Performance analysis of a hierarchical quorum consensus algorithm for replicated objects

A class of algorithms for synchronizing a large number of identical copies of an object is described, and its performance is evaluated. The method is based on organizing a group of objects into a multilevel hierarchy and extending the quorum consensus algorithm to such an environment. The performance of the algorithm is compared, in terms of availability and message cost, with that of two other methods, majority voting and dynamic voting using a simulation model. Although the author´s method uniformly outperforms the other two methods in terms of average message cost, no single method is found to dominate in terms of availability. The conditions under which each method performs well are identified