一种基于有色Petri网的语义Web服务组合验证机制

Web服务组合是一个复杂而易错的过程,现有的组合规范又缺乏有效的验证机制,无法保证组合服务的顺利执行.针对这一问题,并根据目前的语义趋势,利用有色Petri网对基于Web服务本体描述语言的服务组合系统进行形式化描述和建模,通过服务组合代数定义组合运算的基本规则.在此基础上,根据Web服务本体语言组合要素的相关语义建立其对应的有色Petri网结构.另外,给出了分析验证所生成的有色Petri网模型的具体方法,使用该方法可以检验组合系统的各项动态性能,探测死锁等错误,从而提高组合的可靠性,避免执行失败.最后,通过实例直观地描述了建模与验证的工作过程.

Verification mechanism for semantic Web service composition based on colored Petri-nets

Web services composition is a complex and error-prone process,but existing composition specifications provide no way to verify correctness and ensure a smooth execution.To tackle this problem,Colored Petri-nets(CP-nets) was applied as formal tool to describe and model Web services composition.Basic rules for composition algebra were defined by service composition algebra.According to relevant semantics of composition elements of Web service ontology,corresponding operators were constructed.Furthermore,the techniques were provided to analyze and validate the CP-nets,by which the dynamic behaviors of the established model could be verified and composition errors such as deadlocks could be detected in advance,as a result the composition reliability was improved and runtime failure was avoided.Finally,an example was given to illustrate the effectiveness of the approach.