DeW: a dependable Web services framework

Web services (WSs) correspond to conceptual entities with well defined interfaces published by different organizations. For example, with businesses, a WS might correspond to a business process to be invoked by other WSs and Internet applications. To increase availability of a WS, an organization might replicate it across different nodes. This study focuses on data intensive applications that: (a) expose a conceptual entity as a Web service (WS); and (b) disperse copies of their WSs across the nodes of a distributed environment to enhance both performance and availability. We describe the design and implementation of a dependable Web services (DeW) framework to realize physical-location-independence. Physical-location-independence means a plan will execute as long as a copy of its referenced WSs is available. This concept enables the client proxy objects to continue operation in the presence of both failures and WS migrations that balance system load.