Vaadin and EJB Problems

Hello , as far as i know , EJB has authentication system ,
My problem is , i want to make multi tiered architecture.
I will make desktop edition of EJB Services on JavaFX and Web side on Vaadin.

But i’ve some problems on authentication to EJB.
There is no example on internet for vaadin to login EJB and make some operations on EJB.

How can i login to EJB for session ?

and for best performance , how can i stay connection alive to EJB for every session ?

Can i use
ThreadLocal contextData;

so , i will per thread connection to EJB server.But when all connections done , i need per InitialContext session data.

I’m in dilemma now , i need some highest performance solution to connect remote EJB from Vaadin and how to make authentication from EJB.

I’m using Glassfish EJB Modules.