How can I see global locks in MySQL (innodb)?


In order to see the global locks in MySQL (Innodb), use the SHOW command. The below query shows the global locks as well owner of locks and waiters. The following query will also show transaction id and more related to Innodb.

The query is as follows:

mysql> SHOW ENGINE INNODB STATUS\G

The following is the output:

*************************** 1. row ***************************
Type: InnoDB
Name:
Status:
=====================================
2019-01-23 14:46:58 0x2914 INNODB MONITOR OUTPUT
=====================================
Per second averages calculated from the last 23 seconds
-----------------
BACKGROUND THREAD
-----------------
srv_master_thread loops: 87 srv_active, 0 srv_shutdown, 51953 srv_idle
srv_master_thread log flush and writes: 0
----------
SEMAPHORES
----------
OS WAIT ARRAY INFO: reservation count 244
OS WAIT ARRAY INFO: signal count 241
RW-shared spins 23, rounds 37, OS waits 14
RW-excl spins 16, rounds 380, OS waits 9
RW-sx spins 1, rounds 4, OS waits 0
Spin rounds per wait: 1.61 RW-shared, 23.75 RW-excl, 4.00 RW-sx
------------
TRANSACTIONS
------------
Trx id counter 60219
Purge done for trx's n:o < 60218 undo n:o < 0 state: running but idle
History list length 32
LIST OF TRANSACTIONS FOR EACH SESSION:
---TRANSACTION 284507225290560, not started
0 lock struct(s), heap size 1136, 0 row lock(s)
--------
FILE I/O
--------
I/O thread 0 state: wait Windows aio (insert buffer thread)
I/O thread 1 state: wait Windows aio (log thread)
I/O thread 2 state: wait Windows aio (read thread)
I/O thread 3 state: wait Windows aio (read thread)
I/O thread 4 state: wait Windows aio (read thread)
I/O thread 5 state: wait Windows aio (read thread)
I/O thread 6 state: wait Windows aio (write thread)
I/O thread 7 state: wait Windows aio (write thread)
I/O thread 8 state: wait Windows aio (write thread)
I/O thread 9 state: wait Windows aio (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
2134 OS file reads, 2843 OS file writes, 1186 OS fsyncs
0.00 reads/s, 0 avg bytes/read, 0.00 writes/s, 0.00 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 2267, node heap has 0 buffer(s)
Hash table size 2267, node heap has 1 buffer(s)
Hash table size 2267, node heap has 1 buffer(s)
Hash table size 2267, node heap has 1 buffer(s)
Hash table size 2267, node heap has 0 buffer(s)
Hash table size 2267, node heap has 0 buffer(s)
Hash table size 2267, node heap has 0 buffer(s)
Hash table size 2267, node heap has 0 buffer(s)
0.00 hash searches/s, 0.00 non-hash searches/s
---
LOG
---
Log sequence number 44174557
Log buffer assigned up to 44174557
Log buffer completed up to 44174557
Log written up to 44174557
Log flushed up to 44174557
Added dirty pages up to 44174557
Pages flushed up to 44174557
Last checkpoint at 44174557
1117 log i/o's done, 0.00 log i/o's/second
----------------------
BUFFER POOL AND MEMORY
----------------------
Total large memory allocated 8585216
Dictionary memory allocated 503201
Buffer pool size 512
Free buffers 253
Database pages 256
Old database pages 0
Modified db pages 0
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 2111, created 215, written 1437
0.00 reads/s, 0.00 creates/s, 0.00 writes/s
No buffer pool page gets since the last printout
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[0]:cur[0], unzip sum[0]:cur[0]
--------------
ROW OPERATIONS
--------------
0 queries inside InnoDB, 0 queries in queue
0 read views open inside InnoDB
Process ID=8992, Main thread ID=00000000000029F4 , state=sleeping
Number of rows inserted 247, updated 512, deleted 19, read 6593
0.00 inserts/s, 0.00 updates/s, 0.00 deletes/s, 0.00 reads/s
----------------------------
END OF INNODB MONITOR OUTPUT
============================
1 row in set (0.00 sec)

Updated on: 30-Jul-2019

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