Partially decentralized passive replication protocol for deterministic servers

In this paper, we present a partially decentralized passive replication protocol designed for deterministic servers in message passing systems. This protocol allows each backup to take responsibility for processing its received client request and coordinating with the other replica servers after obtaining the delivery order of the request from the primary. Due to this feature, the protocol with conventional load balancing techniques can avoid extreme load conditions on the primary. Therefore, the protocol promises better scalability at the expense of more complex recovery procedure compared with traditional protocols. The simulation results indicate that the average response time of a client request can be reduced up to 52.3% by using the proposed protocol instead of the traditional ones.