Circuit Breaker
A circuit breaker trips when a downstream service fails, failing fast instead of waiting for timeouts, preventing cascading failures.
Purpose
Prevent downstream failures from cascading, improving system resilience.
Mechanism
Three states: Closed (normal requests), Open (trips and fails fast once failures hit the threshold), Half-Open (probing recovery). Failure rate/timeouts trigger the trip. After a cooldown, half-open probes; success closes the circuit.
Use cases
- Fault isolation
- Cascading failure defense
- System resilience