解决MySQL死锁的方法
admin
2023-05-04 09:21:51
0

下面一起来了解下解决MySQL死锁的方法,相信大家看完肯定会受益匪浅,文字在精不在多,希望解决MySQL死锁的方法这篇短内容是你想要的。 

一、查看MySQL死锁

MySQL数据库会自己解决死锁,kill掉一个session的事务,让另外一个session的事务可以执行

 SQL>SHOW ENGINE INNODB STATUS\G

    LATEST DETECTED DEADLOCK

2018-02-12 15:42:06 0x7f6bd43df700
(1) TRANSACTION:
TRANSACTION 3368, ACTIVE 16717 sec starting index read
mysql tables in use 1, locked 1
LOCK WAIT 7 lock struct(s), heap size 1136, 6 row lock(s), undo log entries 2
MySQL thread id 35, OS thread handle 140101230081792, query id 297 localhost root updating
delete from  employees  where emp_no=10001
(1) WAITING FOR THIS LOCK TO BE GRANTED:
RECORD LOCKS space id 26 page no 4 n bits 408 index PRIMARY of table employees.employees trx id 3368 lock_mode X locks rec but not gap waiting
Record lock, heap no 2 PHYSICAL RECORD: n_fields 8; compact format; info bits 0
0: len 4; hex 80002711; asc   ' ;;
1: len 6; hex 000000000b20; asc       ;;
2: len 7; hex be0000013a0110; asc     :  ;;
3: len 3; hex 8f4322; asc  C";;
4: len 6; hex 47656f726769; asc Georgi;;
5: len 7; hex 466163656c6c6f; asc Facello;;
6: len 1; hex 01; asc  ;;
7: len 3; hex 8f84da; asc    ;;

(2) TRANSACTION:
TRANSACTION 3374, ACTIVE 79 sec starting index read
mysql tables in use 1, locked 1
4 lock struct(s), heap size 1136, 2 row lock(s)
MySQL thread id 36, OS thread handle 140101099058944, query id 298 localhost root updating
delete from  employees  where emp_no=10001
(2) HOLDS THE LOCK(S):
RECORD LOCKS space id 26 page no 4 n bits 408 index PRIMARY of table employees.employees trx id 3374 lock mode S locks rec but not gap
Record lock, heap no 2 PHYSICAL RECORD: n_fields 8; compact format; info bits 0
0: len 4; hex 80002711; asc   ' ;;
1: len 6; hex 000000000b20; asc       ;;
2: len 7; hex be0000013a0110; asc     :  ;;
3: len 3; hex 8f4322; asc  C";;
4: len 6; hex 47656f726769; asc Georgi;;
5: len 7; hex 466163656c6c6f; asc Facello;;
6: len 1; hex 01; asc  ;;
7: len 3; hex 8f84da; asc    ;;

*** (2) WAITING FOR THIS LOCK TO BE GRANTED:
RECORD LOCKS space id 26 page no 4 n bits 408 index PRIMARY of table employees.employees trx id 3374 lock_mode X locks rec but not gap waiting
Record lock, heap no 2 PHYSICAL RECORD: n_fields 8; compact format; info bits 0
0: len 4; hex 80002711; asc   ' ;;
1: len 6; hex 000000000b20; asc       ;;
2: len 7; hex be0000013a0110; asc     :  ;;
3: len 3; hex 8f4322; asc  C";;
4: len 6; hex 47656f726769; asc Georgi;;
5: len 7; hex 466163656c6c6f; asc Facello;;
6: len 1; hex 01; asc  ;;
7: len 3; hex 8f84da; asc    ;;

*** WE ROLL BACK TRANSACTION (2)

注意:死锁不记录在错误日志中,只能通过 SHOW ENGINE INNODB STATUS\G查看,而且 SHOW ENGINE INNODB STATUS\G只会记录上一次的死锁,如果要看上上次的则看不到

死锁模拟

session1:
mysql> begin;
Query OK, 0 rows affected (0.00 sec)

mysql> select * from employees  where emp_no=10001 lock in share mode;
+--------+------------+------------+-----------+--------+------------+
| emp_no | birth_date | first_name | last_name | gender | hire_date  |
+--------+------------+------------+-----------+--------+------------+
|  10001 | 1953-09-02 | Georgi     | Facello   | M      | 1986-06-26 |
+--------+------------+------------+-----------+--------+------------+
1 row in set (0.00 sec)

session2:

mysql> delete from  employees  where emp_no=10001;  -- 卡住

session1:

mysql> delete from  employees  where emp_no=10001;
ERROR 1213 (40001): Deadlock found when trying to get lock; try restarting transaction

session2:

上面卡住的语句已经被执行

Query OK, 1 row affected (5.76 sec)

死锁分析:
session1持有s锁,session2执行删除操作请求x,但s、x互斥,session2进入请求队列等待(等待session1释放s锁),session1又在请求x锁,这个时候队列中session2在排队,还轮不上session1,session1就等待,这种循环等待出现,死锁就出现了。

看完解决MySQL死锁的方法这篇文章后,很多读者朋友肯定会想要了解更多的相关内容,如需获取更多的行业信息,可以关注我们的行业资讯栏目。

相关内容

热门资讯

Google在港推出AI代理G... 观点网讯:7月29日,Google在香港推出AI代理Gemini Spark,该代理可全天候在后台运...
5G+165Hz!联想新品官宣... 近两年来,小屏平板一直是比较有趣的一个品类。 不同于大平板注重效率、手机追求万能的特点,拯救者Y70...
原创 马... 马斯克又出来了。这次说2036年钱就没用了。 理由是人工智能加机器人,东西多到你用不完,还拿钱干嘛...
美的集团:我国智能家居互联互通... IT之家 7 月 30 日消息,美的集团今日发布公告,7 月 21 日至 23 日,智能家居互联互通...
华为新款MatePad Pro... 【CNMO科技消息】7月30日,@华为终端 官宣全新旗舰平板华为MatePad Pro。 新款华为...
从实验室到实景验证:6G光子太... 全息通信是第六代移动通信(6G)的典型应用场景之一,旨在通过融合无线传输与全息三维成像技术,实现超大...
从“能对话”到“能干活”——人... 【经济界面】 光明日报记者 刘坤 李晓东 周洪双 人工智能(AI)眼镜化身为个人“助理”,实时进行...
【全新发布】UminiP Pr... (来源:洲明科技)
日本通过“H3火箭8号”发射失... △H3火箭(资料图) 日本文部科学省30日召开关于去年“H3火箭8号”发射失败的会议。会议通过的最终...
互联网巨头抢滩健康硬件,上游芯... 封面新闻记者 付文超 当下,互联网巨头对健康硬件的押注,正在成为产业现实,加速拉动整个产业链步入新一...