You can KILL the processid.
mysql> show full processlist;
+---------+------------+-------------------+------+---------+-------+-------+-----------------------+
| Id | User | Host | db | Command | Time | State | Info |
+---------+------------+-------------------+------+---------+-------+-------+-----------------------+
| 1193777 | TestUser12 | 192.168.1.11:3775 | www | Sleep | 25946 | | NULL |
+---------+------------+-------------------+------+---------+-------+-------+-----------------------+
mysql> kill 1193777;
But:
Or you configure your mysql-server by setting a shorter timeout on wait_timeout and interactive_timeout
mysql> show variables like "%timeout%";
+--------------------------+-------+
| Variable_name | Value |
+--------------------------+-------+
| connect_timeout | 5 |
| delayed_insert_timeout | 300 |
| innodb_lock_wait_timeout | 50 |
| interactive_timeout | 28800 |
| net_read_timeout | 30 |
| net_write_timeout | 60 |
| slave_net_timeout | 3600 |
| table_lock_wait_timeout | 50 |
| wait_timeout | 28800 |
+--------------------------+-------+
9 rows in set (0.00 sec)
Set with:
set global wait_timeout=3;
set global interactive_timeout=3;
(and also set in your configuration file, for when your server restarts)
But you're treating the symptoms instead of the underlying cause - why are the connections open? If the PHP script finished, shouldn't they close? Make sure your webserver is not using connection pooling...