Efficient flash-aware page-mapping cache management for on-board remote sensing image processing

The use of flash-based storage devices has become popular in both research and practice due to their intrinsic advantages over traditional magnetic counterparts. Many advanced flash-aware data management techniques have been developed to exploit the full potential of flash storage devices. It is then reasonable to adopt flash storage devices to deliver high I/O performance for on-board remote sensing image processing tasks, which pose particular challenges in data storage and I/O management. In this work, we focus on caching issues and propose a page-mapping cache management approach based on a page-level flash translation layer (FTL) to accommodate various types of workloads presented by different remote sensing image processing operations. The adaptability is achieved by three major techniques: 1) separating mapping cache into hot and cold regions according to access frequency; 2) a probability-based locality-aware cache replacement priority model to balance high hit ratio and low write/erase costs; and 3) adaptive mapping cache replacement algorithms that are seamlessly integrated with 1) and 2) to handle complicated I/O patterns efficiently. Combining these above three techniques, the proposed FTL-based cache management approach is superior to several existing methods, as demonstrated by extensive experiments running on realistic on-board remote sensing processing I/O traces.