Add a script to terminate idle pg connections

[glehmann]

Koji keeps opening new connections to the database, and keeps them open
up to the point where no new connection can be open. Koji then starts
to fail, with a database outage error message.

This scripts terminates the connexions older that 10 minutes, and is
intended to run every minute on the koji server.

[ydirson]

There should be some context, what pg connections are we talking about?

[ydirson]

lgtm (not 100% sure though, whether that the print() before commit() should not be saying "terminating", but that should not have much impact 😉)

[glehmann]

Yes, that was a weird place to add it.
I've also used the connection as a context manager.

[stormi]

It looks like a temporary workaround, so I'm not entirely at ease with merging this and risking to make it a long lived hack.

Unless that's what the koji developers recommend?

[nathanael-h]

It is not what koji developers recommend at all. Quoting Mike McLean from :

Koji works on a one connection per thead model. If httpd leaves threads active, then they will keep their db connection.
See discussion in https://pagure.io/koji/issue/4175

Issue #4175: Add an limit for the database connections - koji - Pagure.io

Most likely the solution to your issue lies in httpd configuration
That said, it is normal for kojihub to keep a lot of connections open.

[glehmann]

It is indeed a temporary workaround.

[stormi]

I'm converting this to draft. We probably don't want to spend more time on it unless we can't find a proper fix (and @nathanael-h might already have found one).

[glehmann]

We don't need it anymore 🎉