Aspect Oriented Decision Making Model for Byzantine Agreement

Abstract

Problem statement: The main aim of this research study is to develop an enhanced strategy for decision making whether to commit or rollback a request to a Web service in the presence of Byzantine faults using aspects. The proposed study extends the Lamport’s algorithm for Byzantine agreement to have an effective decision while handling the service request. When the service is initiated based on the request, its execution behaviour is being monitored before, after and at the time of execution and being handled with aspect concerns to provide the corresponding responses as input to the Lamport’s Byzantine agreement algorithm. The decision on the client requests is based on the outcome of the aspect advices before, after and around the execution of the services. Approach: This approach identifies the inception of the process which starts to exhibit abnormal behaviour before, after or during the execution of the service and instigates that helps in resolving the faulty service and identifies the root cause of the problem to rectify it. Aspect oriented advices do not require any external invocation as it executes with the service and hence no additional overhead involved in processing the service request. Results: In the existing methodology only the around advice decision is considered for reaching an agreement in the presence of Byzantine faults. An enhancement in the decision making process is proposed by including the state of the services: before, after and around advices of the aspects. Conclusion: The obtained experimental results based on the proposed methodology depict that the performance measure, Round Trip Time is slightly increased when compared with the existing Lamport’s algorithm for Byzantine Agreement and this performance overhead is not a major concern as the proposed approach produces an enhanced decision by considering aspect concerns and also determines the origin of the fault. The change in execution behaviour of Byzantine algorithm when aspects are introduced is compared with the implementation of the algorithm without aspects in various distributed environments.