大家好,今天碰到一个纯insert操作造成的死锁问题,网上查了一下,有人说是由于GAP LOCK,阅读了相关文档以后,还是不能完全理解为什么会产生死锁,希望哪位朋友能帮忙解释一下。表结构如下:
mysql> show create table MySQLBug;
+----------+----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| Table | Create Table |
+----------+----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| MySQLBug | CREATE TABLE `MySQLBug` (
`id` int(10) unsigned NOT NULL AUTO_INCREMENT,
`value` int(10) unsigned NOT NULL,
PRIMARY KEY (`id`),
UNIQUE KEY `Test_Index` (`value`)
) ENGINE=InnoDB AUTO_INCREMENT=22 DEFAULT CHARSET=utf8 |
+----------+----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
1 row in set (0.00 sec)开启两个不同的会话
session1
mysql> set autocommit=0;
Query OK, 0 rows affected (0.00 sec)mysql> insert into MySQLBug(value) values(34);
Query OK, 1 row affected (0.00 sec)mysql> insert into MySQLBug(value) values(680);
ERROR 1213 (40001): Deadlock found when trying to get lock; try restarting transaction
mysql>
session2
mysql> set autocommit=0;
Query OK, 0 rows affected (0.00 sec)mysql> insert into MySQLBug(value) values(680);
Query OK, 1 row affected (0.00 sec)mysql> insert into MySQLBug(value) values(565); --这句一执行session1就报死锁搜到一篇文章是类似现象
http://bugs.mysql.com/bug.php?id=51140
在文章的最后面有人给出了一些解释,不过没看太明白,还望大家指点一二,谢谢!
mysql> show create table MySQLBug;
+----------+----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| Table | Create Table |
+----------+----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| MySQLBug | CREATE TABLE `MySQLBug` (
`id` int(10) unsigned NOT NULL AUTO_INCREMENT,
`value` int(10) unsigned NOT NULL,
PRIMARY KEY (`id`),
UNIQUE KEY `Test_Index` (`value`)
) ENGINE=InnoDB AUTO_INCREMENT=22 DEFAULT CHARSET=utf8 |
+----------+----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
1 row in set (0.00 sec)开启两个不同的会话
session1
mysql> set autocommit=0;
Query OK, 0 rows affected (0.00 sec)mysql> insert into MySQLBug(value) values(34);
Query OK, 1 row affected (0.00 sec)mysql> insert into MySQLBug(value) values(680);
ERROR 1213 (40001): Deadlock found when trying to get lock; try restarting transaction
mysql>
session2
mysql> set autocommit=0;
Query OK, 0 rows affected (0.00 sec)mysql> insert into MySQLBug(value) values(680);
Query OK, 1 row affected (0.00 sec)mysql> insert into MySQLBug(value) values(565); --这句一执行session1就报死锁搜到一篇文章是类似现象
http://bugs.mysql.com/bug.php?id=51140
在文章的最后面有人给出了一些解释,不过没看太明白,还望大家指点一二,谢谢!
mysql> insert into MySQLBug(value) values(565); --这句一执行session1就报死锁SESSION1等待一段时间后才是报错超时ERROR 1205 (HY000): Lock wait timeout exceeded; try restarting transaction
+------------+
| version() |
+------------+
| 5.1.45-log |
+------------+
1 row in set (0.00 sec)mysql>