Specific Circuit Breaker Configuration

Similarly to providing a default configuration, you can create a Customizer bean this is passed a Resilience4JCircuitBreakerFactory or ReactiveResilience4JCircuitBreakerFactory.

@Bean
public Customizer<Resilience4JCircuitBreakerFactory> slowCustomizer() {
	return factory -> factory.configure(builder -> builder.circuitBreakerConfig(CircuitBreakerConfig.ofDefaults())
			.timeLimiterConfig(TimeLimiterConfig.custom().timeoutDuration(Duration.ofSeconds(2)).build()), "slow");
}

In addition to configuring the circuit breaker that is created you can also customize the circuit breaker after it has been created but before it is returned to the caller. To do this you can use the addCircuitBreakerCustomizer method. This can be useful for adding event handlers to Resilience4J circuit breakers.

@Bean
public Customizer<Resilience4JCircuitBreakerFactory> slowCustomizer() {
	return factory -> factory.addCircuitBreakerCustomizer(circuitBreaker -> circuitBreaker.getEventPublisher()
	.onError(normalFluxErrorConsumer).onSuccess(normalFluxSuccessConsumer), "normalflux");
}

If you need to propogate the security context to the Circuit Breaker you must configure the circuit breaker to use DelegatingSecurityContextExecutorService.

@Bean
public Customizer<Resilience4JCircuitBreakerFactory> groupExecutorServiceCustomizer() {
	return factory -> factory.configureGroupExecutorService(group -> new DelegatingSecurityContextExecutorService(Executors.newVirtualThreadPerTaskExecutor()));
}

Reactive Example

@Bean
public Customizer<ReactiveResilience4JCircuitBreakerFactory> slowCustomizer() {
	return factory -> {
		factory.configure(builder -> builder
		.timeLimiterConfig(TimeLimiterConfig.custom().timeoutDuration(Duration.ofSeconds(2)).build())
		.circuitBreakerConfig(CircuitBreakerConfig.ofDefaults()), "slow", "slowflux");
		factory.addCircuitBreakerCustomizer(circuitBreaker -> circuitBreaker.getEventPublisher()
        	.onError(normalFluxErrorConsumer).onSuccess(normalFluxSuccessConsumer), "normalflux");
     };
}