Quality of Service in Service-Oriented Architectures

Quality of Service in Service-Oriented Architectures

It is noted that there are two ways in which the term Quality of Service (QoS) is commonly used: firstly in its traditional distributed multimedia sense, which relates almost entirely to network performance, and secondly in its service-centric sense which refers to a wider range of non-functional service characteristics. In this paper the complexity of enabling this latter QoS definition in service-centric systems is discussed. A survey of existing technologies which are applicable in this area is undertaken, concentrating on QoS specification. From this survey it is concluded that there are a number of areas in which these technologies lack, or that remain open for research. In particular, the following needs are identified: a general purpose QoS specification language; a QoS-based service discovery mechanism to complement UDDI; a system for Service Level Agreement (SLA) negotiation, which should work with specifications in the aforementioned language; and systems for QoS measurement and monitoring. Research into using underlying technologies to provide QoS in service-centric systems and into mapping from SLA specifications to configuration of such technologies is also identified as key