Cache admission control and replacement algorithm for VBR video servers with interval caching

摘要

Interval caching can boost the throughput of video server by caching consecutive video request in a global cache. In this paper, we propose a novel cache admission control and replacement algorithm called ROC (Resist-Overload Capability) to efficiently manage cache usage in video server with interval caching. First, we introduce a deterministic cache admission control scheme to guarantee the QoS but serve under-utilization of the cache resources. Then a statistic-multiplex based admission control scheme is presented to improve the efficiency of cache usage by converting the characteristic of VBR video into the number of memory pages that the video interval requires during the service round. The statistic scheme suffers from the heavy convolution computation which deceases its efficiency. Thirdly, we simplify the convolution computation by using the Central Limit Theorem, and propose the Resist-Overload Capability metric to characterize the capability that resists the occurrences of cache overload. The related ROC based admission control scheme and replacement algorithm are proposed accordingly. The simulation results indicate that ROC scheme highly improves the efficiency of cache management for VBR video server with interval caching.