Global and local QoS guarantee in Web service selection

Abstract

In Service Oriented systems, complex applications can be composed from a variety of functionally equivalent Web services which may differ for quality parameters. Under this scenario, applications are defined as high level business processes and service composition can be implemented dynamically by identifying the best set of services available at run time. In this paper, we model the service composition problem as a mixed integer linear problem where local constraints, i.e., constraints for component Web services, and global constraints, i.e., constraints for the whole application, can be specified. Our approach proposes the formulation of the optimization problem as a global optimization, not optimizing separately each possible execution path as in other approaches. Experimental results demonstrate the effectiveness of our approach. © Springer-Verlag Berlin Heidelberg 2006.