Spring Cloud Spring Cloud Circuit Breaker & Resilience

Question 1

Which library replaced Hystrix as the recommended circuit breaker in Spring Cloud after Netflix put Hystrix in maintenance mode?

Accepted Answer

Resilience4j

Answer

Resilience4j became the recommended circuit breaker library in Spring Cloud after Netflix officially put Hystrix into maintenance mode.

Question 2

What are the three states a circuit breaker cycles through in the circuit breaker pattern?

Accepted Answer

Closed, Open, Half-Open

Answer

A circuit breaker transitions between Closed (normal operation), Open (rejecting calls after failures), and Half-Open (testing recovery) states.

Question 3

Which annotation is used in Spring Cloud Resilience4j to apply a circuit breaker declaratively to a method?

Accepted Answer

@CircuitBreaker

Answer

The @CircuitBreaker annotation from Spring Cloud Resilience4j is placed on methods to enable circuit breaker behavior declaratively.

Question 4

What is the role of a fallback method in a Spring Cloud circuit breaker setup?

Accepted Answer

Provide an alternative response when the primary method fails or the circuit is open

Answer

A fallback method returns a default or cached response when the circuit is open or the primary method throws an exception, maintaining graceful degradation.

Question 5

Which Resilience4j configuration property sets the percentage of failures required to trip the circuit breaker to Open state?

Accepted Answer

failureRateThreshold

Answer

failureRateThreshold specifies the failure percentage within the sliding window that triggers the circuit breaker to transition to the Open state.

Spring Cloud Practice Test

Spring Cloud Practice Test

Spring Cloud Spring Cloud Circuit Breaker & Resilience