CAREL: Computer aided reliability evaluator for distributed computing networks

Abstract

An efficient method to compute the terminal reliability (the probability of communication between a pair of nodes) of a distributed computing system (DCS) is presented. It is assumed that the graph model G(V, E) for DCS is given and that the path and/or cut information for the network G(V, E) is available. Boolean algebraic concepts are used to define four operators: compare, reduce, combine, and generate. The proposed method, called CAREL, uses the four operators to generate exclusive and mutually disjoint events. CAREL has been implemented using bit vector representation on an Encore MULTIMAX 320 system. It is shown that CAREL solves large DCS networks (having a pathset on the order of 780 and a cutset on the order of 7300 or more) with a reasonable memory requirement. A comparison with other algorithms reveals the computational efficiency of the method. The proof of correctness of CAREL is included.