InnoDB Standard Monitor and Lock Monitor Output Standard Monitor output is limited to 1MB when produced using the  SHOW ENGINE INNODB STATUS statement. This limit does not apply to output written to server standard error output ( stderr ). Example Standard Monitor output: mysql>  SHOW ENGINE INNODB STATUS\G *************************** 1. row *************************** Type: InnoDB Name: Status: ===================================== 2018-04-12 15:14:08 0x7f971c063700 INNODB MONITOR OUTPUT ===================================== Per second averages calculated from the last 4 seconds ----------------- BACKGROUND THREAD ----------------- srv_master_thread loops: 15 srv_active, 0 srv_shutdown, 1122 srv_idle srv_master_thread log flush and writes: 0 ---------- SEMAPHORES ---------- OS WAIT ARRAY INFO: reservation count 24 OS WAIT ARRAY INFO: signal count 24 RW-shared spins 4, rounds 8, OS waits 4 RW-excl spins 2, rounds 60, OS waits 2 RW-sx spins 0, rounds 0, OS waits 0 Spin rounds per wait: 2.00 RW-shared, 30.00 RW-excl, 0.00 RW-sx ------------------------ LATEST FOREIGN KEY ERROR ------------------------ 2018-04-12 14:57:24 0x7f97a9c91700 Transaction: TRANSACTION 7717, ACTIVE 0 sec inserting mysql tables in use 1, locked 1 4 lock struct(s), heap size 1136, 3 row lock(s), undo log entries 3 MySQL thread id 8, OS thread handle 140289365317376, query id 14 localhost root update INSERT INTO child VALUES (NULL, 1), (NULL, 2), (NULL, 3), (NULL, 4), (NULL, 5), (NULL, 6) Foreign key constraint fails for table ‘test‘.‘child‘: , CONSTRAINT ‘child_ibfk_1‘ FOREIGN KEY (‘parent_id‘) REFERENCES ‘parent‘ (‘id‘) ON DELETE CASCADE ON UPDATE CASCADE Trying to add in child table, in index par_ind tuple: DATA TUPLE: 2 fields;  0: len 4; hex 80000003; asc ;;  1: len 4; hex 80000003; asc ;; But in parent table ‘test‘.‘parent‘, in index PRIMARY, the closest match we can find is record: PHYSICAL RECORD: n_fields 3; compact format; info bits 0  0: len 4; hex 80000004; asc ;;  1: len 6; hex 000000001e19; asc ;;  2: len 7; hex 81000001110137; asc 7;; ------------ TRANSACTIONS ------------ Trx id counter 7748 Purge done for trx’s n:o < 7747 undo n:o < 0 state: running but idle History list length 19 LIST OF TRANSACTIONS FOR EACH SESSION: ---TRANSACTION 421764459790000, not started 0 lock struct(s), heap size 1136, 0 row lock(s) ---TRANSACTION 7747, ACTIVE 23 sec starting index read mysql tables in use 1, locked 1 LOCK WAIT 2 lock struct(s), heap size 1136, 1 row lock(s) MySQL thread id 9, OS thread handle 140286987249408, query id 51 localhost root updating DELETE FROM t WHERE i = 1 3342