客服反饋后臺無法查詢，原因大概知道，是因為MySQL的事務產生了死鎖，以往都不知道是哪個事務鎖住了，只能很粗暴地重啟MySQL

最近查找到一個方法，不用重啟MySQL，記錄如下

登錄到MySQL，來看下有哪些MySQL事務

可以看到一個時間持續了比較久的事務，現在時間是13點了，而這個事務的開始時間是2012-11-09 12:15:14，顯然是不正常的，

我們看這個事務對應的mysql的線程ID(trx_mysql_thread_id)是82230715，就是這個事務導致的

13:01:48pm> SELECT * FROM INFORMATION_SCHEMA.INNODB_TRX;

+-----------+-----------+---------------------+-----------------------+------------------+------------+---------------------+-----------+---------------------+-------------------+-------------------+------------------+-----------------------+-----------------+-------------------+-------------------------+---------------------+-------------------+------------------------+----------------------------+---------------------------+---------------------------+

| trx_id | trx_state | trx_started | trx_requested_lock_id | trx_wait_started | trx_weight | trx_mysql_thread_id | trx_query | trx_operation_state | trx_tables_in_use | trx_tables_locked | trx_lock_structs | trx_lock_memory_bytes | trx_rows_locked | trx_rows_modified | trx_concurrency_tickets | trx_isolation_level | trx_unique_checks | trx_foreign_key_checks | trx_last_foreign_key_error | trx_adaptive_hash_latched | trx_adaptive_hash_timeout |

+-----------+-----------+---------------------+-----------------------+------------------+------------+---------------------+-----------+---------------------+-------------------+-------------------+------------------+-----------------------+-----------------+-------------------+-------------------------+---------------------+-------------------+------------------------+----------------------------+---------------------------+---------------------------+

| 31868CED0 | RUNNING | 2012-11-09 12:15:14 | NULL | NULL | 2 | 82230715 | NULL | NULL | 0 | 0 | 2 | 376 | 1 | 0 | 0 | REPEATABLE READ | 1 | 1 | NULL | 0 | 10000 |

+-----------+-----------+---------------------+-----------------------+------------------+------------+---------------------+-----------+---------------------+-------------------+-------------------+------------------+-----------------------+-----------------+-------------------+-------------------------+---------------------+-------------------+------------------------+----------------------------+---------------------------+---------------------------+

我們登錄到mysql把它kill掉

13:01:55pm>

kill 82230715;

這樣，就可以查詢了

其他

查看

正在鎖的事務

SELECT * FROM INFORMATION_SCHEMA.INNODB_LOCKS;

查看

等待鎖的事務

SELECT * FROM INFORMATION_SCHEMA.INNODB_LOCK_WAITS;