Managing inconsistency in reconfigurable systems

This paper discusses an approach to managing inconsistencies in real-time control applications that are the result of dynamic reconfiguration. In particular, systems based on Simplex are examined: a fault tolerant technology that supports dependable upgrade of systems. Simplex-based systems tolerate residual errors in upgraded components and can be upgraded incrementally and while the system is in operation. Runtime reconfiguration is a key mechanism for Simplex. Reconfiguration of components due to an encountered error may result in inconsistent configurations. The paper focuses on design time analysis to determine inconsistencies in configurations and identify reconfiguration paths to recover to consistent configurations. Runtime support uses the analysis results to recover from inconsistent configurations. Identification of inconsistent configurations is improved through modelling of application semantics in the control domain and utilising them in the analysis