MySQL死锁的解释需要

Question

我通过“ SHOW INNODB
STATUS”收到了以下死锁日志。有人可以解释一下为什么交易被中止吗？似乎事务2持有该锁，但也卡住以请求相同的锁（“等待”部分除外），当事务1也需要它时，这将导致死锁。

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091205  6:25:01 INNODB MONITOR OUTPUT                                                                                                                                                                          
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Per second averages calculated from the last 39 seconds                                                                                                                                                        
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SEMAPHORES                                                                                                                                                                                                     
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OS WAIT ARRAY INFO: reservation count 233826, signal count 229982                                                                                                                                              
Mutex spin waits 0, rounds 1569878, OS waits 4740                                                                                                                                                              
RW-shared spins 517345, OS waits 227127; RW-excl spins 4390, OS waits 1945                                                                                                                                     
------------------------                                                                                                                                                                                       
LATEST DETECTED DEADLOCK                                                                                                                                                                                       
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091205  6:19:35                                                                                                                                                                                                
*** (1) TRANSACTION:                                                                                                                                                                                           
TRANSACTION 0 479286429, ACTIVE 0 sec, process no 17618, OS thread id 2963139472 fetching rows                                                                                                                 
mysql tables in use 1, locked 1                                                                                                                                                                                
LOCK WAIT 176 lock struct(s), heap size 11584                                                                                                                                                                  
MySQL thread id 330396, query id 97467367 64-71-26-218.static.wiline.com 64.71.26.218 autotaggeruser Sorting result                                                                                            
SELECT api_key,completed,compute_units,created,deleted,flags,func_name,group_id,hostname,is_meta,jid,label,language,num_children,parent_ujid,priority,process_id,restartable,status,type,uid,ujid,version,wid FROM jobs WHERE status='new' and is_meta=0 ORDER BY priority asc,jid asc FOR UPDATE                                                                                                                             
*** (1) WAITING FOR THIS LOCK TO BE GRANTED:                                                                                                                                                                   
RECORD LOCKS space id 0 page no 17549 n bits 128 index `PRIMARY` of table `takeyourorder/jobs` trx id 0 479286429 lock_mode X waiting                                                               
Record lock, heap no 61 PHYSICAL RECORD: n_fields 26; compact format; info bits 0                                                                                                                              
0: len 8; hex 800000000000277c; asc       '|;; 1: len 6; hex 00001c915499; asc     T ;; 2: len 7; hex 00000006e21e2a; asc       *;; 3: len 8; hex 8000000000000002; asc         ;; 4: len 8; hex 8000000000000845; asc        E;; 5: SQL NULL; 6: len 8; hex 8000000000002773; asc       's;; 7: len 1; hex 80; asc  ;; 8: len 8; hex 8000000000000002; asc         ;; 9: len 16; hex 636f72656f66746865627261696e2d75; asc coreofthebrain-u;; 10: len 4; hex 80000eb8; asc     ;; 11: len 1; hex 01; asc  ;; 12: len 30; hex 322e362e32202872656c6561736532362d6d61696e742c20417072203139; asc 2.6.2 (release26-maint, Apr 19;...(truncated); 13: len 30; hex 5f5f6d61696e5f5f2e3c6c616d6264613e206174203c737464696e3e3a31; asc __main__.<lambda> at <stdin>:1;; 14: len 5; hex 8000000001; asc      ;; 15: len 0; hex ; asc ;; 16: len 4; hex 80000000; asc     ;; 17: len 4; hex 80000005; asc     ;; 18: len 4; hex 4b19fb58; asc K  X;; 19: len 4; hex 4b19fb77; asc K  w;; 20: len 1; hex 07; asc  ;; 21: len 1; hex 80; asc  ;; 22: len 4; hex 80000000; asc     ;; 23: len 4; hex 80000000; asc     ;; 24: len 1; hex 80; asc  ;; 25: len 4; hex 80001415; asc     ;;

