A Web Service Monitoring System Supporting For The Qos Measurement

As the Web Service and Service-Oriented Architecture become more and more popular in industry and academy, the number of Service-Oriented applications grows rapidly, so do the available Web Services offered by different provider, and thus more and more Web Services have the same or similar functions. Besides functional property, non-functional attributes, so called Quality of Service(QoS) of Web Services have become a very important factor for differentiating similar Web Services.For the broadly definition, Web Service QoS contains lots of attributes within a wide range, which have their own characteristics, including subjectivity, relativity, and so on, which make it full of challenge to obtain their values. The existing research work mainly on the basis of the assumption that the QoS information has already existed, so the fundamental issues of how to obtain the QoS information of Web Services have been overlooked, to a large extent.In this paper, we believe that the majority of Web Service QoS information can be obtained objectively by the monitoring of the Web Service and study on the QoS monitoring model and support system for these category of QoS. The main works of this paper include proposals of:1. A QoS monitoring metamodel of Web Service is proposed.QoS monitoring metamodel define the schema of the monitoring model in specific applications, which give a unified description framework for different categories of QoS attributes and their measurement. It provides different monitoring strategy for different QoS metrics according to the characteristics of the QoS attributes. The metamodel can be used to construct various QoS monitoring models for the specific applications or domains.2. Presents an architecture of Web Service monitoring system to support the collection of the QoS information.Building upon our previous work on service mediator, which extends the Service Oriented Architecture and plays as an proxy role between the service provider and consumer and provides an unified way for the Web Service access, we further enrich the infrastructure to enable the monitoring activity, including the QoS monitoring model management, compute engine, monitoring strategy, data services and so on.3. We also developed a prototype system under the background of the distributed Science and Technology information Integration and sharing software System, and combined the practical application scene and got the QoS information successfully which was applied to the relative applications.