[Volume 5] 인덱스 설계,Redis 캐시 조회 최적화 - 임나현

apps/commerce-api/build.gradle.kts

@@ -9,6 +9,9 @@ dependencies {
     // web
     implementation("org.springframework.boot:spring-boot-starter-web")
 
+    // local cache
+    implementation("com.github.ben-manes.caffeine:caffeine")
+
     // security (BCrypt)
     implementation("org.springframework.security:spring-security-crypto")
     implementation("org.springframework.boot:spring-boot-starter-actuator")

apps/commerce-api/src/main/java/com/loopers/application/brand/BrandAdminFacade.java

@@ -1,5 +1,6 @@
 package com.loopers.application.brand;
 
+import com.loopers.application.cache.ProductCacheManager;
 import com.loopers.application.product.ProductInfo;
 import com.loopers.domain.brand.Brand;
 import com.loopers.domain.brand.BrandService;
@@ -26,13 +27,16 @@ public class BrandAdminFacade {
     private final ProductService productService;
     private final InventoryService inventoryService;
     private final CartItemService cartItemService;
+    private final ProductCacheManager productCacheManager;
 
     public BrandAdminFacade(BrandService brandService, ProductService productService,
-                            InventoryService inventoryService, CartItemService cartItemService) {
+                            InventoryService inventoryService, CartItemService cartItemService,
+                            ProductCacheManager productCacheManager) {
         this.brandService = brandService;
         this.productService = productService;
         this.inventoryService = inventoryService;
         this.cartItemService = cartItemService;
+        this.productCacheManager = productCacheManager;
     }
 
     /** 어드민 브랜드 상세 조회 (브랜드 + 전체 상품 목록, status 포함) */
@@ -54,11 +58,15 @@ public void deleteBrand(Long brandId) {
         brandService.delete(brandId);
 
         List<Product> products = productService.getAllProductsByBrandId(brandId);
+        List<Long> productIds = products.stream().map(Product::getId).toList();
+
         for (Product product : products) {
             productService.delete(product.getId());
             inventoryService.delete(product.getId());
             cartItemService.deleteByProductId(product.getId());
         }
+
+        productCacheManager.registerBrandDeleteEvictAfterCommit(productIds);
     }
 
     /** 전체 브랜드 목록 페이지네이션 조회 */
@@ -89,10 +97,13 @@ public BrandInfo updateBrand(Long brandId, String name, String description) {
         return BrandInfo.from(brand);
     }
 
-    /** 브랜드 상태 변경 */
+    /** 브랜드 상태 변경 — 상품 목록 캐시 무효화 (브랜드 필터 변경) */
     @Transactional
     public BrandInfo changeBrandStatus(Long brandId, BrandStatus status) {
         Brand brand = brandService.changeStatus(brandId, status);
+
+        productCacheManager.registerListOnlyEvictAfterCommit();
+
         return BrandInfo.from(brand);
     }
 

apps/commerce-api/src/main/java/com/loopers/application/cache/OrderCacheManager.java

@@ -0,0 +1,98 @@
+package com.loopers.application.cache;
+
+import com.fasterxml.jackson.core.JsonProcessingException;
+import com.fasterxml.jackson.databind.ObjectMapper;
+import com.loopers.application.order.OrderFacade;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.springframework.data.redis.core.RedisTemplate;
+import org.springframework.stereotype.Component;
+import org.springframework.transaction.support.TransactionSynchronization;
+import org.springframework.transaction.support.TransactionSynchronizationManager;
+
+import java.time.Duration;
+import java.util.Optional;
+import java.util.concurrent.ThreadLocalRandom;
+
+/**
+ * 주문 목록 캐시 매니저
+ *
+ * Cache-Aside 패턴의 캐시 읽기/저장/무효화를 담당한다.
+ * 무효화 전략: afterCommit DELETE + TTL 안전망 (Double Delete 안 함)
+ *
+ * 키 설계:
+ *   주문 목록: orders:list:{userId}
+ *   - 첫 페이지(cursor=null) + 기본 조회(최근 3개월)만 캐싱
+ *   - 커스텀 기간 조회는 캐시 우회
+ */
+@Component
+public class OrderCacheManager {
+
+    private static final Logger log = LoggerFactory.getLogger(OrderCacheManager.class);
+
+    private static final String LIST_KEY_PREFIX = "orders:list:";
+    private static final int LIST_TTL_BASE = 120;
+    private static final int LIST_TTL_JITTER = 15;
+
+    private final RedisTemplate<String, String> redisTemplate;
+    private final ObjectMapper objectMapper;
+
+    public OrderCacheManager(RedisTemplate<String, String> redisTemplate,
+                             ObjectMapper objectMapper) {
+        this.redisTemplate = redisTemplate;
+        this.objectMapper = objectMapper;
+    }
+
+    // ── 주문 목록 캐시 ──
+
+    public Optional<OrderFacade.OrderCursorResult> getOrderList(Long userId) {
+        String key = LIST_KEY_PREFIX + userId;
+        String json = redisTemplate.opsForValue().get(key);
+        if (json == null) {
+            return Optional.empty();
+        }
+        try {
+            return Optional.of(objectMapper.readValue(json, OrderFacade.OrderCursorResult.class));
+        } catch (JsonProcessingException e) {
+            log.warn("주문 목록 캐시 역직렬화 실패 (userId={}), 캐시 삭제 후 DB 조회", userId, e);
+            redisTemplate.delete(key);
+            return Optional.empty();
+        }
+    }
+
+    public void putOrderList(Long userId, OrderFacade.OrderCursorResult result) {
+        String key = LIST_KEY_PREFIX + userId;
+        try {
+            String json = objectMapper.writeValueAsString(result);
+            redisTemplate.opsForValue().set(key, json, ttlWithJitter());
+        } catch (JsonProcessingException e) {
+            log.warn("주문 목록 캐시 직렬화 실패 (userId={})", userId, e);
+        }
+    }
+
+    /**
+     * @Transactional 메서드에서 호출 — afterCommit에서 캐시 삭제.
+     */
+    public void registerEvictAfterCommit(Long userId) {
+        TransactionSynchronizationManager.registerSynchronization(
+                new TransactionSynchronization() {
+                    @Override
+                    public void afterCommit() {
+                        evictOrderList(userId);
+                    }
+                }
+        );
+    }
+
+    /**
+     * txTemplate 등 프로그래밍 방식 트랜잭션에서 커밋 후 직접 호출.
+     */
+    public void evictOrderList(Long userId) {
+        redisTemplate.delete(LIST_KEY_PREFIX + userId);
+    }
+
+    private Duration ttlWithJitter() {
+        int jitter = ThreadLocalRandom.current().nextInt(-LIST_TTL_JITTER, LIST_TTL_JITTER + 1);
+        return Duration.ofSeconds(LIST_TTL_BASE + jitter);
+    }
+}