A Scenario-based Approach to Increasing Service Availability at Runtime Reconfiguration of Component-based Systems

Component-based business-critical systems evolve during their life cycle in order to meet changing requirements or to improve quality properties. At the same time, maintaining continuous availability of services is an issue with increasing importance for these systems. Runtime reconfiguration supports evolution of systems while maintaining availability of services they provide. In this paper, we present a new approach to runtime reconfiguration of component-based systems, which aims at optimising availability of requested services during reconfiguration. For a particular reconfiguration request, we analyse relevant scenarios based on the usage model of the system and exploit the component protocol information. Considering varying number of requests for a service at different points in time as well as the priority of each service, we compute minimal runtime dependency graphs among component instances and thus the maximal possible availability of services provided by the system. Finally, we sketch the system architecture for evaluating our approach.