Willow system demonstration

Dealing with damage that arises during operation of networked information systems is essential if such systems are to provide the dependability required by modem critical applications. Extensive damage can arise from environmental factors, malicious actions and so on, and in most cases it is impractical to mask the effects of such damage using typical redundancy techniques. Reconfiguration is required of both the application and the underlying computing and communications fabric. Such reconfiguration is difficult to achieve because it requires communication with a significant number of nodes both to determine the problem and to effect a repair In this demonstration we present an approach to the implementation of such reconfiguration. The approach to reactive control includes formal description of the error states, synthesis of the implementation, a novel new communications mechanism for communication between the error detection system and the application, and a system for coordinating the effects of independent actions.