Adaptive and Dynamic Service Compositions in the OSGi Service Platform

Abstract

Service-oriented architectures provide a good level of decoupling between the elements that compose an application. Service compositions may take into account that services that take part in the composition can appear and disappear. This is typically not the case when using Web Services. In dynamic environments this uncertain service availability is a recurrent scenario. Applications should be ready to handle that and dynamically adapt their behavior based on the application’s context and the available services. Although typically presented using Web Services, there are also SOAs that use other technologies. In this chapter we provide an overview on some dynamic service oriented platforms, giving special focus on the OSGi Service Platform. Also, we present what principles and mechanisms help to handle dynamicity, and we provide information on the dynamic service-based component models targeting the OSGi platform. These models allow the realization of applications that are adaptive upon dynamic scenarios where service availability is uncertain.