If using MaxScale in Binlog Server mode, and you try to issue a CHANGE MASTER .. MASTER_PASSWORD=.. command with a password that happens to have a comma (",") in the password (which is allowed, in general, by MariaDB), then you receive an error:

mysql> CHANGE MASTER TO MASTER_USER='maxscale_repl_user', MASTER_PASSWORD='a,a';

ERROR 1234 (42000): option 'a'' is not supported

If you update the password to contain, say an underscore, instead of a comma, then it works as expected:

mysql> CHANGE MASTER TO MASTER_USER='maxscale_repl_user', MASTER_PASSWORD='a_a';

Query OK, 0 rows affected (0.00 sec)

MaxScale version 1.4.3.

It seems it is parsing on the comma, and ignoring the single quotes surrounding the password.