Customizable middleware for modular distributed software

Abstract

a result, changing requirements and the rapid pace at which new hardware is introduced lead to protocols which are constantly evolving. Currently, however, application code and protocol code are often intermixed. This lack of modularity significantly reduces the flexibility, maintainability and portability of distributed code. We describe a system architecture and programming techniques that enable the clean separation of protocols from application code. In particular, we provide modularity via two mechanisms (see Figure 1): ffl Separation of Policies and Protocols: Policies, which define the rules by which components interact (e.g. client-server, transactions, publish-subscribe), are specified separately from protocols, which define the mechanisms by which policies are implemented. ffl Protocol Composition: In cases where a single component must adhere to multiple policies, a framework for proto