# Session 1
# sleep for 120 seconds
select sleep(120)
# Session 2
show processlist
# kill process you have identified for sleep(120)
MariaDB [(none)]> show processlist;
+----+------+-----------+----------+---------+------+------------+-------------------+----------+
| Id | User | Host | db | Command | Time | State | Info | Progress |
+----+------+-----------+----------+---------+------+------------+-------------------+----------+
| 36 | root | localhost | NULL | Query | 0 | starting | show processlist | 0.000 |
| 37 | root | localhost | training | Query | 4 | User sleep | select sleep(120) | 0.000 |
+----+------+-----------+----------+---------+------+------------+-------------------+----------+
2 rows in set (0.000 sec)
# take 37
kill 37
# Session 1: query terminates
ERROR 2013 (HY000): Lost connection to MySQL server during query