OpenMemDB: A Wait-Free, In-Memory Database

OpenMemDB is an in-memory database that is implemented solely using wait-free data structures. OpenMemDB is the first and only database currently developed in such a way. OpenMemDB also provides linearizable correctness guarantees for all operations executed on the database. OpenMemDB uses a form of snapshot isolation to ensure linearizability, and avoids the write-skew problem that can occur when using snapshot isolation by eliminating writes that are out of data. OpenMemDBs biggest contribution is its completely wait-free implementation. Every operation executed in OpenMemDB is guaranteed to be wait-free and linearizable. This implementation also scales competitively when compared against similar in-memory database management systems. OpenMemDB achieves its best scaling in select heavy operation loads with nearly 12 times speedup at 16 threads. This is better scaling than either VoltDB or MemSQL showed in our testing.