Dynamic Selection of Web Services Using Qos Constraints in Bpel

Abstract

Business Process Execution Language for Web Services (BPEL) is an industry standard language for web services composition. BPEL allows users to compose and execute web services-based business workflows, utilizing distributed web services. Standard BPEL allows dynamic execution of web services, but automatic service selection is not supported. We propose to extend BPEL to allow users to specify Quality of Service (QoS) parameters that will guide a BPEL execution engine to select appropriate service providers during run-time that will consequently improve the engine performance towards higher system throughputs. We implemented our proposal by extending an open-source BPEL engine to support QoS constraints. We present preliminary results showing that QoS-supported BPEL execution improves the overall system throughput by lowering the average execution times of BPEL processes.