Circuit Breaker with Resilience4J

The Circuit Breaker pattern is essential for managing resilience in microservices architectures. Resilience4J is a lightweight, functional library that implements this pattern, along with other resilience patterns.

1. Basic Configuration

1.1 Adding Dependencies

<dependency>
    <groupId>io.github.resilience4j</groupId>
    <artifactId>resilience4j-spring-boot3</artifactId>
    <version>2.1.0</version>
</dependency>
<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-aop</artifactId>
</dependency>

1.2 Configuring the Circuit Breaker

# application.yml
resilience4j:
  circuitbreaker:
    instances:
      productService:
        slidingWindowSize: 10
        failureRateThreshold: 50
        waitDurationInOpenState: 5000
        permittedNumberOfCallsInHalfOpenState: 3
        eventConsumerBufferSize: 10
  ratelimiter:
    instances:
      productService:
        limitForPeriod: 100
        limitRefreshPeriod: 1s
        timeoutDuration: 0
  retry:
    instances:
      productService:
        maxAttempts: 3
        waitDuration: 100
        enableExponentialBackoff: true
        exponentialBackoffMultiplier: 2
        exponentialBackoffMaxDuration: 600
        retryExceptions:
          - org.springframework.web.client.RestClientException