Expiration time, invalidation time, and removal time of a document. The closer the removal time, the lower a document's validity. The higher the validity level, the longer Oracle Web Cache serves documents stale from the cache before invalidating them. For documents with lower validity levels, Oracle Web Cache serves these documents stale for a short amount of time before invalidating them.
Expiration time, invalidation time, and removal time of a document. OracleAS Web Cache calculates validity by comparing the current time relative to an object's expiration/invalidation time and the object's scheduled removal time. Prior to expiration/invalidation time, the object is considered valid. Between expiration/invalidation time and removal time, the object's validity level decreases linearly. During this interim state, objects with a higher validity level have a higher propensity to be served stale. When current time reaches removal time, the object is considered totally invalid and can no longer be served stale. Scheduled removal time is something that administrators can control. When expiring/invalidating content, administrators can remove objects immediately, which may be necessary for sensitive objects that should never be served stale. Likewise, where some degree of inconsistency is tolerable, administrators can specify a removal time in the near future.