Host Side Caching: Solutions and Opportunities

Host side caches use a form of storage faster than disk and less expensive than DRAM to deliver the speed demanded by data intensive applications. Today, this form of storage is NAND Flash, complementing a disk-based solution. A host side cache may integrate into an existing application seamlessly. This may be realized by using an infrastructure component (such as a storage stack middleware or the operating system) to intercept the application read and write requests for disk pages, populate the flash cache with disk pages, and use the flash to service read and write requests intelligently. This study provides an overview of host side caches, an analysis of its overhead and costs to justify its use, alternative architectures including the use of the emerging Non Volatile Memory (NVM) for the host-side cache, and future research directions. We show results using Dell’s host-side caching solution named Fluid Cache. It was built to improve the performance of OLTP workloads. However, our results using a social networking benchmark named BG shows that Fluid Cache also enhances the performance of social networking workloads anywhere from a factor of 3.6 to 18. ∗This work was conducted at Dell Research, Santa Clara, California 54080. In Proceedings of the IEEE 12th International Baltic Conference on Databases and Information Systems (DB&IS), Riga, Latvia, July 2016.