🐞 BugFix - RabbitMQ와 Optimistic Lock을 이용한 동시성 문제 해결 (#176)

* 🐞 BugFix/#175 - add: RabbitMQ 의존성 추가

* 🐞 BugFix/#175 - feat: RabbitMQConfig 구현

* 🐞 BugFix/#175 - refactor: Optimistic Lock 적용

* 🐞 BugFix/#175 - feat: comment 생성 시 동시성 문제 해결

* 🐞 BugFix/#175 - feat: like 생성 시 동시성 문제 해결

build.gradle

@@ -75,6 +75,10 @@ dependencies {
     // Secheduler
     implementation 'org.springframework.boot:spring-boot-starter-quartz'
 
+    // RabbitMQ
+    implementation group: 'org.springframework.amqp', name: 'spring-amqp', version: '3.1.7'
+    implementation group: 'org.springframework.amqp', name: 'spring-rabbit', version: '3.1.7'
+
     // Testing Dependencies
     testImplementation 'org.springframework.boot:spring-boot-starter-test'
     testRuntimeOnly 'org.junit.platform:junit-platform-launcher'

src/main/java/com/daon/onjung/core/config/RabbitMQConfig.java

@@ -0,0 +1,58 @@
+package com.daon.onjung.core.config;
+
+import org.springframework.amqp.core.Binding;
+import org.springframework.amqp.core.BindingBuilder;
+import org.springframework.amqp.core.DirectExchange;
+import org.springframework.amqp.core.Queue;
+import org.springframework.amqp.rabbit.annotation.EnableRabbit;
+import org.springframework.amqp.rabbit.connection.ConnectionFactory;
+import org.springframework.amqp.rabbit.core.RabbitTemplate;
+import org.springframework.amqp.support.converter.Jackson2JsonMessageConverter;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+
+@Configuration
+@EnableRabbit
+public class RabbitMQConfig {
+
+    @Bean
+    public DirectExchange boardExchange() {
+        return new DirectExchange("board-exchange");
+    }
+
+    @Bean
+    public Queue likeQueue() {
+        return new Queue("like-queue", true);
+    }
+
+    @Bean
+    public Queue commentQueue1() {
+        return new Queue("comment-queue-1", true);
+    }
+
+    @Bean Queue commentQueue2() {
+        return new Queue("comment-queue-2", true);
+    }
+
+    @Bean
+    public Binding boardQueue1Binding(DirectExchange boardExchange, Queue commentQueue1) {
+        return BindingBuilder.bind(commentQueue1).to(boardExchange).with("board.1");
+    }
+
+    @Bean
+    public Binding boardQueue2Binding(DirectExchange boardExchange, Queue commentQueue2) {
+        return BindingBuilder.bind(commentQueue2).to(boardExchange).with("board.0");
+    }
+
+    @Bean
+    public Jackson2JsonMessageConverter jsonMessageConverter() {
+        return new Jackson2JsonMessageConverter();
+    }
+
+    @Bean
+    public RabbitTemplate rabbitTemplate(ConnectionFactory connectionFactory) {
+        RabbitTemplate rabbitTemplate = new RabbitTemplate(connectionFactory);
+        rabbitTemplate.setMessageConverter(jsonMessageConverter()); // JSON 컨버터 설정
+        return rabbitTemplate;
+    }
+}

src/main/java/com/daon/onjung/core/exception/error/ErrorCode.java

@@ -43,6 +43,9 @@ public enum ErrorCode {
     TOKEN_GENERATION_ERROR(40106, HttpStatus.UNAUTHORIZED, "토큰 생성에 실패하였습니다."),
     TOKEN_UNKNOWN_ERROR(40107, HttpStatus.UNAUTHORIZED, "알 수 없는 토큰입니다."),
 
