Have you used patterns for error handling in communication between microservices?

Yes, patterns that enhance the stability and reliability of the system are often used for managing errors in communication between microservices.

Main patterns:

• Circuit Breaker: prevents repeated calls to a service if it is unavailable, to avoid excessive load and rapid failure.

• Retry: in case of temporary errors, requests are retried with a delay, helping to cope with temporary failures.

• Fallback: if the main service is unavailable, alternative logic is invoked or a default response is returned.

• Timeout: limits the waiting time for a response to avoid blocking resources.

Example of using Circuit Breaker with the Resilience4j library in Java:

import io.github.resilience4j.circuitbreaker.CircuitBreaker;
import io.github.resilience4j.circuitbreaker.CircuitBreakerConfig;
import java.time.Duration;

CircuitBreakerConfig config = CircuitBreakerConfig.custom()
    .failureRateThreshold(50)
    .waitDurationInOpenState(Duration.ofSeconds(30))
    .build();

CircuitBreaker circuitBreaker = CircuitBreaker.of("myService", config);

Supplier<String> decoratedSupplier = CircuitBreaker.decorateSupplier(circuitBreaker, () -> callRemoteService());

try {
    String response = decoratedSupplier.get();
} catch (CallNotPermittedException ex) {
    // fallback logic
}

Using such patterns helps make interactions between microservices more reliable and resilient to failures.