Enhancing the Web Service Description and Discovery Processes with QoS
As the Web service (WS) paradigm gains popularity for its promise to transform the way business is conducted, the number of deployed WSs grows with a fast rate. While sophisticated semantic discovery mechanisms have been devised to overcome the UDDI’s syntactic discovery solution in order to increase recall and precision, the amount of functionally equivalent WSs returned is still large. One solution to this problem is the description of the nonfunctional aspects of WSs, including quality of service (QoS). QoS encompasses the performance of WSs and can be used as a discriminating factor for refining WS advertisement results. However, most efforts presented so far are purely syntactic in nature and do not capture all aspects of QoS-based WS description, leading to imprecise syntactic discovery mechanisms. In this chapter, a definition of QoS for WSs is provided and its important role in WS management is emphasized. An analysis of the requirements that are imposed on the WS description and discovery processes based on QoS is given along with a review of related work in QoS-based WS description and discovery, highlighting the main deficiencies of recent approaches. Then, a complete semantic approach for QoS-based WS description and discovery is presented and analyzed. The chapter concludes by drawing directions for further research.