[Refactor] SLO에 영향을 미치는 쿼리 개선 작업

src/main/java/eatda/domain/cheer/Cheer.java

@@ -49,6 +49,12 @@ public class Cheer extends AuditingEntity {
     @OneToMany(mappedBy = "cheer", cascade = CascadeType.ALL, orphanRemoval = true)
     private Set<CheerImage> images = new HashSet<>();
 
+    /*
+    CheerTags가 Embedded이기 때문에 BatchSize를 그대로 적용하지 못함.
+    성능을 위해서는 Embedded 제거 후 직접 @OneToMany로 매핑 필요함.
+    현재 데이터가 많지 않음으로 현상 유지하며 모니터링.
+    추후 재설계 필요
+     */
     @Embedded
     private CheerTags cheerTags;
 

src/main/java/eatda/domain/store/Store.java

@@ -57,6 +57,12 @@ public class Store extends AuditingEntity {
     @Embedded
     private Coordinates coordinates;
 
+    /*
+    현재는 가게당 평균 응원 수가 5개 이하이므로 BatchSize=10이 적절함.
+    데이터 증가를 고려하여 IN 쿼리 한 번당 최대 30개 Store의 Cheer를 로딩하도록 설정.
+    향후 응원 수가 증가하거나 Store 리스트 조회 규모가 커질 경우
+    성능 모니터링 후 BatchSize 조정 및 Fetch 전략 재검토 필요.
+    */
     @OneToMany(mappedBy = "store")
     private List<Cheer> cheers = new ArrayList<>();
 

src/main/java/eatda/repository/cheer/CheerRepository.java

@@ -8,19 +8,18 @@
 import eatda.domain.store.StoreCategory;
 import jakarta.persistence.criteria.JoinType;
 import java.util.List;
+import org.springframework.data.domain.Page;
 import org.springframework.data.domain.PageRequest;
 import org.springframework.data.domain.Pageable;
 import org.springframework.data.jpa.domain.Specification;
-import org.springframework.data.jpa.repository.EntityGraph;
 import org.springframework.data.jpa.repository.JpaRepository;
 import org.springframework.lang.Nullable;
 
 public interface CheerRepository extends JpaRepository<Cheer, Long> {
 
-    @EntityGraph(attributePaths = {"member", "cheerTags.values"})
-    List<Cheer> findAllByStoreOrderByCreatedAtDesc(Store store, PageRequest pageRequest);
+    Page<Cheer> findAllByStoreOrderByCreatedAtDesc(Store store, PageRequest pageRequest);
 
-    default List<Cheer> findAllByConditions(@Nullable StoreCategory category,
+    default Page<Cheer> findAllByConditions(@Nullable StoreCategory category,
                                             List<CheerTagName> cheerTagNames,
                                             List<District> districts, Pageable pageable) {
         Specification<Cheer> spec = createSpecification(category, cheerTagNames, districts);
@@ -36,7 +35,9 @@ private Specification<Cheer> createSpecification(@Nullable StoreCategory categor
         }
         if (!cheerTagNames.isEmpty()) {
             spec = spec.and(((root, query, cb) -> {
-                query.distinct(true);
+                if (query != null) {
+                    query.distinct(true);
+                }
                 return root.join("cheerTags").join("values", JoinType.LEFT)
                         .get("name").in(cheerTagNames);
             }));
@@ -47,8 +48,7 @@ private Specification<Cheer> createSpecification(@Nullable StoreCategory categor
         return spec;
     }
 
-    @EntityGraph(attributePaths = {"store", "member", "cheerTags.values"})
-    List<Cheer> findAll(Specification<Cheer> specification, Pageable pageable);
+    Page<Cheer> findAll(Specification<Cheer> specification, Pageable pageable);
 
     int countByMember(Member member);
 

src/main/java/eatda/repository/store/StoreRepository.java

@@ -8,9 +8,9 @@
 import eatda.exception.BusinessException;
 import java.util.List;
 import java.util.Optional;
+import org.springframework.data.domain.Page;
 import org.springframework.data.domain.Pageable;
 import org.springframework.data.jpa.domain.Specification;
-import org.springframework.data.jpa.repository.EntityGraph;
 import org.springframework.data.jpa.repository.JpaRepository;
 import org.springframework.data.jpa.repository.Query;
 import org.springframework.lang.Nullable;
@@ -33,16 +33,15 @@ default Store getById(Long id) {
             """)
     List<Store> findAllByCheeredMemberId(long memberId);
 
