refactor: 비동기 + 이벤트 리스닝 방식으로 알림 로직 개선

backend/src/main/java/com/ody/common/config/AsyncConfig.java

@@ -0,0 +1,35 @@
+package com.ody.common.config;
+
+import com.ody.common.exception.AsyncExceptionHandler;
+import java.util.concurrent.Executor;
+import java.util.concurrent.ThreadPoolExecutor;
+import lombok.RequiredArgsConstructor;
+import org.springframework.aop.interceptor.AsyncUncaughtExceptionHandler;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.scheduling.annotation.AsyncConfigurer;
+import org.springframework.scheduling.annotation.EnableAsync;
+import org.springframework.scheduling.concurrent.ThreadPoolTaskExecutor;
+
+@EnableAsync
+@Configuration
+@RequiredArgsConstructor
+public class AsyncConfig implements AsyncConfigurer {
+
+    private final AsyncExceptionHandler asyncExceptionHandler;
+
+    @Override
+    public Executor getAsyncExecutor() {
+        ThreadPoolTaskExecutor executor = new ThreadPoolTaskExecutor();
+        executor.setRejectedExecutionHandler(new ThreadPoolExecutor.CallerRunsPolicy()); //스레드풀이 가득찼을 경우 톰캣 스레드에서 처리
+        int coreCount = Runtime.getRuntime().availableProcessors();
+        executor.setCorePoolSize(coreCount);
+        executor.setThreadNamePrefix("ody-fcm");
+        executor.initialize();
+        return executor;
+    }
+
+    @Override
+    public AsyncUncaughtExceptionHandler getAsyncUncaughtExceptionHandler() {
+        return asyncExceptionHandler;
+    }
+}

backend/src/main/java/com/ody/common/exception/AsyncExceptionHandler.java

@@ -0,0 +1,16 @@
+package com.ody.common.exception;
+
+import java.lang.reflect.Method;
+import lombok.extern.slf4j.Slf4j;
+import org.springframework.aop.interceptor.AsyncUncaughtExceptionHandler;
+import org.springframework.stereotype.Component;
+
+@Slf4j
+@Component
+public class AsyncExceptionHandler implements AsyncUncaughtExceptionHandler {
+
+    @Override
+    public void handleUncaughtException(Throwable exception, Method method, Object... params) {
+        log.error("비동기 메서드 에러 : method: {} exception: {}", method.getName(), exception.getMessage());
+    }
+}

backend/src/main/java/com/ody/mate/service/MateService.java

@@ -14,6 +14,7 @@
 import com.ody.meeting.domain.Meeting;
 import com.ody.meeting.dto.response.MateEtaResponsesV2;
 import com.ody.member.domain.Member;
+import com.ody.notification.domain.Notification;
 import com.ody.notification.service.NotificationService;
 import com.ody.route.domain.RouteTime;
 import com.ody.route.service.RouteService;
@@ -132,14 +133,16 @@ public void deleteAllByMember(Member member) {
 
     @Transactional
     public void withdraw(Mate mate) {
-        notificationService.saveMemberDeletionNotification(mate);
+        Notification memberDeletionNotification = Notification.createMemberDeletion(mate);
+        notificationService.save(memberDeletionNotification);
         delete(mate);
     }
 
     @Transactional
     public void leaveByMeetingIdAndMemberId(Long meetingId, Long memberId) {
         Mate mate = findByMeetingIdAndMemberId(meetingId, memberId);
-        notificationService.saveMateLeaveNotification(mate);
+        Notification leaveNotification = Notification.createMateLeave(mate);
+        notificationService.save(leaveNotification);
         delete(mate);
     }
 

backend/src/main/java/com/ody/meeting/service/MeetingService.java

@@ -17,18 +17,14 @@
 import com.ody.member.domain.Member;
 import com.ody.notification.domain.NotificationType;
 import com.ody.notification.domain.message.GroupMessage;
-import com.ody.notification.service.FcmPushSender;
 import com.ody.notification.service.NotificationService;
-import com.ody.util.InstantConverter;
 import com.ody.util.InviteCodeGenerator;
-import java.time.Instant;
 import java.time.LocalDateTime;
 import java.util.Comparator;
 import java.util.List;
 import java.util.stream.Collectors;
 import lombok.RequiredArgsConstructor;
 import lombok.extern.slf4j.Slf4j;
-import org.springframework.scheduling.TaskScheduler;
 import org.springframework.scheduling.annotation.Scheduled;
 import org.springframework.stereotype.Service;
 import org.springframework.transaction.annotation.Transactional;
@@ -45,8 +41,6 @@ public class MeetingService {
     private final MeetingRepository meetingRepository;
     private final MateRepository mateRepository;
     private final NotificationService notificationService;
-    private final FcmPushSender fcmPushSender;
-    private final TaskScheduler taskScheduler;
 
