Functional Paradigm for Designing Dependable Large-Scale Parallel Computing Systems

This paper proposes the use of a functional language and of a dataflow computing model for the design of large-scale parallel computing systems for which dependability, in its aspects of reliability, timeliness, parallelism and distributedness are requirements of main concern. The proposed design methodology is sufficiently flexible to allow for verification and validation of such systems from the very first steps of the design. The advantages of such an approach resides in the potential for parallelism it admits, in being characterised by referential transparency and in the property of composability. The design description language is extended for dealing with dependability issues, with the creation of a library of fault tolerance schemes which can be used for modular insertion of redundancy. A set of tools are being defined as part of a design development environment allowing the designer to proceed in successive interactive steps, each of which can be validated. 1