Re: Missing import in 035_standby_logical_decoding.pl

Hi,

On Fri, Aug 01, 2025 at 03:04:20PM -0400, Melanie Plageman wrote:
> Hi,
> 
> 035_standby_logical_decoding.pl has this code
> 
> # wait for postgres to terminate
> foreach my $i (0 .. 10 * $PostgreSQL::Test::Utils::timeout_default)
> {
>     last if !-f $node_standby->data_dir . '/postmaster.pid';
>     usleep(100_000);
> }
> 
> but it does not import usleep as other tests do (like this)
> use Time::HiRes qw(usleep);
> 
> I think it simply hasn't been called because postgres exits and
> terminates the loop before it has had a chance to be called. If you
> reorder the sleep and the loop termination condition, it fails
> immediately because it can't find usleep.

Thanks for the report! I think it's an oversight in commit 48796a98d5ae. Fixed
in the attached.

> On an unrelated note, I also noticed that hot_standby_feedback is not
> turned on during the test until we are explicitly checking for
> recovery conflicts.

Yeah, it's expected.

> When it is enabled, the comment says "Turn
> hot_standby_feedback back on" -- but it was never on to begin with. I
> suspect this doesn't produce test instability because autovacuum is
> turned off for the whole test. But, I was wondering if the test
> authors meant for hot_standby_feedback to be enabled during the
> initial phases of the test (until it is explicitly disabled for
> testing purposes).

It's typo/bad wording fixed in the attached. hot_standby_feedback does not need
to be enabled during the initial phases of the test because there is no catalog
changes that could produce a conflict.

Regards,

-- 
Bertrand Drouvot
PostgreSQL Contributors Team
RDS Open Source Databases
Amazon Web Services: https://aws.amazon.com