Abstract:

KeyValue (KV) store systems use SSD device to improve the response speed of I/O. However, the existing KV store systems adopt the standard file system to handle storing data in SSD devices, so the physical characteristics of SSDs are invisible to applications and the I/O behaviors of applications are invisible to storage media, limiting the further performance improvement of KV store systems. Therefore, we  design a storage mechanism, which concerns both KV data patterns and SSD device characteristics.. By combining with LevelDB, a LSMTreebased KV store, we implement a SSD friendly KV system—SSDKV, which is a lightweight KV store and runs in user space. Besides the basic function of providing KV interfaces, SSDKV introduces an innovative ondisk data deployment. By reducing the extra procedures required by the traditional file systems to handle  KV data, and managing the SSD storage space in a more proper way according to KV data, SSDKV can improve the performance significantly on the KV store. Compared with other file systems, SSDKV can improve write performance by 4 times and read performance by 1.5 times.

Key words: KV store;SSD;storage management;raw storage device;levelDB;host FTL