Unclear circuitbreak "fallback" behavior

Question

I want to use a fallback in case of failing, so the behavior in "open" state should be to call a fallback instead of throwing an exception.

Problem is that the fallback is called during the "closed" state, while for "open" state I still get the exception. Is this the intended behavior? No way to attain what I am searching for?

I have defined my custom circuit break:

resilience4j:
  circuitbreaker:
 configs:
  default:
    register-health-indicator: true
    slidingWindowSize: 10
    minimumNumberOfCalls: 2
    permittedNumberOfCallsInHalfOpenState: 2
    automaticTransitionFromOpenToHalfOpenEnabled: true
    waitDurationInOpenState: 20s
    failureRateThreshold: 20
    slowCallDurationThreshold: 2s
    slowCallRateThreshold: 20
instances:
  backendA:
    base-config: default

Now, I defined my method as follows:

public class ExampleService {


@CircuitBreaker(name = "default", fallbackMethod = "fall")
public List<String> doSomething(Long id) {
    return Arrays.asList("a", "b", "c");

}

private List<String> fall(Long id, Exception ex) {
    return Arrays.asList("faaaallingggg");
}
 }

Answer 1

Just change your signature of the fallback method to

private List<String> fall(Long id, CallNotPermittedException ex) {
    return Arrays.asList("faaaallingggg");
}