Storage engines
InnoDB
Supports transactions, row-level locking, foreign keys and encryption for tables
[
Variables
|
Buffer Pool
|
InnoDB Status
]
=====================================
2026-07-22 07:12:33 0x3ed8 INNODB MONITOR OUTPUT
=====================================
Per second averages calculated from the last 3 seconds
-----------------
BACKGROUND THREAD
-----------------
srv_master_thread loops: 77480 srv_active, 0 srv_shutdown, 632 srv_idle
srv_master_thread log flush and writes: 78109
----------
SEMAPHORES
----------
OS WAIT ARRAY INFO: reservation count 205275
OS WAIT ARRAY INFO: signal count 208351
RW-shared spins 77188, rounds 1031912, OS waits 29239
RW-excl spins 159195, rounds 2408344, OS waits 62798
RW-sx spins 17535, rounds 349108, OS waits 10244
Spin rounds per wait: 13.37 RW-shared, 15.13 RW-excl, 19.91 RW-sx
------------
TRANSACTIONS
------------
Trx id counter 934487263
Purge done for trx's n:o < 903168240 undo n:o < 0 state: running but idle
History list length 15576863
LIST OF TRANSACTIONS FOR EACH SESSION:
---TRANSACTION 283506092306792, not started
0 lock struct(s), heap size 1128, 0 row lock(s)
---TRANSACTION 283506092298456, not started
0 lock struct(s), heap size 1128, 0 row lock(s)
---TRANSACTION 283506092302624, not started flushing log
mysql tables in use 1, locked 1
0 lock struct(s), heap size 1128, 0 row lock(s)
---TRANSACTION 283506092294288, ACTIVE 76996 sec
0 lock struct(s), heap size 1128, 0 row lock(s)
MySQL thread id 3995, OS thread handle 14968, query id 54615839 localhost 127.0.0.1 root
Trx read view will not see trx with id >= 903168240, sees < 903168238
--------
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: 1; buffer pool: 0
167722 OS file reads, 41643511 OS file writes, 19271636 OS fsyncs
1.00 reads/s, 16384 avg bytes/read, 274.91 writes/s, 59.98 fsyncs/s
-------------------------------------
INSERT BUFFER AND ADAPTIVE HASH INDEX
-------------------------------------
Ibuf: size 1, free list len 405, seg size 407, 2896 merges
merged operations:
insert 1233, delete mark 1974, delete 0
discarded operations:
insert 0, delete mark 0, delete 0
Hash table size 553253, node heap has 341 buffer(s)
Hash table size 553253, node heap has 2138 buffer(s)
Hash table size 553253, node heap has 236 buffer(s)
Hash table size 553253, node heap has 18 buffer(s)
Hash table size 553253, node heap has 496 buffer(s)
Hash table size 553253, node heap has 55 buffer(s)
Hash table size 553253, node heap has 396 buffer(s)
Hash table size 553253, node heap has 10 buffer(s)
2016.66 hash searches/s, 4099.30 non-hash searches/s
---
LOG
---
Log sequence number 898605971926
Log flushed up to 898605971672
Pages flushed up to 898605120801
Last checkpoint at 898604745550
1 pending log flushes, 0 pending chkp writes
15864643 log i/o's done, 17.33 log i/o's/second
----------------------
BUFFER POOL AND MEMORY
----------------------
Total large memory allocated 2281701376
Dictionary memory allocated 227864
Buffer pool size 128432
Free buffers 8183
Database pages 116559
Old database pages 42863
Modified db pages 2371
Percent of dirty pages(LRU & free pages): 1.901
Max dirty pages percent: 75.000
Pending reads 0
Pending writes: LRU 0, flush list 0, single page 0
Pages made young 994983, not young 4530611
0.67 youngs/s, 1.67 non-youngs/s
Pages read 167628, created 542498, written 24297406
1.00 reads/s, 7.33 creates/s, 237.25 writes/s
Buffer pool hit rate 999 / 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: 116559, unzip_LRU len: 0
I/O sum[103960]:cur[2240], unzip sum[0]:cur[0]
----------------------
INDIVIDUAL BUFFER POOL INFO
----------------------
---BUFFER POOL 0
Buffer pool size 16054
Free buffers 1024
Database pages 14523
Old database pages 5341
Modified db pages 292
Percent of dirty pages(LRU & free pages): 1.878
Max dirty pages percent: 75.000
Pending reads 0
Pending writes: LRU 0, flush list 0, single page 0
Pages made young 137794, not young 220331
0.00 youngs/s, 0.00 non-youngs/s
Pages read 19737, created 67626, written 3128996
0.00 reads/s, 0.33 creates/s, 26.32 writes/s
Buffer pool hit rate 1000 / 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: 14523, unzip_LRU len: 0
I/O sum[12995]:cur[280], unzip sum[0]:cur[0]
---BUFFER POOL 1
Buffer pool size 16054
Free buffers 1015
Database pages 14588
Old database pages 5365
Modified db pages 328
Percent of dirty pages(LRU & free pages): 2.102
Max dirty pages percent: 75.000
Pending reads 0