-    default List<Store> findAllByConditions(@Nullable StoreCategory category,
+    default Page<Store> findAllByConditions(@Nullable StoreCategory category,
                                             List<CheerTagName> cheerTagNames,
                                             List<District> districts,
                                             Pageable pageable) {
         Specification<Store> spec = createSpecification(category, cheerTagNames, districts);
         return findAll(spec, pageable);
     }
 
-    @EntityGraph(attributePaths = {"cheers"})
-    List<Store> findAll(Specification<Store> spec, Pageable pageable);
+    Page<Store> findAll(Specification<Store> spec, Pageable pageable);
 
     private Specification<Store> createSpecification(@Nullable StoreCategory category,
                                                      List<CheerTagName> cheerTagNames,
@@ -52,8 +51,12 @@ private Specification<Store> createSpecification(@Nullable StoreCategory categor
             spec = spec.and((root, query, cb) -> cb.equal(root.get("category"), category));
         }
         if (!cheerTagNames.isEmpty()) {
-            spec = spec.and(((root, query, cb) ->
-                    root.join("cheers").join("cheerTags").join("values").get("name").in(cheerTagNames)));
+            spec = spec.and(((root, query, cb) -> {
+                if (query != null) {
+                    query.distinct(true);
+                }
+                return root.join("cheers").join("cheerTags").join("values").get("name").in(cheerTagNames);
+            }));
         }
         if (!districts.isEmpty()) {
             spec = spec.and((root, query, cb) -> root.get("district").in(districts));

src/main/java/eatda/repository/story/StoryRepository.java

@@ -3,15 +3,12 @@
 import eatda.domain.story.Story;
 import org.springframework.data.domain.Page;
 import org.springframework.data.domain.Pageable;
-import org.springframework.data.jpa.repository.EntityGraph;
 import org.springframework.data.jpa.repository.JpaRepository;
 
 public interface StoryRepository extends JpaRepository<Story, Long> {
-    @EntityGraph(attributePaths = "images")
     Page<Story> findAllByOrderByCreatedAtDesc(Pageable pageable);
 
     Page<Story> findAllByMemberIdOrderByCreatedAtDesc(Long memberId, Pageable pageable);
 
-    @EntityGraph(attributePaths = {"member", "images"})
     Page<Story> findAllByStoreKakaoIdOrderByCreatedAtDesc(String storeKakaoId, Pageable pageable);
 }

src/main/java/eatda/service/cheer/CheerService.java

@@ -25,6 +25,7 @@
 import java.util.stream.IntStream;
 import lombok.RequiredArgsConstructor;
 import org.springframework.beans.factory.annotation.Value;
+import org.springframework.data.domain.Page;
 import org.springframework.data.domain.PageRequest;
 import org.springframework.data.domain.Sort;
 import org.springframework.data.domain.Sort.Direction;
@@ -115,12 +116,15 @@ private void saveCheerImages(Cheer cheer,
 
     @Transactional(readOnly = true)
     public CheersResponse getCheers(CheerSearchParameters parameters) {
-        List<Cheer> cheers = cheerRepository.findAllByConditions(
+        Page<Cheer> cheerPage = cheerRepository.findAllByConditions(
                 parameters.getCategory(),
                 parameters.getCheerTagNames(),
                 parameters.getDistricts(),
-                PageRequest.of(parameters.getPage(), parameters.getSize(), Sort.by(Direction.DESC, "createdAt"))
+                PageRequest.of(parameters.getPage(), parameters.getSize(),
+                        Sort.by(Direction.DESC, "createdAt"))
         );
+
+        List<Cheer> cheers = cheerPage.getContent();
         return toCheersResponse(cheers);
     }
 
@@ -140,11 +144,12 @@ private CheersResponse toCheersResponse(List<Cheer> cheers) {
     @Transactional(readOnly = true)
     public CheersInStoreResponse getCheersByStoreId(Long storeId, int page, int size) {
         Store store = storeRepository.getById(storeId);
-        List<Cheer> cheers = cheerRepository.findAllByStoreOrderByCreatedAtDesc(store, PageRequest.of(page, size));
+        Page<Cheer> cheersPage = cheerRepository.findAllByStoreOrderByCreatedAtDesc(store, PageRequest.of(page, size));
 
