Storage engines
InnoDB
Supports transactions, row-level locking, foreign keys and encryption for tables
[
Variables
|
Buffer Pool
|
InnoDB Status
]
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2026-07-30 17:24:53 0x7fd7a8079640 INNODB MONITOR OUTPUT
=====================================
Per second averages calculated from the last 3 seconds
-----------------
BACKGROUND THREAD
-----------------
srv_master_thread loops: 1269 srv_active, 0 srv_shutdown, 157336 srv_idle
srv_master_thread log flush and writes: 158550
----------
SEMAPHORES
----------
OS WAIT ARRAY INFO: reservation count 24426
OS WAIT ARRAY INFO: signal count 20074
RW-shared spins 13001, rounds 98730, OS waits 1538
RW-excl spins 12364, rounds 151923, OS waits 2980
RW-sx spins 134, rounds 3083, OS waits 87
Spin rounds per wait: 7.59 RW-shared, 12.29 RW-excl, 23.01 RW-sx
------------------------
LATEST FOREIGN KEY ERROR
------------------------
2026-07-28 23:04:36 0x7fd7ac9b4640 Cannot drop table `cu_theses`.`theses`
because it is referenced by `cu_theses`.`researchers`
------------
TRANSACTIONS
------------
Trx id counter 130289
Purge done for trx's n:o < 130289 undo n:o < 0 state: running
History list length 1
LIST OF TRANSACTIONS FOR EACH SESSION:
---TRANSACTION 422039217803528, not started
0 lock struct(s), heap size 1128, 0 row lock(s)
---TRANSACTION 422039217799312, not started
0 lock struct(s), heap size 1128, 0 row lock(s)
--------
FILE I/O
--------
I/O thread 0 state: waiting for i/o request (insert buffer thread)
I/O thread 1 state: waiting for i/o request (log thread)
I/O thread 2 state: waiting for i/o request (read thread)
I/O thread 3 state: waiting for i/o request (read thread)
I/O thread 4 state: waiting for i/o request (read thread)
I/O thread 5 state: waiting for i/o request (read thread)
I/O thread 6 state: waiting for i/o request (write thread)
I/O thread 7 state: waiting for i/o request (write thread)
I/O thread 8 state: waiting for i/o request (write thread)
I/O thread 9 state: waiting for i/o request (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
228679 OS file reads, 137158 OS file writes, 52020 OS fsyncs
178.61 reads/s, 16384 avg bytes/read, 20.33 writes/s, 10.33 fsyncs/s
-------------------------------------
INSERT BUFFER AND ADAPTIVE HASH INDEX
-------------------------------------
Ibuf: size 1, free list len 17, seg size 19, 347 merges
merged operations:
insert 4914, delete mark 1, delete 0
discarded operations:
insert 0, delete mark 0, delete 0
Hash table size 4441, node heap has 0 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)
33.66 hash searches/s, 100.63 non-hash searches/s
---
LOG
---
Log sequence number 687325482
Log flushed up to 687325462
Pages flushed up to 687305810
Last checkpoint at 687298628
0 pending log flushes, 0 pending chkp writes
8654 log i/o's done, 8.00 log i/o's/second
----------------------
BUFFER POOL AND MEMORY
----------------------
Total large memory allocated 33554432
Dictionary memory allocated 671000
Buffer pool size 1002
Free buffers 732
Database pages 263
Old database pages 0
Modified db pages 42
Percent of dirty pages(LRU & free pages): 4.217
Max dirty pages percent: 75.000
Pending reads 0
Pending writes: LRU 0, flush list 0, single page 0
Pages made young 3728, not young 6352257
1.67 youngs/s, 410.20 non-youngs/s
Pages read 228232, created 11861, written 107284
178.61 reads/s, 0.00 creates/s, 11.33 writes/s
Buffer pool hit rate 941 / 1000, young-making rate 0 / 1000 not 135 / 1000
Pages read ahead 53.32/s, evicted without access 0.00/s, Random read ahead 0.00/s
LRU len: 263, unzip_LRU len: 0
I/O sum[1039]:cur[12], unzip sum[0]:cur[0]
--------------
ROW OPERATIONS
--------------
0 queries inside InnoDB, 0 queries in queue
0 read views open inside InnoDB
Process ID=106707, Main thread ID=140563777041984, state: sleeping
Number of rows inserted 55369, updated 4736, deleted 580, read 9242364
0.00 inserts/s, 7.33 updates/s, 0.00 deletes/s, 21507.50 reads/s
Number of system rows inserted 0, updated 0, deleted 0, read 75002
0.00 inserts/s, 0.00 updates/s, 0.00 deletes/s, 0.00 reads/s
----------------------------
END OF INNODB MONITOR OUTPUT
============================
