Active Mediation Technology for Service Composition
David Liua, Neal Sampleb, Jun Pengc, Kincho Lawc, Gio Wiederholdb · 2003
This paper discusses how active mediation allows information clients to modify the processing behavior of source information services to facilitate service composition. A new computing paradigm is enabled by incorporating active mediators into autonomous services to allow execution of mobile classes – dynamic information processing modules. We describe two key components of active mediation in the FICAS service composition infrastructure: (1) the programming language support for specifying mobile classes and using mobile classes in a composed service; and (2) the runtime support that enables the execution of mobile classes by autonomous services. The power of active mediation is demonstrated by a few examples of mobile classes that conduct complex information processing for service composition. Finally, we discuss the performance issues in deploying active mediation. Specifically, we introduce an algorithm that determines the optimal placement of mobile classes on alternative autonomous services, and discuss the applicability of the algorithm using example mobile classes.