     @Transactional
     public MeetingSaveResponseV1 saveV1(MeetingSaveRequestV1 meetingSaveRequestV1) {
@@ -59,9 +53,8 @@ public MeetingSaveResponseV1 saveV1(MeetingSaveRequestV1 meetingSaveRequestV1) {
     private void scheduleEtaNotice(Meeting meeting) {
         GroupMessage noticeMessage = GroupMessage.createMeetingNotice(meeting, NotificationType.ETA_NOTICE);
         LocalDateTime etaNoticeTime = meeting.getMeetingTime().minusMinutes(ETA_NOTICE_TIME_DEFER);
-        Instant startTime = InstantConverter.kstToInstant(etaNoticeTime);
-        taskScheduler.schedule(() -> fcmPushSender.sendNoticeMessage(noticeMessage), startTime);
-        log.info("{} 타입 알림 {}에 스케줄링 예약", NotificationType.ETA_NOTICE, InstantConverter.instantToKst(startTime));
+        notificationService.scheduleNotice(noticeMessage, etaNoticeTime);
+        log.info("{} 타입 알림 {}에 스케줄링 예약", NotificationType.ETA_NOTICE, etaNoticeTime);
     }
 
     private String generateUniqueInviteCode() {

backend/src/main/java/com/ody/notification/service/FcmEventListener.java

@@ -0,0 +1,72 @@
+package com.ody.notification.service;
+
+import com.ody.mate.domain.Mate;
+import com.ody.member.domain.DeviceToken;
+import com.ody.notification.domain.FcmTopic;
+import com.ody.notification.domain.Notification;
+import com.ody.notification.domain.message.DirectMessage;
+import com.ody.notification.domain.message.GroupMessage;
+import com.ody.notification.service.event.NoticeEvent;
+import com.ody.notification.service.event.NudgeEvent;
+import com.ody.notification.service.event.PushEvent;
+import com.ody.notification.service.event.SubscribeEvent;
+import com.ody.notification.service.event.UnSubscribeEvent;
+import lombok.RequiredArgsConstructor;
+import lombok.extern.slf4j.Slf4j;
+import org.springframework.context.event.EventListener;
+import org.springframework.scheduling.annotation.Async;
+import org.springframework.stereotype.Component;
+import org.springframework.transaction.annotation.Propagation;
+import org.springframework.transaction.annotation.Transactional;
+import org.springframework.transaction.event.TransactionPhase;
+import org.springframework.transaction.event.TransactionalEventListener;
+
+@Slf4j
+@Component
+@RequiredArgsConstructor
+public class FcmEventListener {
+
+    private final FcmPushSender fcmPushSender;
+    private final FcmSubscriber fcmSubscriber;
+
+    @Async
+    @EventListener
+    public void subscribeTopic(SubscribeEvent subscribeEvent) {
+        FcmTopic topic = subscribeEvent.getTopic();
+        DeviceToken deviceToken = subscribeEvent.getDeviceToken();
+        fcmSubscriber.subscribeTopic(topic, deviceToken);
+    }
+
+    @Async
+    @EventListener
+    public void unSubscribeTopic(UnSubscribeEvent subscribeEvent) {
+        FcmTopic topic = subscribeEvent.getTopic();
+        DeviceToken deviceToken = subscribeEvent.getDeviceToken();
+        fcmSubscriber.subscribeTopic(topic, deviceToken);
+    }
+
+    @Async
+    @EventListener
+    public void sendNoticeMessage(NoticeEvent noticeEvent) {
+        GroupMessage groupMessage = noticeEvent.getGroupMessage();
+        fcmPushSender.sendNoticeMessage(groupMessage);
+    }
+
+    @Async
+    @Transactional(propagation = Propagation.REQUIRES_NEW) // 추가 커밋 허용을 위해 트랜잭션을 염
+    @TransactionalEventListener(phase = TransactionPhase.AFTER_COMMIT)// 커밋 이후 발송
+    public void sendPushMessage(PushEvent pushEvent) {
+        Notification notification = pushEvent.getNotification();
+        GroupMessage groupMessage = GroupMessage.from(notification);
+        fcmPushSender.sendGeneralMessage(groupMessage.message(), notification);
+    }
+
+    @Async
+    @EventListener
+    public void sendNudgeMessage(NudgeEvent nudgeEvent) {
+        Notification nudgeNotification = nudgeEvent.getNudgeNotification();
+        Mate requestMate = nudgeEvent.getRequestMate();
+        DirectMessage nudgeMessage = DirectMessage.createMessageToOther(requestMate, nudgeNotification);
+        fcmPushSender.sendGeneralMessage(nudgeMessage.message(), nudgeNotification);
+    }
+}

