Spring Retry - Quick Reference

Full Reference: See advanced.md for RetryTemplate patterns, custom retry policies, retry listeners, stateful retry, async retry, and testing.

Deep Knowledge: Use mcp__documentation__fetch_docs with technology: spring-retry for comprehensive documentation.

Dependencies

<dependency> <groupId>org.springframework.retry</groupId> <artifactId>spring-retry</artifactId> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-aspects</artifactId> </dependency>

Enable Retry

@SpringBootApplication @EnableRetry public class Application { public static void main(String[] args) { SpringApplication.run(Application.class, args); } }

@Retryable Annotation

Basic Usage

@Retryable(maxAttempts = 3) public String callExternalApi(String endpoint) { return restClient.get(endpoint); }

With Specific Exceptions

@Retryable( retryFor = {ServiceUnavailableException.class, TimeoutException.class}, noRetryFor = {PaymentDeclinedException.class}, maxAttempts = 5 ) public PaymentResult processPayment(PaymentRequest request) { return paymentGateway.charge(request); }

With Backoff

@Retryable( maxAttempts = 4, backoff = @Backoff( delay = 1000, // Initial delay: 1 second multiplier = 2, // Exponential: 1s, 2s, 4s maxDelay = 10000 // Max delay: 10 seconds ) ) public void sendNotification(Notification notification) { notificationClient.send(notification); }

@Recover public void recoverNotification(Exception e, Notification notification) { log.error("Failed to send notification after retries: {}", notification.getId()); deadLetterQueue.add(notification); }

@Recover Method

@Service public class UserService {

@Retryable(retryFor = ServiceException.class, maxAttempts = 3)
public User getUser(Long id) {
    return userClient.findById(id);
}

// Must have same return type
// First parameter can be the exception
@Recover
public User recoverGetUser(ServiceException e, Long id) {
    log.warn("Falling back to cached user for id: {}", id);
    return userCache.get(id);
}

// Multiple recover methods for different exceptions
@Recover
public User recoverGetUserTimeout(TimeoutException e, Long id) {
    return User.unknown(id);
}

}

Best Practices

Do Don't

Use exponential backoff Fixed rapid retries

Set max attempts limit Retry indefinitely

Handle non-retryable exceptions Retry business errors

Log retry attempts Silent retries

Implement recovery fallback Let retries fail silently

When NOT to Use This Skill

• Circuit breaker - Use spring-cloud-circuitbreaker or Resilience4j

• Message retry - Use Kafka retry topics or DLT

• Non-idempotent operations - Ensure idempotency first

• Business errors - Only retry transient failures

Anti-Patterns

Anti-Pattern Problem Solution

Retry indefinitely Hangs forever Set max attempts

Fixed rapid retry Overwhelms service Use exponential backoff

Retrying business errors Wastes resources Use noRetryFor

No recovery method Silent failures Implement @Recover

Quick Troubleshooting

Problem Diagnostic Fix

Retry not happening Check @EnableRetry Add to config class

@Recover not called Check method signature Match return type and params

Too many retries Check maxAttempts Reduce or add timeout

Backoff not working Check annotation Verify @Backoff config

Production Checklist

• Appropriate max attempts set

• Exponential backoff configured

• Max delay capped

• Non-retryable exceptions defined

• Recovery methods implemented

• Retry listeners for monitoring

• Metrics on retry counts

Reference Documentation

• Spring Retry Reference