6. Auditing and Event Sourcing

A benefit of the command pattern is that it allows for the operations applied to an applications state to be audited and, with further work, to be replayed to reconstitute a systems state from a known point (be that a backup or an empty system) using a pattern known as event sourcing.

The AccidentalFish.Commanding framework includes a configurable auditing system that is extensible with the addition of custom data stores and with the enrichment of the data that is audited. It also supports immediate inline auditing (the audit is written before a command executes) or deferred auditing (for example placing the audit payload on a queue).

work in progress