Design and Reliability of a User Space Write-Ahead Log in Rust

Abstract: Write-ahead logs (WALs) are a fundamental fault-tolerance technique found in many areas of computer science. WALs must be reliable while maintaining high performance, because all operations will be written to the WAL to ensure their stability. Without reliability a WAL is useless, because its utility is tied to its ability to recover data after a failure. In this paper we describe our experience creating a prototype user space WAL in Rust. We observed that Rust is easy to use, compact and has a very rich set of libraries. More importantly, we have found that the overhead is minimal, with the WAL prototype operating at basically the expected performance of the stable memory device.