Designing for MaxScale's Read Connection Router
MaxScale's Read Connection Router (readconnroute) performs connection-based load balancing. For each client connected to MaxScale, it opens up a connection to a single back-end database server. When the client sends a query to MaxScale, it routes the query to the connection opened up with the back-end database server. It can be configured to load balance connections between primary servers, replica servers, or any server.
Additional information is available in the MariaDB Knowledge Base.