A CONCEPTUAL FRAMEWORK AND IMPLEMENTATION FOR DEVELOPING WS - QoS AWARE ARCHITECTURES
Cosmina Ivan, Vasile Teodor Dădârlat · 2010
Web Services and SOA are becoming more and more popular these days and more and more businesses are planning to build their future solutions on Web Services technology. By now, SOAP and WSDL have become reliable standards in the field of Web Services execution. While the concept of UDDI allows for automatic discovery of services implementing a common public tModel interface, there have been only few attempts to find a standardized form to describe the Quality of service (QoS) with which the service is performed. Nevertheless, the QoS a provider delivers will become a decisive feature when it comes to selecting one from many availably services providing the same functionality. Today, we have sophisticated technology to actively differentiate between various QoS levels both on transport level (DiffServ, IPQoS, CoS for UMTS/ATM/RCL) and server level (load balancing, transaction differentiation, HTTP request differentiation), yet there are only few means to describe the desired QoS on application layer. To tackle this, we propose a conceptual framework based on a Xml schema to declare both clients' QoS requirements and the QoS level service providers, and we have designed and implemented a framework for C# / .NET application developers to assign QoS requirements to a client application's service proxy which can then be used to inquire a QoS service broker for the best QoS offer fulfilling the requirements from all offers available for services that implement the specified interface.