Distributed
← Caching

Lesson 04.3

Cache stampede / thundering herd

A cache stampede happens when many requests miss the same expired key together and repeat the same source work before the cache can be refilled.

🍪 The fast copy can be wrong

Ava and Ben are workers using the computer to manage menu. If the fast copy disappears just as a crowd arrives, every person can ask the slow computer for the same answer.

In this lesson you'll

  1. 1Watch the fast copy answer a request
  2. 2Guess where the unsafe gap appears
  3. 3Change the rule and protect the source of truth