QoS mechanism composition at design-time and runtime

In this paper we present a model-driven approach to the composition of QoS mechanisms. The support of multiple QoS categories as well as runtime adaptation requires the ability to change the message path of a middleware on the fly This leads to a new set of problems regarding the composition of individual mechanisms to a functioning message path. Especially the order in which messages are passed through the QoS mechanisms is of great importance. We show how QoS mechanisms and their composition constraints can be modeled using the UML. Furthermore, a mapping from these UML models to our NET Remoting based QoS management framework DotQoS is presented.