A Framework for QoS Contract Negotiation in Component-Based Applications

The support of QoS properties in component-based software requires the run-time selection of appropriate concrete QoS contracts at the ports of the interacting components. Such a selection process is called QoS contract negotiation. This paper discusses the architecture of a QoS contract negotiation framework and how it is implemented in our prototype. The framework can be integrated in a component container and act as a run-time support environment when QoS Contracts are negotiated under different application scenarios. Our approach is based on: (i) the notion that the required and provided QoS properties as well as resource demands are specified at the component level; and (ii) that QoS contract negotiation is modeled as a constraint solving problem.