Problem to Read Mysql Proxy Backend Addresses


Recently i installed mysql-proxy-0.7.2 in ubuntu operating system.
I assigned proxy-backend-addresses = (default)
through command prompt.

And i logged into mysql-proxy admin with default port of 4041

and checked the backend servers type like

SELECT * FROM backends;

i am getting the result as NULL .

Can anybody help how to resolve this issue.

Thanks in Advance