Lock wait timeout exceeded

源：http://my.oschina.net/jiaoya/blog/92194
http://www.cnblogs.com/freeliver54/archive/2010/09/30/1839042.html
评：
mysql : Lock wait timeout exceeded; try restarting transaction

原因是你使用的InnoDB   表类型的时候,
默认参数:innodb_lock_wait_timeout设置锁等待的时间是50s,
因为有的锁等待超过了这个时间,所以抱错.

你可以把这个时间加长,或者优化存储过程,事务避免过长时间的等待.



my.ini文件：
#innodb_lock_wait_timeout = 50
-》
innodb_lock_wait_timeout = 500



重启mysql服务。
-----------------------------------------

SHOW INNODB STATUS and, probably, SHOW PROCESSLIST can give you

some additional information about what's going on. Use:

  show variables like 'tx_isolation';



to find out the transaction isolation level. See:

  http://dev.mysql.com/doc/mysql/en/InnoDB_Monitor.html

http://dev.mysql.com/doc/mysql/en/show-processlist.html
-------------查找  持有锁的 线程  -----------------------------------
java.lang.Exception:
### Error updating database.  Cause: java.sql.SQLException: Lock wait timeout exceeded; try restarting transaction
### The error may involve defaultParameterMap
### The error occurred while setting parameters
### Cause: java.sql.SQLException: Lock wait timeout exceeded; try restarting transaction
; SQL []; Lock wait timeout exceeded; try restarting transaction; nested exception is java.sql.SQLException: Lock wait timeout exceeded; try restarting transaction

select * from information_schema.innodb_trx 之后找到了一个一直没有提交的只读事务，

kill 到了对应的线程后ok 了。

==============================================


转载:http://blog.sina.com.cn/s/blog_6bb63c9e0100s7cb.html
MySQL 5.5 -- innodb_lock_wait 锁 等待

记得以前，当出现：ERROR 1205 (HY000): Lock wait timeout exceeded; try restarting transaction，
要解决是一件麻烦的事情 ；
特别是当一个SQL执行完了，但未COMMIT，后面的SQL想要执行就是被锁，超时结束；
DBA光从数据库无法着手找出源头是哪个SQL锁住了；
有时候看看show engine innodb status , 并结合 show full processlist; 能暂时解决问题；但一直不能精确定位；

在5.5中，information_schema 库中增加了三个关于锁的表（MEMORY引擎）；
innodb_trx ## 当前运行的所有事务
innodb_locks ## 当前出现的锁
innodb_lock_waits ## 锁等待的对应关系

看到这个就非常激动 ； 这可是解决了一个大麻烦，先来看一下表结构


root@127.0.0.1  : information_schema 13:28:38> desc innodb_locks;
+-------------+---------------------+------+-----+---------+-------+
| Field | Type | Null | Key | Default | Extra |
+-------------+---------------------+------+-----+---------+-------+
| lock_id | varchar(81) | NO | | | |#锁ID
| lock_trx_id | varchar(18) | NO | | | |#拥有锁的事务ID
| lock_mode | varchar(32) | NO | | | |#锁模式
| lock_type | varchar(32) | NO | | | |#锁类型
| lock_table | varchar(1024) | NO | | | |#被锁的表
| lock_index | varchar(1024) | YES | | NULL | |#被锁的索引
| lock_space | bigint(21) unsigned | YES | | NULL | |#被锁的表空间号
| lock_page | bigint(21) unsigned | YES | | NULL | |#被锁的页号
| lock_rec | bigint(21) unsigned | YES | | NULL | |#被锁的记录号
| lock_data | varchar(8192) | YES | | NULL | |#被锁的数据
+-------------+---------------------+------+-----+---------+-------+
10 rows in set (0.00 sec)

