Time to live
Section titled “Time to live”Time to live, or TTL, is a lifetime attached to data after which the data is considered expired for the relevant protocol or cache.
TTL bounds how long stale state can survive when expiry is the invalidation mechanism. A shorter TTL reduces staleness but increases refresh work.
TTL does not prove freshness before expiry. It only defines the maximum lifetime allowed by that expiry policy.
Related knowledge
CachingReuse a previously computed or fetched result to avoid repeating expensive work, at the cost of managing staleness and invalidation.