+    // Conflict Error
+    OPTIMISTIC_EXCEPTION(40900, HttpStatus.CONFLICT, "Optimistic Locking 예외가 발생하였습니다."),
+
     // Internal Server Error
     INTERNAL_SERVER_ERROR(50000, HttpStatus.INTERNAL_SERVER_ERROR, "서버 내부 에러입니다."),
     INTERNAL_DATA_ERROR(50001, HttpStatus.INTERNAL_SERVER_ERROR, "서버 내부 데이터 에러입니다."),

src/main/java/com/daon/onjung/suggestion/application/controller/command/SuggestionCommandV1Controller.java

@@ -48,10 +48,7 @@ public ResponseDto<Void> likeBoard(
             @AccountID UUID accountId,
             @PathVariable Long id
     ) {
-        if (createOrDeleteLikeUseCase.execute(accountId, id)) {
-            return ResponseDto.created(null);
-        } else {
-            return ResponseDto.ok(null);
-        }
+        createOrDeleteLikeUseCase.execute(accountId, id);
+        return ResponseDto.ok(null);
     }
 }

src/main/java/com/daon/onjung/suggestion/application/controller/consumer/CommentV1Consumer.java

@@ -0,0 +1,90 @@
+package com.daon.onjung.suggestion.application.controller.consumer;
+
+import com.daon.onjung.account.domain.User;
+import com.daon.onjung.account.repository.mysql.UserRepository;
+import com.daon.onjung.core.exception.error.ErrorCode;
+import com.daon.onjung.core.exception.type.CommonException;
+import com.daon.onjung.suggestion.application.dto.request.CommentMessage;
+import com.daon.onjung.suggestion.domain.Board;
+import com.daon.onjung.suggestion.domain.Comment;
+import com.daon.onjung.suggestion.domain.service.BoardService;
+import com.daon.onjung.suggestion.domain.service.CommentService;
+import com.daon.onjung.suggestion.repository.mysql.BoardRepository;
+import com.daon.onjung.suggestion.repository.mysql.CommentRepository;
+import lombok.RequiredArgsConstructor;
+import org.hibernate.dialect.lock.OptimisticEntityLockException;
+import org.springframework.amqp.rabbit.annotation.RabbitListener;
+import org.springframework.stereotype.Service;
+import org.springframework.transaction.annotation.Transactional;
+
+@Service
+@RequiredArgsConstructor
+public class CommentV1Consumer {
+
+    private final BoardRepository boardRepository;
+    private final CommentRepository commentRepository;
+    private final UserRepository userRepository;
+
+    private final CommentService commentService;
+    private final BoardService boardService;
+
+    @Transactional
+    @RabbitListener(queues = "comment-queue-1")
+    public void processCommentMessage1(CommentMessage commentMessage) {
+        try {
+
+            // 게시글 조회
+            Board board = boardRepository.findById(commentMessage.boardId())
+                    .orElseThrow(() -> new CommonException(ErrorCode.NOT_FOUND_RESOURCE));
+
+            // 유저 조회
+            User user = userRepository.findById(commentMessage.userId())
+                    .orElseThrow(() -> new CommonException(ErrorCode.NOT_FOUND_RESOURCE));
+
+            // 댓글 생성
+            Comment comment = commentService.createComment(
+                    commentMessage.content(),
+                    user,
+                    board
+            );
+            commentRepository.save(comment);
+
+            // 게시글 댓글 수 증가
+            board = boardService.addCommentCount(board);
+            boardRepository.save(board);
+        } catch (OptimisticEntityLockException e) {
+            throw new CommonException(ErrorCode.OPTIMISTIC_EXCEPTION);
+        }
+    }
+
+    @Transactional
+    @RabbitListener(queues = "comment-queue-2")
+    public void processCommentMessage2(CommentMessage commentMessage) {
+        try {
+
+            // 게시글 조회
+            Board board = boardRepository.findById(commentMessage.boardId())
+                    .orElseThrow(() -> new CommonException(ErrorCode.NOT_FOUND_RESOURCE));
+
+            // 유저 조회
+            User user = userRepository.findById(commentMessage.userId())
+                    .orElseThrow(() -> new CommonException(ErrorCode.NOT_FOUND_RESOURCE));
+
+            // 댓글 생성
+            Comment comment = commentService.createComment(
+                    commentMessage.content(),
+                    user,
+                    board
+            );
+            commentRepository.save(comment);
+
+            // 게시글 댓글 수 증가
+            board = boardService.addCommentCount(board);
+            boardRepository.save(board);
+        } catch (OptimisticEntityLockException e) {
+            throw new CommonException(ErrorCode.OPTIMISTIC_EXCEPTION);
+        }
+    }
+
+
+}

src/main/java/com/daon/onjung/suggestion/application/controller/consumer/LikeV1Consumer.java

