MySQL [(none)]> select version();
+--------------------+
| VERSION()          |
+--------------------+
| 8.0.11-v0.20.0-rc1 |
+--------------------+
1 row in set (0.01 sec)

MySQL [(none)]> select connection_id();
+-----------------+
| connection_id() |
+-----------------+
|               1 |
+-----------------+
1 row in set (0.00 sec)

MySQL [(none)]> show processlist;
+------+------+-----------------+---------+---------+------+---------+------------------+
| Id   | User | Host            | db      | Command | Time | State   | Info             |
+------+------+-----------------+---------+---------+------+---------+------------------+
|    8 | root | 127.0.0.1:52482 | gitbase | query   |    0 | running | show processlist |
+------+------+-----------------+---------+---------+------+---------+------------------+
1 row in set (0.01 sec)

MySQL [(none)]> kill connection 1;
ERROR 1105 (HY000): unknown error: Connection not found:
MySQL [(none)]> select 1;
+------+
| 1    |
+------+
|    1 |
+------+
1 row in set (0.01 sec)

MySQL [(none)]>

mysql> select version();
+-----------+
| version() |
+-----------+
| 8.0.15    |
+-----------+
1 row in set (0.00 sec)

mysql> select connection_id();
+-----------------+
| connection_id() |
+-----------------+
|               8 |
+-----------------+
1 row in set (0.00 sec)

mysql> show processlist;
+----+-----------------+-----------+------+---------+------+------------------------+------------------+
| Id | User            | Host      | db   | Command | Time | State                  | Info             |
+----+-----------------+-----------+------+---------+------+------------------------+------------------+
|  4 | event_scheduler | localhost | NULL | Daemon  |  256 | Waiting on empty queue | NULL             |
|  8 | root            | localhost | NULL | Query   |    0 | starting               | show processlist |
+----+-----------------+-----------+------+---------+------+------------------------+------------------+
2 rows in set (0.00 sec)

mysql> kill connection 8;
ERROR 1317 (70100): Query execution was interrupted
mysql> select 1;
ERROR 2006 (HY000): MySQL server has gone away
No connection. Trying to reconnect...
Connection id:    9
Current database: *** NONE ***

+---+
| 1 |
+---+
| 1 |
+---+
1 row in set (0.00 sec)

mysql>