Fix notification cleanup failures on post actions

src/main/java/com/daramg/server/aicomment/application/AiCommentService.java

@@ -145,7 +145,12 @@ public void scheduleForPost(Post post) {
     }
 
     @Transactional
-    public void scheduleReplyForAiComment(Comment aiComment, Post post) {
+    public void scheduleReplyForAiComment(Long aiCommentId, Long postId) {
+        Comment aiComment = commentRepository.findById(aiCommentId).orElse(null);
+        if (aiComment == null) {
+            return;
+        }
+
         if (aiComment.getAiReplyCount() >= MAX_AI_REPLY_COUNT) {
             return;
         }
@@ -160,6 +165,11 @@ public void scheduleReplyForAiComment(Comment aiComment, Post post) {
             return;
         }
 
+        Post post = postRepository.findById(postId).orElse(null);
+        if (post == null) {
+            return;
+        }
+
         aiComment.incrementAiReplyCount();
 
         Instant scheduledAt = Instant.now().plusSeconds(replyDelayMinutes * 60L);

src/main/java/com/daramg/server/aicomment/event/AiReplyScheduleEvent.java

@@ -0,0 +1,7 @@
+package com.daramg.server.aicomment.event;
+
+public record AiReplyScheduleEvent(
+        Long aiCommentId,
+        Long postId
+) {
+}

src/main/java/com/daramg/server/aicomment/event/AiReplyScheduleEventListener.java

@@ -0,0 +1,26 @@
+package com.daramg.server.aicomment.event;
+
+import com.daramg.server.aicomment.application.AiCommentService;
+import lombok.RequiredArgsConstructor;
+import lombok.extern.slf4j.Slf4j;
+import org.springframework.stereotype.Component;
+import org.springframework.transaction.event.TransactionalEventListener;
+
+import static org.springframework.transaction.event.TransactionPhase.AFTER_COMMIT;
+
+@Slf4j
+@Component
+@RequiredArgsConstructor
+public class AiReplyScheduleEventListener {
+
+    private final AiCommentService aiCommentService;
+
+    @TransactionalEventListener(phase = AFTER_COMMIT)
+    public void handleAiReplyScheduleEvent(AiReplyScheduleEvent event) {
+        try {
+            aiCommentService.scheduleReplyForAiComment(event.aiCommentId(), event.postId());
+        } catch (Exception e) {
+            log.warn("AI 답글 잡 등록 실패 - aiCommentId={}, postId={}", event.aiCommentId(), event.postId(), e);
+        }
+    }
+}

src/main/java/com/daramg/server/comment/application/CommentService.java

@@ -1,6 +1,6 @@
 package com.daramg.server.comment.application;
 
-import com.daramg.server.aicomment.application.AiCommentService;
+import com.daramg.server.aicomment.event.AiReplyScheduleEvent;
 import com.daramg.server.comment.domain.Comment;
 import com.daramg.server.comment.domain.CommentLike;
 import com.daramg.server.comment.dto.CommentLikeResponseDto;
@@ -30,7 +30,6 @@ public class CommentService {
     private final CommentRepository commentRepository;
     private final CommentLikeRepository commentLikeRepository;
     private final ApplicationEventPublisher eventPublisher;
-    private final AiCommentService aiCommentService;
 
     public void createComment(Long postId, CommentCreateDto request, User user){
         Post post = entityUtils.getEntity(postId, Post.class);
@@ -80,7 +79,7 @@ public void createReply(Long commentId, CommentReplyCreateDto request, User user
         }
 
         if (parentComment.isAi()) {
-            aiCommentService.scheduleReplyForAiComment(parentComment, post);
+            eventPublisher.publishEvent(new AiReplyScheduleEvent(parentComment.getId(), post.getId()));
         }
     }
 

src/main/java/com/daramg/server/notification/application/NotificationService.java

