Versionized process based on non-volatile random-access memory for fine-grained fault tolerance

Abstract

Non-volatile random-access memory (NVRAM) technology is maturing rapidly and its byte-persistence feature allows the design of new and efficient fault tolerance mechanisms. In this paper we propose the versionized process (VerP), a new process model based on NVRAM that is natively non-volatile and fault tolerant. We introduce an intermediate software layer that allows us to run a process directly on NVRAM and to put all the process states into NVRAM, and then propose a mechanism to versionize all the process data. Each piece of the process data is given a special version number, which increases with the modification of that piece of data. The version number can effectively help us trace the modification of any data and recover it to a consistent state after a system crash. Compared with traditional checkpoint methods, our work can achieve fine-grained fault tolerance at very little cost.