4cb6d9227e
When a master server is set into read-only mode, it can be treated as an always up-to-date slave. This gives us a somewhat graceful way to prevent writes to a master. Usually setting the master into read-only mode is done before a change in the replication topology to prevent stray writes arriving on the master. MaxScale should respect the read-only mode and not send any writes to a server that's in read-only mode.