@@ -2,22 +2,41 @@
 
 import com.daramg.server.common.application.EntityUtils;
 import com.daramg.server.common.exception.BusinessException;
-import com.daramg.server.notification.exception.NotificationErrorStatus;
 import com.daramg.server.notification.domain.Notification;
+import com.daramg.server.notification.event.NotificationEvent;
+import com.daramg.server.notification.exception.NotificationErrorStatus;
 import com.daramg.server.notification.repository.NotificationRepository;
+import com.daramg.server.post.domain.Post;
 import com.daramg.server.user.domain.User;
 import lombok.RequiredArgsConstructor;
+import org.springframework.data.domain.PageRequest;
 import org.springframework.stereotype.Service;
+import org.springframework.transaction.annotation.Propagation;
 import org.springframework.transaction.annotation.Transactional;
 
+import java.util.List;
+
 @Service
 @Transactional
 @RequiredArgsConstructor
 public class NotificationService {
 
+    private static final int MAX_NOTIFICATIONS = 100;
+
     private final NotificationRepository notificationRepository;
     private final EntityUtils entityUtils;
 
+    @Transactional(propagation = Propagation.REQUIRES_NEW)
+    public void createFromEvent(NotificationEvent event) {
+        User receiver = entityUtils.getEntity(event.receiver().getId(), User.class);
+        User sender = entityUtils.getEntity(event.sender().getId(), User.class);
+        Post post = entityUtils.getEntity(event.post().getId(), Post.class);
+
+        Notification notification = Notification.of(receiver, sender, post, event.type());
+        notificationRepository.save(notification);
+        trimNotifications(receiver.getId());
+    }
+
     public void markAsRead(Long notificationId, User user) {
         Notification notification = entityUtils.getEntity(notificationId, Notification.class);
         validateReceiver(notification, user);
@@ -34,6 +53,21 @@ public void delete(Long notificationId, User user) {
         notificationRepository.delete(notification);
     }
 
+    private void trimNotifications(Long receiverId) {
+        if (notificationRepository.countByReceiverId(receiverId) <= MAX_NOTIFICATIONS) {
+            return;
+        }
+
+        List<Long> keepIds = notificationRepository.findRecentIdsByReceiverId(
+                receiverId,
+                PageRequest.of(0, MAX_NOTIFICATIONS)
+        );
+
+        if (!keepIds.isEmpty()) {
+            notificationRepository.deleteByReceiverIdAndIdNotIn(receiverId, keepIds);
+        }
+    }
+
     private void validateReceiver(Notification notification, User user) {
         if (!notification.getReceiver().getId().equals(user.getId())) {
             throw new BusinessException(NotificationErrorStatus.NOT_OWN_NOTIFICATION);

src/main/java/com/daramg/server/notification/event/NotificationEventListener.java

@@ -1,36 +1,37 @@
 package com.daramg.server.notification.event;
 
-import com.daramg.server.notification.domain.Notification;
-import com.daramg.server.notification.repository.NotificationRepository;
+import com.daramg.server.notification.application.NotificationService;
 import lombok.RequiredArgsConstructor;
+import lombok.extern.slf4j.Slf4j;
 import org.springframework.stereotype.Component;
 import org.springframework.transaction.event.TransactionalEventListener;
 
-import static org.springframework.transaction.event.TransactionPhase.BEFORE_COMMIT;
+import static org.springframework.transaction.event.TransactionPhase.AFTER_COMMIT;
 
+@Slf4j
 @Component
 @RequiredArgsConstructor
 public class NotificationEventListener {
 
-    private final NotificationRepository notificationRepository;
+    private final NotificationService notificationService;
 
-    @TransactionalEventListener(phase = BEFORE_COMMIT)
+    @TransactionalEventListener(phase = AFTER_COMMIT)
     public void handleNotificationEvent(NotificationEvent event) {
         if (event.receiver().getId().equals(event.sender().getId())) {
             return;
         }
 
-        Notification notification = Notification.of(
-                event.receiver(),
-                event.sender(),
-                event.post(),
-                event.type()
-        );
-
-        notificationRepository.save(notification);
-
-        if (notificationRepository.countByReceiverId(event.receiver().getId()) > 100) {
-            notificationRepository.deleteOldestByReceiverIdExceedingLimit(event.receiver().getId());
+        try {
+            notificationService.createFromEvent(event);
+        } catch (RuntimeException e) {
+            log.warn(
+                    "Failed to process notification event. receiverId={}, senderId={}, postId={}, type={}",
+                    event.receiver().getId(),
+                    event.sender().getId(),
+                    event.post().getId(),
+                    event.type(),
+                    e
+            );
         }
     }
 }

src/main/java/com/daramg/server/notification/repository/NotificationRepository.java

