Quartz: Supporting QoS-Constrained Services in Heterogeneous Environments
Frank Siqueira, Vinny Cahill · 1998
This paper describes an architecture that addresses common problems found in systems supporting QoS specification and enforcement, such as lack of flexibility and expressiveness in the specification of requirements and dependencies on specific platforms. The Quartz QoS architecture aims to solve these problems by adopting a highly extensible and platform-independent design. 1. Introduction `Quality of Service', or QoS for short, represents the set of requirements imposed by a user (human being or software component) on the behaviour of services being provided to an application. In order to achieve the level of QoS requested by users, applications such as distributed multimedia, including video on demand, media broadcast and video telephony, as well as real-time control systems, which are migrating from embedded architectures to open environments, require that the access to resources provided by the underlying system support occur in a predictable fashion. Despite the evolution of comp...