WS-Data Model: A Data Model for Web Services Composition and Optimization

Abstract

Recent enthusiasm in service science attracts more attention on the design and analysis of service systems. A service system, from the engineering point of view, can be regarded as the interactions between various service elements, and service elements can be innovatively assembled to provide customizable services. To embody service elements in service-oriented architecture, Web services that conform to industrial standard have been proposed and widely adopted, and many researches are devoted into automatic Web service composition. However, most of these researches focus on control flow specification and enforcement. Data mismatch between Web services appears as an orthogonal problem that can be solved using XML-based query languages. We argue that greater optimization is possible if Web service composition can be considered into data manipulation operations. A proposed model, the WS-data model, focuses on data exchanges in composing Web services. Several operators with varying properties can compose Web services and manipulate their input and output data. Experiments conducted on the Amazon Cloud platform show that these operators' properties can help identify a more efficient way to realize a complex task, expressed according to the proposed WS-data model.