Stale-while-revalidate.
also: stale while revalidate · SWR · serve staleServing the stale cached value immediately while refreshing it in the background, so no user waits on a miss.
the two-minute refresher
- Request → stale hit → fast response, and in parallel a background refresh.
- The next user gets fresh data.
- Also an HTTP directive: Cache-Control: stale-while-revalidate=60.
- Only where slightly stale data is acceptable.