goorm-dev · jihyungkim0011 · Aug 10, 2026 · Aug 10, 2026 · Aug 10, 2026 · Aug 10, 2026
diff --git a/.github/pull_request_template.md b/.github/pull_request_template.md
@@ -0,0 +1,53 @@
+# 성능 개선
+
+## 🚀 개선 내용
+
+- 개선 대상:
+- 변경 내용:
+
+## 🔍 문제 및 원인
+
+- 확인된 문제:
+- 원인:
+
+## 📊 개선 결과
+
+| 지표       | 개선 전 | 개선 후 |
+| ---------- | ------: | ------: |
+| TPS / RPS  |         |         |
+| Avg        |         |         |
+| P95        |         |         |
+| P99        |         |         |
+| Error Rate |         |         |
+
+## ✅ 추가 확인
+
+- 추가 테스트 또는 확인이 필요한 부분:
+
+---
+
+# 테스트
+
+## 🧪 테스트 내용
+
+- 테스트 대상:
+- 테스트 목적:
+
+## ⚙️ 테스트 조건
+
+- VU:
+- 테스트 시간:
+- 요청 수 / 요청 빈도:
+
+## 📊 테스트 결과
+
+- TPS / RPS:
+- Avg:
+- P95:
+- P99:
+- Error Rate:
+
+## 🔍 확인된 문제
+
+- 특이사항 또는 확인된 병목:
+- 추가 확인이 필요한 부분:
diff --git a/.gitignore b/.gitignore
@@ -0,0 +1,12 @@
+node_modules/
+**/node_modules/
+
+**/.next/
+
+# 환경 변수
+.env
+.env.*
+!.env.example
+
+# Java / Maven build
+**/target/
diff --git a/apps/backend/.mvn/wrapper/maven-wrapper.jar b/apps/backend/.mvn/wrapper/maven-wrapper.jar
diff --git a/apps/backend/src/main/java/com/ktb/chatapp/repository/MessageRepository.java b/apps/backend/src/main/java/com/ktb/chatapp/repository/MessageRepository.java
@@ -2,9 +2,12 @@
 
 import com.ktb.chatapp.model.Message;
 import java.time.LocalDateTime;
+import java.util.List;
 import java.util.Optional;
+import java.util.Set;
 import org.springframework.data.domain.Page;
 import org.springframework.data.domain.Pageable;
+import org.springframework.data.mongodb.repository.Aggregation;
 import org.springframework.data.mongodb.repository.MongoRepository;
 import org.springframework.data.mongodb.repository.Query;
 import org.springframework.stereotype.Repository;
@@ -19,6 +22,15 @@ public interface MessageRepository extends MongoRepository<Message, String> {
     @Query(value = "{ 'room': ?0, 'timestamp': { $gte: ?1 } }", count = true)
     long countRecentMessagesByRoomId(String roomId, LocalDateTime since);
 
+    @Aggregation(pipeline = {
+        "{ '$match': { 'room': { '$in': ?0 }, 'timestamp': { '$gte': ?1 } } }",
+        "{ '$group': { '_id': '$room', 'count': { '$sum': 1 } } }",
+        "{ '$project': { '_id': 0, 'roomKey': '$_id', 'count': 1 } }"
+    })
+    List<RecentMessageCount> countRecentMessagesByRoomIds(
+        Set<String> roomIds,
+        LocalDateTime since);
+
     /**
      * fileId로 메시지 조회 (파일 권한 검증용)
      */

diff --git a/apps/backend/src/main/java/com/ktb/chatapp/repository/RecentMessageCount.java b/apps/backend/src/main/java/com/ktb/chatapp/repository/RecentMessageCount.java
@@ -0,0 +1,4 @@
+package com.ktb.chatapp.repository;
+
+public record RecentMessageCount(String roomKey, long count) {
+}
diff --git a/apps/backend/src/main/java/com/ktb/chatapp/service/RecentMessageCounter.java b/apps/backend/src/main/java/com/ktb/chatapp/service/RecentMessageCounter.java
@@ -1,8 +1,12 @@
 package com.ktb.chatapp.service;
 
 import com.ktb.chatapp.repository.MessageRepository;
+import com.ktb.chatapp.repository.RecentMessageCount;
 import java.time.Duration;
 import java.time.LocalDateTime;
+import java.util.Map;
+import java.util.Set;
+import java.util.stream.Collectors;
 import lombok.RequiredArgsConstructor;
 import org.springframework.stereotype.Component;
 
