connection node_2; connection node_1; connect con1,127.0.0.1,root,,test,$NODE_MYPORT_1; call mtr.add_suppression("WSREP: ALTER TABLE isolation failure"); CREATE TABLE t1(c1 INT PRIMARY KEY, c2 INT) ENGINE=InnoDB; SET DEBUG_SYNC = 'wsrep_append_fk_toi_keys_before_close_tables SIGNAL may_alter WAIT_FOR bf_abort'; ALTER TABLE t1 DROP COLUMN c2; connection node_1; SET DEBUG_SYNC = 'now WAIT_FOR may_alter'; ALTER TABLE t1 ADD COLUMN c3 INT; connection con1; ERROR 70100: Query execution was interrupted INSERT INTO t1 (c1, c2, c3) VALUES (1, 0, 0); connection node_2; INSERT INTO t1 (c1, c2, c3) VALUES (2, 0, 0); connection node_1; SET DEBUG_SYNC = 'RESET'; DROP TABLE t1; disconnect con1; disconnect node_2; disconnect node_1;