--proxy-address=hostort — the listening hostname (or IP address) and port of the proxy server. The default is localhost:4040.
--proxy-read-only-address=hostort — the listening hostname (or IP address) and port of the proxy server for read-only connections. The default is localhost:4042.
--proxy-backend-addresses=hostort — the hostname (or IP address) and port of the MySQL server to connect to. You can specify multiple backend servers by supplying multiple options. Clients are connected to each backend server in round-robin fashion. For example, if you specify two servers A and B, the first client connection will go to server A; the second client connection to server B and the third client connection to server A.