Research On Service Continuity For Stateful Services

Many industries such as Banking, Airline reservation, Communication,Network payment, Online file transfer, Online video conference and so on, putforward higher requirements on the Server, a few minutes of service disruption maybring tens of thousands of dollars of losses on these industries. Server works under24hours of uninterrupted environment is the pursuant target of these industries.Service down will bring direct huge economic loss to the enterprise, and even affectthe corporate image in the public. Therefore, these enterprises spend a lot of moneyto improve the stability of the server. How to improve the stability of the system andensure the service continuity becomes an urgent problem to be solved. The service isdivided into stateful service and stateless service. This paper mainly focuses on theresearch of service continuity problem with stateful services, distinguished thestateful services and stateless services, established the service continuity model,designed and implementation the3tactics based on the status of the service to bestorage at client, service status to be storage in shared memory and servicesynchronization based on the improved Paxos algorithm. The design of file transfersystem based on Distributed, solved the problem of the sustainable service throughthe3methods, Guarantee uninterrupted service. The main work and innovationpoints are as follows:First, Discussed in details the Stateful services and stateless services based onthe status of the service, established a sustainable model of stateful services. Themodel uses a distributed architecture system, it can solve the problem of statefulservices effectively.Second, Classified the currently technology which used to solve the statefulservices problem, summarized three resolution to solve the service sustainableproblem as follows: Client storage technology, Shared memory technology based onthe service and service synchronization based on the Paxos algorithm.Third, Analysis the Paxos algorithm in-depth, illustrated the process by graph.Then,improved the Paxos algorithm based on following two points. First, byintroducing the leader role to enhance the program’s execution, avoid the proposerrole request prepare services with not stop and lead to the occurrence of deadlocksituations. Second, combined message passing and shared memory technology, LetPaxos algorithm from a simple message passing to use part of sharing memorystorage technology. This improved is a great value to solve distributed servicesustainable problem with Paxos algorithm, ensured the continuity of distributed services from the theoretical and practical significance.Fourth, combined with these three technologies which used to solve the problemof service continuity, designed a distributed file transfer system to test the threetechnologies: Client storage technology, Shared memory technology and servicesynchronization based on the Paxos algorithm, especially the improved Paxosalgorithm and compared each other. Last, this paper points out that: The improvedPaxos algorithm is more stable and more efficient used to solve services continuity.