Stop repeated failed requests
An online shop asks a delivery service for shipping prices. If that service is down, repeated retries make shoppers wait and slow the shop. A circuit breaker stops requests after enough failures, letting the shop respond quickly.
While it blocks requests, the breaker is open. After a pause, it becomes half-open and tries the service a few times. If those attempts work, it closes and requests resume; if they fail, it opens again.
Plan for customers
The breaker does not fix the delivery service. The team decides what shoppers see while prices are unavailable and checks that it does not open too often or stay open too long.