Distributed Computing Over New Technology Networks: Quality of Service for CORBAObjects

摘要

This project investigated how 'middleware' can be extended to allow distributedprograms to exploit recent and anticipated advances in networking technology. This was accomplished in four (largely sequential) steps: (1) Study the impact of new technology networks on distributed computing environments, which lead to the conclusion that Quality of Service (QoS) was the most promising attribute of new networking technologies in terms of improving distributed programs such as C3 or collaborative planning applications; (2) Study how Distributed Computing Environments (DCEs) should support QoS in WAN environments; (3) Architecting a QoS Framework for CORBA; and (4) Experimentation. This report describes an architecture for Quality of Service for CORBA Objects (QuO), which was developed to overcome performance limitations encountered in wide-area network environments. Distributed applications must become adaptable to cope with system properties which vary greatly over time, if they are to be acceptable for mission critical use and cost effectively evolve. QuO develops a cohesive framework for constructing adaptable applications by introducing the concepts of quality of service for object access, and by providing the mechanisms which can be used to integrate these concepts into emerging applications.