4.4. Cache Entry Expiration Behavior

Red Hat JBoss Data Grid does not guarantee that an entry is removed immediately upon timeout. Instead, a number of mechanisms are used in collaboration to ensure efficient removal. An expired entry is removed from the cache when either:
  • An entry is passivated/overflowed to disk and is discovered to have expired.
  • The expiration maintenance thread discovers that an entry it has found is expired.
If a user requests an entry that is expired but not yet removed, a null value is sent to the user. This mechanism ensures that the user never receives an expired entry. The entry is eventually removed by the expiration thread.