Re: standby recovery fails (tablespace related) (tentative patch and discussion)

On Sun, Jul 31, 2022 at 3:46 PM Thomas Munro <thomas(dot)munro(at)gmail(dot)com> wrote:
> On Sun, Jul 31, 2022 at 2:37 AM Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:
> > Alvaro Herrera <alvherre(at)alvh(dot)no-ip(dot)org> writes:
> > > WFM, pushed that way.
> >
> > Looks like conchuela is still intermittently unhappy.
> >
> > https://buildfarm.postgresql.org/cgi-bin/show_log.pl?nm=conchuela&dt=2022-07-30%2004%3A57%3A51
>
> And here's one from CI that failed on Linux (this was a cfbot run with
> an unrelated patch, parent commit b998196 so a few commits after "Fix
> test instability"):
>
> https://cirrus-ci.com/task/5282155000496128
>
> https://api.cirrus-ci.com/v1/artifact/task/5282155000496128/log/src/test/recovery/tmp_check/log/033_replay_tsp_drops_primary1_WAL_LOG.log
>
> It looks like this sequence is racy and we need to wait for more than
> just "connection is made" before dropping the slot?
>
> $node_standby->start;
>
> # Make sure connection is made
> $node_primary->poll_query_until('postgres',
> 'SELECT count(*) = 1 FROM pg_stat_replication');
> $node_primary->safe_psql('postgres', "SELECT
> pg_drop_replication_slot('slot')");
>
> Why not set the replication slot name so that the standby uses it
> "properly", like in other tests?

Or to keep doing it this way, does that pg_stat_replication query need
a WHERE clause looking at the state?