Systems and/or methods for rapid recovery from write-ahead logs

摘要

Certain example embodiments provide a single pass, reverse chronological approach to write-ahead log recovery, enabling space- and time-efficient the recovery of stored data from large write-ahead logs to a transient storage medium. The techniques described herein can in certain instances enable fast and efficient recovery, even in scenarios where at the time of a failure requiring such a recovery the live log is potentially multiple terabytes or larger in size. Certain example embodiments make use of a filtering mechanism (e.g., involving potentially stateful delete, skip, and/or transaction filters), a key/value property (allowing a live set of data, once identified, to be applied in any arbitrary order), etc. A simplified environment with a small closed set of mutative operations allows for the performing of recovery backwards by scanning the log from the most recent written record backwards in time (and, in other words, finishing with the oldest record).