-        List<CheerInStoreResponse> cheersResponse = cheers.stream()
+        List<CheerInStoreResponse> cheersResponse = cheersPage.getContent().stream()
                 .map(CheerInStoreResponse::new)
-                .toList(); // TODO N+1 문제 해결
+                .toList();
+
         return new CheersInStoreResponse(cheersResponse);
     }
 }

src/main/java/eatda/service/store/StoreService.java

@@ -19,6 +19,7 @@
 import java.util.Optional;
 import lombok.RequiredArgsConstructor;
 import org.springframework.beans.factory.annotation.Value;
+import org.springframework.data.domain.Page;
 import org.springframework.data.domain.PageRequest;
 import org.springframework.data.domain.Sort;
 import org.springframework.data.domain.Sort.Direction;
@@ -45,7 +46,7 @@ public StoreResponse getStore(long storeId) {
     // TODO : N+1 문제 해결
     @Transactional(readOnly = true)
     public StoresResponse getStores(StoreSearchParameters parameters) {
-        List<Store> stores = storeRepository.findAllByConditions(
+        Page<Store> stores = storeRepository.findAllByConditions(
                 parameters.getCategory(),
                 parameters.getCheerTagNames(),
                 parameters.getDistricts(),

src/main/resources/application-dev.yml

@@ -27,6 +27,9 @@ spring:
   jpa:
     hibernate:
       ddl-auto: validate
+    properties:
+      hibernate:
+        default_batch_fetch_size: 30
 
   flyway:
     enabled: true

src/main/resources/application-local.yml

@@ -22,6 +22,7 @@ spring:
       max-file-size: 5MB
       max-request-size: 20MB
 
+  # BatchSize 미적용시를 비교하기 위해 local에는 BatchSize를 추가하지 않음
   jpa:
     hibernate:
       ddl-auto: validate

src/main/resources/application-prod.yml

@@ -27,6 +27,9 @@ spring:
   jpa:
     hibernate:
       ddl-auto: validate
+    properties:
+      hibernate:
+        default_batch_fetch_size: 30
 
   flyway:
     enabled: true

src/test/java/eatda/repository/cheer/CheerRepositoryTest.java

@@ -13,6 +13,7 @@
 import java.util.List;
 import org.junit.jupiter.api.Nested;
 import org.junit.jupiter.api.Test;
+import org.springframework.data.domain.Page;
 import org.springframework.data.domain.Pageable;
 
 class CheerRepositoryTest extends BaseRepositoryTest {
@@ -64,7 +65,7 @@ class FindAllByConditions {
             Cheer cheer2_2 = cheerGenerator.generateCommon(member2, store2);
             Cheer cheer3_2 = cheerGenerator.generateCommon(member2, store3);
 
-            List<Cheer> actual = cheerRepository.findAllByConditions(
+            Page<Cheer> actual = cheerRepository.findAllByConditions(
                     StoreCategory.KOREAN, List.of(), List.of(), Pageable.unpaged());
 
             assertThat(actual).map(Cheer::getId)
@@ -90,7 +91,7 @@ class FindAllByConditions {
             cheerTagGenerator.generate(cheer2_2, List.of(CheerTagName.CLEAN_RESTROOM));
             cheerTagGenerator.generate(cheer3_1, List.of(CheerTagName.ENERGETIC, CheerTagName.QUIET));
 
-            List<Cheer> actual = cheerRepository.findAllByConditions(null,
+            Page<Cheer> actual = cheerRepository.findAllByConditions(null,
                     List.of(CheerTagName.INSTAGRAMMABLE, CheerTagName.CLEAN_RESTROOM), List.of(), Pageable.unpaged());
 
             assertThat(actual)
@@ -110,7 +111,7 @@ class FindAllByConditions {
             Cheer cheer2_2 = cheerGenerator.generateCommon(member2, store2);
             Cheer cheer3_2 = cheerGenerator.generateCommon(member2, store3);
 
-            List<Cheer> actual = cheerRepository.findAllByConditions(
+            Page<Cheer> actual = cheerRepository.findAllByConditions(
                     null, List.of(), List.of(District.GANGNAM), Pageable.unpaged());
 
             assertThat(actual)
@@ -145,7 +146,7 @@ class FindAllByConditions {
             cheerTagGenerator.generate(cheer4_2, List.of(CheerTagName.INSTAGRAMMABLE));
             cheerTagGenerator.generate(cheer5_2, List.of(CheerTagName.CLEAN_RESTROOM, CheerTagName.ENERGETIC));
 
