CREATE TABLE t (f1 INTEGER PRIMARY KEY) Engine=InnoDB;
SET DEBUG_SYNC = 'wsrep_before_replication WAIT_FOR continue';
INSERT INTO t values (1);;
SET SESSION wsrep_sync_wait = 0;
FLUSH TABLES;
SELECT SLEEP(1);
SLEEP(1)
0
SET DEBUG_SYNC= 'now SIGNAL continue';
DROP TABLE t;