From b97a42edd66ccb7f8f4d5d2fa24df0b02b6f4f68 Mon Sep 17 00:00:00 2001
From: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Date: Fri, 8 Mar 2024 09:29:29 +0000
Subject: [PATCH v2] Remove spurious pgstat_drop_replslot() call

There is no need to remove stats for an invalidated slot as one could still
be interested to look at them.
---
 src/backend/replication/slot.c                 |  1 -
 .../recovery/t/035_standby_logical_decoding.pl | 18 ++++++++++++++++++
 2 files changed, 18 insertions(+), 1 deletion(-)
   3.5% src/backend/replication/
  96.4% src/test/recovery/t/

diff --git a/src/backend/replication/slot.c b/src/backend/replication/slot.c
index b8bf98b182..91ca397857 100644
--- a/src/backend/replication/slot.c
+++ b/src/backend/replication/slot.c
@@ -1726,7 +1726,6 @@ InvalidatePossiblyObsoleteSlot(ReplicationSlotInvalidationCause cause,
 			ReplicationSlotMarkDirty();
 			ReplicationSlotSave();
 			ReplicationSlotRelease();
-			pgstat_drop_replslot(s);
 
 			ReportSlotInvalidation(conflict, false, active_pid,
 								   slotname, restart_lsn,
diff --git a/src/test/recovery/t/035_standby_logical_decoding.pl b/src/test/recovery/t/035_standby_logical_decoding.pl
index 0710bccc17..855f37016e 100644
--- a/src/test/recovery/t/035_standby_logical_decoding.pl
+++ b/src/test/recovery/t/035_standby_logical_decoding.pl
@@ -494,6 +494,8 @@ $node_subscriber->stop;
 ##################################################
 # Recovery conflict: Invalidate conflicting slots, including in-use slots
 # Scenario 1: hot_standby_feedback off and vacuum FULL
+# In passing, ensure that replication slot stats are not removed when the active
+# slot is invalidated.
 ##################################################
 
 # One way to produce recovery conflict is to create/drop a relation and
@@ -502,6 +504,15 @@ $node_subscriber->stop;
 reactive_slots_change_hfs_and_wait_for_xmins('behaves_ok_', 'vacuum_full_',
 	0, 1);
 
+# Ensure replication slot stats are not empty before triggering the conflict
+$node_primary->safe_psql('testdb',
+	qq[INSERT INTO decoding_test(x,y) SELECT 100,'100';]
+);
+
+$node_standby->poll_query_until('testdb',
+	qq[SELECT total_txns > 0 FROM pg_stat_replication_slots WHERE slot_name = 'vacuum_full_activeslot']
+) or die "slot stat total_txns not > 0 for vacuum_full_activeslot";
+
 # This should trigger the conflict
 wait_until_vacuum_can_remove(
 	'full', 'CREATE TABLE conflict_test(x integer, y text);
@@ -515,6 +526,13 @@ check_for_invalidation('vacuum_full_', 1, 'with vacuum FULL on pg_class');
 # Verify conflict_reason is 'rows_removed' in pg_replication_slots
 check_slots_conflict_reason('vacuum_full_', 'rows_removed');
 
+# Ensure replication slot stats are not removed after invalidation
+is( $node_standby->safe_psql(
+		'testdb',
+		qq[SELECT total_txns > 0 FROM pg_stat_replication_slots WHERE slot_name = 'vacuum_full_activeslot']),
+	't',
+	'replication slot stats are not removed after invalidation');
+
 $handle =
   make_slot_active($node_standby, 'vacuum_full_', 0, \$stdout, \$stderr);
 
-- 
2.34.1