一、关于锁的三张表(MEMORY引擎)
## 当前运行的所有事务
mysql> select * from information_schema.innodb_trx\G;
*************************** 1. row ***************************
trx_id: 613963
trx_state: LOCK WAIT #事务状态
trx_started: 2019-02-22 10:48:48
trx_requested_lock_id: 613963:460:3:4
trx_wait_started: 2019-02-22 11:08:41
trx_weight: 2
trx_mysql_thread_id: 140
trx_query: update tx1 set c1='heyfffff',c2='heyffffff' where id =3
trx_operation_state: starting index read
trx_tables_in_use: 1
trx_tables_locked: 1
trx_lock_structs: 2
trx_lock_memory_bytes: 1136
trx_rows_locked: 7 #事务锁住的行数
trx_rows_modified: 0
trx_concurrency_tickets: 0 #事务并发票数
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: 0
trx_is_read_only: 0
trx_autocommit_non_locking: 0
*************************** 2. row ***************************
trx_id: 613962
trx_state: RUNNING
trx_started: 2019-02-22 10:46:29
trx_requested_lock_id: NULL
trx_wait_started: NULL
trx_weight: 3
trx_mysql_thread_id: 138
trx_query: select * from information_schema.innodb_trx
trx_operation_state: NULL
trx_tables_in_use: 0
trx_tables_locked: 1
trx_lock_structs: 2
trx_lock_memory_bytes: 1136
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: 0
trx_is_read_only: 0
trx_autocommit_non_locking: 0
2 rows in set (0.00 sec)
## 当前出现的锁
mysql> select * from information_schema.innodb_locks\G;
*************************** 1. row ***************************
lock_id: 613963:460:3:4
lock_trx_id: 613963
lock_mode: X
lock_type: RECORD
lock_table: `test`.`tx1`
lock_index: PRIMARY
lock_space: 460
lock_page: 3
lock_rec: 4
lock_data: 3
*************************** 2. row ***************************
lock_id: 613962:460:3:4
lock_trx_id: 613962
lock_mode: X
lock_type: RECORD
lock_table: `test`.`tx1`
lock_index: PRIMARY
lock_space: 460
lock_page: 3
lock_rec: 4
lock_data: 3
2 rows in set, 1 warning (0.00 sec)
## 锁等待的对应关系
mysql> select * from information_schema.innodb_lock_waits\G;
*************************** 1. row ***************************
requesting_trx_id: 613963
requested_lock_id: 613963:460:3:4 #请求锁的锁ID
blocking_trx_id: 613962 #当前拥有锁的事务ID
blocking_lock_id: 613962:460:3:4
1 row in set, 1 warning (0.00 sec)
二、查看锁的情况
mysql> show status like 'innodb_row_lock_%';
+-------------------------------+--------+
| Variable_name | Value |
+-------------------------------+--------+
| Innodb_row_lock_current_waits | 1 |
| Innodb_row_lock_time | 479764 |
| Innodb_row_lock_time_avg | 39980 |
| Innodb_row_lock_time_max | 51021 |
| Innodb_row_lock_waits | 12 |
+-------------------------------+--------+
5 rows in set (0.00 sec)
解释如下:
Innodb_row_lock_current_waits : 当前等待锁的数量
Innodb_row_lock_time : 系统启动到现在,锁定的总时间长度
Innodb_row_lock_time_avg : 每次平均锁定的时间
Innodb_row_lock_time_max : 最长一次锁定时间
Innodb_row_lock_waits : 系统启动到现在总共锁定的次数
# 查询是否锁表
mysql> show OPEN TABLES where In_use > 0;
+----------+-------+--------+-------------+
| Database | Table | In_use | Name_locked |
+----------+-------+--------+-------------+
| test | tx1 | 1 | 0 |
+----------+-------+--------+-------------+
1 row in set (0.00 sec)
三、杀死进程
# 1.查询进程
mysql> show processlist\G # \G 结构旋转90度变成纵向
*************************** 1. row ***************************
Id: 138
User: root
Host: localhost:55106
db: test
Command: Query
Time: 0
State: starting
Info: show processlist
*************************** 2. row ***************************
Id: 140
User: root
Host: localhost:56158
db: test
Command: Sleep
Time: 145
State:
Info: NULL
2 rows in set (0.00 sec)
2 rows in set (0.00 sec)
# 2.杀死对应进程ID
mysql> kill 140;
Query OK, 0 rows affected (0.00 sec)
mysql> show processlist\G
*************************** 1. row ***************************