Retransmission-based error control in a many-to-many client-server environment

Large-scale continuous media (CM) system implementations require scalable servers most likely built from clusters of storage nodes. Across such nodes random data placement is an attractive alternative to the traditional round-robin striping. One benefit of random placement is that additional nodes can be added with low data-redistribution overhead such that the system remains load balanced. One of the challenges in this environment is the implementation of a retransmission-based error control (RBEC) technique. Because data is randomly placed, a client may not know which server node to ask for a lost packet retransmission. We have designed and implemented a RBEC technique that utilizes the benefits of random data placement in a cluster server environment while allowing a client to efficiently identify the correct server node for lost packet requests. We have implemented and evaluated our technique with a one-, two-, and four-way server cluster and across local and wide-area networks. Our results show the feasibility and effectiveness of our approach in a real-world environment.