Batawar ajiya (cache invalidation) — kiyaye data da aka ajiya daidai da tushen gaskiya — sananne ne a matsayin ɗaya daga matakaici matakai a sarrafa kwamfuta. Matsala ita ce tabbatarwa cewa caches ba sa ba da data tsoho yayin daidaita sauri, daidaituwa, da sarkarfi. Akwai niyoyi da ƙwararru da yawa da suke da mahimmanci don fahimta.
Matsalar tunani
When the source data changes, the cached copy becomes STALE.
→ Serve stale data? (fast but wrong) vs invalidate? (consistent but complex/slower)
→ "There are only two hard things in CS: cache invalidation and naming things."
The difficulty: knowing WHEN and WHAT to invalidate, across distributed systems,
without races, while keeping good cache hit rates.
