feat: AI 이미지 생성 DLQ 및 재시도 메커니즘 구현

src/main/java/hanium/modic/backend/common/amqp/config/RabbitMqConfig.java

@@ -1,5 +1,8 @@
 package hanium.modic.backend.common.amqp.config;
 
+import java.util.HashMap;
+import java.util.Map;
+
 import org.springframework.amqp.core.AmqpAdmin;
 import org.springframework.amqp.core.Binding;
 import org.springframework.amqp.core.BindingBuilder;
@@ -27,11 +30,22 @@ public class RabbitMqConfig {
 	public static final String AI_IMAGE_CREATED_EXCHANGE = "ai.image.created.exchange";
 	public static final String AI_IMAGE_CREATED_ROUTING_KEY = "ai.image.created";
 
+	// DLQ (Dead Letter Queue) 및 재시도 관련 상수
+	public static final String AI_IMAGE_REQUEST_DLX = "ai.image.request.dlx";
+	public static final String AI_IMAGE_REQUEST_DLQ = "ai.image.request.dlq";
+	public static final String AI_IMAGE_REQUEST_RETRY_EXCHANGE = "ai.image.request.retry.exchange";
+	public static final String AI_IMAGE_REQUEST_RETRY_QUEUE = "ai.image.request.retry.queue";
+	public static final String AI_IMAGE_REQUEST_DLQ_ROUTING_KEY = "ai.image.request.dlq";
+	public static final String AI_IMAGE_REQUEST_RETRY_ROUTING_KEY = "ai.image.request.retry";
+
 	private final RabbitMqProperties rabbitMqProperties;
 
 	@Bean
 	public Queue aiImageRequestQueue() {
-		return new Queue(AI_IMAGE_REQUEST_QUEUE, true);
+		Map<String, Object> args = new HashMap<>();
+		args.put("x-dead-letter-exchange", AI_IMAGE_REQUEST_DLX);
+		args.put("x-dead-letter-routing-key", AI_IMAGE_REQUEST_RETRY_ROUTING_KEY); // 기본적으로 재시도로 라우팅
+		return new Queue(AI_IMAGE_REQUEST_QUEUE, true, false, false, args);
 	}
 
 	@Bean
@@ -63,6 +77,58 @@ public Binding aiImageCreatedBinding(Queue aiImageCreatedQueue, TopicExchange ai
 			.with(AI_IMAGE_CREATED_ROUTING_KEY);
 	}
 
+	// DLX (Dead Letter Exchange) - 실패한 메시지를 받아서 재시도 또는 최종 처리로 라우팅
+	@Bean
+	public TopicExchange aiImageRequestDlx() {
+		return new TopicExchange(AI_IMAGE_REQUEST_DLX, true, false);
+	}
+
+	// 최종 실패 메시지 저장소
+	@Bean
+	public Queue aiImageRequestDlq() {
+		return new Queue(AI_IMAGE_REQUEST_DLQ, true);
+	}
+
+	// DLX에서 최종 DLQ로의 바인딩
+	@Bean
+	public Binding aiImageRequestDlqBinding(Queue aiImageRequestDlq, TopicExchange aiImageRequestDlx) {
+		return BindingBuilder.bind(aiImageRequestDlq)
+			.to(aiImageRequestDlx)
+			.with(AI_IMAGE_REQUEST_DLQ_ROUTING_KEY);
+	}
+
+	// 재시도용 Exchange
+	@Bean
+	public TopicExchange aiImageRequestRetryExchange() {
+		return new TopicExchange(AI_IMAGE_REQUEST_RETRY_EXCHANGE, true, false);
+	}
+
+	// 재시도 대기 Queue (TTL 60초 설정, 만료 시 원래 exchange로 재전송)
+	@Bean
+	public Queue aiImageRequestRetryQueue() {
+		Map<String, Object> args = new HashMap<>();
+		args.put("x-message-ttl", 60000); // 60초
+		args.put("x-dead-letter-exchange", AI_IMAGE_REQUEST_EXCHANGE); // 만료 시 원래 exchange로
+		args.put("x-dead-letter-routing-key", AI_IMAGE_REQUEST_ROUTING_KEY);
+		return new Queue(AI_IMAGE_REQUEST_RETRY_QUEUE, true, false, false, args);
+	}
+
+	// 재시도 Exchange와 Queue 바인딩
+	@Bean
+	public Binding aiImageRequestRetryBinding(Queue aiImageRequestRetryQueue, TopicExchange aiImageRequestRetryExchange) {
+		return BindingBuilder.bind(aiImageRequestRetryQueue)
+			.to(aiImageRequestRetryExchange)
+			.with(AI_IMAGE_REQUEST_RETRY_ROUTING_KEY);
+	}
+
+	// DLX에서 재시도 Exchange로의 바인딩
+	@Bean
+	public Binding aiImageRequestDlxToRetryBinding(TopicExchange aiImageRequestRetryExchange, TopicExchange aiImageRequestDlx) {
+		return BindingBuilder.bind(aiImageRequestRetryExchange)
+			.to(aiImageRequestDlx)
+			.with(AI_IMAGE_REQUEST_RETRY_ROUTING_KEY);
+	}
+
 	@Bean
 	public CachingConnectionFactory connectionFactory() {
 		CachingConnectionFactory connectionFactory = new CachingConnectionFactory();

src/main/java/hanium/modic/backend/domain/ai/listener/DlqListener.java

@@ -0,0 +1,43 @@
+package hanium.modic.backend.domain.ai.listener;
+
+import static hanium.modic.backend.common.amqp.config.RabbitMqConfig.*;
+
+import java.util.Optional;
+
+import org.springframework.amqp.core.Message;
+import org.springframework.amqp.rabbit.annotation.RabbitListener;
+import org.springframework.stereotype.Component;
+import org.springframework.transaction.annotation.Transactional;
+
+import hanium.modic.backend.domain.ai.domain.AiRequestEntity;
+import hanium.modic.backend.domain.ai.dto.AiImageRequestMessageDto;
+import hanium.modic.backend.domain.ai.enums.AiImageStatus;
+import hanium.modic.backend.domain.ai.repository.AiRequestRepository;
+import lombok.RequiredArgsConstructor;
+import lombok.extern.slf4j.Slf4j;
+
+@Slf4j
+@Component
+@RequiredArgsConstructor
+public class DlqListener {
+
+    private final AiRequestRepository aiRequestRepository;
+
+    @Transactional
+    @RabbitListener(queues = AI_IMAGE_REQUEST_DLQ)
+    public void handleFinalFailedMessage(AiImageRequestMessageDto messageDto, Message message) {
+        log.error("[최종 실패] AI 이미지 생성 요청 최종 실패: requestId={}", messageDto.requestId());
+
+        // AiRequestEntity 상태를 FAILED로 변경
+        Optional<AiRequestEntity> aiRequestOpt = aiRequestRepository.findByRequestId(messageDto.requestId());
+        if (aiRequestOpt.isPresent()) {
+            AiRequestEntity aiRequest = aiRequestOpt.get();
+            aiRequest.updateStatus(AiImageStatus.FAILED);
+            aiRequestRepository.save(aiRequest);
+            log.info("[상태 업데이트] requestId={} 상태를 FAILED로 변경", messageDto.requestId());
+        } else {
+            log.error("[데이터 오류] requestId={}에 해당하는 AI 요청을 찾을 수 없습니다", messageDto.requestId());
+        }
+    }
+
+}