Engineering complex adaptations in highly heterogeneous distributed systems

Distributed systems now encounter extreme heterogen eity in the form of diverse devices, network types etc., and al so need to dynamically adapt to changing environmental conditi ons. Selfadaptive middleware is ideally situated to address these challenges. However, developing such software is a complex task. In this paper, we present the Gridkit self* approac h to the engineering of reflective middleware; this embraces state of the art software engineering practices, and flexible dy namic adaptation mechanisms to better support system deve lopers. Domain specific frameworks are modeled and develope d to enhance configurability and reconfigurability. We e valuate this approach using case studies in the domains of servi ce discovery and network overlays. These demonstrate the benefit s o the approach in terms of aiding and simplifying the pro cess of creating self-configuring and self-adaptive softwar e.