@@ -0,0 +1,69 @@
+package com.daon.onjung.suggestion.application.controller.consumer;
+
+import com.daon.onjung.account.domain.User;
+import com.daon.onjung.account.repository.mysql.UserRepository;
+import com.daon.onjung.core.exception.error.ErrorCode;
+import com.daon.onjung.core.exception.type.CommonException;
+import com.daon.onjung.suggestion.application.dto.request.LikeMessage;
+import com.daon.onjung.suggestion.domain.Board;
+import com.daon.onjung.suggestion.domain.Like;
+import com.daon.onjung.suggestion.domain.service.BoardService;
+import com.daon.onjung.suggestion.domain.service.LikeService;
+import com.daon.onjung.suggestion.repository.mysql.BoardRepository;
+import com.daon.onjung.suggestion.repository.mysql.LikeRepository;
+import lombok.RequiredArgsConstructor;
+import org.hibernate.dialect.lock.OptimisticEntityLockException;
+import org.springframework.amqp.rabbit.annotation.RabbitListener;
+import org.springframework.stereotype.Service;
+import org.springframework.transaction.annotation.Transactional;
+
+@Service
+@RequiredArgsConstructor
+public class LikeV1Consumer {
+
+    private final LikeRepository likeRepository;
+    private final BoardRepository boardRepository;
+    private final UserRepository userRepository;
+
+    private final LikeService likeService;
+    private final BoardService boardService;
+
+    @Transactional
+    @RabbitListener(queues = "like-queue")
+    public void processLikeMessage(LikeMessage likeMessage) {
+        try {
+
+            // 게시글 조회
+            Board board = boardRepository.findById(likeMessage.boardId())
+                    .orElseThrow(() -> new CommonException(ErrorCode.NOT_FOUND_RESOURCE));
+
+            // 유저 조회
+            User user = userRepository.findById(likeMessage.userId())
+                    .orElseThrow(() -> new CommonException(ErrorCode.NOT_FOUND_RESOURCE));
+
+            // 좋아요가 존재하는지 확인
+            Like like = likeRepository.findByBoardAndUser(board, user)
+                    .orElse(null);
+
+            if (like != null) {
+
+                // 좋아요가 이미 존재하면 삭제
+                likeRepository.delete(like);
+                // 게시글 좋아요 수 감소
+                board = boardService.subtractLikeCount(board);
+                boardRepository.save(board);
+            } else {
+
+                // 좋아요가 존재하지 않으면 생성
+                likeRepository.save(likeService.createLike(user, board));
+
+                // 게시글 좋아요 수 증가
+                board = boardService.addLikeCount(board);
+                boardRepository.save(board);
+            }
+        } catch (OptimisticEntityLockException e) {
+            throw new CommonException(ErrorCode.OPTIMISTIC_EXCEPTION);
+        }
+    }
+
+}

src/main/java/com/daon/onjung/suggestion/application/controller/producer/CommentV1Producer.java

@@ -0,0 +1,18 @@
+package com.daon.onjung.suggestion.application.controller.producer;
+
+import com.daon.onjung.suggestion.application.dto.request.CommentMessage;
+import com.daon.onjung.suggestion.application.usecase.SendCommentRequestUseCase;
+import lombok.RequiredArgsConstructor;
+import org.springframework.stereotype.Service;
+
+@Service
+@RequiredArgsConstructor
+public class CommentV1Producer {
+
+    private final SendCommentRequestUseCase sendCommentRequestUseCase;
+
+    public void sendComment (CommentMessage commentMessage) {
+        sendCommentRequestUseCase.execute(commentMessage);
+    }
+
+}

src/main/java/com/daon/onjung/suggestion/application/controller/producer/LikeV1Producer.java

