Decentralized Resource Management for a Distributed Continuous Media Server

Distributed continuous media server (DCMS) architectures are proposed to minimize the communication-storage cost for those continuous media applications that serve a large number of geographically distributed clients. Typically, a DCMS is designed as a pure hierarchy of centralized continuous media servers. RedHi, a Redundant Hierarchical topology for DCMS networks, can result in higher utilization and better reliability over pure hierarchy. We focus on the design of a resource management system (RMS) for RedHi that can exploit the resources of its DCMS network to achieve these performance objectives. Our RMS is based on a fully decentralized approach to achieve optimal scalability and robustness. The major drawback of a fully decentralized design is the increase in latency time and communication overhead to locate the requested object. However, as compared to the typically long duration and high resource/bandwidth requirements of continuous media objects, the extra latency and overhead of a decentralized resource management approach become negligible. Moreover, our RMS collapses three management tasks (object location, path selection and resource reservation) into one fully decentralized object delivery mechanism, reducing the latency even further. Decentralization of the resource management satisfies our scalability and robustness objectives, whereas collapsing the management tasks helps alleviate the latency and overhead constraints. To achieve a high resource utilization, the object delivery scheme uses our proposed cost function, as well as various object location and resource reservation policies to select and allocate the best streaming path to serve each request. The object delivery scheme is designed as an application-layer resource management middleware for the DCMS architecture to be independent of the underlying telecommunication infrastructure. Experiments show that our RMS is successful in realization of the higher resource utilization for the DCMS networks with the RedHi topology.