Local Storage

Nearly all possible data management solutions rely on local storage systems to fetch or store data in an efficient and reliable manner. We build next-generation local storage systems to make data management more efficient and reliable.

Offline Flash Caching

We explore offline algorithms for flash caching in terms of both hit ratio and flash lifespan. We design and implement a multi-stage heuristic by synthesizing several techniques that manage data at the granularity of a flash erasure unit (which we call a container) to approximate the offline optimal algorithm. We find that simple techniques contribute most of the available erasure savings. Our evaluation shows that the container-optimized offline heuristic is able to provide the same optimal read hit ratio as MIN with 67% fewer flash erasures. More fundamentally, our investigation provides a useful approximate baseline for evaluating any online algorithm, highlighting the importance of comparing new policies for caching compound blocks in flash.

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Related Publications    Full list

Erasing Belady's Limitations: In Search of Flash Cache Offline Optimality

Yue Cheng, Fred Douglis, Philip Shilane, Michael Trachtman, Grant Wallace, Peter Desnoyers, Kai Li

USENIX ATC '16     video poster