Design a Circuit Breaker
Medium · Low-Level Design · about 40 minutes
Asked at Netflix, Amazon, Uber.
Design a circuit breaker library like Netflix's Hystrix or Resilience4j. It wraps calls to a remote service. After too many failures in a window it opens and fails calls fast, without calling the service. After a cooldown it lets a trial call through (half-open) and closes again if that succeeds.