Pending writes: LRU 0, flush list 0, single page 0
Pages made young 79985, not young 485170
0.33 youngs/s, 0.67 non-youngs/s
Pages read 18153, created 67412, written 2397164
0.33 reads/s, 4.00 creates/s, 29.66 writes/s
Buffer pool hit rate 999 / 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: 14588, unzip_LRU len: 0
I/O sum[12995]:cur[280], unzip sum[0]:cur[0]
---BUFFER POOL 2
Buffer pool size 16054
Free buffers 1024
Database pages 14584
Old database pages 5363
Modified db pages 375
Percent of dirty pages(LRU & free pages): 2.402
Max dirty pages percent: 75.000
Pending reads 0
Pending writes: LRU 0, flush list 0, single page 0
Pages made young 187576, not young 289613
0.00 youngs/s, 0.00 non-youngs/s
Pages read 20744, created 68369, written 3411957
0.00 reads/s, 0.33 creates/s, 34.66 writes/s
Buffer pool hit rate 1000 / 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: 14584, unzip_LRU len: 0
I/O sum[12995]:cur[280], unzip sum[0]:cur[0]
---BUFFER POOL 3
Buffer pool size 16054
Free buffers 1024
Database pages 14571
Old database pages 5358
Modified db pages 296
Percent of dirty pages(LRU & free pages): 1.898
Max dirty pages percent: 75.000
Pending reads 0
Pending writes: LRU 0, flush list 0, single page 0
Pages made young 91874, not young 1083653
0.00 youngs/s, 0.00 non-youngs/s
Pages read 22583, created 67733, written 3753298
0.00 reads/s, 0.00 creates/s, 23.99 writes/s
Buffer pool hit rate 1000 / 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: 14571, unzip_LRU len: 0
I/O sum[12995]:cur[280], unzip sum[0]:cur[0]
---BUFFER POOL 4
Buffer pool size 16054
Free buffers 1024
Database pages 14573
Old database pages 5359
Modified db pages 356
Percent of dirty pages(LRU & free pages): 2.282
Max dirty pages percent: 75.000
Pending reads 0
Pending writes: LRU 0, flush list 0, single page 0
Pages made young 135107, not young 806303
0.00 youngs/s, 0.00 non-youngs/s
Pages read 22193, created 66581, written 3303569
0.00 reads/s, 1.33 creates/s, 31.99 writes/s
Buffer pool hit rate 1000 / 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: 14573, unzip_LRU len: 0
I/O sum[12995]:cur[280], unzip sum[0]:cur[0]
---BUFFER POOL 5
Buffer pool size 16054
Free buffers 1024
Database pages 14550
Old database pages 5350
Modified db pages 508
Percent of dirty pages(LRU & free pages): 3.262
Max dirty pages percent: 75.000
Pending reads 0
Pending writes: LRU 0, flush list 0, single page 0
Pages made young 123463, not young 625491
0.00 youngs/s, 0.33 non-youngs/s
Pages read 22302, created 68740, written 2918024
0.33 reads/s, 1.00 creates/s, 43.99 writes/s
Buffer pool hit rate 999 / 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: 14550, unzip_LRU len: 0
I/O sum[12995]:cur[280], unzip sum[0]:cur[0]
---BUFFER POOL 6
Buffer pool size 16054
Free buffers 1024
Database pages 14576
Old database pages 5360
Modified db pages 76
Percent of dirty pages(LRU & free pages): 0.487
Max dirty pages percent: 75.000
Pending reads 0
Pending writes: LRU 0, flush list 0, single page 0
Pages made young 99924, not young 446175
0.33 youngs/s, 0.00 non-youngs/s
Pages read 20577, created 67236, written 2673252
0.00 reads/s, 0.33 creates/s, 23.33 writes/s
Buffer pool hit rate 1000 / 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: 14576, unzip_LRU len: 0
I/O sum[12995]:cur[280], unzip sum[0]:cur[0]
---BUFFER POOL 7
Buffer pool size 16054
Free buffers 1024
Database pages 14594
Old database pages 5367
Modified db pages 140
Percent of dirty pages(LRU & free pages): 0.896
Max dirty pages percent: 75.000
Pending reads 0
Pending writes: LRU 0, flush list 0, single page 0
Pages made young 139260, not young 573875
0.00 youngs/s, 0.67 non-youngs/s
Pages read 21339, created 68801, written 2711146
0.33 reads/s, 0.00 creates/s, 23.33 writes/s
Buffer pool hit rate 999 / 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: 14594, unzip_LRU len: 0
I/O sum[12995]:cur[280], unzip sum[0]:cur[0]
--------------
ROW OPERATIONS
--------------
0 queries inside InnoDB, 0 queries in queue
1 read views open inside InnoDB
Process ID=4272, Main thread ID=5704, state: sleeping
Number of rows inserted 14256, updated 13001591, deleted 1759, read 295385155
0.00 inserts/s, 89.30 updates/s, 0.00 deletes/s, 344.89 reads/s
Number of system rows inserted 0, updated 0, deleted 0, read 113962
0.00 inserts/s, 0.00 updates/s, 0.00 deletes/s, 0.00 reads/s
----------------------------
END OF INNODB MONITOR OUTPUT
============================