An Online Fault Tolerance Server Consolidation Algorithm

We study server consolidation problem in clouds under simultaneous failures of multiple servers, where consolidation means that cloud providers put tenants on shared servers to improve resource utilization and thus reduce operation and maintenance costs. With replicas of each tenant put on multiple servers, our objective is to minimize the total number of opened servers and ensure that a particular failure will not result in overload on any remaining server. In this paper, we propose Rotation algorithm. It packs comparable sizes replicas into the same type of servers and adopts a cyclic shift method to quickly reuse those already-opened servers without the need of new ones for new tenants. Through experimental evaluations, we show that the proposed algorithms can achieve a better performance than existing works and produce near-optimal replications allocation.