spring-boot-resilience4j

Spring Boot Resilience4j Patterns

Overview

Provides Resilience4j patterns (circuit breaker, retry, rate limiter, bulkhead, time limiter, fallback) for Spring Boot 3.x fault tolerance with configuration and testing workflows.

When to Use

• Implementing fault tolerance and preventing cascading failures
• Adding circuit breakers, retry logic, or rate limiting to service calls
• Handling transient failures with exponential backoff
• Protecting services from overload and resource exhaustion
• Combining multiple patterns for comprehensive resilience

Instructions

1. Setup and Dependencies

Add Resilience4j dependencies to your project. For Maven, add to pom.xml:

<dependency>
    <groupId>io.github.resilience4j</groupId>
    <artifactId>resilience4j-spring-boot3</artifactId>
    <version>2.2.0</version> // Use latest stable version
</dependency>
<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-aop</artifactId>
</dependency>
<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-actuator</artifactId>
</dependency>

For Gradle, add to build.gradle:

implementation "io.github.resilience4j:resilience4j-spring-boot3:2.2.0"
implementation "org.springframework.boot:spring-boot-starter-aop"
implementation "org.springframework.boot:spring-boot-starter-actuator"

Enable AOP annotation processing with @EnableAspectJAutoProxy (auto-configured by Spring Boot).

2. Circuit Breaker Pattern

Apply @CircuitBreaker annotation to methods calling external services:

@Service
public class PaymentService {
    private final RestTemplate restTemplate;

    public PaymentService(RestTemplate restTemplate) {
        this.restTemplate = restTemplate;
    }

    @CircuitBreaker(name = "paymentService", fallbackMethod = "paymentFallback")
    public PaymentResponse processPayment(PaymentRequest request) {
        return restTemplate.postForObject("http://payment-api/process",
            request, PaymentResponse.class);
    }

    private PaymentResponse paymentFallback(PaymentRequest request, Exception ex) {
        return PaymentResponse.builder()
            .status("PENDING")
            .message("Service temporarily unavailable")
            .build();
    }
}