Supporting communications infrastructure evolution

• Authors: Andrew D. Marshall
• Venue: CASCON '94 Proceedings of the 1994 conference of the Centre for Advanced Studies on Collaborative research
• Year: 1994

As network architectures have evolved from mainframe-centered terminal networks to today's LANs to the ubiquitous high-speed networks promised in the future, application programs have also evolved and will continue to evolve. The evolutionary process for applications, as they change to match the changing underlying communications layers, has been ad hoc and expensive. The current interest in transforming monolithic applications into client-server versions is simply the latest in-stantiation of the general problem. Further, in the near future tools may be needed to port applications from existing networks to high-speed networks. What is missing from these efforts is a theoretical framework capable of 1. expressing the assumptions embedded in an application about its existing underlying communications layer; 2. identifying the invariant and mutable portions of the application as it is transformed to run in a new communications environment; 3. expressing transformations necessary to accommodate the new or changed communications infrastructure. Once a theoretical framework is in place, semi-automatic tools to facilitate application evolution can be developed.This paper examines the partitioning of single process applications into multiprocess client-server applications, to help identify the issues involved in such transformations, as a first step toward developing a general theoretical framework.