@@ -0,0 +1,18 @@
+package com.daon.onjung.suggestion.application.controller.producer;
+
+import com.daon.onjung.suggestion.application.dto.request.LikeMessage;
+import com.daon.onjung.suggestion.application.usecase.SendLikeRequestUseCase;
+import lombok.RequiredArgsConstructor;
+import org.springframework.stereotype.Service;
+
+@Service
+@RequiredArgsConstructor
+public class LikeV1Producer {
+
+    private final SendLikeRequestUseCase sendLikeRequestUseCase;
+
+    public void sendLike (LikeMessage likeMessage) {
+        sendLikeRequestUseCase.execute(likeMessage);
+    }
+
+}

src/main/java/com/daon/onjung/suggestion/application/dto/request/CommentMessage.java

@@ -0,0 +1,13 @@
+package com.daon.onjung.suggestion.application.dto.request;
+
+import lombok.Builder;
+
+import java.util.UUID;
+
+@Builder
+public record CommentMessage(
+        String content,
+        Long boardId,
+        UUID userId
+) {
+}

src/main/java/com/daon/onjung/suggestion/application/dto/request/LikeMessage.java

@@ -0,0 +1,12 @@
+package com.daon.onjung.suggestion.application.dto.request;
+
+import lombok.Builder;
+
+import java.util.UUID;
+
+@Builder
+public record LikeMessage(
+        Long boardId,
+        UUID userId
+) {
+}

src/main/java/com/daon/onjung/suggestion/application/service/CreateCommentService.java

@@ -4,14 +4,12 @@
 import com.daon.onjung.account.repository.mysql.UserRepository;
 import com.daon.onjung.core.exception.error.ErrorCode;
 import com.daon.onjung.core.exception.type.CommonException;
+import com.daon.onjung.suggestion.application.controller.producer.CommentV1Producer;
+import com.daon.onjung.suggestion.application.dto.request.CommentMessage;
 import com.daon.onjung.suggestion.application.dto.request.CreateCommentRequestDto;
 import com.daon.onjung.suggestion.application.usecase.CreateCommentUseCase;
 import com.daon.onjung.suggestion.domain.Board;
-import com.daon.onjung.suggestion.domain.Comment;
-import com.daon.onjung.suggestion.domain.service.BoardService;
-import com.daon.onjung.suggestion.domain.service.CommentService;
 import com.daon.onjung.suggestion.repository.mysql.BoardRepository;
-import com.daon.onjung.suggestion.repository.mysql.CommentRepository;
 import lombok.RequiredArgsConstructor;
 import org.springframework.stereotype.Service;
 import org.springframework.transaction.annotation.Transactional;
@@ -24,10 +22,8 @@ public class CreateCommentService implements CreateCommentUseCase {
 
     private final UserRepository userRepository;
     private final BoardRepository boardRepository;
-    private final CommentRepository commentRepository;
 
-    private final CommentService commentService;
-    private final BoardService boardService;
+    private final CommentV1Producer commentProducer;
 
     @Override
     @Transactional
@@ -41,16 +37,12 @@ public void execute(UUID accountId, Long boardId, CreateCommentRequestDto reques
         Board board = boardRepository.findById(boardId)
                 .orElseThrow(() -> new CommonException(ErrorCode.NOT_FOUND_RESOURCE));
 
-        // 댓글 생성
-        Comment comment = commentService.createComment(
-                requestDto.content(),
-                user,
-                board
+        // 댓글 생성 요청 발송
+        commentProducer.sendComment(CommentMessage.builder()
+                        .content(requestDto.content())
+                        .userId(user.getId())
+                        .boardId(board.getId())
+                        .build()
         );
-        commentRepository.save(comment);
-
-        // 게시글 댓글 수 증가
-        board = boardService.addCommentCount(board);
-        boardRepository.save(board);
     }
 }