add invalidate_inactive_shared_connections udf

src/backend/distributed/connection/shared_connection_stats.c

@@ -109,6 +109,19 @@ static uint32 SharedConnectionHashHash(const void *key, Size keysize);
 
 
 PG_FUNCTION_INFO_V1(citus_remote_connection_stats);
+PG_FUNCTION_INFO_V1(invalidate_inactive_shared_connections);
+
+/*
+ * invalidate_inactive_shared_connections invalidates inactive
+ * and not used shared connections by removing from the global hash.
+ */
+Datum
+invalidate_inactive_shared_connections(PG_FUNCTION_ARGS)
+{
+	RemoveInactiveNodesFromSharedConnections();
+	PG_RETURN_VOID();
+}
+
 
 /*
  * citus_remote_connection_stats returns all the avaliable information about all

src/backend/distributed/sql/citus--9.2-4--9.3-2.sql

@@ -9,6 +9,7 @@
 #include "udfs/worker_create_or_alter_role/9.3-2.sql"
 #include "udfs/truncate_local_data_after_distributing_table/9.3-2.sql"
 
+#include "udfs/invalidate_inactive_shared_connections/9.3-2.sql"
 -- add citus extension owner as a distributed object, if not already in there
 INSERT INTO citus.pg_dist_object SELECT
   (SELECT oid FROM pg_class WHERE relname = 'pg_authid') AS oid,

src/backend/distributed/sql/udfs/invalidate_inactive_shared_connections/9.3-2.sql

@@ -0,0 +1,10 @@
+CREATE OR REPLACE FUNCTION pg_catalog.invalidate_inactive_shared_connections()
+RETURNS VOID
+LANGUAGE C STRICT
+AS 'MODULE_PATHNAME', $$invalidate_inactive_shared_connections$$;
+
+COMMENT ON FUNCTION pg_catalog.invalidate_inactive_shared_connections()
+     IS 'invalidated inactive shared connections';
+
+REVOKE ALL ON FUNCTION pg_catalog.invalidate_inactive_shared_connections()
+FROM PUBLIC;

src/backend/distributed/sql/udfs/invalidate_inactive_shared_connections/latest.sql

@@ -0,0 +1,10 @@
+CREATE OR REPLACE FUNCTION pg_catalog.invalidate_inactive_shared_connections()
+RETURNS VOID
+LANGUAGE C STRICT
+AS 'MODULE_PATHNAME', $$invalidate_inactive_shared_connections$$;
+
+COMMENT ON FUNCTION pg_catalog.invalidate_inactive_shared_connections()
+     IS 'invalidated inactive shared connections';
+
+REVOKE ALL ON FUNCTION pg_catalog.invalidate_inactive_shared_connections()
+FROM PUBLIC;