From c2f5d79611bd97c5c7f5bc18e8ffdcb4c5ba3b11 Mon Sep 17 00:00:00 2001 From: Masahiko Sawada Date: Tue, 16 May 2023 09:56:40 +0900 Subject: [PATCH v2] pgstat: fix subscription stats entry leak Commit 7b64e4b3 taught DropSubscription() to drop stats entry of subscription that is not associated with a replication slot for apply worker at DROP SUBSCRIPTION but missed covering the case where the subscription is not associated with replication slots for both apply worker and tablesync worker. Also add a test to verify that the stats for slot-less subscription is removed at DROP SUBSCRIPTION time. Backpatch down to 15. Author: Masahiko Sawada Reviewed-by: Nathan Bossart, Hayato Kuroda, Melih Mutlu Discussion: https://postgr.es/m/CAD21AoB71zkP7uPT7JDPsZcvp0749ExEQnOJxeNKPDFisHar+w@mail.gmail.com Backpatch-through: 15 --- src/backend/commands/subscriptioncmds.c | 12 ++++++------ src/test/subscription/t/026_stats.pl | 20 ++++++++++++++++++++ 2 files changed, 26 insertions(+), 6 deletions(-) diff --git a/src/backend/commands/subscriptioncmds.c b/src/backend/commands/subscriptioncmds.c index e8b288d01c..128d03608f 100644 --- a/src/backend/commands/subscriptioncmds.c +++ b/src/backend/commands/subscriptioncmds.c @@ -1646,6 +1646,12 @@ DropSubscription(DropSubscriptionStmt *stmt, bool isTopLevel) ReplicationOriginNameForLogicalRep(subid, InvalidOid, originname, sizeof(originname)); replorigin_drop_by_name(originname, true, false); + /* + * Tell the cumulative stats system that the subscription is getting + * dropped. + */ + pgstat_drop_subscription(subid); + /* * If there is no slot associated with the subscription, we can finish * here. @@ -1734,12 +1740,6 @@ DropSubscription(DropSubscriptionStmt *stmt, bool isTopLevel) } PG_END_TRY(); - /* - * Tell the cumulative stats system that the subscription is getting - * dropped. - */ - pgstat_drop_subscription(subid); - table_close(rel, NoLock); } diff --git a/src/test/subscription/t/026_stats.pl b/src/test/subscription/t/026_stats.pl index 96a6d686eb..f24b27b09c 100644 --- a/src/test/subscription/t/026_stats.pl +++ b/src/test/subscription/t/026_stats.pl @@ -267,6 +267,26 @@ is( $node_subscriber->safe_psql( qq(f), qq(Subscription stats for subscription '$sub1_name' should be removed.)); +# Get subscription 2 oid +my $sub2_oid = $node_subscriber->safe_psql($db, + qq(SELECT oid FROM pg_subscription WHERE subname = '$sub2_name')); + +# Diassociate the subscription 2 from its replication slot and drop it +$node_subscriber->safe_psql( + $db, + qq( +ALTER SUBSCRIPTION $sub2_name DISABLE; +ALTER SUBSCRIPTION $sub2_name SET (slot_name = NONE); +DROP SUBSCRIPTION $sub2_name; + )); + +# Subscription stats for sub2 should be gone +is( $node_subscriber->safe_psql( + $db, qq(SELECT pg_stat_have_stats('subscription', 0, $sub2_oid))), + qq(f), + qq(Subscription stats for subscription '$sub2_name' should be removed.)); +$node_publisher->safe_psql($db, + qq(SELECT pg_drop_replication_slot('$sub2_name'))); $node_subscriber->stop('fast'); $node_publisher->stop('fast'); -- 2.31.1