The Multi-Queue Replacement Algorithm for Second Level Buffer Caches

This paper reports our research results that improve second level bu er cache performance. Several previous studies have shown that a good single level cache replacement algorithm such as LRU does not work well with second level bu er caches. Second level bu er caches have di erent access pattern from rst level bu er caches because Accesses to second level bu er caches are actually misses from rst level bu er caches. The paper presents our study of second level bu er cache access patterns using four large traces from various servers. We also introduce a new second level bu er cache replacement algorithm called Multi-Queue (MQ). Our trace-driven simulation results show that MQ performs better than all seven tested alternatives. Our implementation on a real storage system validates these results.