A General, Tractable and Accurate Model for a Cascade of LRU Caches

The recent evolution of the Internet towards "Information-centric" transfer modes has renewed the interest in characterizing multi-cache systems, in which requests not satisfied by a cache are forwarded to other caches. In this work, we characterize the traffic statistics of the output (miss) stream, via a simple but accurate approximate analysis for LRU caches feeded by general "renewal" traffic patterns. In turn, we exploit such output stream traffic pattern to analyze the performance of the subsequent cache stage, and so on. The computational efficiency of our model, joint with its ability to handle traffic patterns beyond the traditional independent reference model, permits simple and tractable assessment of cache hierarchies.