BabuDB: Fast and Efficient File System Metadata Storage
Today's distributed file system architectures scale well to large amounts of data. Their performance, however, is often limited by their metadata server. In this paper, the authors reconsider the database backend of the metadata server and propose a design that simplifies implementation and enhances performance. In particular, they argue that the concept of Log-Structured Merge (LSM) trees is a better foundation for the storage layer of a metadata server than the traditionally used B-trees. They present BabuDB, a database that relies on LSM-tree-like index structures, and describe how it stores file system metadata.