Horton

Re: Allow non-superuser to cancel superuser tasks.

Nathan Bossart <nathandbossart@gmail.com>

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From: Nathan Bossart <nathandbossart@gmail.com>
To: Michael Paquier <michael@paquier.xyz>
Cc: "Leung, Anthony" <antholeu@amazon.com>, "Andrey M. Borodin" <x4mmm@yandex-team.ru>, Kirill Reshke <reshkekirill@gmail.com>, "pgsql-hackers@postgresql.org" <pgsql-hackers@postgresql.org>
Date: 2024-04-06T01:07:51Z
Lists: pgsql-hackers 
On Sat, Apr 06, 2024 at 08:56:04AM +0900, Michael Paquier wrote:
> There is pg_read_all_stats as well, so I don't see a big issue in
> requiring to be a member of this role as well for the sake of what's
> proposing here.

Well, that tells you quite a bit more than just which PIDs correspond to
autovacuum workers, but maybe that's good enough for now.

> I'd rather not leak any information at the end for
> anybody calling pg_signal_backend without access to the stats, so
> checking the backend type after the role sounds kind of a safer
> long-term approach for me.

I'm not following what you mean by this.  Are you suggesting that we should
keep the existing superuser message for the autovacuum workers?

-- 
Nathan Bossart
Amazon Web Services: https://aws.amazon.com

Commits

  1. Look up backend type in pg_signal_backend() more cheaply.

  2. Add tap test for pg_signal_autovacuum role

  3. Introduce pg_signal_autovacuum_worker.

  4. Add a slot synchronization function.

  5. Ban role pg_signal_backend from more superuser backend types.