How to Choose a Timing Model?
When employing a consensus algorithm for state machine replication, should one optimize for the case that all communication links are usually timely, or for fewer timely links? Does optimizing a protocol for better message complexity hamper the time complexity? In this paper, the authors investigate these types of questions using mathematical analysis as well as experiments over PlanetLab (WAN) and a LAN. They present a new and efficient leader-based consensus protocol that has O(n) stable-state message complexity (in a system with n processes) and requires only O(n) links to be timely at stable times.