Web Service Composition Based on QoS Rules

For workflow-based service composition approach, the relations between the Web service QoS and environments are usually not considered, so that the information about QoS for composite service selection is inaccurate It makes the selected composite service inefficient, or even unexecutable To address this problem, a novel service composition approach based on production QoS rules is proposed in this paper Generally, it is very difficult to directly analyze how different kinds of environment factors influence the Web service QoS We adopt "black-box" analysis method of optimizing compositc services, discovering the knowledge such as "the QoS of one Web service will be higher in specific environments" In out approach, the execution information of the composite service is recorded into a log first, which will be taken as the basis of the subsequent statistical analysis and data mining Then, the timely QoS values of the Web services are estimated and the production QoS rules being used to qualitatively express the different performances of the Web service QoS in different environments are mined At last, we employ the mined QoS knowledge of the Web services to optimize the composite service selection Extensive experimental results show that our approach can improve the performance of selected composite services on the premise of assuring the selecting computation cost