Storage engines

InnoDB

Percona-XtraDB, Supports transactions, row-level locking, and foreign keys

[ Variables | Buffer Pool | InnoDB Status ]

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2026-04-15 14:39:10 1694 INNODB MONITOR OUTPUT
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Per second averages calculated from the last 48 seconds
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BACKGROUND THREAD
-----------------
srv_master_thread loops: 61383 srv_active, 0 srv_shutdown, 2429540 srv_idle
srv_master_thread log flush and writes: 2490903
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SEMAPHORES
----------
OS WAIT ARRAY INFO: reservation count 3170654
OS WAIT ARRAY INFO: signal count 1724622
Mutex spin waits 3158738, rounds 141265077, OS waits 3029871
RW-shared spins 44366, rounds 1494701, OS waits 49532
RW-excl spins 10713, rounds 68694, OS waits 1030
Spin rounds per wait: 44.72 mutex, 33.69 RW-shared, 6.41 RW-excl
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TRANSACTIONS
------------
Trx id counter 90772813
Purge done for trx's n:o < 86487140 undo n:o < 0 state: running but idle
History list length 872
LIST OF TRANSACTIONS FOR EACH SESSION:
---TRANSACTION 0, not started
MySQL thread id 24677666, OS thread handle 0x1694, query id 312912678 localhost 127.0.0.1 root init
SHOW ENGINE INNODB STATUS
---TRANSACTION 0, not started
MySQL thread id 24677663, OS thread handle 0x1694, query id 312912673 localhost 127.0.0.1 root 
---TRANSACTION 69168643, not started
MySQL thread id 1, OS thread handle 0x9398, query id 0 Waiting for background binlog tasks
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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 (read thread)
I/O thread 7 state: native aio handle (read thread)
I/O thread 8 state: native aio handle (read thread)
I/O thread 9 state: native aio handle (read thread)
I/O thread 10 state: native aio handle (write thread)
I/O thread 11 state: native aio handle (write thread)
I/O thread 12 state: native aio handle (write thread)
I/O thread 13 state: native aio handle (write thread)
I/O thread 14 state: native aio handle (write thread)
I/O thread 15 state: native aio handle (write thread)
I/O thread 16 state: native aio handle (write thread)
I/O thread 17 state: native aio handle (write thread)
Pending normal aio reads: 0 [0, 0, 0, 0, 0, 0, 0, 0] , aio writes: 0 [0, 0, 0, 0, 0, 0, 0, 0] ,
 ibuf aio reads: 0, log i/o's: 0, sync i/o's: 0
Pending flushes (fsync) log: 0; buffer pool: 0
119872 OS file reads, 4535167 OS file writes, 204860 OS fsyncs
0.00 reads/s, 0 avg bytes/read, 0.17 writes/s, 0.17 fsyncs/s
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INSERT BUFFER AND ADAPTIVE HASH INDEX
-------------------------------------
Ibuf: size 1, free list len 0, seg size 2, 3 merges
merged operations:
 insert 0, delete mark 3, delete 0
discarded operations:
 insert 0, delete mark 0, delete 0
17.87 hash searches/s, 7.94 non-hash searches/s
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LOG
---
Log sequence number 121237317822
Log flushed up to   121237317822
Pages flushed up to 121237317822
Last checkpoint at  121237317822
Max checkpoint age    869019772
Checkpoint age target 841862905
Modified age          0
Checkpoint age        0
0 pending log writes, 0 pending chkp writes
3377897 log i/o's done, 0.08 log i/o's/second
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BUFFER POOL AND MEMORY
----------------------
Total memory allocated 5557452800; in additional pool allocated 0
Total memory allocated by read views 88115256
Internal hash tables (constant factor + variable factor)
    Adaptive hash index 130026448 	(84999016 + 45027432)
    Page hash           1329176 (buffer pool 0 only)
    Dictionary cache    32420671 	(21251248 + 11169423)
    File system         5641712 	(812272 + 4829440)
    Lock system         13283056 	(13281976 + 1080)
    Recovery system     0 	(0 + 0)
