PWSMS: A peer-to-peer web service management system for data sharing in collaborative environments

摘要

In today's collaborative environments such as bioinformatics and healthcare, access to an increasing number of data sources has been made in the form of Data-Providing Web Services. Current approaches to composing Web services are not suitable for this special class of Web services as they do not take into consideration the semantic relationship that holds between input and output sets of a Web service. In this paper, we present our Peer-to-Peer Web Service Management System (PWSMS) for data exchange through Data-Providing Web Services. A novel approach is proposed for automatically composing data-providing services by making usage of the mature work that has been done in the conventional data integration and mediation systems. Specifically, we model data-providing services as RDF parameterized views over mediated ontologies. We devise an algorithm for composing services based on conventional query rewriting techniques. Similarly to the conventional services composition, users may want to run the generated composite service over several values of the same input parameters. To deal with this issue, we treat parameterized queries where values for input parameters are specified as ranges or not given at all. We also propose an efficient probabilistic algorithm for detecting the minimum set of services satisfying constraints (over inputs/outputs) specified in the query. Finally, we present algorithms for optimizing the generated composition. These algorithms have been implemented in our PWSMS system.