RE: Fix 035_standby_logical_decoding.pl race conditions

Dear Bertrand,

> > SIGSTOP signal for pg_recvlogical may do the idea,
>
> Yeah, but would we be "really" testing an "active" slot?

Yeah, this is also a debatable point.

> At the end we want to produce an invalidation that may or not happen on a real
> environment. The corner case is in the test, not an issue of the feature to
> fix.

I also think this is the test-issue, not the codebase.

> So, I'm not sure I like the idea that much, but thinking out loud: I wonder if
> we could bypass the "active" slot checks in 16 and 17 and use injection points as
> proposed as of 18 (as we need the injection points changes proposed in 0001
> up-thread). Thoughts?

I do not have other idea neither. I checked your patch set could solve the issue.

Comments for the patch:
I'm not sure whether new API is really needed. Isn't it enough to use both
injection_points_wakeup() and injection_points_detach()? This approach does not
require bumping the version, and can be backported to PG17.

Also, another check whether the extension can be installed for the node is required.
Please see 041_checkpoint_at_promote.pl.

Best regards,
Hayato Kuroda
FUJITSU LIMITED