Modeling the performance of the web service platform using layered queueing networks

The current evolution towards complex software systems consisting of relatively loosely coupled components, owned and exploited by different players, implies important challenges for both the application developers as well as the providers of the final software system. In this area, we currently witness the adaption of the Web service model as one of the major component standards. This paper presents an analytical model to evaluate the impact of using Web services as middleware on the overall system performance. Specifically, Layered Queueing Networks are used to model the Web service middleware layer. When designing a distributed application, this model can be used to predict the overall system performance, even for complex systems. For comparison reasons, the LQN model when using CORBA as middleware is presented as well. The results show that the proposed LQN models, of both the Web services framework as well as CORBA, produce very accurate estimates of the response time.