MySQL死锁检查处理的正常方法

#step 1：窗口一
mysql> start transaction;
mysql> update aa set name='aaa' where id = 1;
 
#step 2：窗口二
mysql> start transaction;
mysql> update bb set name='bbb' where id = 1;
 
#step 3：窗口一
mysql> update bb set name='bbb';

#step 4：窗口三
#是否自动提交
mysql> show variables like 'autocommit';
+---------------+-------+
| Variable_name | Value |
+---------------+-------+
| autocommit | ON |
+---------------+-------+
 
#查看当前连接
mysql> show processlist;
mysql> show full processlist;
mysql> SELECT * FROM INFORMATION_SCHEMA.PROCESSLIST;
+----+------+-----------+------+---------+------+-------+------------------+
| Id | User | Host  | db | Command | Time | State | Info    |
+----+------+-----------+------+---------+------+-------+------------------+
| 4 | root | localhost | test | Sleep | 244 |  | NULL    |
| 5 | root | localhost | test | Sleep | 111 |  | NULL    |
| 6 | root | localhost | NULL | Query | 0 | init | show processlist |
+----+------+-----------+------+---------+------+-------+------------------+
 
 
#查看当前正在被锁的事务（锁请求超时后则查不到）
mysql> SELECT * FROM INFORMATION_SCHEMA.INNODB_LOCKS;
+------------------+-------------+-----------+-----------+-------------+-----------------+------------+-----------+----------+----------------+
| lock_id   | lock_trx_id | lock_mode | lock_type | lock_table | lock_index  | lock_space | lock_page | lock_rec | lock_data  |
+------------------+-------------+-----------+-----------+-------------+-----------------+------------+-----------+----------+----------------+
| 130718495:65:3:4 | 130718495 | X   | RECORD | `test`.`bb` | GEN_CLUST_INDEX |   65 |   3 |  4 | 0x000000000300 |
| 130718496:65:3:4 | 130718496 | X   | RECORD | `test`.`bb` | GEN_CLUST_INDEX |   65 |   3 |  4 | 0x000000000300 |
+------------------+-------------+-----------+-----------+-------------+-----------------+------------+-----------+----------+----------------+
 
#查看当前等待锁的事务（锁请求超时后则查不到）
mysql> SELECT * FROM INFORMATION_SCHEMA.INNODB_LOCK_WAITS; 
+-------------------+-------------------+-----------------+------------------+
| requesting_trx_id | requested_lock_id | blocking_trx_id | blocking_lock_id |
+-------------------+-------------------+-----------------+------------------+
| 130718499   | 130718499:65:3:4 | 130718500  | 130718500:65:3:4 |
+-------------------+-------------------+-----------------+------------------+
 
 
#查看当前未提交的事务（如果死锁等待超时,事务可能还没有关闭）
mysql> SELECT * FROM INFORMATION_SCHEMA.INNODB_TRX;
+--------------------------------------------------------------------------------------------------------+
| trx_id | trx_state | trx_started   | trx_requested_lock_id | trx_wait_started | trx_weight |
+-----------+-----------+---------------------+-----------------------+---------------------+------------+
| 130718500 | RUNNING | 2018-03-12 09:28:10 | NULL     | NULL    |   3 |
| 130718499 | LOCK WAIT | 2018-03-12 09:27:59 | 130718499:65:3:4  | 2018-03-12 09:32:48 |   5 |
==========================================================================================================
| trx_mysql_thread_id | trx_query        | trx_operation_state | trx_tables_in_use |
+---------------------+---------------------------------------+---------------------+-------------------+
|     4 | NULL         | NULL    |     0 |
|     5 | update bb set name='bbb'    | starting index read |     1 |
=========================================================================================================
| trx_tables_locked | trx_lock_structs | trx_lock_memory_bytes | trx_rows_locked | trx_rows_modified |
+-------------------+------------------+-----------------------+-----------------+-------------------+
|     0 |    2 |     360 |    3 |     1 |
|     1 |    4 |     1184 |    4 |<span>本文来源gaodai#ma#com搞*!代#%^码$网*</span>     1 |
===========================================================================================================================
| trx_concurrency_tickets | trx_isolation_level | trx_unique_checks | trx_foreign_key_checks | trx_last_foreign_key_error |
+-------------------------+---------------------+-------------------+------------------------+----------------------------+
|      0 | REPEATABLE READ  |     1 |      1 | NULL      |
|      0 | REPEATABLE READ  |     1 |      1 | NULL      |
===========================================================================================================================
| trx_adaptive_hash_latched | trx_adaptive_hash_timeout | trx_is_read_only | trx_autocommit_non_locking |
+---------------------------+---------------------------+------------------+----------------------------+
|       0 |      10000 |    0 |       0 |
|       0 |      10000 |    0 |       0 |
+---------------------------+---------------------------+------------------+----------------------------+
 
 
#查看正在被访问的表
mysql> show OPEN TABLES where In_use > 0;
+----------+-------+--------+-------------+
| Database | Table | In_use | Name_locked |
+----------+-------+--------+-------------+
| test  | bb |  1 |   0 |
+----------+-------+--------+-------------+

#step 3：窗口一 （若第三步中锁请求太久，则出现锁超时而终止执行）
mysql> update bb set name='bbb';
ERROR 1205 (HY000): Lock wait timeout exceeded; try restarting transaction
 
 
#"窗口一" 锁请求超时前，执行第五步，使死锁产生，则该连接 "窗口二" 执行终止，"窗口一" 顺利执行
#step 5：窗口二
mysql> update aa set name='aa';
ERROR 1213 (40001): Deadlock found when trying to get lock; try restarting transaction