如何找出长时间未提交的事务session ID

收到报警某台mysql数据库慢查询数量超过5，登陆上去看，发现阻塞的SQL所有是update，处于Updating状态

+---------+------+-----------+------+---------+------+----------+------------------------------------+
| ID      | USER | HOST      | DB   | COMMAND | TIME | STATE    | INFO                               |
+---------+------+-----------+------+---------+------+----------+------------------------------------+
| 4364109 | root | localhost | test | Query   |   39 | Updating | update T_1 set col3='' where FID=3 |
+---------+------+-----------+------+---------+------+----------+------------------------------------+

查看系统状态，各项都正常，但在InnoDB Row Lock Time值上有个较大的毛刺，基本得出是锁等待致使的。show processlist看到的线程里面，活动状态的没有发现执行慢的SQL，都是经过主键update，极有多是某个事务对这个表作了dml操做没有提交commit，致使一直持有锁未释放，后面的session等待X锁。根据这个思路，在show engine innodb status的事务栏里面找到ACTIVE状态的，执行时间最长的那个session，发现是sleep状态的，kill掉这个session，阻塞现象消失。

---TRANSACTION 21427F91, ACTIVE 1421 sec, process no 69177, OS thread id 139633152562944
2 lock struct(s), heap size 376, 1 row lock(s), undo log entries 1
MySQL thread id 4364618, query id 282683146 localhost root

至于为何会出现未提交SQL，再和开发一块儿去排查

经过show engine innodb status去查session比较麻烦，简单的SQL以下

mysql> select a.trx_mysql_thread_id,b.TIME from information_schema.INNODB_TRX a inner join information_schema.processlist b on a.trx_mysql_thread_id=b.id where a.trx_state='RUNNING' and b.time>10 and b.COMMAND='Sleep';
+---------------------+------+
| trx_mysql_thread_id | TIME |
+---------------------+------+
|             4364618 |  614 |
+---------------------+------+
1 row in set (0.00 sec)

事务ID=4364618，事务时长：614秒。