Modeling the Performance of a Distributed Application Based on Web Services

This paper presents an analytical model to estimate the impact of using Web Services as middleware technology. Explicitly, Queueing Networks (QN) are used to model a distributed application that use a Web Services middleware layer, with support of a set of open source and multiplatform tools for testing and modeling purposes. The model is used to foresee the overall system performance, taking into account both the service provider and the service consumer side. The results demonstrate that the proposed QN model produces accurate estimates of the response time and scalability, and can be used to evaluate and compare different hardware and software configurations.