v73-0002-Add-TAP-test-for-slot-invalidation-based-on-inac.patch

From 87cf5eeb9d6fc1e21d192d1a94e58d43055ed510 Mon Sep 17 00:00:00 2001
From: Nisha Moond <nisha.moond412@gmail.com>
Date: Mon, 10 Feb 2025 16:26:17 +0530
Subject: [PATCH v73 2/2] Add TAP test for slot invalidation based on inactive
 timeout.

This test uses injection points to bypass the time overhead caused by the
idle_replication_slot_timeout GUC, which has a minimum value of one minute.
---
 src/backend/replication/slot.c                |  29 +++--
 src/test/recovery/meson.build                 |   1 +
 .../t/044_invalidate_inactive_slots.pl        | 110 ++++++++++++++++++
 3 files changed, 131 insertions(+), 9 deletions(-)
 create mode 100644 src/test/recovery/t/044_invalidate_inactive_slots.pl

diff --git a/src/backend/replication/slot.c b/src/backend/replication/slot.c
index 1b34d256a5..d7040db955 100644
--- a/src/backend/replication/slot.c
+++ b/src/backend/replication/slot.c
@@ -55,6 +55,7 @@
 #include "storage/proc.h"
 #include "storage/procarray.h"
 #include "utils/builtins.h"
+#include "utils/injection_point.h"
 #include "utils/guc_hooks.h"
 #include "utils/varlena.h"
 
@@ -1724,16 +1725,26 @@ InvalidatePossiblyObsoleteSlot(int possible_causes,
 			{
 				Assert(now > 0);
 
