A Hierarchical Cache Scheme for Object Storage System

HCOS is a scheme of OSS (object storage system) proposed by us from the size of object aspect by which performance of read/write (R/W) can be promoted effectively. In this paper, the hierarchy cache scheme for OSS called as HCOS is discussed. The prominent feature of HCOS is that the two-level cache model which is different from traditional cache scheme for OSS is adopted in our hierarchy cache scheme. The two-level cache model in HCOS includes two parts called as L-cache and S-cache which is divided according to the size of object, and the two parts in the model is cooperated to accomplish the overall workload of cache according to judging rule of our scheme. The working principle of HCOS and the cache replacement strategy which combined with LRU algorithm and characteristic of object size are also discussed in our paper. Our HCOS provides a hierarchy cache scheme for promoting performance of R/W for OSS.