Research On Consistent Dynamic Evolution Of WS-BPEL Services

Nowadays,service computing is becoming a hotspot along with the fast growing of Internet.In service oriented architecture(SOA)area,service composition is an important method which can be used to satisfy various demands from customers and integrate kinds of heterogeneous resources(such as hardware,software,data,processes etc.).In the open and changing environment,service composition must have the ability of dynamic evolution.There exist some technologies and systems in this area,while they can not work efficiently in the real environment.To support correct,efficient and low cost dynamic evolution of service composi-tion,we propose a method to analyse dynamic dependency of WS-BPEL(Web Ser-vice Business Process Execution Language)and give a proof on the correctness of our method.Based on the dynamic dependency,we implement a system ensuring global consistency of service composition during dynamic evolution,and we conduct some experiments on this system.The contribution of this extension includes:?We propose a method to analyse dynamic dependency of WS-BPEL.We perform this analysis on our WS-BPEL model which preserves most semantics of WS-BPEL.In addition,we give a proof on correctness of our analysis method.The dynamic dependency we proposed contributes to efficient evolution of services,but has low overhead at runtime.?We implement a system which holds the ability of dynamic evolution of WS-BPEL.In this system,there are kinds of evolving methods including Version-ing,Quiescence and Version Consistent with Wait,Block,Concurrent strategies.These dynamic update algorithms introduced from component-based distributed system(CBDS)area are able to guarantee the global consistency of service com-position.? We conduct several empirical studies on our analysis method of dynamic depen-dency and CBPM system.Effectiveness of the dynamic dependency analysing method is evaluated and on our CBPM system we also design various experi-ments to evaluate correctness,efficiency and service disruption of dynamic up-date algorithms.The results of experiments show that dynamic dependency pro-motes the efficiency of dynamic update and CBPM holds the ability of correct and efficient dynamic evolution.At last,by comparing with original JBPM,we show that our CBPM system has insignificant overhead.