Research On Cloud Service Programming Language Apla+ And Its Implementation Method

All kinds of computing resources interconnected with high-speed network constitute a huge global computer system.Requesting resources in the form of sharing cloud services,which is changing the users' habits to obtain,consume and provide computing capacity.Major countries and well-known enterprises have launched their cloud computing development plan to accelerate the construction of cloud computing platform.However,the cloud service which is requested through the network has the characteristics of dynamic,which makes it difficult to use the traditional programming method in closed environments to develop the cloud based service system.On the one hand,the vendor lock-in makes it hard to directly describe the interaction between cloud services due to the lack of the technology compatibility of cloud services provided by different vendors,on the other hand,the dynamic of the network environment calls for the integration of cloud services should not only consider the diversity of user requirements but also analyze the binding approach of cloud services competing with each other.Therefore,according to the new characteristic of cloud services,this dissertation presents a new cloud service programming language Apla+,which develops cloud service based system conveniently.Cloud services are the basic programming elements in Apla+ language,Apla+eliminates the platform dependencies of cloud services by the resource description mechanism Bundle.Based on the uncertain candidate service set defined by the service-oriented analysis method,Apla+ proposes an abstract service request mechanism to bind cloud service at runtime efficiently.By defining the service composition mechanism to integrate cloud services,it can easily achieve the value-added big service from the combination of small-scale services.By defining the formal semantics of Apla+,this dissertation studies the equivalence relation for analyzing dynamic reconfiguration for cloud service system.Finally,the program written by Apla+ will automatically generate the target code from the support environment then compile it.Specifically,this dissertation has done the following:(1)Proposing the cloud service programming mechanism in Apla+Service is the capacities provided in the dynamic execution of resources,so that different resources can provide the same service.Based on the new definition of cloud service,Apla+ language presents the resource description mechanism Bundle to represent different resources to provide service.According to the uncertain candidate service set defined in the service-oriented analysis,Apla+ language defines the abstract service request mechanism in which the contract containing time and assertion can be used to resolve the network uncertainty in cloud computing environment,and in which the contract can be used to describe the individual and personalized needs.Through the analysis of the basic structure and parallel features of composition services,Apla+ language defines five service composition operators with parallel semantics to describe the composition service conveniently,and the invoking operator provides an idea to deal with big data conveniently in cloud computing environment.These new mechanisms constitute the core elements of the cloud service programming in Apla+.(2)Defining the formal semantics of Apla+ languageAccording to Apla+ language having the characteristics of parallel meaning and dynamic binding,a timed labeled transform system is defined by marking occurrence time of events,combining variable values and execution status to define states and constraining states with assertion.Based on the precise definition of the semantic information of Apla+language through this system,strong timed bisimulation and weak timed bisimulation are defined,and then the relationship of strong equivalence and weak equivalence,which can be used to analyze the equivalence of composition cloud service with the same structure and the compatibility of composition cloud service with the different structure separately,is established.At the same time,for the cloud service in the specific environment,this dissertation proposes environment equivalence algorithm and its verification algorithm,and then this algorithm is proved formally.It realizes to analyze and optimize the cloud service system formally.(3)Research on the implementation method of Apla+Based on the idea of model driven development,this dissertation mainly studies the system architecture and implementation principle of Apla+ program development support platform,and implements the prototype system by generative programming method.The core problems and its implementation algorithm,such as the request method of heterogeneous resources,the data interaction strategy between heterogeneous resources,and the concurrent execution of distributed services in the open environment,are studied mainly.Based on the semantics of Apla+ language,a rule base for program generation from Apla+ to Java and a component library are defined,which can automatically generate the corresponding Java program,or cloud service can be directly released and deployed.(4)Proposing an iteration-based interactive service-oriented analysis methodIteration-based interactive service-oriented analysis divides the process of system analysis into two parts:interactive service-oriented analysis and iterative analysis.The interactive service-oriented analysis puts design process to complete creative activities in system analysis,and finding service satisfying the specification which is non-creative activity is completed by an automated approach.The iterative analysis process can effectively avoid the defect of the local view in analysis process,and realize the reuse of existing service as much as possible.Finally,the uncertain candidate service set is obtained by setting reusable service threshold.Parallel binding operator is used to invoke this set to achieve selecting and binding service according to the running state of services.