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Research On Evolution Method And Key Technology Of Service Choreography Oriented Web Service Composition With Larger-granularity

Posted on:2015-02-03Degree:DoctorType:Dissertation
Country:ChinaCandidate:D L YouFull Text:PDF
GTID:1268330422470598Subject:Computer application technology
Abstract/Summary:PDF Full Text Request
With the gradual maturity of the technologies in service computing and cloudcomputing, the large-granularity composite service with wide functions and complexinternal logic are increasingly adopted in service-oriented software development andsystem integration.Given the environmental changes and customers’ demands, thelarge-granularity composite service need to constantly evolve in the service choreography,affecting the partner service and the adjusted service choreography protocol. Thepost-evolutional incompatibility exists among the service port, process structure andbehavior. Consequently, it is critical to solve how to determine the evolution of the servicebefore and after the service node, and the internal business processes, how to determinethe involved scope of the evolution, how to comply with the various services involved inthe evolution of service choreography protocol and how to determine the compatibility ofthe service composition after evolution occurred. The main research works are as follows.Firstly, the evolution result of the current Web service composition is studied, and ain-design service choreography-oriented large-granularity composite service technicalframework is proposed in line with the features of large-granularity composite service.Demand changes description and target design is conducted based on the evolutionprocesses, with evolution type determination, evolution rotocol negotiation, feasibleanalysis, affected scope determination and scheduling protocol mapping being given. Thesuitability and the completeness of this method will be explored by analyzing theeffectiveness of framework and the comparing with other methods.Secondly, above the evolution type analysis, the evolutions are classified into singlestate node, single service and service composition according to function changesfeatures.The corresponding determination rules of evolution are given on the basis ofbisimulation theory. The rules can determine the evolution types of the optional evolutionprograms, comparing costs and operations of different programs, identifying the changesof service composition before and after evolution, and keeping a note of the changesinformation. The cases show the determination process of evolution type and application circumstance and confirm the effectiveness of determination rules.Thirdly, given the changed inner business logic of member service caused byevolution, based on the bisimulation theory, the determination rules, algorithm andimplemntation mechanisms of affected scope are given from three levels of the a internalbusiness process, internal business processes in a single service and global businessprocesses in service composition. The rules can determine the scopes of the affectedevolution, confining the evolution to the affected areas, overcoming the problem ofunaffected state node being replaced as well in traditional evolution. Meanwhile, theimplementation mechanism ensures the determination’s implementation process, solvingthe problem of unable to determine the affected scopes of parter service owning to beingunclear about internal details of parter service. The cases show the determination flow ofthe affected scope by evolution and confirm the applicability of the rules.Fourthly, the role-oriented mapping methods of service choreography protocol willbe proposed.The service choreography protocol is described by WS-CDL; using afour-tuple defined the protocol structural model to describe the protocol declarationsection. The global actions execution sequences is defined by π-calculus to represent theglobal behavior of the protocol.the definition of a behavioral models of the protocol isdefined by a finite state automaton to describe the choreography body of the protocol.Then, using the mapping operator, the role-oriented structure mapping model and thebehavior mapping model are given. The mapping models meet the features oflarge-granularity composite service is integrated by distributed service orchestrationion,and parter service respectively implement evolution.and avoiding the protocol is disclosebecause the entire protocol document is published to the parter service. And it would besolved by the mapping models that WS-CDL and BPEL can not be directly transformedbecause of the not correspondness to the grammar between them.Finally, given the partly-changing features of service function in the evolution, on thebasis of determining the compatibility with the service integration, a evolution-orientedWeb service composition compatibility determination method is proposed from threeaspects of service port, flow structure and behavior, with the determination rules,algorithms and examples being given. It solves the problem of the time sequence, deadlock and unspecified reception existing in the determination methods of co-servicescompatibility. The MWB of π-calculus describes the interactional flow expression,simulates the deriving process of behavior compatibility and verifies the effectiveness ofdetermining rules.
Keywords/Search Tags:Web service composition, large-granularity service, service choreography, evolution type, affected scope, protocol mapping, compatibilitydetermination
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