A proposal for ensuring high availability of distributed multimedia applications

Recent advances in computing, like high-speed networks and data-compression, make extensible distributed multimedia applications a challenging application-domain of distributed systems. Such applications like VoD (Video on Demand) or real-time conferencing are characterized by QoS (quality of service) requirements which depend on the quality of video and sound transmitted to the client and on the respect of time constraints associated to video and audio data. Much work has been done in order to provide system support aimed at meeting these requirements. However, existing proposals do not integrate the consequence of failure occurrence on the guaranteed QoS. To deal with this issue, we propose a resource reservation model that integrates availability requirements of multimedia services in addition to the QoS constraints introduced above. Our paper details the resulting model together with its integration in a distributed system. In particular we show how the model implementation can be customized in the case of a VoD server