MELODY: a distributed real-time testbed for adaptive systems

The authors analyze current and future needs in building adaptive real-time systems and formulate a series of design requirements for their hardware/interconnection, operating system, and application levels that could be satisfied together only in an integrated system design. They describe the major features of the corresponding model. On the operating-system level, novel services are rendered by their own file system, Dragon Slayer. The file system, in order to both meet real-time constraints and provide for high availability in a hazardous environment, allows for replicating, relocating, or deleting of file copies. A distributed implementation of the integrated system design model is currently being completed in order to serve as a distributed real-time testbed. The authors also report on a sensitivity study that shows how promptly the model file system reacts to changing environmental situations (changing request patterns)