-				/*
-				 * Check if the slot needs to be invalidated due to
-				 * idle_replication_slot_timeout GUC.
-				 */
-				if (CanInvalidateIdleSlot(s) &&
-					TimestampDifferenceExceedsSeconds(s->inactive_since, now,
-													  idle_replication_slot_timeout_mins * SECS_PER_MINUTE))
+				if (CanInvalidateIdleSlot(s))
 				{
-					invalidation_cause = RS_INVAL_IDLE_TIMEOUT;
-					inactive_since = s->inactive_since;
+					/*
+					 * Check if the slot needs to be invalidated due to
+					 * idle_replication_slot_timeout GUC.
+					 *
+					 * To test idle timeout slot invalidation, if the
+					 * "slot-timeout-inval" injection point is attached,
+					 * immediately invalidate the slot.
+					 */
+					if (
+#ifdef USE_INJECTION_POINTS
+						IS_INJECTION_POINT_ATTACHED("slot-timeout-inval") ||
+#endif
+						TimestampDifferenceExceedsSeconds(s->inactive_since, now,
+														  idle_replication_slot_timeout_mins * SECS_PER_MINUTE))
+					{
+						invalidation_cause = RS_INVAL_IDLE_TIMEOUT;
+						inactive_since = s->inactive_since;
+					}
 				}
 			}
 		}
diff --git a/src/test/recovery/meson.build b/src/test/recovery/meson.build
index 0428704dbf..057bcde143 100644
--- a/src/test/recovery/meson.build
+++ b/src/test/recovery/meson.build
@@ -52,6 +52,7 @@ tests += {
       't/041_checkpoint_at_promote.pl',
       't/042_low_level_backup.pl',
       't/043_no_contrecord_switch.pl',
+      't/044_invalidate_inactive_slots.pl',
     ],
   },
 }
diff --git a/src/test/recovery/t/044_invalidate_inactive_slots.pl b/src/test/recovery/t/044_invalidate_inactive_slots.pl
new file mode 100644
index 0000000000..2392f24711
--- /dev/null
+++ b/src/test/recovery/t/044_invalidate_inactive_slots.pl
@@ -0,0 +1,110 @@
+# Copyright (c) 2025, PostgreSQL Global Development Group
+
+# Test for replication slots invalidation due to idle_timeout
+use strict;
+use warnings FATAL => 'all';
+
+use PostgreSQL::Test::Utils;
+use PostgreSQL::Test::Cluster;
+use Test::More;
+
+# This test depends on injection point that forces slot invalidation
+# due to idle_timeout. Enabling injections points requires
+# --enable-injection-points with configure or
+# -Dinjection_points=true with Meson.
+if ($ENV{enable_injection_points} ne 'yes')
+{
+	plan skip_all => 'Injection points not supported by this build';
+}
+
+# Wait for slot to first become idle and then get invalidated
+sub wait_for_slot_invalidation
+{
+	my ($node, $slot_name, $offset) = @_;
+	my $node_name = $node->name;
+
+	# The slot's invalidation should be logged
+	$node->wait_for_log(
+		qr/invalidating obsolete replication slot \"$slot_name\"/, $offset);
+
+	# Check that the invalidation reason is 'idle_timeout'
+	$node->poll_query_until(
+		'postgres', qq[
+		SELECT COUNT(slot_name) = 1 FROM pg_replication_slots
+			WHERE slot_name = '$slot_name' AND
+			invalidation_reason = 'idle_timeout';
+	])
+	  or die
+	  "Timed out while waiting for invalidation reason of slot $slot_name to be set on node $node_name";
+}
+
+# ========================================================================
+# Testcase start
+#
+# Test invalidation of streaming standby slot and logical slot due to idle
+# timeout.
+
+# Initialize the node
+my $node = PostgreSQL::Test::Cluster->new('node');
+$node->init(allows_streaming => 'logical');
+
+# Avoid unpredictability
+$node->append_conf(
+	'postgresql.conf', qq{
+checkpoint_timeout = 1h
+idle_replication_slot_timeout = 1min
+});
+$node->start;
+
+# Create both streaming standby and logical slot
+$node->safe_psql(
+	'postgres', qq[
+    SELECT pg_create_physical_replication_slot(slot_name := 'physical_slot', immediately_reserve := true);
+]);
+$node->safe_psql('postgres',
+	q{SELECT pg_create_logical_replication_slot('logical_slot', 'test_decoding');}
+);
+
+my $log_offset = -s $node->logfile;
+
+# Register an injection point on the node to forcibly cause a slot
+# invalidation due to idle_timeout
+$node->safe_psql('postgres', 'CREATE EXTENSION injection_points;');
+
+# Check if the 'injection_points' extension is available, as it may be
+# possible that this script is run with installcheck, where the module
+# would not be installed by default.
+if (!$node->check_extension('injection_points'))
+{
+	plan skip_all => 'Extension injection_points not installed';
+}
+
+$node->safe_psql('postgres',
+	"SELECT injection_points_attach('slot-timeout-inval', 'error');");
+
+# Idle timeout slot invalidation occurs during a checkpoint, so run a
+# checkpoint to invalidate the slots.
+$node->safe_psql('postgres', "CHECKPOINT");
+
+# Wait for slots to become inactive. Note that since nobody has acquired the
+# slot yet, then if it has been invalidated that can only be due to the idle
+# timeout mechanism.
+wait_for_slot_invalidation($node, 'physical_slot', $log_offset);
+wait_for_slot_invalidation($node, 'logical_slot', $log_offset);
+
+# Check that the invalidated slot cannot be acquired
+my $node_name = $node->name;
+my ($result, $stdout, $stderr);
+($result, $stdout, $stderr) = $node->psql(
+	'postgres', qq[
+		SELECT pg_replication_slot_advance('logical_slot', '0/1');
+]);
+ok( $stderr =~ /can no longer access replication slot "logical_slot"/,
+	"detected error upon trying to acquire invalidated slot on node")
+  or die
+  "could not detect error upon trying to acquire invalidated slot \"logical_slot\" on node";
+
+# Testcase end
+# =============================================================================
+
+done_testing();
-- 
2.34.1