Managing Evolution in Distributed, Heterogeneous Systems

University Of California-Davis, Davis CA

Investigators

Abstract

Distributed, heterogeneous (DH) software systems are critical for the operation of modern, globalized organizations. Like all software, DH systems come under evolutionary pressure as organizational needs evolve. Adapting DH systems to meet changing needs in areas such as security is challenging: Co-ordinated changes, made in different languages, and on different platforms must still preserve type-safety, and must not increase complexity and/or complicate maintenance. This project investigates enhancements to standards-based middleware (e.g., CORBA) to support evolution. We preserve and enhance the core IDL-based heterogeneous philosophy of middleware. First, interface-description language (IDL), used to model the architecture-level interfaces of components, is enhanced to support modeling of the evolutionary changes made to a DH systems. Location of changes, types and life-times of new information to be created are all explicitly modeled in an aspect-oriented style at the IDL level. Code generation supports a wide range of implementation choices to realize these architectural change-models. All implementations are fully inter-operable. Finally, change-models and implementations can be "compononentized", packaged up and added to existing systems. Like this research, our educational plans also span several topics areas, including functional programming, object-orientation, and architecture. We develop practically-grounded pedagogy on software evolution, comparing the varying approaches to separation of concerns in object-orientation, higher-order polymorphism (including monadic programming), connectors, and aspects.