@@ -1,11 +1,14 @@
 package com.daramg.server.notification.repository;
 
 import com.daramg.server.notification.domain.Notification;
+import org.springframework.data.domain.Pageable;
 import org.springframework.data.jpa.repository.JpaRepository;
 import org.springframework.data.jpa.repository.Modifying;
 import org.springframework.data.jpa.repository.Query;
 
 import java.time.Instant;
+import java.util.Collection;
+import java.util.List;
 
 public interface NotificationRepository extends JpaRepository<Notification, Long> {
 
@@ -18,8 +21,10 @@ public interface NotificationRepository extends JpaRepository<Notification, Long
     @Query("UPDATE Notification n SET n.isRead = true WHERE n.receiver.id = :receiverId AND n.isRead = false")
     void markAllAsReadByReceiverId(Long receiverId);
 
+    @Query("SELECT n.id FROM Notification n WHERE n.receiver.id = :receiverId ORDER BY n.createdAt DESC, n.id DESC")
+    List<Long> findRecentIdsByReceiverId(Long receiverId, Pageable pageable);
+
     @Modifying
-    @Query("DELETE FROM Notification n WHERE n.receiver.id = :receiverId AND n.id NOT IN " +
-            "(SELECT n2.id FROM Notification n2 WHERE n2.receiver.id = :receiverId ORDER BY n2.createdAt DESC LIMIT 100)")
-    void deleteOldestByReceiverIdExceedingLimit(Long receiverId);
+    @Query("DELETE FROM Notification n WHERE n.receiver.id = :receiverId AND n.id NOT IN :keepIds")
+    void deleteByReceiverIdAndIdNotIn(Long receiverId, Collection<Long> keepIds);
 }

src/test/java/com/daramg/server/aicomment/application/AiCommentServiceTest.java

@@ -220,14 +220,14 @@ class ScheduleReplyTest {
             commentRepository.save(aiComment);
 
             // when
-            aiCommentService.scheduleReplyForAiComment(aiComment, post);
+            aiCommentService.scheduleReplyForAiComment(aiComment.getId(), post.getId());
 
             // then
             List<AiCommentJob> jobs = aiCommentJobRepository.findAll();
             assertThat(jobs).hasSize(1);
             assertThat(jobs.get(0).getTriggerType()).isEqualTo(AiCommentJobTriggerType.USER_REPLY);
             assertThat(jobs.get(0).getParentComment().getId()).isEqualTo(aiComment.getId());
-            assertThat(aiComment.getAiReplyCount()).isEqualTo((byte) 1);
+            assertThat(commentRepository.findById(aiComment.getId()).get().getAiReplyCount()).isEqualTo((byte) 1);
         }
 
         @Test
@@ -240,9 +240,10 @@ class ScheduleReplyTest {
             Comment aiComment = Comment.ofAi(post, botUser, "AI 댓글", null, composer);
             commentRepository.save(aiComment);
             ReflectionTestUtils.setField(aiComment, "aiReplyCount", (byte) 2);
+            commentRepository.save(aiComment);
 
             // when
-            aiCommentService.scheduleReplyForAiComment(aiComment, post);
+            aiCommentService.scheduleReplyForAiComment(aiComment.getId(), post.getId());
 
             // then
             assertThat(aiCommentJobRepository.findAll()).isEmpty();

src/test/java/com/daramg/server/notification/application/NotificationServiceIntegrationTest.java