backend/src/main/java/com/ody/notification/service/FcmEventPublisher.java

@@ -0,0 +1,25 @@
+package com.ody.notification.service;
+
+import lombok.RequiredArgsConstructor;
+import lombok.extern.slf4j.Slf4j;
+import org.springframework.context.ApplicationEvent;
+import org.springframework.context.ApplicationEventPublisher;
+import org.springframework.stereotype.Component;
+import org.springframework.transaction.annotation.Transactional;
+
+@Slf4j
+@Component
+@RequiredArgsConstructor
+public class FcmEventPublisher {
+
+    private final ApplicationEventPublisher eventPublisher;
+
+    public void publish(ApplicationEvent applicationEvent) {
+        eventPublisher.publishEvent(applicationEvent);
+    }
+
+    @Transactional
+    public void publishWithTransaction(ApplicationEvent applicationEvent) {
+        eventPublisher.publishEvent(applicationEvent);
+    }
+}

backend/src/main/java/com/ody/notification/service/FcmPushSender.java

@@ -5,7 +5,6 @@
 import com.google.firebase.messaging.Message;
 import com.ody.common.exception.OdyServerErrorException;
 import com.ody.notification.domain.Notification;
-import com.ody.notification.domain.message.DirectMessage;
 import com.ody.notification.domain.message.GroupMessage;
 import com.ody.notification.repository.NotificationRepository;
 import com.ody.util.TimeUtil;
@@ -20,36 +19,31 @@
 @RequiredArgsConstructor
 public class FcmPushSender {
 
-    private final NotificationRepository notificationRepository;
     private final FirebaseMessaging firebaseMessaging;
+    private final NotificationRepository notificationRepository;
 
     @Transactional
-    public void sendPushNotification(Notification notification) {
-        Notification savedNotification = notificationRepository.findById(notification.getId())
-                .orElse(notification); // noti 생성과 동시에 실행되는 경우, 다른 트랜잭션이므로 즉시 findById 할 수 없어 기존 noti 사용
-
-        if (savedNotification.isStatusDismissed()) {
-            log.info("DISMISSED 상태 푸시 알림 전송 스킵 : {}", savedNotification);
-            return;
-        }
-        GroupMessage groupMessage = GroupMessage.from(savedNotification);
-        sendGeneralMessage(groupMessage.message(), savedNotification);
-    }
-
-    public void sendNudgeMessage(Notification notification, DirectMessage directMessage) {
-        sendGeneralMessage(directMessage.message(), notification);
-    }
-
-    private void sendGeneralMessage(Message message, Notification notification) {
+    public void sendGeneralMessage(Message message, Notification notification) {
         try {
+            Notification savedNotification = findNotification(notification);
+            if (savedNotification.isStatusDismissed()) {
+                log.info("DISMISSED 상태 푸시 알림 전송 스킵 : {}", notification);
+                return;
+            }
+
             firebaseMessaging.send(message);
-            updateDepartureReminderToDone(notification);
+            updateDepartureReminderToDone(savedNotification);
         } catch (FirebaseMessagingException exception) {
             log.error("FCM 알림(ID : {}) 전송 실패 : {}", notification.getId(), exception.getMessage());
             throw new OdyServerErrorException(exception.getMessage());
         }
     }
 
+    private Notification findNotification(Notification notification) {
+        return notificationRepository.findById(notification.getId())
+                .orElseThrow(() -> new OdyServerErrorException("저장된 알림을 찾을 수 없습니다.")); // 트랜잭션 완료 후 실행
+    }
+
     private void updateDepartureReminderToDone(Notification notification) {
         if (notification.isDepartureReminder()) {
             notification.updateStatusToDone();