Research Of Consensus Algorithm Based On Replicated State Machine

In recent years,with the continuous development of networks and information technologies,distributed systems have replaced centralized systems and become the focus of researchers.Consistency issues have always been a fundamental and complex problem in the implementation of distributed systems.The design goal of the consensus algorithm is to enable the cluster nodes to reach a consensus on a certain issue in an environment where the network and nodes are not controllable.Paxos algorithm is a consensus algorithm that is widely considered to be the most effective.However,when the Paxos algorithm is applied in the actual situation,due to the complexity of the algorithm itself and the particularity of the practical application,the researchers usually need to improve the Paxos algorithm accordingly.In this paper,Paxos algorithm is applied to the usage of replicated state machines,and according to this circumstance,a new consensus protocol is designed by adding certain strategies.The design goal of this new consensus protocol is to maintain servers' usability and capability of fault tolerating,even if the failure rate of the network and nodes is higher than normal.This article is mainly organized with the following parts:(1)Explore the significance of researching distributed consensus algorithm,and discuss the development of the research domestically and abroad.(2)To achieve the consistency of the replicated state machine,the Paxos algorithm and Multi-Paxos algorithm are introduced.(3)In order to maintain the consistency of the replica node in the distributed environment with high failure rate,a new consensus protocol named xm-Paxos is proposed,and the basic algorithm and implementation details of the protocol are introduced.(4)In order to test various aspects of the new protocol xm-Paxos,a series of experiments were performed to perform acomparative analysis.Experiments have proved that in the operating environment with high failure rate whose network and nodes break down now and then,the newly designed consensus protocol xm-Paxos can provide better availability and fault tolerance for the cluster and it will not cause extra message-passing.