connection node_2; connection node_1; connection node_1; SET SESSION wsrep_sync_wait = 0; SET SESSION lock_wait_timeout = 60; SET SESSION innodb_lock_wait_timeout=60; SET SESSION wait_timeout=60; CREATE TABLE t1 (f1 INTEGER PRIMARY KEY) ENGINE=InnoDB; FLUSH TABLE t1 WITH READ LOCK; connection node_2; ALTER TABLE t1 ADD COLUMN f2 INTEGER; connection node_1; SELECT 1 FROM DUAL; 1 1 SELECT COUNT(*) = 1 FROM INFORMATION_SCHEMA.PROCESSLIST WHERE USER = 'system user' AND STATE = 'Waiting for table metadata lock'; COUNT(*) = 1 1 UNLOCK TABLES; SET SESSION wsrep_sync_wait = 15; SHOW CREATE TABLE t1; Table Create Table t1 CREATE TABLE `t1` ( `f1` int(11) NOT NULL, `f2` int(11) DEFAULT NULL, PRIMARY KEY (`f1`) ) ENGINE=InnoDB DEFAULT CHARSET=latin1 SELECT COUNT(*) = 0 FROM INFORMATION_SCHEMA.PROCESSLIST WHERE USER = 'system user' AND STATE = 'Waiting for table metadata lock'; COUNT(*) = 0 1 DROP TABLE t1;