Non-volatile Memory through Customized Key-value Stores

Non-volatile memory, or NVM, is coming. Several technologies are maturing (FeRAM, ReRAM, PCM, DWM, FJG RAM), and soon we expect products from Intel, Micron, HP, SanDisk, and/or Samsung. Some of these products promise memory density close to flash and performance within a reasonable factor of DRAM. This technology could substantially improve the performance of software systems, especially storage systems.

Unfortunately, using NVM is hard: each technology has its quirks, and the details of products are not yet available. We need a way to integrate NVM into our software systems, without full knowledge of all the NVM product details and without having to redesign every software system for each forthcoming NVM technology.

We advocate the use of customized key-value stores. Rather than programming directly on NVM, developers (1) design a key-value store customized for the application, (2) implement the key-value store for the target NVM technology, and (3) program the application using the key-value store. When new NVM products emerge, with similar performance characteristics but different access mechanisms, developers need only modify the keyvalue store implementation, which is simpler, faster, and cheaper than redesigning the application. Thus, the keyvalue store serves as a middle layer that hides the details of the NVM technology, while providing a simple and familiar interface to the application. Customization ensures that the design is performant and simple.