Testing and Debugging Persistently Reactive Systems − A New Challenge in Software Engineering −

The ultimate goal of ubiquitous computing is to provide users with the way of computing anytime and anywhere A necessary condition and/or fundamental assumption to underlie ubiquitous computing is that there certainly are computing (information) systems working anytime available anywhere throughout the physical world. This paper raises a completely new technical issue in the age of ubiquitous computing: how to test and debug a persistently reactive system running continuously? A persistently reactive system is a reactive system that can run continuously anytime without stopping its service even then it had some trouble, it is being attacked, or it is being maintained or reconfigured. The maintenance, upgrade, and reconfiguration of a persistently reactive system have to be performed during its continuous running. However, almost all the existing testing and debugging technologies take programs of a system rather than the running system itself as the objects and/or targets, and assume that any program can be executed repeatedly with various input data only for testing and debugging without regard to stopping the task that program has to perform. In order to develop, use, and maintain persistently reactive systems, we have to find a new way to test and debug a system running continuously and persistently. This is a completely new challenge in software engineering. Keyword Ubiquitous Computing, Persistently Reactive Systems, Soft System Buses, Highly Reliability, Highly Security