A model-driven approach to describe and predict the performance of composite services

Distributed applications are rapidly converging towards the adoption of a computing paradigm based on service-oriented architectures (SOA), according to which an application results from the composition of a set of services in execution on networked server hosts. In a SOA context, service providers are strategically interested both to describe the performance characteristics of offered services, to better qualify their offer and gain a significant advantage in the global marketplace, and to predict the level of performance that can be offered to service consumers when building composite web services that make use of services managed by various service providers. This paper introduces a model-driven approach for integrating performance prediction into service composition processes carried out by use of BPEL (Business Process Execution Language for Web Services). The proposed approach is founded on P-WSDL (Performance-enabled WSDL), a performance-oriented extension of WSDL, the language for describing the information about service capabilities and invocation mechanisms. P-WSDL is a lightweight WSDL extension for the description of performance characteristics of a web service. The approach is illustrated by use of an example application to a composite web service for travel planning.