MySQL事务发生死锁，但SHOW ENGINE INNODB STATUS不显示真正的死锁

Question

我在修改MySQL数据库中的同一个表的2个进程中遇到了一些问题。偶尔它会导致死锁，并且其中一个或另一个进程得到一个'尝试锁定时发现的死锁;尝试重新启动事务'错误。

我发现了几个答案，为什么这发生在stackoverflow上，这让我有一些解决问题的方法。 （只需重试交易）。我希望有一个比这更好的解决方案，因此开始使用SHOW ENGINE INNODB STATUS进行调查。

我一直困惑的STATUS命令的输出。从我所看到的情况来看，它并没有表现出真正的僵局。第一笔交易等待一行锁定购买第二笔交易，第一笔交易不持有其他锁定。第二个事务持有4个锁，其中一个是第一个事务所需的锁，并且正在等待第5个锁。没有提到任何其他交易持有的第五把锁。

有关僵局的输出是：

------------------------ 
LATEST DETECTED DEADLOCK 
------------------------ 
130514 8:54:12 
*** (1) TRANSACTION: 
TRANSACTION 0 487333931, ACTIVE 0 sec, process no 1007, OS thread id 2990889792 fetching rows 
mysql tables in use 1, locked 1 
LOCK WAIT 3 lock struct(s), heap size 320, 24 row lock(s), undo log entries 3 
MySQL thread id 774102, query id 166772615 localhost 127.0.0.1 nesie updating 
DELETE FROM DeviceStatus WHERE serialNo=1234567 AND subDevice=1 AND (parameter='band' OR parameter='arfcn' OR parameter='txPower' OR parameter='lac' OR parameter='cellId' OR parameter='channel' OR parameter='rxReversePower' OR parameter='reverseSnr' OR parameter='reverseGmp' OR parameter='reverseBepm' OR parameter='mobileHeldOn' OR parameter='mobileHeldBand' OR parameter='mobileTxPower' OR parameter='mobileCommandedPower' OR parameter='rxPathLoss' OR parameter='holdState' OR parameter='band' OR parameter='channel' OR parameter='arfcn' OR parameter='rxForwardPower' OR parameter='forwardSnr' OR parameter='forwardGmp' OR parameter='forwardBepm' OR parameter='lac' OR parameter='cellId') 
*** (1) WAITING FOR THIS LOCK TO BE GRANTED: 
RECORD LOCKS space id 1267 page no 3 n bits 96 index `PRIMARY` of table `nesie`.`DeviceStatus` trx id 0 487333931 lock_mode X waiting 
Record lock, heap no 20 PHYSICAL RECORD: n_fields 6; compact format; info bits 0 
0: len 4; hex 80151487; asc  ;; 1: len 4; hex 80000001; asc  ;; 2: len 10; hex 6d6f6e69746f72696e67; asc monitoring;; 3: len 6; hex 00001d0c202a; asc  *;; 4: len 7; hex 00000000342dbd; asc  4- ;; 5: len 4; hex 80000000; asc  ;; 

*** (2) TRANSACTION: 
TRANSACTION 0 487333930, ACTIVE 0 sec, process no 1007, OS thread id 3063302976 inserting, thread declared inside InnoDB 488 
mysql tables in use 1, locked 1 
5 lock struct(s), heap size 320, 6 row lock(s), undo log entries 4 
MySQL thread id 774099, query id 166772616 localhost nesie update 
REPLACE INTO DeviceStatus VALUES (1381511,1,'scanning',1),(1381511,1,'monitoring',0),(1381511,1,'transmitting',0),(1381511,1,'power',-84),(1381511,1,'band',1),(1381511,1,'uarfcn',10661),(1381511,1,'scramblingCode',377) 
*** (2) HOLDS THE LOCK(S): 
RECORD LOCKS space id 1267 page no 3 n bits 96 index `PRIMARY` of table `nesie`.`DeviceStatus` trx id 0 487333930 lock_mode X locks rec but not gap 
Record lock, heap no 20 PHYSICAL RECORD: n_fields 6; compact format; info bits 0 
0: len 4; hex 80151487; asc  ;; 1: len 4; hex 80000001; asc  ;; 2: len 10; hex 6d6f6e69746f72696e67; asc monitoring;; 3: len 6; hex 00001d0c202a; asc  *;; 4: len 7; hex 00000000342dbd; asc  4- ;; 5: len 4; hex 80000000; asc  ;; 

Record lock, heap no 21 PHYSICAL RECORD: n_fields 6; compact format; info bits 0 
0: len 4; hex 80151487; asc  ;; 1: len 4; hex 80000001; asc  ;; 2: len 5; hex 706f776572; asc power;; 3: len 6; hex 00001d0c202a; asc  *;; 4: len 7; hex 00000000342e11; asc  4. ;; 5: len 4; hex 7fffffac; asc  ;; 

Record lock, heap no 22 PHYSICAL RECORD: n_fields 6; compact format; info bits 0 
0: len 4; hex 80151487; asc  ;; 1: len 4; hex 80000001; asc  ;; 2: len 8; hex 7363616e6e696e67; asc scanning;; 3: len 6; hex 00001d0c202a; asc  *;; 4: len 7; hex 00000000342d96; asc  4- ;; 5: len 4; hex 80000001; asc  ;; 

Record lock, heap no 24 PHYSICAL RECORD: n_fields 6; compact format; info bits 0 
0: len 4; hex 80151487; asc  ;; 1: len 4; hex 80000001; asc  ;; 2: len 12; hex 7472616e736d697474696e67; asc transmitting;; 3: len 6; hex 00001d0c202a; asc  *;; 4: len 7; hex 00000000342de6; asc  4- ;; 5: len 4; hex 80000000; asc  ;; 

*** (2) WAITING FOR THIS LOCK TO BE GRANTED: 
RECORD LOCKS space id 1267 page no 3 n bits 96 index `PRIMARY` of table `nesie`.`DeviceStatus` trx id 0 487333930 lock_mode X locks rec but not gap waiting 
Record lock, heap no 17 PHYSICAL RECORD: n_fields 6; compact format; info bits 0 
0: len 4; hex 80151487; asc  ;; 1: len 4; hex 80000001; asc  ;; 2: len 4; hex 62616e64; asc band;; 3: len 6; hex 00001d0c19ff; asc  ;; 4: len 7; hex 000000003428a7; asc  4(;; 5: len 4; hex 80000001; asc  ;; 

*** WE ROLL BACK TRANSACTION (1) 

我的问题是：

为什么这个标记为死锁，事务1可以排队，直到交易2次完成，因为它没有保持所需的锁通过交易2？

有没有人知道这是MySQL的正常行为还是它可能是一个错误？

谢谢，

西蒙。

Answer 1

您可以使用新的5.6变量：http://dev.mysql.com/doc/refman/5.6/en/innodb-parameters.html#sysvar_innodb_print_all_deadlocks

这样你就可以记录所有死锁，也许发现该交易引发的僵局。