Re: BUG #17103: WAL segments are not removed after exceeding max_slot_wal_keep_size

On 2021-Jul-16, Alvaro Herrera wrote:

> The buildfarm has remained green so far, but clearly this is something
> we need to fix.  Maybe it's as simple as adding the loop we use below,
> starting at line 219.

There are a few failures of this on buildfarm now,

https://buildfarm.postgresql.org/cgi-bin/show_log.pl?nm=flaviventris&dt=2021-07-16%2022%3A30%3A35
https://buildfarm.postgresql.org/cgi-bin/show_log.pl?nm=desmoxytes&dt=2021-07-16%2021%3A52%3A04
https://buildfarm.postgresql.org/cgi-bin/show_log.pl?nm=dragonet&dt=2021-07-16%2021%3A52%3A05

I am running the test in a loop with the attached; if it doesn't fail in
a few more rounds I'll push it.

There are two instances of a different failure:
https://buildfarm.postgresql.org/cgi-bin/show_log.pl?nm=kittiwake&dt=2021-07-17%2013%3A39%3A43
https://buildfarm.postgresql.org/cgi-bin/show_log.pl?nm=hornet&dt=2021-07-16%2021%3A14%3A14

#   Failed test 'check that segments have been removed'
#   at t/019_replslot_limit.pl line 213.
#          got: '000000010000000000000021'
#     expected: '000000010000000000000022'
# Looks like you failed 1 test of 19.
[23:55:14] t/019_replslot_limit.pl .............. 
Dubious, test returned 1 (wstat 256, 0x100)

I'm afraid about this not being something we can fix with some
additional wait points ...

-- 
Álvaro Herrera              Valdivia, Chile  —  https://www.EnterpriseDB.com/
"La grandeza es una experiencia transitoria.  Nunca es consistente.
Depende en gran parte de la imaginación humana creadora de mitos"
(Irulan)