Yiying Zhang

Storage-Level Caching

Storage data caching is important to provide good application performance. With the fast growth of storage data size and the emerging of new memory technologies, storage-level caches are becoming bigger and can be persistent. We explore problems of large-scale storage-level caches in system design.

Storage-Level Cache Warmup

Large caches in storage servers have become essential for meeting service levels required by applications. These caches need to be warmed with data often today due to various scenarios including dynamic creation of cache space and server restarts that clear cache contents. Our analysis of real-world data-center traces shows that large storage cache can take hours or even days to warm up, affecting both application performance and server load over a long period of time.

Bonfire is a system for accelerating cache warmup. Bonfire monitors storage server workloads, logs important warmup data, and efficiently preloads storage-level caches with warmup data. We show through both simulation and trace replay that Bonfire reduces both warmup time and backend server load significantly, compared to a cache that is warmed up on demand.

Solid State Cache

FlashTier is a system architecture built upon solid-state cache (SSC), a flash device with an interface designed for caching. The FlashTier design addresses three limitations of using traditional SSDs for caching. First, FlashTier provides a unified logical address space to reduce the cost of cache block management within both the OS and the SSD. Second, FlashTier provides cache consistency guarantees allowing the cached data to be used following a crash. Finally, FlashTier leverages cache behavior to silently evict data blocks during garbage collection to improve performance of the SSC.

Related Publications

Warming up Storage-Level Caches with Bonfire
Yiying Zhang, Gokul Soundararajan, Mark W. Storer, Lakshmi N. Bairavasundaram, Sethuraman Subbiah, Andrea C. Arpaci-Dusseau, Remzi H. Arpaci-Dusseau
Proceedings of the 11th Conference on File and Storage Technologies (FAST '13)

FlashTier: a Lightweight, Consistent and Durable Storage Cache
Mohit Saxena, Michael M. Swift, Yiying Zhang
Proceedings of the 7th European Conference on Computer Systems (EuroSys'12)

System and Method for an Efficient Cache Warm-up
Lakshmi N. Bairavasundaram, Gokul Soundararajan, Mark W. Storer, Yiying Zhang
US Patent WO2014100253 A1