-            List<Cheer> actual = cheerRepository.findAllByConditions(StoreCategory.KOREAN,
+            Page<Cheer> actual = cheerRepository.findAllByConditions(StoreCategory.KOREAN,
                     List.of(CheerTagName.CLEAN_RESTROOM), List.of(District.GANGNAM), Pageable.unpaged());
 
             assertThat(actual)
@@ -169,7 +170,7 @@ class FindAllByConditions {
             cheerTagGenerator.generate(cheer2_1, List.of(CheerTagName.CLEAN_RESTROOM));
             cheerTagGenerator.generate(cheer2_2, List.of(CheerTagName.CLEAN_RESTROOM));
 
-            List<Cheer> actual = cheerRepository.findAllByConditions(null, List.of(), List.of(), Pageable.unpaged());
+            Page<Cheer> actual = cheerRepository.findAllByConditions(null, List.of(), List.of(), Pageable.unpaged());
 
             assertThat(actual)
                     .map(Cheer::getId)

src/test/java/eatda/repository/store/StoreRepositoryTest.java

@@ -14,6 +14,7 @@
 import java.util.List;
 import org.junit.jupiter.api.Nested;
 import org.junit.jupiter.api.Test;
+import org.springframework.data.domain.Page;
 import org.springframework.data.domain.Pageable;
 
 class StoreRepositoryTest extends BaseRepositoryTest {
@@ -61,7 +62,7 @@ class FindAllByConditions {
             Store store2 = storeGenerator.generate("1236", "서울시 강남구 역삼동 123-45", StoreCategory.WESTERN, startAt);
             Store store3 = storeGenerator.generate("1237", "서울시 강남구 역삼동 123-45", StoreCategory.KOREAN, startAt);
 
-            List<Store> actual = storeRepository.findAllByConditions(
+            Page<Store> actual = storeRepository.findAllByConditions(
                     StoreCategory.KOREAN, List.of(), List.of(), Pageable.unpaged());
 
             assertThat(actual).map(Store::getId)
@@ -87,7 +88,7 @@ class FindAllByConditions {
             cheerTagGenerator.generate(cheer2_2, List.of(CheerTagName.CLEAN_RESTROOM));
             cheerTagGenerator.generate(cheer3_1, List.of(CheerTagName.ENERGETIC, CheerTagName.QUIET));
 
-            List<Store> actual = storeRepository.findAllByConditions(null,
+            Page<Store> actual = storeRepository.findAllByConditions(null,
                     List.of(CheerTagName.INSTAGRAMMABLE, CheerTagName.CLEAN_RESTROOM), List.of(), Pageable.unpaged());
 
             assertThat(actual).map(Store::getId)
@@ -100,7 +101,7 @@ class FindAllByConditions {
             Store store2 = storeGenerator.generate("1236", "서울시 강남구 역삼동 123-45", District.GANGNAM);
             Store store3 = storeGenerator.generate("1237", "서울시 성북구 석관동 123-45", District.SEONGBUK);
 
-            List<Store> actual = storeRepository.findAllByConditions(
+            Page<Store> actual = storeRepository.findAllByConditions(
                     null, List.of(), List.of(District.GANGNAM), Pageable.unpaged());
 
             assertThat(actual).map(Store::getId)
@@ -134,7 +135,7 @@ class FindAllByConditions {
             cheerTagGenerator.generate(cheer4_2, List.of(CheerTagName.INSTAGRAMMABLE));
             cheerTagGenerator.generate(cheer5_2, List.of(CheerTagName.CLEAN_RESTROOM, CheerTagName.ENERGETIC));
 
-            List<Store> actual = storeRepository.findAllByConditions(StoreCategory.KOREAN,
+            Page<Store> actual = storeRepository.findAllByConditions(StoreCategory.KOREAN,
                     List.of(CheerTagName.CLEAN_RESTROOM), List.of(District.GANGNAM), Pageable.unpaged());
 
             assertThat(actual).map(Store::getId)
@@ -157,7 +158,7 @@ class FindAllByConditions {
             cheerTagGenerator.generate(cheer2_1, List.of(CheerTagName.CLEAN_RESTROOM));
             cheerTagGenerator.generate(cheer2_2, List.of(CheerTagName.CLEAN_RESTROOM));
 
-            List<Store> actual = storeRepository.findAllByConditions(null, List.of(), List.of(), Pageable.unpaged());
+            Page<Store> actual = storeRepository.findAllByConditions(null, List.of(), List.of(), Pageable.unpaged());
 
             assertThat(actual).map(Store::getId)
                     .containsExactlyInAnyOrder(store1.getId(), store2.getId(), store3.getId());