@@ -8,11 +8,11 @@
 import com.daramg.server.notification.domain.NotificationType;
 import com.daramg.server.notification.dto.NotificationResponseDto;
 import com.daramg.server.notification.repository.NotificationRepository;
+import com.daramg.server.post.application.PostService;
 import com.daramg.server.post.domain.FreePost;
 import com.daramg.server.post.domain.Post;
 import com.daramg.server.post.domain.PostStatus;
 import com.daramg.server.post.domain.vo.PostCreateVo;
-import com.daramg.server.post.application.PostService;
 import com.daramg.server.post.dto.CommentCreateDto;
 import com.daramg.server.post.dto.CommentReplyCreateDto;
 import com.daramg.server.post.repository.PostRepository;
@@ -31,6 +31,7 @@
 import java.util.List;
 
 import static org.assertj.core.api.Assertions.assertThat;
+import static org.assertj.core.api.Assertions.assertThatCode;
 import static org.assertj.core.api.Assertions.assertThatThrownBy;
 
 public class NotificationServiceIntegrationTest extends ServiceTestSupport {
@@ -61,6 +62,7 @@ public class NotificationServiceIntegrationTest extends ServiceTestSupport {
 
     private User postAuthor;
     private User actor;
+    private User seedSender;
     private Post post;
 
     @BeforeEach
@@ -71,6 +73,9 @@ void setUp() {
         actor = new User("actor@test.com", "password", "행위자", LocalDate.now(), "profile", "행위자닉", "bio", null);
         userRepository.save(actor);
 
+        seedSender = new User("seed@test.com", "password", "시드", LocalDate.now(), "profile", "시드닉", "bio", null);
+        userRepository.save(seedSender);
+
         post = FreePost.from(new PostCreateVo.Free(
                 postAuthor, "제목", "내용", PostStatus.PUBLISHED, List.of(), null, List.of()
         ));
@@ -242,6 +247,50 @@ class CommentLikeNotificationTest {
         }
     }
 
+    @Nested
+    @DisplayName("알림 개수 제한")
+    class NotificationLimitTest {
+        @Test
+        void 게시글_댓글_알림이_101개째_생겨도_댓글_생성은_성공하고_최신_100개만_유지한다() {
+            // given
+            createNotificationsUpToLimit();
+
+            // when
+            assertThatCode(() -> commentService.createComment(post.getId(), new CommentCreateDto("새 댓글"), actor))
+                    .doesNotThrowAnyException();
+
+            // then
+            assertThat(notificationRepository.countByReceiverId(postAuthor.getId())).isEqualTo(100);
+            assertThat(notificationRepository.findAll())
+                    .filteredOn(notification -> notification.getReceiver().getId().equals(postAuthor.getId()))
+                    .anyMatch(notification ->
+                            notification.getSender().getId().equals(actor.getId()) &&
+                                    notification.getType() == NotificationType.COMMENT &&
+                                    notification.getPost().getId().equals(post.getId())
+                    );
+        }
+
+        @Test
+        void 게시글_좋아요_알림이_101개째_생겨도_좋아요는_성공하고_최신_100개만_유지한다() {
+            // given
+            createNotificationsUpToLimit();
+
+            // when
+            assertThatCode(() -> postService.toggleLike(post.getId(), actor))
+                    .doesNotThrowAnyException();
+
+            // then
+            assertThat(notificationRepository.countByReceiverId(postAuthor.getId())).isEqualTo(100);
+            assertThat(notificationRepository.findAll())
+                    .filteredOn(notification -> notification.getReceiver().getId().equals(postAuthor.getId()))
+                    .anyMatch(notification ->
+                            notification.getSender().getId().equals(actor.getId()) &&
+                                    notification.getType() == NotificationType.POST_LIKE &&
+                                    notification.getPost().getId().equals(post.getId())
+                    );
+        }
+    }
+
     @Nested
     @DisplayName("알림 조회")
     class QueryNotificationTest {
@@ -340,4 +389,15 @@ class DeleteIntegrationTest {
                     .hasMessage("본인의 알림만 처리할 수 있습니다.");
         }
     }
+
+    private void createNotificationsUpToLimit() {
+        for (int i = 0; i < 100; i++) {
+            notificationRepository.save(Notification.of(
+                    postAuthor,
+                    seedSender,
+                    post,
+                    NotificationType.COMMENT_LIKE
+            ));
+        }
+    }
 }