root@127.0.0.1  : information_schema 13:28:56> desc innodb_lock_waits;
+-------------------+-------------+------+-----+---------+-------+
| Field | Type | Null | Key | Default | Extra |
+-------------------+-------------+------+-----+---------+-------+
| requesting_trx_id | varchar(18) | NO | | | |#请求锁的事务ID
| requested_lock_id | varchar(81) | NO | | | |#请求锁的锁ID
| blocking_trx_id | varchar(18) | NO | | | |#当前拥有锁的事务ID
| blocking_lock_id | varchar(81) | NO | | | |#当前拥有锁的锁ID
+-------------------+-------------+------+-----+---------+-------+
4 rows in set (0.00 sec)

root@127.0.0.1  : information_schema 13:29:05> desc innodb_trx ;
+----------------------------+---------------------+------+-----+---------------------+-------+
| Field | Type | Null | Key | Default | Extra |
+----------------------------+---------------------+------+-----+---------------------+-------+
| trx_id | varchar(18) | NO | | | |#事务ID
| trx_state | varchar(13) | NO | | | |#事务状态：
| trx_started | datetime | NO | | 0000-00-00 00:00:00 | |#事务开始时间；
| trx_requested_lock_id | varchar(81) | YES | | NULL | |#innodb_locks.lock_id
| trx_wait_started | datetime | YES | | NULL | |#事务开始等待的时间
| trx_weight | bigint(21) unsigned | NO | | 0 | |#
| trx_mysql_thread_id | bigint(21) unsigned | NO | | 0 | |#事务线程ID
| trx_query | varchar(1024) | YES | | NULL | |#具体SQL语句
| trx_operation_state | varchar(64) | YES | | NULL | |#事务当前操作状态
| trx_tables_in_use | bigint(21) unsigned | NO | | 0 | |#事务中有多少个表被使用
| trx_tables_locked | bigint(21) unsigned | NO | | 0 | |#事务拥有多少个锁
| trx_lock_structs | bigint(21) unsigned | NO | | 0 | |#
| trx_lock_memory_bytes | bigint(21) unsigned | NO | | 0 | |#事务锁住的内存大小（B）
| trx_rows_locked | bigint(21) unsigned | NO | | 0 | |#事务锁住的行数
| trx_rows_modified | bigint(21) unsigned | NO | | 0 | |#事务更改的行数
| trx_concurrency_tickets | bigint(21) unsigned | NO | | 0 | |#事务并发票数
| trx_isolation_level | varchar(16) | NO | | | |#事务隔离级别
| trx_unique_checks | int(1) | NO | | 0 | |#是否唯一性检查
| trx_foreign_key_checks | int(1) | NO | | 0 | |#是否外键检查
| trx_last_foreign_key_error | varchar(256) | YES | | NULL | |#最后的外键错误
| trx_adaptive_hash_latched | int(1) | NO | | 0 | |#
| trx_adaptive_hash_timeout | bigint(21) unsigned | NO | | 0 | |#
+----------------------------+---------------------+------+-----+---------------------+-------+
22 rows in set (0.01 sec)

下面我们来动手看看数据吧：
##建立测试数据：
use test;
create table tx1
(id int primary key ,
c1 varchar(20),
c2 varchar(30))
engine=innodb default charset = utf8 ;

insert into tx1 values
(1,'aaaa','aaaaa2'),
(2,'bbbb','bbbbb2'),
(3,'cccc','ccccc2');

commit;

###产生事务；
### Session1
start transaction;
update tx1 set c1='heyf',c2='heyf' where id =3 ;

## 产生事务，在innodb_trx就有数据 ；
root@127.0.0.1  : information_schema 13:38:21> select * from innodb_trx G
*************************** 1. row ***************************
trx_id: 3669D82
trx_state: RUNNING
trx_started: 2010-12-24 13:38:06
trx_requested_lock_id: NULL
trx_wait_started: NULL
trx_weight: 3
trx_mysql_thread_id: 2344
trx_query: NULL
trx_operation_state: NULL
trx_tables_in_use: 0
trx_tables_locked: 0
trx_lock_structs: 2
trx_lock_memory_bytes: 376
trx_rows_locked: 1
trx_rows_modified: 1
trx_concurrency_tickets: 0
trx_isolation_level: REPEATABLE READ
trx_unique_checks: 1
trx_foreign_key_checks: 1
trx_last_foreign_key_error: NULL
trx_adaptive_hash_latched: 0
trx_adaptive_hash_timeout: 10000
1 row in set (0.00 sec)

