Error while authenticating user throught glassfish jdbc realm mysql connection pool problem

I am able to authenticate the user successfully through realm first time when restart the server and deploy the application. But after few minutes when i try to open the webapp in different browser the i'am unable to authenticate the user..
With localhost mysql it works fine but when i try to connect the remote mysql authentication fails after sometime.
This is my glassfish-resources.xml



I am fed of this error search so many threads but unable to resolve this problem.