Storage engines

InnoDB

Supports transactions, row-level locking, foreign keys and encryption for tables

[ Variables | Buffer Pool | InnoDB Status ]

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2025-07-07 14:07:29 0x8d4 INNODB MONITOR OUTPUT
=====================================
Per second averages calculated from the last 17 seconds
-----------------
BACKGROUND THREAD
-----------------
srv_master_thread loops: 2349223 srv_active, 0 srv_shutdown, 9669638 srv_idle
srv_master_thread log flush and writes: 12018861
----------
SEMAPHORES
----------
OS WAIT ARRAY INFO: reservation count 25104725
OS WAIT ARRAY INFO: signal count 5440181
RW-shared spins 1940395, rounds 58097443, OS waits 1930659
RW-excl spins 33997, rounds 1023760, OS waits 33148
RW-sx spins 400, rounds 11861, OS waits 391
Spin rounds per wait: 29.94 RW-shared, 30.11 RW-excl, 29.65 RW-sx
------------------------
LATEST FOREIGN KEY ERROR
------------------------
2025-03-18 13:35:48 0x758 Transaction:
TRANSACTION 631500, ACTIVE 0 sec inserting
mysql tables in use 1, locked 1
3 lock struct(s), heap size 1128, 1 row lock(s), undo log entries 1
MySQL thread id 2784858, OS thread handle 1880, query id 193900659 localhost ::1 root Update
INSERT INTO ns_mdt_training (user_fivem_id, completed_trainings) VALUES ('fivem:14716877', '[]')
Foreign key constraint fails for table `fivem`.`ns_mdt_training`:
,
  CONSTRAINT `ns_mdt_training_ibfk_1` FOREIGN KEY (`user_fivem_id`) REFERENCES `ns_mdt_user` (`fivem_id`) ON DELETE CASCADE in parent table, in index user_fivem_id tuple:
DATA TUPLE: 2 fields;
 0: len 14; hex 666976656d3a3134373136383737; asc fivem:14716877;;
 1: len 6; hex 00000000044c; asc      L;;

But in parent table `fivem`.`ns_mdt_user`, in index PRIMARY,
the closest match we can find is record:
PHYSICAL RECORD: n_fields 7; compact format; info bits 0
 0: len 14; hex 666976656d3a3135303738373232; asc fivem:15078722;;
 1: len 6; hex 000000000000; asc       ;;
 2: len 7; hex 80000000000000; asc        ;;
 3: len 19; hex 31323932363339393436343630363236393437; asc 1292639946460626947;;
 4: len 21; hex 383439392049204a6f736570682044204920373036; asc 8499 I Joseph D I 706;;
 5: len 4; hex 00000035; asc    5;;
 6: len 5; hex 58582d3030; asc XX-00;;

------------
TRANSACTIONS
------------
Trx id counter 7502277
Purge done for trx's n:o < 7502277 undo n:o < 0 state: running but idle
History list length 1
LIST OF TRANSACTIONS FOR EACH SESSION:
---TRANSACTION 284010788237744, not started
0 lock struct(s), heap size 1128, 0 row lock(s)
---TRANSACTION 284010788233576, not started
0 lock struct(s), heap size 1128, 0 row lock(s)
---TRANSACTION 284010788229408, not started
0 lock struct(s), heap size 1128, 0 row lock(s)
---TRANSACTION 284010788225240, not started
0 lock struct(s), heap size 1128, 0 row lock(s)
---TRANSACTION 284010788221072, not started
0 lock struct(s), heap size 1128, 0 row lock(s)
--------
FILE I/O
--------
I/O thread 0 state: native aio handle (insert buffer thread)
I/O thread 1 state: native aio handle (log thread)
I/O thread 2 state: native aio handle (read thread)
I/O thread 3 state: native aio handle (read thread)
I/O thread 4 state: native aio handle (read thread)
I/O thread 5 state: native aio handle (read thread)
I/O thread 6 state: native aio handle (write thread)
I/O thread 7 state: native aio handle (write thread)
I/O thread 8 state: native aio handle (write thread)
I/O thread 9 state: native aio handle (write thread)
Pending normal aio reads: [0, 0, 0, 0] , aio writes: [0, 0, 0, 0] ,
 ibuf aio reads:, log i/o's:, sync i/o's:
Pending flushes (fsync) log: 0; buffer pool: 0
3436763 OS file reads, 27803241 OS file writes, 18126780 OS fsyncs
1.35 reads/s, 16384 avg bytes/read, 7.23 writes/s, 6.18 fsyncs/s
-------------------------------------
INSERT BUFFER AND ADAPTIVE HASH INDEX
-------------------------------------
Ibuf: size 1, free list len 0, seg size 2, 0 merges
merged operations:
 insert 0, delete mark 0, delete 0
discarded operations:
 insert 0, delete mark 0, delete 0
Hash table size 4441, node heap has 1 buffer(s)
Hash table size 4441, node heap has 1 buffer(s)
Hash table size 4441, node heap has 1 buffer(s)
Hash table size 4441, node heap has 1 buffer(s)
Hash table size 4441, node heap has 1 buffer(s)
Hash table size 4441, node heap has 1 buffer(s)
Hash table size 4441, node heap has 1 buffer(s)
Hash table size 4441, node heap has 1 buffer(s)
45.35 hash searches/s, 94.99 non-hash searches/s
---
LOG
---
Log sequence number 4505388729
Log flushed up to   4505388709
Pages flushed up to 4505219145
Last checkpoint at  4505212914
0 pending log flushes, 0 pending chkp writes
9929973 log i/o's done, 4.18 log i/o's/second
----------------------
BUFFER POOL AND MEMORY
----------------------
Total large memory allocated 33554432
Dictionary memory allocated 540864
Buffer pool size   1003
Free buffers       736
Database pages     259
Old database pages 0
Modified db pages  191
Percent of dirty pages(LRU & free pages): 19.177
Max dirty pages percent: 75.000
Pending reads 0
Pending writes: LRU 0, flush list 0, single page 0
Pages made young 85, not young 854
0.00 youngs/s, 0.00 non-youngs/s
Pages read 3436549, created 194365, written 14823531
1.35 reads/s, 0.18 creates/s, 2.06 writes/s
Buffer pool hit rate 995 / 1000, young-making rate 0 / 1000 not 0 / 1000
Pages read ahead 0.00/s, evicted without access 0.00/s, Random read ahead 0.00/s
LRU len: 259, unzip_LRU len: 0
I/O sum[250]:cur[2], unzip sum[0]:cur[0]
--------------
ROW OPERATIONS
--------------
0 queries inside InnoDB, 0 queries in queue
0 read views open inside InnoDB
Process ID=3236, Main thread ID=4948, state: sleeping
Number of rows inserted 240, updated 3520442, deleted 0, read 56091081
0.00 inserts/s, 3.00 updates/s, 0.00 deletes/s, 38.53 reads/s
Number of system rows inserted 0, updated 0, deleted 0, read 85948861
0.00 inserts/s, 0.00 updates/s, 0.00 deletes/s, 0.00 reads/s
----------------------------
END OF INNODB MONITOR OUTPUT
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