### 由于没有产生锁等待，下面两个表没有数据 ；
root@127.0.0.1  : information_schema 13:38:31> select * from innodb_lock_waits G
Empty set (0.00 sec)

root@127.0.0.1  : information_schema 13:38:57> select * from innodb_locks G
Empty set (0.00 sec)

#### 产生锁等待
#### session 2
start transaction;
update tx1 set c1='heyfffff',c2='heyffffff' where id =3 ;


root@127.0.0.1  : information_schema 13:39:01> select * from innodb_trx G
*************************** 1. row ***************************
trx_id: 3669D83 ##第2个事务
trx_state: LOCK WAIT ## 处于等待状态
trx_started: 2010-12-24 13:40:07
trx_requested_lock_id: 3669D83:49:3:4 ##请求的锁ID
trx_wait_started: 2010-12-24 13:40:07
trx_weight: 2
trx_mysql_thread_id: 2346 ##线程 ID
trx_query: update tx1 set c1='heyfffff',c2='heyffffff' where id =3
trx_operation_state: starting index read
trx_tables_in_use: 1 ##需要用到1个表
trx_tables_locked: 1 ##有1个表被锁
trx_lock_structs: 2
trx_lock_memory_bytes: 376
trx_rows_locked: 1
trx_rows_modified: 0
trx_concurrency_tickets: 0
trx_isolation_level: REPEATABLE READ
trx_unique_checks: 1
trx_foreign_key_checks: 1
trx_last_foreign_key_error: NULL
trx_adaptive_hash_latched: 0
trx_adaptive_hash_timeout: 10000
*************************** 2. row ***************************
trx_id: 3669D82 ##第1个事务
trx_state: RUNNING
trx_started: 2010-12-24 13:38:06
trx_requested_lock_id: NULL
trx_wait_started: NULL
trx_weight: 3
trx_mysql_thread_id: 2344
trx_query: NULL
trx_operation_state: NULL
trx_tables_in_use: 0
trx_tables_locked: 0
trx_lock_structs: 2
trx_lock_memory_bytes: 376
trx_rows_locked: 1
trx_rows_modified: 1
trx_concurrency_tickets: 0
trx_isolation_level: REPEATABLE READ
trx_unique_checks: 1
trx_foreign_key_checks: 1
trx_last_foreign_key_error: NULL
trx_adaptive_hash_latched: 0
trx_adaptive_hash_timeout: 10000
2 rows in set (0.00 sec)

root@127.0.0.1  : information_schema 13:40:12> select * from innodb_locks G
*************************** 1. row ***************************
lock_id: 3669D83:49:3:4 ## 第2个事务需要的锁
lock_trx_id: 3669D83
lock_mode: X
lock_type: RECORD
lock_table: `test`.`tx1`
lock_index: `PRIMARY`
lock_space: 49
lock_page: 3
lock_rec: 4
lock_data: 3
*************************** 2. row ***************************
lock_id: 3669D82:49:3:4 ## 第1个事务需要的锁
lock_trx_id: 3669D82
lock_mode: X
lock_type: RECORD
lock_table: `test`.`tx1`
lock_index: `PRIMARY`
lock_space: 49
lock_page: 3
lock_rec: 4
lock_data: 3
2 rows in set (0.00 sec)

root@127.0.0.1  : information_schema 13:40:15> select * from innodb_lock_waits G
*************************** 1. row ***************************
requesting_trx_id: 3669D83 ## 请求锁的事务
requested_lock_id: 3669D83:49:3:4 ## 请求锁的锁ID
blocking_trx_id: 3669D82 ## 拥有锁的事务
blocking_lock_id: 3669D82:49:3:4 ## 拥有锁的锁ID
1 row in set (0.00 sec)