Edinburgh Napier University

  Owing to the increase in both heterogeneity and complexity in today's networking systems, the need arises for an architecture for network-based services that provides flexibility and efficiency in the definition, deployment and execution of the services and, at the same time, takes care of the adaptability and evolution of such services. In this paper we present an approach that applies a component model to GT4, a Web-service-based grid environment, that enables the provision of parallel applications as QoS-aware (grid) services, whose performance characteristics may be dynamically negotiated between a client application and service providers. Our component model allows context dependencies to be explicitly expressed and dynamically managed with respect to the hosting environment, computational resources, and dependencies on other components. Our work can be seen as a first step towards a component-based programming model for service-oriented infrastructures utilizing standard Web-service technologies.