*** (2) TRANSACTION:
TRANSACTION 0 479286425, ACTIVE 0 sec, process no 17618, OS thread id 2971134864 starting index read, thread declared inside InnoDB 500
mysql tables in use 1, locked 1                                                                                                        
7 lock struct(s), heap size 1024, undo log entries 3                                                                                   
MySQL thread id 330430, query id 97467371 64-71-26-218.static.wiline.com 64.71.26.218 autotaggeruser Updating                          
UPDATE jobs SET status='done' WHERE jid=10099                                                                                          
*** (2) HOLDS THE LOCK(S):                                                                                                             
RECORD LOCKS space id 0 page no 17549 n bits 128 index `PRIMARY` of table `takeyourorder/jobs` trx id 0 479286425 lock_mode X locks rec but not gap
Record lock, heap no 61 PHYSICAL RECORD: n_fields 26; compact format; info bits 0                                                                             
0: len 8; hex 800000000000277c; asc       '|;; 1: len 6; hex 00001c915499; asc     T ;; 2: len 7; hex 00000006e21e2a; asc       *;; 3: len 8; hex 8000000000000002; asc         ;; 4: len 8; hex 8000000000000845; asc        E;; 5: SQL NULL; 6: len 8; hex 8000000000002773; asc       's;; 7: len 1; hex 80; asc  ;; 8: len 8; hex 8000000000000002; asc         ;; 9: len 16; hex 636f72656f66746865627261696e2d75; asc coreofthebrain-u;; 10: len 4; hex 80000eb8; asc     ;; 11: len 1; hex 01; asc  ;; 12: len 30; hex 322e362e32202872656c6561736532362d6d61696e742c20417072203139; asc 2.6.2 (release26-maint, Apr 19;...(truncated); 13: len 30; hex 5f5f6d61696e5f5f2e3c6c616d6264613e206174203c737464696e3e3a31; asc __main__.<lambda> at <stdin>:1;; 14: len 5; hex 8000000001; asc      ;; 15: len 0; hex ; asc ;; 16: len 4; hex 80000000; asc     ;; 17: len 4; hex 80000005; asc     ;; 18: len 4; hex 4b19fb58; asc K  X;; 19: len 4; hex 4b19fb77; asc K  w;; 20: len 1; hex 07; asc  ;; 21: len 1; hex 80; asc  ;; 22: len 4; hex 80000000; asc     ;; 23: len 4; hex 80000000; asc     ;; 24: len 1; hex 80; asc  ;; 25: len 4; hex 80001415; asc     ;;

*** (2) WAITING FOR THIS LOCK TO BE GRANTED:
RECORD LOCKS space id 0 page no 17548 n bits 144 index `PRIMARY` of table `takeyourorder/jobs` trx id 0 479286425 lock_mode X locks rec but not gap waiting
Record lock, heap no 73 PHYSICAL RECORD: n_fields 26; compact format; info bits 0                                                                                     
0: len 8; hex 8000000000002773; asc       's;; 1: len 6; hex 00001c9151f5; asc     Q ;; 2: len 7; hex 800000003c0110; asc     <  ;; 3: len 8; hex 8000000000000002; asc         ;; 4: len 8; hex 800000000000083d; asc        =;; 5: SQL NULL; 6: SQL NULL; 7: len 1; hex 81; asc  ;; 8: len 8; hex 8000000000000002; asc         ;; 9: len 16; hex 636f72656f66746865627261696e2d75; asc coreofthebrain-u;; 10: len 4; hex 80000eb8; asc     ;; 11: len 1; hex 01; asc  ;; 12: len 30; hex 322e362e32202872656c6561736532362d6d61696e742c20417072203139; asc 2.6.2 (release26-maint, Apr 19;...(truncated); 13: len 30; hex 5f5f6d61696e5f5f2e3c6c616d6264613e206174203c737464696e3e3a31; asc __main__.<lambda> at <stdin>:1;; 14: len 5; hex 8000000001; asc      ;; 15: len 0; hex ; asc ;; 16: len 4; hex 80000000; asc     ;; 17: len 4; hex 80000005; asc     ;; 18: len 4; hex 4b19fb58; asc K  X;; 19: SQL NULL; 20: len 1; hex 02; asc  ;; 21: len 1; hex 80; asc  ;; 22: len 4; hex 80000014; asc     ;; 23: len 4; hex 80000000; asc     ;; 24: len 1; hex 80; asc  ;; 25: SQL NULL;

*** WE ROLL BACK TRANSACTION (1)

Answer 1

第一步是确定两个查询是什么：

SELECT
API_KEY，完成compute_units，创建，删除，标记，func_name，GROUP_ID，主机名，is_meta，JID，标签，语言num_children，parent_ujid优先，process_id，重新启动，状态，类型，UID，ujid，版本，妇女参与发展的乔布斯WHERE状态=
‘新’并且is_meta = 0 ORDER BY优先级asc，jid asc FOR UPDATE

..和：

UPDATE作业SET status =’done’WHERE jid = 10099

第一个是SELECT，第二个是UPDATE。但是关键是FOR UPDATESELECT的末尾，我以粗体强调了这一点。

该FOR UPDATE语法用于锁定阅读-
您可以在此处阅读有关锁定的文档。在MySQL的僵局文档suggestes使用READ COMMITTED，如果你遇到类似的锁定这些的问题。

显示INNODB状态