Modelling for Quality of Services in Distributed Geoprocessing

Geographic information (GI) services are increasingly the state of the art in geoprocessing, promising novel geospatial solutions, products and services. Dynamic chaining of GI services however, presents exciting quality of service (QoS) challenges. Consequently, sustainable use of GI services demands careful consideration of the diverse user requirements and the complexities of dynamic service chaining in view of the QoS limitations of the Internet. An initial and necessary step towards provision of QoS guarantees in Internet GIS is QoS-aware service chaining, where services are discovered and composed on the basis of their non-functional quality characteristics. The paper presents an architecture for QoSaware service chaining and defines an extensible QoS model for GI services. Further, to facilitate the successful evolution of GI enterprise into effective service providing nodes on the GI service infrastructure, an integration framework for GI enterprises presented. While the provision of hard QoS guarantees on the Internet remains elusive, QoS-aware service chaining will greatly improve the quality experienced by Internet GI applications and users.