create_child: CREATE TABLE child (a INT PRIMARY KEY, create_fk_snip ON UPDATE CASCADE) ENGINE = InnoDB ; create_fk_snip: CONSTRAINT fk FOREIGN KEY (a) REFERENCES parent(a) ; create_parent: CREATE TABLE parent (a INT PRIMARY KEY) ENGINE = InnoDB ; dml: update | insert | insert ; insert: INSERT INTO parent (a) VALUES rand_values ; my_int: { $my_int = $prng->int(513, 4096) } ; rand_values: ( my_int) , ( my_int) ; thread: { sleep 1 ; return undef } ; thread1: TRUNCATE TABLE child ; thread1_connect: ; thread1_init: create_parent ; create_child ; thread2: dml ; thread2_connect: ; thread2_init: ; thread_connect: ; thread_init: ; update: UPDATE parent SET a = my_int ;