@@ -21,4 +25,16 @@ public int countRecentMessages(String roomId) {
         LocalDateTime since = LocalDateTime.now().minus(RECENT_WINDOW);
         return (int) messageRepository.countRecentMessagesByRoomId(roomId, since);
     }
+
+    public Map<String, Integer> countRecentMessagesByRoomIds(Set<String> roomIds) {
+        if (roomIds.isEmpty()) {
+            return Map.of();
+        }
+
+        LocalDateTime since = LocalDateTime.now().minus(RECENT_WINDOW);
+        return messageRepository.countRecentMessagesByRoomIds(roomIds, since).stream()
+            .collect(Collectors.toMap(
+                RecentMessageCount::roomKey,
+                count -> Math.toIntExact(count.count())));
+    }
 }
diff --git a/apps/backend/src/main/java/com/ktb/chatapp/service/RoomService.java b/apps/backend/src/main/java/com/ktb/chatapp/service/RoomService.java
@@ -10,9 +10,11 @@
 import java.time.LocalDateTime;
 import java.util.Comparator;
 import java.util.HashMap;
+import java.util.HashSet;
 import java.util.List;
 import java.util.Map;
 import java.util.Optional;
+import java.util.Set;
 import java.util.stream.Collectors;
 import lombok.RequiredArgsConstructor;
 import lombok.extern.slf4j.Slf4j;
@@ -35,27 +37,39 @@ public RoomsResponse getAllRooms(String name) {
 
         try {
             // 전체 방을 조회해 최신순으로 정렬한다
-            List<RoomResponse> roomResponses = roomRepository.findAll().stream()
-                .map(room -> mapToRoomResponse(room, name))
+            List<Room> rooms = roomRepository.findAll();
+            if (rooms.isEmpty()) {
+                return successfulRoomsResponse(List.of());
+            }
+
+            Set<String> userIds = new HashSet<>();
+            Set<String> roomIds = new HashSet<>();
+            for (Room room : rooms) {
+                if (room.getId() != null) {
+                    roomIds.add(room.getId());
+                }
+                if (room.getCreator() != null) {
+                    userIds.add(room.getCreator());
+                }
+                if (room.getParticipantIds() != null) {
+                    userIds.addAll(room.getParticipantIds());
+                }
+            }
+
+            Map<String, User> usersById = new HashMap<>();
+            userRepository.findAllById(userIds)
+                .forEach(user -> usersById.put(user.getId(), user));
+            Map<String, Integer> recentMessageCounts =
+                recentMessageCounter.countRecentMessagesByRoomIds(roomIds);
+
+            List<RoomResponse> roomResponses = rooms.stream()
+                .map(room -> mapToRoomResponse(room, name, usersById, recentMessageCounts))
                 .sorted(Comparator.comparing(
                     RoomResponse::getCreatedAtDateTime,
                     Comparator.nullsLast(Comparator.reverseOrder())))
                 .collect(Collectors.toList());
 
-            PageMetadata metadata = PageMetadata.builder()
-                .total(roomResponses.size())
-                .page(0)
-                .pageSize(roomResponses.size())
-                .totalPages(1)
-                .hasMore(false)
-                .currentCount(roomResponses.size())
-                .build();
-
-            return RoomsResponse.builder()
-                .success(true)
-                .data(roomResponses)
-                .metadata(metadata)
-                .build();
+            return successfulRoomsResponse(roomResponses);
 
         } catch (Exception e) {
             log.error("방 목록 조회 에러", e);
@@ -194,6 +208,33 @@ private RoomResponse mapToRoomResponse(Room room, String name) {
 
         int recentMessageCount = recentMessageCounter.countRecentMessages(room.getId());
 
