SET DEBUG_SYNC='RESET';
From con ddl :DDL acquiring bml_shared_lock and waits at a SYNC POINT
CREATE DATABASE db1;
CREATE TABLE db1.t1(a int);
INSERT INTO db1.t1 VALUES(1);
SET DEBUG_SYNC='before_execute_sql_command SIGNAL got_bml_shared_lock WAIT_FOR killed';
CREATE TABLE db1.t2 (prime int, nat int);
SET DEBUG_SYNC='now WAIT_FOR got_bml_shared_lock';
BACKUP DATABASE db1 TO 'db1.bak';
SET DEBUG_SYNC='now WAIT_FOR got_bml_shared_lock';
KILL QUERY 3;
SHOW TABLES IN db1;
Tables_in_db1
t1
ERROR 70100: Query execution was interrupted
backup_id
276