A scalable, distributed middleware service architecture to support mobile Internet applications

Middleware layers placed between user clients and application servers have been used to perform a variety of functions to support the vision of nomadic computing across varying platforms. In previous work we have used middleware to perform a new capability, application session handoff, using a single Middleware Server to provide all functionality. However, to improve the scalability of our architecture, we have designed an efficient distributed Middleware Service layer that properly maintains application session handoff semantics while being able to service a large number of clients. We show that this service layer improves the scalability of general client-to-application server interaction as well as the specific case of application session handoff. We detail protocols involved in performing handoff and analyse an implementation of the architecture that supports the use of a real medical teaching tool. From experimental results it can be seen that our Middleware Service effectively provides scalability as a response to increased workload.