An Early-Delivery Alogrithm for Consensus-based Atomic Broadcast

Although a large number of consensus and atomic broadcast algorithms based on failure detectors have been published during the years, they are still criticized for poor performance in terms of communication latency. To reduce the latency, some algorithms based on optimistic assumptions have been proposed. When the optimistic assumption holds, these algorithms deliver messages more quickly than other ones. However, if the assumption does not hold, the efficiency of these algorithms deteriorates. In this paper, we propose an early-delivery atomic broadcast algorithm which exploits the optimistic assumption in a way that never leads to high latency. This is achieved by attaching information to all sending messages and collecting the information from communication history records. The simulation experiments show that our algorithm is a good trade-off between conservative ones and optimistic ones