Re: Replication slot drop message is sent after pgstats shutdown.

Hi,

On 2021-12-22 22:34:45 +0900, Masahiko Sawada wrote:
> I've attached an updated patch. Please review it.

Sorry for dropping the ball on this again :(. I've pushed the fix with some
very minor polishing.

> > The attached detects that bug, but I'm not sure it's worth expending
> > test time, or this might be in the server test suit.
>
> Thanks. It's convenient to test this issue but I'm also not sure it's
> worth adding to the test suit.

I think it's definitely worth adding a test, but I don't particularly like the
specific test implementation. Primarily because I think it's better to test
this in a cluster that stays running, so that we can verify that the slot drop
worked. It also doesn't seem necessary to create a separate cluster.

I wrote the attached isolation test. I ended up not committing it yet - I'm
worried that there could be some OS dependent output difference, due to some
libpq error handling issues. See [1], which Tom pointed out is caused by the
issue discussed in [2].

Greetings,

Andres Freund

[1] https://postgr.es/m/20220215004143.dlzsn72oqsmqa7uw%40alap3.anarazel.de
[2] https://postgr.es/m/20220215004143.dlzsn72oqsmqa7uw%40alap3.anarazel.de