✨ feat: 이벤트 all-time 조회 성능 개선을 위한 Redis 캐시 도입

- EventScheduleCacheService를 추가하여 AllTimeScheduleResponse 캐싱
- 10분 TTL 설정
- 캐시 무효화 로직 추가 (createOrUpdateMyTime, completeMyTime, joinEvent)
- 자주 조회되는 이벤트 시간대 데이터의 DB 부하 감소
- 캐시 실패 시 DB 조회로 자동 fallback 처리

✨ feat: 이벤트 all-time 조회 성능 개선을 위한 Redis 캐시 도입

- EventScheduleCacheService를 추가하여 AllTimeScheduleResponse 캐싱
- 10분 TTL 설정
- 캐시 무효화 로직 추가 (createOrUpdateMyTime, completeMyTime, joinEvent)
- 자주 조회되는 이벤트 시간대 데이터의 DB 부하 감소
- 캐시 실패 시 DB 조회로 자동 fallback 처리

Author: leeseojun34

src/main/java/com/grepp/spring/app/model/event/service/EventCommandService.java

@@ -46,6 +46,7 @@ public class EventCommandService {
     private final TempScheduleRepository tempScheduleRepository;
     private final EventScheduleResultService eventScheduleResultService;
     private final EventCreationStrategyFactory strategyFactory;
+    private final EventScheduleCacheService cacheService;
 
     public CreateEventResponse createEvent(CreateEventRequest webRequest, String currentMemberId) {
         CreateEventDto serviceRequest = CreateEventDto.toDto(webRequest, currentMemberId);
@@ -77,6 +78,8 @@ public void joinEvent(Long eventId, Long groupId, String currentMemberId) {
 
         EventMemberDto memberDto = EventMemberDto.toDto(dto.getEventId(), dto.getMemberId(), Role.ROLE_MEMBER);
         createEventMember(memberDto);
+
+        cacheService.invalidateEventCache(eventId);
     }
 
     public void createOrUpdateMyTime(MyTimeScheduleRequest request, Long eventId, String currentMemberId) {
@@ -90,6 +93,8 @@ public void createOrUpdateMyTime(MyTimeScheduleRequest request, Long eventId, St
         for (MyTimeScheduleDto.DailyTimeSlotDto slot : dto.getDailyTimeSlots()) {
             updateOrCreateTempSchedule(eventMember, slot);
         }
+
+        cacheService.invalidateEventCache(eventId);
     }
 
     private void updateOrCreateTempSchedule(EventMember eventMember, MyTimeScheduleDto.DailyTimeSlotDto slot) {
@@ -126,6 +131,8 @@ public void completeMyTime(Long eventId, String currentMemberId) {
 
         eventMember.confirmScheduleOrThrow();
         eventMemberRepository.save(eventMember);
+
+        cacheService.invalidateEventCache(eventId);
     }
 
     public void createScheduleResult(Long eventId, String currentMemberId) {

src/main/java/com/grepp/spring/app/model/event/service/EventQueryService.java

@@ -45,6 +45,7 @@ public class EventQueryService {
     private final TempScheduleRepository tempScheduleRepository;
     private final ScheduleQueryRepository scheduleQueryRepository;
     private final ScheduleMemberQueryRepository scheduleMemberQueryRepository;
+    private final EventScheduleCacheService cacheService;
 
     public ShowEventResponse getEvent(Long eventId, String currentMemberId) {
         Event event = eventRepository.findById(eventId)
@@ -75,6 +76,14 @@ public AllTimeScheduleResponse getAllTimeSchedules(Long eventId, String currentM
             throw new NotEventMemberException(EventErrorCode.NOT_EVENT_MEMBER);
         }
 
+        // 캐시에서 조회 시도
+        AllTimeScheduleResponse cachedResponse = cacheService.getCachedAllTimeSchedule(eventId);
+
+        if (cachedResponse != null) {
+            return cachedResponse;
+        }
+
+        // 캐시 미스 시 데이터베이스에서 조회
         List<CandidateDate> candidateDates = candidateDateRepository
             .findAllByEventIdAndActivatedTrueOrderByDate(eventId);
 
@@ -107,7 +116,11 @@ public AllTimeScheduleResponse getAllTimeSchedules(Long eventId, String currentM
             .participantCounts(participantCounts)
             .build();
 
-        return AllTimeScheduleDto.fromDto(dto);
+        AllTimeScheduleResponse response = AllTimeScheduleDto.fromDto(dto);
+
+        cacheService.cacheAllTimeSchedule(eventId, response);
+
+        return response;
     }
 
 

src/main/java/com/grepp/spring/app/model/event/service/EventScheduleCacheService.java

@@ -0,0 +1,69 @@
+package com.grepp.spring.app.model.event.service;
+
+import com.fasterxml.jackson.databind.ObjectMapper;
+import com.grepp.spring.app.controller.api.event.payload.response.AllTimeScheduleResponse;
+import lombok.RequiredArgsConstructor;
+import lombok.extern.slf4j.Slf4j;
+import org.springframework.data.redis.core.RedisTemplate;
+import org.springframework.stereotype.Service;
+
+import java.time.Duration;
+
+@Service
+@RequiredArgsConstructor
+@Slf4j
+public class EventScheduleCacheService {
+
+    private final RedisTemplate<String, Object> redisTemplate;
+    private final ObjectMapper objectMapper;
+
+    private static final String CACHE_KEY_PREFIX = "event:all-time:";
+
+    private static final Duration DEFAULT_TTL = Duration.ofMinutes(10);
+
+    // 캐시에서 전체 시간대 조회 결과를 가져옴. 캐시 조회 실패 시 null 반환
+    public AllTimeScheduleResponse getCachedAllTimeSchedule(Long eventId) {
+        try {
+            String key = buildCacheKey(eventId);
+            Object cached = redisTemplate.opsForValue().get(key);
+
+            if (cached == null) {
+                return null;
+            }
+
+            AllTimeScheduleResponse response = objectMapper.convertValue(cached, AllTimeScheduleResponse.class);
+
+            if (response != null) {
+                log.debug("Cache hit for eventId: {}", eventId);
+                return response;
+            }
+
+            return null;
+
+        } catch (Exception e) {
+            log.warn("Cache get failed for eventId: {}, falling back to DB: {}", eventId, e.getMessage());
+            return null;
+        }
+    }
+
+    // 전체 시간대 조회 결과를 캐시에 저장
+    public void cacheAllTimeSchedule(Long eventId, AllTimeScheduleResponse response) {
+        String key = buildCacheKey(eventId);
+        redisTemplate.opsForValue().set(key, response, DEFAULT_TTL);
+
+        log.debug("Cached data for eventId: {}", eventId);
+    }
+
+    // 특정 이벤트의 캐시를 무효화
+    public void invalidateEventCache(Long eventId) {
+        String key = buildCacheKey(eventId);
+        Boolean deleted = redisTemplate.delete(key);
+
+        log.debug("Cache invalidated for eventId: {}, deleted: {}", eventId, deleted);
+    }
+
+    // 캐시 키 생성
+    private String buildCacheKey(Long eventId) {
+        return CACHE_KEY_PREFIX + eventId;
+    }
+}