Storage engines

InnoDB

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

[ Variables | Buffer Pool | InnoDB Status ]

=====================================
2026-09-05 22:52:04 0x2a04 INNODB MONITOR OUTPUT
=====================================
Per second averages calculated from the last 60 seconds
-----------------
BACKGROUND THREAD
-----------------
srv_master_thread loops: 4058 srv_active, 0 srv_shutdown, 5497 srv_idle
srv_master_thread log flush and writes: 9555
----------
SEMAPHORES
----------
OS WAIT ARRAY INFO: reservation count 71284
--Thread 8488 has waited at buf0lru.cc line 936 for 0.00 seconds the semaphore:
Mutex at 00000173A48522C0, Mutex BUF_POOL created buf0buf.cc:1683, lock var 2

--Thread 3744 has waited at buf0lru.cc line 936 for 0.00 seconds the semaphore:
Mutex at 00000173A48522C0, Mutex BUF_POOL created buf0buf.cc:1683, lock var 2

--Thread 10520 has waited at row0ins.cc line 2697 for 0.00 seconds the semaphore:
X-lock (wait_ex) on RW-latch at 00000173A4F32538 created in file buf0buf.cc line 1390
a writer (thread id 10520) has reserved it in mode  wait exclusive
number of readers 2, waiters flag 0, lock_word: fffffffe
Last time write locked in file btr0cur.cc line 305
OS WAIT ARRAY INFO: signal count 8141
RW-shared spins 2461, rounds 69411, OS waits 2173
RW-excl spins 901, rounds 11241, OS waits 274
RW-sx spins 5, rounds 150, OS waits 5
Spin rounds per wait: 28.20 RW-shared, 12.48 RW-excl, 30.00 RW-sx
------------
TRANSACTIONS
------------
Trx id counter 11224
Purge done for trx's n:o < 11223 undo n:o < 0 state: running
History list length 9
LIST OF TRANSACTIONS FOR EACH SESSION:
---TRANSACTION 283071172686328, not started
0 lock struct(s), heap size 1128, 0 row lock(s)
---TRANSACTION 283071172682160, ACTIVE 0 sec starting index read
mysql tables in use 1, locked 0
0 lock struct(s), heap size 1128, 0 row lock(s)
MySQL thread id 14027, OS thread handle 8488, query id 732645 localhost 127.0.0.1 pma Statistics
SELECT `tables` FROM `phpmyadmin`.`pma__recent` WHERE `username` = 'root'
Trx read view will not see trx with id >= 11223, sees < 11223
---TRANSACTION 283071172665488, ACTIVE 0 sec starting index read
mysql tables in use 1, locked 0
0 lock struct(s), heap size 1128, 0 row lock(s)
MySQL thread id 14025, OS thread handle 3744, query id 732661 localhost 127.0.0.1 pma Statistics
SELECT `tables` FROM `phpmyadmin`.`pma__recent` WHERE `username` = 'root'
Trx read view will not see trx with id >= 11223, sees < 11223
---TRANSACTION 283071172677992, not started
0 lock struct(s), heap size 1128, 0 row lock(s)
---TRANSACTION 283071172673824, not started
0 lock struct(s), heap size 1128, 0 row lock(s)
---TRANSACTION 283071172711336, not started
0 lock struct(s), heap size 1128, 0 row lock(s)
---TRANSACTION 11223, ACTIVE 0 sec inserting
mysql tables in use 1, locked 1
1 lock struct(s), heap size 1128, 0 row lock(s)
MySQL thread id 14019, OS thread handle 10520, query id 732665 localhost 127.0.0.1 pma Update
REPLACE INTO `phpmyadmin`.`pma__recent` (`username`, `tables`) VALUES ('root', '[{\"db\":\"information_schema\",\"table\":\"INNODB_CMP\"},{\"db\":\"information_schema\",\"table\":\"EVENTS\"},{\"db\":\"information_schema\",\"table\":\"INNODB_CMP_RESET\"},{\"db\":\"information_schema\",\"table\":\"ROUTINES\"},{\"db\":\"information_schema\",\"table\":\"PROCESSLIST\"},{\"db\":\"information_schema\",\"table\":\"CLIENT_STATISTICS\"},{\"db\":\"information_schema\",\"table\":\"TABLESPACES\"},{\"db\":\"information_schema\",\"table\":\"SYSTEM_VARIABLES\"},{\"db\":\"information_schema\",\"table\":\"TABLE
---TRANSACTION 283071172703000, not started flushing log
mysql tables in use 1, locked 1
0 lock struct(s), heap size 1128, 0 row lock(s)
---TRANSACTION 283071172698832, not started
0 lock struct(s), heap size 1128, 0 row lock(s)
---TRANSACTION 283071172690496, not started
0 lock struct(s), heap size 1128, 0 row lock(s)
---TRANSACTION 283071172669656, 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: complete io for buf page (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: 1
10035 OS file reads, 42127 OS file writes, 24996 OS fsyncs
4.28 reads/s, 16384 avg bytes/read, 14.22 writes/s, 6.17 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 0 buffer(s)
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)
12.38 hash searches/s, 39.27 non-hash searches/s
---
LOG
---
Log sequence number 7376121
Log flushed up to   7374823
Pages flushed up to 7369011
Last checkpoint at  7359702
1 pending log flushes, 0 pending chkp writes
12661 log i/o's done, 3.22 log i/o's/second
----------------------
BUFFER POOL AND MEMORY
----------------------
Total large memory allocated 33554432
Dictionary memory allocated 120192
Buffer pool size   1003
Free buffers       741
Database pages     256
Old database pages 0
Modified db pages  12
Percent of dirty pages(LRU & free pages): 1.202
Max dirty pages percent: 75.000
Pending reads 0
Pending writes: LRU 0, flush list 0, single page 0
Pages made young 0, not young 0
0.00 youngs/s, 0.00 non-youngs/s
Pages read 9999, created 467, written 25166
4.28 reads/s, 0.00 creates/s, 9.75 writes/s
Buffer pool hit rate 963 / 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: 256, unzip_LRU len: 0
I/O sum[745]:cur[1], unzip sum[0]:cur[0]
--------------
ROW OPERATIONS
--------------
0 queries inside InnoDB, 0 queries in queue
2 read views open inside InnoDB
Process ID=2216, Main thread ID=5740, state: sleeping
Number of rows inserted 123, updated 5264, deleted 4, read 45859
0.00 inserts/s, 2.57 updates/s, 0.00 deletes/s, 21.68 reads/s
Number of system rows inserted 0, updated 0, deleted 0, read 7794
0.00 inserts/s, 0.00 updates/s, 0.00 deletes/s, 5.82 reads/s
----------------------------
END OF INNODB MONITOR OUTPUT
============================