Computer Science and Engineering, Department of


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Published in IEEE TRANSACTIONS ON COMPUTERS, Vol. 57, No. 1 (Nov. 27, 2007), pp. 25-40. Digital Object Indentifier 10.1109/TC.2007.70788 © 2007 IEEE. Used by permission.


While many block replacement algorithms for buffer caches have been proposed to address the well-known drawbacks of the LRU algorithm, they are not robust and cannot maintain an consistent performance improvement over all workloads. This paper proposes a novel and simple replacement scheme, called RACE (Robust Adaptive buffer Cache management schemE), which differentiates the locality of I/O streams by actively detecting access patterns inherently exhibited in two correlated spaces: the discrete block space of program contexts from which I/O requests are issued and the continuous block space within files to which I/O requests are addressed. This scheme combines global I/O regularities of an application and local I/O regularities of individual files accessed in that application to accurately estimate the locality strength, which is crucial in deciding which blocks are to be replaced upon a cache miss. Through comprehensive simulations on eight realapplication traces, RACE is shown to high hit ratios than LRU and all other state-of-the-art cache management schemes studied in this paper.