Buffer Sharing for Proxy Caching of Streaming Sessions

With the falling price of the memory, an increasing number of multimedia servers and proxies are now equipped with a large memory space. Caching media objects in the memory of a proxy helps to reduce the network traffic, the disk I/O bandwidth requirement, and the data delivery latency. The running buffer approach and its alternatives are representative techniques to cache streaming data in the memory. There are two limits in the existing techniques. First, although multiple running buffers for the same media object co-exist in a given processing period, data sharing among the multiple buffers is not considered. Second, user access patterns are not insightfully considered in the buffer management. In this study, we propose two techniques based on shared running buffers (SRB) in the proxy to address these limits. Considering user access patterns and characteristics of the requested media objects, our techniques adaptively allocate memory buffers to fully utilize the currently buffered data of streaming sessions to serve existing requests concurrently, with the aim to reduce both the server load and the network traffic. Experimentally comparing with several existing techniques, we have shown that the proposed techniques have achieved significant performance improvement by effectively using the sharing running buffers.