Solving Atomic Multicast When Groups Crash

In this paper, the authors study the atomic multicast problem, a fundamental abstraction for building fault-tolerant systems. In their model, processes are divided into non-empty and disjoint groups. Multicast messages may be addressed to any subset of groups, each message possibly being multicast to a different subset. Several papers previously studied this problem either in local area networks or wide area networks. However, none of them considered atomic multicast when groups may crash. They present two atomic multicast algorithms that tolerate the crash of groups.