数据库在出现锁或者死锁的时候，处理起来应该综合分析，应该配合数据库监控系统、结合业务同时分析数据库寻找问题，下面是一些常用的手动供参考：
查看是否有表锁住：
show OPEN TABLES where In_use > 0;
show processlist ；
show engine innodb status;
或者查询
SELECT * FROM INFORMATION_SCHEMA.INNODB_LOCKS;
SELECT * from INFORMATION_SCHEMA.INNODB_TRX;
SELECT * FROM INFORMATION_SCHEMA.INNODB_LOCK_WAITS;
应该熟悉常用的表INNODB_LOCKS、INNODB_TRX、INNODB_LOCK_WAITS的一些字段含义，这样可以快速的分析问题。
其中show OPEN TABLES where In_use > 0;只能看到那些表被锁住；
show processlist 看不到锁的信息，判读起来比较麻烦；
show engine innodb status; 可以查看到很多信息，特别是一些死锁信息，但是分析起来比较麻烦。
下面为常用的sql语句供参考：
SELECT
r.trx_id waiting_trx_id,
r.trx_mysql_thread_Id waiting_thread,
r.trx_query waiting_query,
b.trx_id blocking_trx_id,
b.trx_mysql_thread_id blocking_thread,
b.trx_query blocking_query
FROM
information_schema.innodb_lock_waits w
INNER JOIN information_schema.innodb_trx b ON b.trx_id = w.blocking_trx_id
INNER JOIN information_schema.innodb_trx r ON r.trx_id = w.requesting_trx_id;
表对应的字段含义参考：
SELECT
trx_id AS `事务ID`,
trx_state AS `事务状态`,
trx_requested_lock_id AS `事务需要等待的资源`,
trx_wait_started AS `事务开始等待时间`,
trx_tables_in_use AS `事务使用表`,
trx_tables_locked AS `事务拥有锁`,
trx_rows_locked AS `事务锁定行`,
trx_rows_modified AS `事务更改行`
FROM
information_schema.innodb_trx ;
SELECT
lock_id AS `锁ID`,
lock_trx_id AS `拥有锁的事务ID`,
lock_mode AS `锁模式 `,
lock_type AS `锁类型`,
lock_table AS `被锁的表`,
lock_index AS `被锁的索引`,
lock_space AS `被锁的表空间号`,
lock_page AS `被锁的页号`,
lock_rec AS `被锁的记录号`,
lock_data AS `被锁的数据`
FROM
information_schema.innodb_locks;
SELECT
requesting_trx_id AS `请求锁的事务ID`,
requested_lock_id AS `请求锁的锁ID`,
blocking_trx_id AS `当前拥有锁的事务ID`,
blocking_lock_id AS `当前拥有锁的锁ID`
FROM
innodb_lock_waits;