Virtual trees for the byzantine generals algorithm

Abstract

The Byzantine Generals algorithm for achieving reliability in the presence of faults is a classic topic in distributed computation and operating systems, not the least because of its colorful story. We describe a concept called virtual data structures, which are concrete representations of global data structures that is not actually maintained by the nodes of a distributed system, but are required in order to understand the correctness of algorithms. We show that the use of virtual trees for the Byzantine Generals algorithm can improve the understanding of this algorithm, and we describe a visualization of the trees. Copyright 2004 ACM.