如何在MySQL上调试超出锁等待超时的时间？
由于某些线程，发生了调试锁定等待超时情况。如果一个线程长时间保留某些记录，则意味着该线程已超过时间。
要查看所有详细信息，请实施以下查询-
mysql> SHOW ENGINE INNODB STATUS;
以下是输出。
+--------+------+---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| Type | Name | Status |
+--------+------+------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| InnoDB | |
=====================================
2018-10-23 09:55:05 0x19e8 INNODB MONITOR OUTPUT
=====================================
Per second averages calculated from the last 7 seconds
-----------------
BACKGROUND THREAD
-----------------
srv_master_thread loops: 2 srv_active, 0 srv_shutdown, 17805 srv_idle
srv_master_thread log flush and writes: 0
----------
SEMAPHORES
----------
OS WAIT ARRAY INFO: reservation count 3
OS WAIT ARRAY INFO: signal count 3
RW-shared spins 0, rounds 0, OS waits 0
RW-excl spins 0, rounds 0, OS waits 0
RW-sx spins 0, rounds 0, OS waits 0
Spin rounds per wait: 0.00 RW-shared, 0.00 RW-excl, 0.00 RW-sx
------------
TRANSACTIONS
------------
Trx id counter 21000
Purge done for trx's n:o < 20998 undo n:o < 0 state: running but idle
History list length 3
LIST OF TRANSACTIONS FOR EACH SESSION:
---TRANSACTION 283438498772800, 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
1025 OS file reads, 545 OS file writes, 11 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 3 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, 0.29 non-hash searches/s
---
LOG
---
Log sequence number 24309079
Log buffer assigned up to 24309079
Log buffer completed up to 24309079
Log written up to 24309079
Log flushed up to 24309079
Added dirty pages up to 24309079
Pages flushed up to 24309079
Last checkpoint at 24309079
388 log i/o's done, 0.00 log i/o's/second
----------------------
BUFFER POOL AND MEMORY
----------------------
Total large memory allocated 8585216
Dictionary memory allocated 361173
Buffer pool size 512
Free buffers 251
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 1002, created 132, written 144
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: 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 = 3260, Main thread ID = 000000000000106C , state = sleeping
Number of rows inserted 0, updated 313, deleted 0, read 4534
0.00 inserts/s, 0.00 updates/s, 0.00 deletes/s, 0.14 reads/s
----------------------------
END OF INNODB MONITOR OUTPUT
============================
|
+--------+------+-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
1 row in set (0.00 sec)
mysql>上面显示了与线程和I/O相关的所有详细信息。