In resilient Spring applications, failures can happen at any time—whether due to network issues, service downtime, or unexpected errors. By combining retry and fallback strategies, you ensure that your application can handle these failures gracefully. Retries automatically attempt an operation again when it fails, while fallbacks provide a safe alternative if all retries are unsuccessful. This approach helps you maintain a reliable user experience and protect your critical workflows from unexpected disruptions.

Combining Retry Patterns with Fallback Strategies

Combining retry and fallback approaches helps your Spring application recover gracefully from failures. Use retry to automatically attempt an operation several times, and apply a fallback to provide an alternative result if all retries fail.

Why Combine Retry and Fallback?

• Improve reliability by handling temporary errors automatically;
• Provide users with a default or cached response if a service remains unavailable;
• Minimize user disruption and error messages.

Example Scenario

Suppose you have a service that fetches user profiles from a remote API. Sometimes the API is slow or temporarily unavailable. You want to:

• Retry the call up to 3 times if it fails;
• Return a default profile if all retries fail.

Basic Code Example

You can use Spring’s @Retryable and @Recover annotations for this pattern. Here’s how you can implement it:

import org.springframework.retry.annotation.Retryable;
import org.springframework.retry.annotation.Recover;
import org.springframework.stereotype.Service;

@Service
public class UserProfileService {

    @Retryable(value = Exception.class, maxAttempts = 3)
    public String fetchUserProfile(String userId) {
        // Simulate a call to a remote API that might fail
        if (Math.random() < 0.7) {
            throw new RuntimeException("Remote API failed");
        }
        return "Profile data for user: " + userId;
    }

    @Recover
    public String fallbackUserProfile(Exception e, String userId) {
        // This method is called if all retries fail
        return "Default profile for user: " + userId;
    }
}

Code Breakdown

• The fetchUserProfile method tries to get profile data. If it throws an exception, Spring automatically retries up to 3 times.
• If all attempts fail, the fallbackUserProfile method is called. This method provides a default profile instead of letting the error propagate.
• The @Retryable annotation specifies when to retry and how many times.
• The @Recover method acts as the fallback handler. It must have the same return type and accept the exception as the first parameter.

Key Points

• Always place fallback logic in a separate method annotated with @Recover;
• Use @Retryable for methods likely to fail temporarily, such as remote calls;
• Make sure your fallback provides a meaningful response to users.

Combining these patterns makes your application more robust and user-friendly, even when external services are unreliable.