQL Hackers <pgsql-hackers@postgresql.org>,
	Euler Taveira <euler.taveira@enterprisedb.com>
Subject: Re: [PATCH] pg_stat_activity: make slow/hanging authentication more
 visible
Message-ID: <20240709000401.0b.nmisch@google.com>
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On Mon, Jul 08, 2024 at 02:09:21PM -0700, Jacob Champion wrote:
> On Sun, Jun 30, 2024 at 10:48 AM Noah Misch <noah@leadboat.com> wrote:
> > That said, it
> > may be more fruitful to arrange for authentication timeout to cut through PAM
> > etc.
> 
> That seems mostly out of our hands -- the misbehaving modules are free
> to ignore our signals (and do). Is there another way to force the
> issue?

Two ways at least (neither of them cheap):
- Invoke PAM in a subprocess, and SIGKILL that process if needed.
- Modify the module to be interruptible.

> > Hanging connection slots hurt even if they lack an xmin.
> 
> Oh, would releasing the xmin not really move the needle, then?

It still moves the needle.