Research On Interaction Mechanism Of Cloud Services In Apla+ Language

As a crystal of cloud computing and service computing,cloud services provide value-added function to meet the diverse needs of users through SaaS or PaaS,etc.Depending on its interaction and collaboration,multiple cloud services can be assembled into a more powerful system.Hence,the interaction of cloud services,the basis of service composition,plays a critical role in the overall performance of system.Due to the concurrency,failure-tolerant and distributed features of cloud services,how to describe and design its interaction mechanism is an challenging problem.Current related research mainly has three issues:Firstly,there has no suitable model to describe the sophisticated interaction of cloud services;Secondly,current work hasn't taken into account the design of concurrency control from both state and resource perspectives.Finally,it still lacks the appropriate language and developing framework for interaction mechanism of cloud service.With regard to the above problems,we studied the interaction mechanism of cloud service from four perspectives,which includes model,mechanism,language and MDD framework.As the result,this dissertation proposed SCSM model and Apla+ session programming.Moreover,we also designed a novel interaction mechanism based on PAR,then construct its related MDD framework.The concrete contents of our work as followed.(1)SCSM:a design model for the interaction of cloud services.We first analyzed the interaction features of cloud service,and induced it layers and category.In order to encapsulate concurrent interaction,we proposed session con-cept.Based on session,we presented SCSM,a cloud service oriented model which describes the elements and its relationship.Compared with other work,SCSM model comprehensively takes into account the core features of cloud services,then refines the concepts of session,role and pool,which provides a abstract model for languages.(2)a novel interaction mechanism of Apla+ session.Considering the concurrent,distributed and fault-tolerant features of cloud services,we designed a novel interaction mechanism of Apla+ session,including selecting and fault-handle strategy.In view of the characteristics of cloud service' interaction,our work presented a comprehensive the protocol of concurrency control from state sharing and resource competition viewpoints.Hence,we can guarantee the correctness of cloud services' interaction and data consistency by means of that protocol.By using resource-oriented decomposed algorithm,selecting protocol turn selecting problem into Lagrange dual problem.The simulating experiments show that,comparing to old methods,the new one increases at least 6.5%in the aspect of optimal solution.By utilzing selecting protocol,the fault handling mechanism of session presents a light-weight fault-tolerant strategy,which paves a novel path for cloud service fault-handling.Differ with other mechanisms,our work provides more efficient safety measures and more flexible fault handling.(3)Apla+ programming for cloud services session.Considering the demands of programming for cloud service,we presented a session programming based on Apla+.As a multi-paradigm language,Apla+,which integrates with functional language and Apla OOP style,can structurally describe concurrent interaction processes.To deal with dataflow and fault,Apla+ session programming also augments new functional combinators,such as pipeline combinator etc.In addition,we defined its operation semantic,then constructed its session-base type system,which facilitates proving the safety characteristic of Apla+ session programming.(4)The MDD framework for developing interaction mechanism.Inspired by MDD idea,we designed and built a MDD framework for developing interaction mechanism.So,we implemented the compiler of Apla+ session program-ming,which translates session to Java.In addition,we also proposed the related design methodology,including the mapping from UML sequence diagram to Apla+ session and the solution to the session coupling problem.Those aboved work provides a one-stop development solutions for the interaction mechanism of cloud services.