| With the increasing demand for long running and highly available distributed services, the ability to upgrade without taking down the operations of the mission critical software deployed in the field is of great significance to today's fast growing telecommunication and information industry. It is noted that none of the existing software maintenance approaches has provided a feasible solution to fulfil this goal. This thesis therefore proposes a software hot swapping technique to accomplish a generic and robust infrastructure at the initial design stage to accommodate the need of future software maintenance with minimum system service disruption. A description and thorough discussion of issues concerning the software swappability as well as software hot swapping infrastructure consisting of S-module, S-manager and S-proxy, is systematically presented for the purpose of dynamic reconfiguration.; The software hot-swapping infrastructure provides a auto-managed framework where subset of the software can be reconfigured on a module by module basis while overall software execution consistency is maintained. The developed hot swap transaction algorithm places special emphasis on minimizing the interference to the rest of the system and suits well for the applications with zero-down time requirements. The research demonstrates that the object-oriented paradigm combined with mobile code technology provides a solid foundation for the software hot-swapping technique. By applying the software hot-swapping technique, the maintenance cost for software product, especially for distributed, mission critical application, can be significantly reduced. |
