Dependable Approach to Supporting Service Composition′s QoS
In current web computing systems,the QoS of composed service is usually accomplished via the QoS contract of underlying service.However,it is hard to be guaranteed.In this paper,virtual atom service is introduced to overcome the problem.The virtual service can dynamically select one or a group of underlying atom service to achieve better QoS assurance.The scheduling framework and algorithms of virtual service are introduced and implemented in ICE framework.The experiment shows that the mechanism can improve QoS assurance significantly.