MySQL错误：超过了锁定等待超时； 尝试重新启动事务查询

Question

我发现许多人从MySQL收到了相同的错误消息，错误状态相同= 41000，错误代码相同= 1205。

但是，其中大多数涉及2个事务和一个僵局。

根据SHOW ENGINE INNODB STATUS输出，只有1个事务：

=====================================
140715  4:42:37 INNODB MONITOR OUTPUT
=====================================
Per second averages calculated from the last 21 seconds
----------
SEMAPHORES
----------
OS WAIT ARRAY INFO: reservation count 1630, signal count 1612
Mutex spin waits 0, rounds 10461, OS waits 205
RW-shared spins 2051, OS waits 1024; RW-excl spins 407, OS waits 380
------------
TRANSACTIONS
------------
Trx id counter 0 8450727
Purge done for trx's n:o < 0 8450719 undo n:o < 0 0
History list length 10
LIST OF TRANSACTIONS FOR EACH SESSION:
---TRANSACTION 0 0, not started, process no 8967, OS thread id 140114720237312
MySQL thread id 31142, query id 6206904 localhost root
SHOW ENGINE INNODB STATUS
---TRANSACTION 0 8450588, not started, process no 8967, OS thread id 140114589861632
MySQL thread id 30909, query id 6153062 [my IP] [my username]
---TRANSACTION 0 8450484, not started, process no 8967, OS thread id 140114719172352
MySQL thread id 30899, query id 6152893 [my IP] [my username]
---TRANSACTION 0 8450702, not started, process no 8967, OS thread id 140114586134272
MySQL thread id 28747, query id 6206903 [my IP] [my username]
---TRANSACTION 0 8450726, ACTIVE 34 sec, process no 8967, OS thread id 140114484233984 inserting
mysql tables in use 1, locked 1
LOCK WAIT 3 lock struct(s), heap size 1216, 1 row lock(s)
MySQL thread id 31147, query id 6206832 [my IP] [my username] update
INSERT INTO [My table] [the rest of the statement....]
------- TRX HAS BEEN WAITING 34 SEC FOR THIS LOCK TO BE GRANTED:
RECORD LOCKS space id 0 page no 45066 n bits 432 index `PRIMARY` of table `[My DB]`.`[some table]` trx id 0 8450726 lock mode S locks rec but not gap waiting
Record lock, heap no 359 PHYSICAL RECORD: n_fields 6; compact format; info bits 0
 0: len 8; hex 000000000000bdca; asc         ;; 1: len 6; hex 00000080f2a0; asc       ;; 2: len 7; hex 80000000390110; asc     9  ;; 3: len 6; hex 73797374656d; asc system;; 4: len 1; hex 02; asc  ;; 5: len 4; hex 53c4b11b; asc S   ;;

------------------
---TRANSACTION 0 8450725, ACTIVE 35 sec, process no 8967, OS thread id 140114588530432
MySQL thread id 31146, query id 6206822 [my IP] [my username]
Trx read view will not see trx with id >= 0 8450726, sees < 0 8450720
---TRANSACTION 0 8450720, ACTIVE 36 sec, process no 8967, OS thread id 140114590127872
393 lock struct(s), heap size 47088, 31495 row lock(s), undo log entries 229
MySQL thread id 31145, query id 6206823 [my IP] [my username]
--------
FILE I/O
--------
I/O thread 0 state: waiting for i/o request (insert buffer thread)
I/O thread 1 state: waiting for i/o request (log thread)
I/O thread 2 state: waiting for i/o request (read thread)
I/O thread 3 state: waiting for i/o request (write thread)
Pending normal aio reads: 0, aio writes: 0,
 ibuf aio reads: 0, log i/o's: 0, sync i/o's: 0
Pending flushes (fsync) log: 0; buffer pool: 0
10744 OS file reads, 25629 OS file writes, 18087 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 5, seg size 7,
519 inserts, 519 merged recs, 76 merges
Hash table size 17393, node heap has 12 buffer(s)
0.00 hash searches/s, 0.00 non-hash searches/s
---
LOG
---
Log sequence number 5 2505544157
Log flushed up to   5 2505544157
Last checkpoint at  5 2505544157
0 pending log writes, 0 pending chkp writes
15981 log i/o's done, 0.00 log i/o's/second
----------------------
BUFFER POOL AND MEMORY
----------------------
Total memory allocated 21017578; in additional pool allocated 1048576
Dictionary memory allocated 466176
Buffer pool size   512
Free buffers       0
Database pages     498
Modified db pages  0
Pending reads 0
Pending writes: LRU 0, flush list 0, single page 0
Pages read 12504, created 289, written 10838
0.00 reads/s, 0.00 creates/s, 0.00 writes/s
Buffer pool hit rate 1000 / 1000
--------------
ROW OPERATIONS
--------------
0 queries inside InnoDB, 0 queries in queue
2 read views open inside InnoDB
Main thread process no. 8967, id 140114495788800, state: waiting for server activity
Number of rows inserted 38311, updated 16430, deleted 36, read 6456822
0.00 inserts/s, 0.00 updates/s, 0.00 deletes/s, 0.00 reads/s
----------------------------
END OF INNODB MONITOR OUTPUT
============================

mysql> SELECT @@GLOBAL.tx_isolation, @@tx_isolation, @@session.tx_isolation;
+-----------------------+-----------------+------------------------+
| @@GLOBAL.tx_isolation | @@tx_isolation  | @@session.tx_isolation |
+-----------------------+-----------------+------------------------+
| REPEATABLE-READ       | REPEATABLE-READ | REPEATABLE-READ        |
+-----------------------+-----------------+------------------------+
1 row in set (0.00 sec)

如果我在自动提交设置为true的情况下建立连接，则不存在此问题（我正在使用Apache Common DBCP 1.4）。

Answer 1

我发现了问题。

问题在于，MySQL希望同一事务中的所有查询都可以在同一TCP连接中完成，而通过QueryRunner进行的每个SQL执行都可能会启动与数据库的新TCP连接（尽管可以通过几种方式控制它）。