In this paper, we propose an Efficient Two-Level I/O Caching Architecture (ETICA) for virtualized platforms that can significantly improve I/O latency, endurance, and cost (in terms of cache size) while preserving the reliability of write-pending data blocks. As opposed to previous one-level I/O caching schemes in virtualized platforms, our proposed architecture 1) provides two levels of cache by employing both Dynamic Random-Access Memory (DRAM) and SSD in the I/O caching layer of virtualized platforms and 2) effectively partitions the cache space between running VMs to achieve maximum performance and minimum cache size. To manage the two-level cache, unlike the previous reuse distance calculation schemes such as Useful Reuse Distance (URD), which only consider the request type and neglect the impact of cache write policy, we propose a new metric, Policy Optimized reuse Distance (POD). The key idea of POD is to effectively calculate the reuse distance and estimate the amount of two-level DRAM+SSD cache space to allocate by considering both 1) the request type and 2) the cache write policy. Doing so results in enhanced performance and reduced cache size due to the allocation of cache blocks only for the requests that would be served by the I/O cache. ETICA maintains the reliability of write-pending data blocks and improves performance by 1) assigning an effective and fixed write policy at each level of the I/O cache hierarchy and 2) employing effective promotion and eviction methods between cache levels. Our extensive experiments conducted with a real implementation of the proposed two-level storage caching architecture show that ETICA provides 45% higher performance, compared to the state-of-the-art caching schemes in virtualized platforms, while improving both cache size and SSD endurance by 51.7% and 33.8%, respectively.
翻译:在本文中,我们建议为虚拟化平台建立一个高效的双级I/O缓冲架构(ETICA),该平台可以大大改进I/O 软性性能、耐力和成本(以缓冲大小为单位),同时保持写待数据块的可靠性。与以前在虚拟化平台中的一级I/O缓冲计划相比,我们拟议的架构1提供了两级缓存,在虚拟化平台的一/O缓冲层中采用动态随机成功存储(DRAM)和SSD(SD),在运行 VM 之间的缓存空间有效分隔,以实现最大性能和最小缓存规模。管理双级缓存(以缓存大小为单位),不同于以往的再利用远程计算计划,例如仅考虑请求类型,而忽略了缓存政策的影响。 我们提议的PODD(DRAM+SSD)的关键想法是通过考虑1个请求类型和2个缓存预写政策之间的双级性能计算再利用距离并估算DRAM+SD缓冲空间的数量。 通过提高E-O(I)的快速化执行比例,通过提高E-O(SQ)的准确度分配,在1级政策级别上1级的1级纸质化纸质化)和1级协议化的1级的1级政策水平上分配,在1级的1级的1级的1级纸质化纸质化1级化1级化1级化1级化1级化1级化1级上,通过提高1级化1级化1级化1级化1级化1级化1级性能分配1级性能和1级性能性能性能分配1级数。