After getting the feel of basic programming model of Java RMI, i tried to dig further into the model to see more practical tricks used in RMI architecture which makes it more practical.
few things to look into:
1. RMI Threading
2. RMI Callback
3. RMI (Blocking or Non-blocking)
4. RMI Serialization
5. RMI Classloader
6. RMI Synchronization

This are the four key issues i should raise today.
1. RMI threading.
each client request is initiated in a separate thread but server is just a single object.
It means whenever client makes a remote call, a new thread will be created on server which will be representing that client but only a single instance of server module would be running.
*****Problem Here*******
How to resolve this: Make your server multithreaded or launch the application using web services which will automatically make it multithreaded.

2. RMI serialization
stub and skeleton will automatically serialize the results back to caller.
Object are serialized and send back as pass by value mode.