Date: Sun, 5 Sep 2021 13:28:33 +0200
From: hubert depesz lubaczewski <depesz@depesz.com>
Sender: depesz@depesz.com
To: PostgreSQL mailing lists <pgsql-bugs@lists.postgresql.org>
Subject: Logs vanish after partial log destination change
Message-ID: <20210905112832.GA8707@depesz.com>
Reply-To: depesz@depesz.com
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Hi,
I'm not entirely sure if it's a bug, or what, but it caught me by
surprise.

Tested it on Linux, on 12.6 and 15devel.

I start with:
log_destination = 'syslog'
logging_collector = false

Logs to to syslog, all is well.

Then, I chance log_destination to 'csvlog' and logging_collector to
'on'.

And then I reload config.

I know I can chance log_destination, but I can't change
logging_collector. I assumed it means that logging will go to where they
did before.

But - logs are gone.
They are not in syslog. They are not in the new location.

When I tried it on test system with 15devel, I noticed by chance that
logs were redirected to terminal from which I issued `pg_ctl reload`
from. Well, that's hardly useful.

I'm not entirely sure what Pg should do in such case, perhaps just
restrict changing any log_* if one of changed gucs require restart?

But, it caught me by surprise, and figured that it might be problematic
for others too.

Best regards,

depesz