Software architecture description supporting component deployment and system runtime reconfiguration

Architecture description languages (ADLs) can be used for describing architectures of component-based software systems. Typical ADLs provide explicit support for specifying components, connectors and configurations as well as for building hierarchical system configurations. All of them allow to specify structural dependencies among components, thus describing static configurations. This may be sufficient for an initial system composition, but does not provide enough information for post-deployment and runtime reconfiguration. Only a few ADLs provide some support for dynamics, usually without a clear differentiation between a possible behaviour of component descriptions and a runtime behaviour of component instances. Even XML-based ADLs such as xADL 2.0, which clearly distinguishes between the design-time and run-time, only defines structural instance schemata. In our approach, we observe the ”use ” dependencies among instances of components (called ”live components”) of an already deployed and running system. The life components are constrained by specified structural dependencies (defined in ”component descriptions”). Live components are hosted in containers. The ”Service-Connector-Container ” view of our model provides a way to describe the runtime behaviour of a system. Thus, it supports dynamic reconfiguration of component-based software systems. We use ”service effect automata ” for runtime behaviour specification and intend to extend them using the timing and liveness concepts of ”live sequence charts”. Topics from CFP dynamic composition of component-based systems, dynamic architectures, architecture description languages suitable to guide COP, system design for hot-swappable components, addressing variability requirements in component-based solutions