公开(公告)号：US20120317338A1

公开(公告)日：2012-12-13

申请号：US13157289

申请日：2011-06-09

申请人： Letian YI ,  Chong (Ethan) HAO ,  Zaide LIU

发明人： Letian YI ,  Chong (Ethan) HAO ,  Zaide LIU

IPC分类号： G06F12/00 ,  G06F12/16

CPC分类号： G06F3/061 ,  G06F3/0647 ,  G06F3/0649 ,  G06F3/0685 ,  G06F3/0688 ,  G06F12/0868 ,  G06F2212/222 ,  G06F2212/463 ,  G06F2212/7208

摘要： A solid state disk (SSD) caches disk-based volumes in a heterogeneous storage system, improving the overall storage-system performance. The hottest data blocks are identified based on two factors: the frequency of access, and temporal locality. Temporal locality is computed using a logarithmic system time. IO latency is reduced by migrating these hottest data blocks from hard-disk-based volumes to the solid-state flash-memory disks. Some dedicated mapping metadata and a novel top-K B-tree structure are used to index the blocks. Data blocks are ranked by awarding a higher current value for recent accesses, but also by the frequency of accesses. A non-trivial value for accesses in the past is retained by accumulating the two factors over many time spans expressed as a logarithmic system time. Having two factors, access frequency and the logarithmic system time, provides for a more balanced caching system.

摘要翻译： 固态磁盘（SSD）在异构存储系统中缓存基于磁盘的卷，从而提高整体存储系统性能。 基于两个因素来识别最热的数据块：访问频率和时间局部性。 使用对数系统时间计算时间局部性。 通过将这些最热的数据块从基于硬盘的卷迁移到固态闪存盘来减少IO延迟。 一些专用的映射元数据和一个新的顶级K B树结构用于对块进行索引。 通过为最近的访问授予更高的当前值，而且通过访问的频率对数据块进行排名。 通过在以对数系统时间表示的许多时间跨度中累积两个因子来保留过去访问的非平凡值。 有两个因素，访问频率和对数系统时间，提供了一个更平衡的缓存系统。