Answer Staleness

Caching improves consistency and cost and introduces a failure mode: an answer that was correct when approved continues to be served after the policy it described was amended. Nothing errors, and the answer remains fluent and cited — to a version of a document that no longer governs. Managing staleness requires tying each cached answer to the records it derived from, so a change to a source invalidates what was built on it rather than leaving the invalidation to a scheduled sweep or to somebody noticing.

Because governed answers in Centralpoint derive from records with version history, the sources behind a cached answer are identifiable and its validity is a function of their state. An answer approved against an earlier version of a policy is distinguishable from one approved against the current version, which turns staleness into a reportable condition rather than a latent one.