MySQL 锁等待超时（Lock wait timeout exceeded）

Posted 2023-04-06

参考技术A

问题：Lock wait timeout exceeded; try restarting transaction

mysql版本：5.6.44

官方文档

意思是：InnoDB在锁等待超时过期时报告此错误。等待时间过长的语句被回滚（而不是整个事务）。如果SQL语句需要等待其他事务完成的时间更长，则可以增加 innodb_lock_wait_timeout 配置选项的值；如果太多长时间运行的事务导致锁定问题并降低繁忙系统上的并发性，则可以减少该选项的值。

锁等待超时，可能是出现了死锁，也可能有事务长时间未提交

库：information_schema

表：

查看各表信息

innodb_trx 表

innodb_locks 表

innodb_lock_waits 表

processlist 表

模拟出现死锁
准备一张只有主键的表：t_test (id)

Navicat 新建查询1

Navicat 新建查询2

检查是否锁表

查询当前正在执行的事务

查询当前出现的锁

查询锁等待对应的关系

查询等待锁的事务所执行的SQL

最后，事务2 等待锁超时报错： Lock wait timeout exceeded; try restarting transaction;

通过事务线程ID查找进程信息

win10 查看端口信息

MySQL事务没有提交导致 锁等待Lock wait timeout exceeded异常的处理办法

java.lang.Exception:
### Error updating database.  Cause:java.sql.SQLException: Lock wait timeout exceeded; try restartingtransaction
### The error may involve defaultParameterMap
### The error occurred while setting parameters
### Cause: java.sql.SQLException: Lock wait timeout exceeded; tryrestarting transaction
; SQL []; Lock wait timeout exceeded; try restarting transaction;nested exception is java.sql.SQLException: Lock wait timeoutexceeded; try restarting transaction

select * from information_schema.innodb_trx之后找到了一个一直没有提交的事务。

kill 到了对应的线程后ok了。

查看所有的进程列表：show processlist

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

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 restartingtransaction，
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_trxG
*************************** 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_waitsG
Empty set (0.00 sec)

root@127.0.0.1  :information_schema 13:38:57> select * from innodb_locksG
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_trxG
*************************** 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_locksG
*************************** 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_waitsG
*************************** 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)

from:http://my.oschina.net/jiaoya/blog/92194