Lumberjack: A log-structured persistent object store

Lumberjack is a log-structured persistent object store intended for use with conventional operating systems such as Unix. The design draws together facets of previous work, in particular, the CPOMS object store used to support PS-algol, and the page-based log-structured store used in the Grasshopper persistent operating system. Lumberjack exhibits a novel store design that provides a number of benefits: i) an efficient commit strategy with respect to meta-data, ii) the avoidance of installation reads and writes during commit, iii) support for incremental parallel garbage collection. Additionally, log-cleaning and garbage collection may be integrated providing the ability to re-cluster data to exploit locality. We see Lumberjack as delivering object-based logging for use in systems such as Napier88 and persistent Java, thereby providing an alternative to the traditional store architectures used in these systems.