Dictionary memory allocated 11169423
Buffer pool size        327676
Buffer pool size, bytes 5368643584
Free buffers            4096
Database pages          320832
Old database pages      118350
Modified db pages       0
Percent of dirty pages(LRU & free pages): 0.000
Max dirty pages percent: 75.000
Pending reads 0
Pending writes: LRU 0, flush list 0, single page 0
Pages made young 63077, not young 5205112
0.00 youngs/s, 0.00 non-youngs/s
Pages read 112920, created 1095829, written 1086096
0.00 reads/s, 0.00 creates/s, 0.04 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: 320832, unzip_LRU len: 0
I/O sum[8]:cur[0], unzip sum[0]:cur[0]
----------------------
INDIVIDUAL BUFFER POOL INFO
----------------------
---BUFFER POOL 0
Buffer pool size        81919
Buffer pool size, bytes 1342160896
Free buffers            1024
Database pages          80216
Old database pages      29590
Modified db pages       0
Percent of dirty pages(LRU & free pages): 0.000
Max dirty pages percent: 75.000
Pending reads 0
Pending writes: LRU 0, flush list 0, single page 0
Pages made young 15439, not young 1530459
0.00 youngs/s, 0.00 non-youngs/s
Pages read 28114, created 274308, written 300941
0.00 reads/s, 0.00 creates/s, 0.04 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: 80216, unzip_LRU len: 0
I/O sum[2]:cur[0], unzip sum[0]:cur[0]
---BUFFER POOL 1
Buffer pool size        81919
Buffer pool size, bytes 1342160896
Free buffers            1024
Database pages          80203
Old database pages      29586
Modified db pages       0
Percent of dirty pages(LRU & free pages): 0.000
Max dirty pages percent: 75.000
Pending reads 0
Pending writes: LRU 0, flush list 0, single page 0
Pages made young 15522, not young 1258873
0.00 youngs/s, 0.00 non-youngs/s
Pages read 28067, created 273468, written 261568
0.00 reads/s, 0.00 creates/s, 0.00 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: 80203, unzip_LRU len: 0
I/O sum[2]:cur[0], unzip sum[0]:cur[0]
---BUFFER POOL 2
Buffer pool size        81919
Buffer pool size, bytes 1342160896
Free buffers            1024
Database pages          80203
Old database pages      29586
Modified db pages       0
Percent of dirty pages(LRU & free pages): 0.000
Max dirty pages percent: 75.000
Pending reads 0
Pending writes: LRU 0, flush list 0, single page 0
Pages made young 16266, not young 1098396
0.00 youngs/s, 0.00 non-youngs/s
Pages read 28483, created 274229, written 258852
0.00 reads/s, 0.00 creates/s, 0.00 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: 80203, unzip_LRU len: 0
I/O sum[2]:cur[0], unzip sum[0]:cur[0]
---BUFFER POOL 3
Buffer pool size        81919
Buffer pool size, bytes 1342160896
Free buffers            1024
Database pages          80210
Old database pages      29588
Modified db pages       0
Percent of dirty pages(LRU & free pages): 0.000
Max dirty pages percent: 75.000
Pending reads 0
Pending writes: LRU 0, flush list 0, single page 0
Pages made young 15850, not young 1317384
0.00 youngs/s, 0.00 non-youngs/s
Pages read 28256, created 273824, written 264735
0.00 reads/s, 0.00 creates/s, 0.00 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: 80210, unzip_LRU len: 0
I/O sum[2]:cur[0], unzip sum[0]:cur[0]
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ROW OPERATIONS
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0 queries inside InnoDB, 0 queries in queue
0 read views open inside InnoDB
0 RW transactions active inside InnoDB
0 RO transactions active inside InnoDB
0 out of 1000 descriptors used
Main thread id 34588, state: sleeping
Number of rows inserted 373856689, updated 1791, deleted 0, read 7465121340
0.00 inserts/s, 0.00 updates/s, 0.00 deletes/s, 3739.34 reads/s
Number of system rows inserted 0, updated 0, deleted 0, read 318
0.00 inserts/s, 0.00 updates/s, 0.00 deletes/s, 0.00 reads/s
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END OF INNODB MONITOR OUTPUT
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