Binlog Dump thread remains open

[altmannmarcelo]

Description

If we stop Readyset, we are not gracefully closing the replication connection, causing it to remain open in mysql:

mysql> show processlist;
+-----+-----------------+------------------+------+-------------+-------+-----------------------------------------------------------------+------------------+
| Id  | User            | Host             | db   | Command     | Time  | State                                                           | Info             |
+-----+-----------------+------------------+------+-------------+-------+-----------------------------------------------------------------+------------------+
|   5 | event_scheduler | localhost        | NULL | Daemon      | 96175 | Waiting on empty queue                                          | NULL             |
| 354 | root            | 172.21.0.1:57826 | sj   | Binlog Dump |  5356 | Source has sent all binlog to replica; waiting for more updates | NULL             |
| 356 | root            | 172.21.0.1:63198 | NULL | Query       |     0 | init                                                            | show processlist |
+-----+-----------------+------------------+------+-------------+-------+-----------------------------------------------------------------+------------------+
3 rows in set, 1 warning (0,002 sec)

Change in user-visible behavior

Requires documentation change