Qos Integration in Value Added Web Services

Nowadays, Value Added Web Services (VAWS) are becoming a hot spot for web services providers. Quality of Service (QoS) support in VAWS is an important issue. The need for providing and assuring an acceptable level of QoS is the objective of most of service providers. Service providers compete in satisfying requirements of potential clients by providing QoS support of VAWS. In this work, we propose an architecture for managing and assuring QoS provision of VAWS. The endeavor of this architecture is to support QoS management and enforcement for both clients and providers of web services. We have developed the components of the architecture that allow providers to introduce QoS-centered annotations in the service description and to guarantee the publication of these QoS carried in the service interface description. Moreover, a validation process is developed to test the service interface and the QoS for the providers before publishing its services. The validation practices will enforce the accurateness of available services and their QoS, and the clients’ trustfulness. The architecture allows clients to introduce theirs QoS requirements in their requests to select web services. It also supports bidirectional QoS negotiation based algorithm for clients and providers. This will add more flexibility for the provision of QoS, for both clients and providers. The validation of the overall architecture is studied through an implementation.