Investigating, modeling and evaluating the interface complexity of Web Services

this paper emphasizes on the interface complexity — one of the most influential factors affecting Web Services invocation performance. Our ultimate goal is to propose a novel and versatile model to measure the interface complexity. First we introduce the term WSDL2Java Cost to measure the overall cost for converting a WSDL file into server-side Java source code. Then we conduct myriads of experiments to respectively figure out the correlations between parameters, operations, their synthetic effects and the WSDL2Java Cost with various SOAP toolkits. We analyze the experimental results, finding an interesting feature called PODU (Parameter-to-Operation Distribution Unrelated), and introduce a model named WSDL Contour to measure the interface complexity. In order to test our model, we ad hoc refer to more than 9,000 WSDL files on the World Wide Web. In the end, based on our experimental results and the WSDL Contour model, we give some advice on Web Services Interface Design Principle, especially on the Web Services Granularity in the aspect of interface complexity.