论文标题
多级双向缓存滤波器
Multilevel Bidirectional Cache Filter
论文作者
论文摘要
通常需要现代缓存来处理大量数据，这超过了可用内存的数量；因此，杂交缓存，特别是DRAM/SSD组合，变得越来越普遍。在这样的环境中，除了经典的命中率目标外，第二级缓存的写入是避免写入放大和磨损的主要因素，这是SSD的两个臭名昭著的现象。 本文介绍了Bidifilter，这是一种新型的多级缓存方案，该方案使用频率草图过滤器来控制缓存水平之间的降级和促销。此外，它将较高的高速缓存级别分为两个区域，以使最新和最常见的项目与用户接近。 与以前的多层次策略相比，我们对现实世界痕迹进行了广泛的评估。我们表明，使用我们的机制在几乎所有情况下都可以节省X10写作，并且通常将潜伏期提高高达20％。
Modern caches are often required to handle a massive amount of data, which exceeds the amount of available memory; thus, hybrid caches, specifically DRAM/SSD combination, become more and more prevalent. In such environments, in addition to the classical hit-ratio target, saving writes to the second-level cache is a dominant factor to avoid write amplification and wear out, two notorious phenomena of SSD. This paper presents BiDiFilter, a novel multilevel caching scheme that controls demotions and promotions between cache levels using a frequency sketch filter. Further, it splits the higher cache level into two areas to keep the most recent and the most frequent items close to the user. We conduct an extensive evaluation over real-world traces, comparing to previous multilevel policies. We show that using our mechanism yields an x10 saving of writes in almost all cases and often improving latencies by up to 20%.
