Design Alternatives for Parallel and Distributed Blackboard Systems

Since its inception, the blackboard paradigm has been viewed as particularly appropriate for parallel and distributed hardware architectures. Yet, the paradigm’s multiprocessing potential remains largely untapped. The availability of multiprocessing hardware and languages in conjunction with tools for building blackboard applications is sparking renewed interest in multiprocessing blackboard architectures. Multiprocessing can be introduced at a number of levels in the blackboard architecture, from low-level parallel coding techniques to concurrent execution of knowledge sources and control components. This chapter details the issues associated with these multiprocessing levels and presents three high-level design alternatives for parallel and distributed blackboard architectures. Each design is appropriate for a particular architectural and application environment, and we discuss the selection criteria for each design and issues associated with its implementation. The three designs are being implemented as extensions to the Generic Blackboard Development System (GBB).