AIR Cache: A Variable-Size Block Cache Based on Fine-Grained Management Method

Yuxiong Li, Yujuan Tan, Congcong Xu, Duo Liu, Xianzhang Chen, Chengliang Wang, Mingliang Zhou, Leong Hou U

Abstract: Recently, adopting large cache blocks has received widespread attention in server-side storage caching. Besides reducing the management overheads of cache blocks, it can significantly boost the I/O throughput. However, although using large blocks has advantages in management overhead and I/O performance, existing fixed-size block management schemes in storage cache cannot effectively handle them under the complicated real-world workloads. We find that existing fixed-size block management methods will suffer from the fragmentation within the cache block and fail to identify hot/cold cache blocks correctly when adopting large blocks for caching.