Adapting applications on the fly

Summary form only given. Adapting a component-based application means adapting one or more of its components, and in general, adapting a component at run-time means disconnecting it from the application and connecting a new version of this component. Many approaches like OLAN and DCUP are based on component models in which each component is constituted by a functional part and a control part. This last part provides a set of services to administrate the component. In our approach we aim to separate the control part outside the component. The benefit is the possibility to apply our solutions to existing models that have not been designed to support the dynamic adaptation. Through a first experimentation on the JavaBeans component model, we define an adaptation process composed of several steps: (1) defining the mapping rules between the old and the new component (correspondence between properties and services); (2) passivating the old and the new components; (3) transferring the state of the old component into the new one according to the mapping rules defined before; (4) disconnecting the old component and connecting the new one; (5) activating the new component. These steps may constitute the basic activities of an adaptation machine.