Static allocation of process replicas in fault tolerant computing systems

It is proved that there exist allocations that are optimal with respect to reliability. A simple transformation rule that derives an optimal allocation of replicated systems from an allocation of a given nonreplicated system is presented. This transformation preserves performance optimizing properties of the original allocation. Generally, replication gives a large number of processor links. A second transformation rule generates a replicated system with authenticated messages. The reliability of this system is also optimal, with, however, significantly fewer communication links.<>