+        return buildRoomResponse(room, name, creator, participants, recentMessageCount);
+    }
+
+    private RoomResponse mapToRoomResponse(
+            Room room,
+            String name,
+            Map<String, User> usersById,
+            Map<String, Integer> recentMessageCounts) {
+        User creator = usersById.get(room.getCreator());
+        List<User> participants = room.getParticipantIds() == null
+            ? List.of()
+            : room.getParticipantIds().stream()
+                .map(usersById::get)
+                .filter(java.util.Objects::nonNull)
+                .toList();
+        int recentMessageCount = recentMessageCounts.getOrDefault(room.getId(), 0);
+
+        return buildRoomResponse(room, name, creator, participants, recentMessageCount);
+    }
+
+    private RoomResponse buildRoomResponse(
+            Room room,
+            String name,
+            User creator,
+            List<User> participants,
+            int recentMessageCount) {
+
         return RoomResponse.builder()
             .id(room.getId())
             .name(room.getName() != null ? room.getName() : "제목 없음")
@@ -216,4 +257,21 @@ private RoomResponse mapToRoomResponse(Room room, String name) {
             .recentMessageCount(recentMessageCount)
             .build();
     }
+
+    private RoomsResponse successfulRoomsResponse(List<RoomResponse> roomResponses) {
+        PageMetadata metadata = PageMetadata.builder()
+            .total(roomResponses.size())
+            .page(0)
+            .pageSize(roomResponses.size())
+            .totalPages(1)
+            .hasMore(false)
+            .currentCount(roomResponses.size())
+            .build();
+
+        return RoomsResponse.builder()
+            .success(true)
+            .data(roomResponses)
+            .metadata(metadata)
+            .build();
+    }
 }
diff --git a/apps/backend/src/test/java/com/ktb/chatapp/repository/MessageRepositoryIntegrationTest.java b/apps/backend/src/test/java/com/ktb/chatapp/repository/MessageRepositoryIntegrationTest.java
@@ -0,0 +1,65 @@
+package com.ktb.chatapp.repository;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+import com.ktb.chatapp.config.MongoTestContainer;
+import com.ktb.chatapp.config.RedisTestContainer;
+import com.ktb.chatapp.model.Message;
+import java.time.LocalDateTime;
+import java.util.List;
+import java.util.Set;
+import org.junit.jupiter.api.AfterEach;
+import org.junit.jupiter.api.DisplayName;
+import org.junit.jupiter.api.Test;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.test.context.SpringBootTest;
+import org.springframework.context.annotation.Import;
+import org.springframework.test.context.TestPropertySource;
+
+@SpringBootTest
+@Import({MongoTestContainer.class, RedisTestContainer.class})
+@TestPropertySource(properties = {
+    "spring.data.mongodb.auto-index-creation=true",
+    "socketio.enabled=false"
+})
+@DisplayName("MessageRepository 통합 테스트")
+class MessageRepositoryIntegrationTest {
+
+    @Autowired private MessageRepository messageRepository;
+
+    @AfterEach
+    void tearDown() {
+        messageRepository.deleteAll();
+    }
+
+    @Test
+    @DisplayName("여러 채팅방의 최근 메시지 수를 한 번의 집계로 반환한다")
+    void countRecentMessagesByRoomIds_GroupsRecentMessagesByRequestedRoom() {
+        LocalDateTime now = LocalDateTime.now();
+        saveMessage("room-1", now.minusMinutes(10));
+        saveMessage("room-1", now.minusMinutes(20));
+        saveMessage("room-1", now.minusMinutes(40));
+        saveMessage("room-2", now.minusMinutes(5));
+        saveMessage("room-3", now.minusMinutes(5));
+
+        List<RecentMessageCount> result =
+            messageRepository.countRecentMessagesByRoomIds(
+                Set.of("room-1", "room-2"),
+                now.minusMinutes(30));
+
+        assertThat(result)
+            .extracting(RecentMessageCount::roomKey, RecentMessageCount::count)
+            .containsExactlyInAnyOrder(
+                org.assertj.core.groups.Tuple.tuple("room-1", 2L),
+                org.assertj.core.groups.Tuple.tuple("room-2", 1L));
+    }
+
+    private void saveMessage(String roomId, LocalDateTime timestamp) {
+        Message saved = messageRepository.save(Message.builder()
+            .roomId(roomId)
+            .content("메시지")
+            .build());
+        saved.setTimestamp(timestamp);
+        messageRepository.save(saved);
+    }
+}