Don't fail for > 1 walsenders in 019_replslot_limit, add debug messages.
So far the first of the retries introduced in
f28bf667f60 resolves the
issue. But I (Andres) am still suspicious that the start of the failures might
indicate a problem.
To reduce noise, stop reporting a failure if a retry resolves the problem. To
allow figuring out what causes the slow slot drop, add a few more debug
messages to ReplicationSlotDropPtr.
See also commit
afdeff10526,
fe0972ee5e6 and
f28bf667f60.
Discussion: https://postgr.es/m/
20220327213219.smdvfkq2fl74flow@alap3.anarazel.de