[10주차] Batch 활용 주간 월간 랭킹 시스템 - 최호석

apps/commerce-api/src/main/java/com/loopers/application/ranking/RankingKeyResolver.java

@@ -4,16 +4,13 @@
 import org.springframework.stereotype.Component;
 
 import java.time.Clock;
-import java.time.Instant;
 import java.time.LocalDate;
 import java.time.format.DateTimeFormatter;
-import java.time.temporal.WeekFields;
 
 @Component
 public class RankingKeyResolver {
 
     private static final DateTimeFormatter DAILY_FORMAT = DateTimeFormatter.ofPattern("yyyyMMdd");
-    private static final DateTimeFormatter MONTHLY_FORMAT = DateTimeFormatter.ofPattern("yyyyMM");
 
     private final Clock clock;
 
@@ -25,18 +22,26 @@ public String resolve(RankingPeriod period, LocalDate date, String groupName) {
         String base = switch (period) {
             case REALTIME -> "ranking:realtime";
             case DAILY -> "ranking:daily:" + date.format(DAILY_FORMAT);
-            case WEEKLY -> {
-                WeekFields iso = WeekFields.ISO;
-                int year = date.get(iso.weekBasedYear());
-                int week = date.get(iso.weekOfWeekBasedYear());
-                yield String.format("ranking:weekly:%d%02d", year, week);
-            }
-            case MONTHLY -> "ranking:monthly:" + date.format(MONTHLY_FORMAT);
+            // LAST_7D / LAST_30D 는 anchor = 어제 (오늘 제외 롤링 윈도우) 기반 키
+            case LAST_7D  -> "ranking:last7d:"  + anchorDateKey(date);
+            case LAST_30D -> "ranking:last30d:" + anchorDateKey(date);
         };
         return base + ":" + groupName;
     }
 
     public String resolve(RankingPeriod period, LocalDate date) {
         return resolve(period, date, "control");
     }
+
+    /**
+     * 조회 기준일(오늘) 로부터 anchor_date (= 어제) 를 반환한다.
+     * 배치가 이 anchor 로 MV / Redis ZSET 을 만들므로 API 도 동일 키로 조회해야 한다.
+     */
+    public LocalDate anchorDateOf(LocalDate date) {
+        return date.minusDays(1);
+    }
+
+    private String anchorDateKey(LocalDate date) {
+        return anchorDateOf(date).format(DAILY_FORMAT);
+    }
 }

apps/commerce-api/src/main/java/com/loopers/application/ranking/RankingService.java

@@ -2,14 +2,14 @@
 
 import com.loopers.domain.ranking.RankEntry;
 import com.loopers.domain.ranking.RankingPeriod;
+import com.loopers.domain.ranking.mv.MvRankEntry;
+import com.loopers.domain.ranking.mv.MvRankingQueryRepository;
 import com.loopers.infrastructure.ranking.RankingRedisRepository;
 import lombok.extern.slf4j.Slf4j;
 import org.springframework.stereotype.Service;
 
-import java.time.DayOfWeek;
 import java.time.LocalDate;
 import java.time.LocalDateTime;
-import java.time.temporal.TemporalAdjusters;
 import java.util.List;
 import java.util.Map;
 import java.util.concurrent.atomic.AtomicInteger;
@@ -21,15 +21,18 @@ public class RankingService {
     private final RankingRedisRepository rankingRedisRepository;
     private final RankingKeyResolver keyResolver;
     private final RankingFallbackAggregator fallbackAggregator;
+    private final MvRankingQueryRepository mvRankingQueryRepository;
     private final ExperimentGroupResolver experimentGroupResolver;
 
     public RankingService(RankingRedisRepository rankingRedisRepository,
                           RankingKeyResolver keyResolver,
                           RankingFallbackAggregator fallbackAggregator,
+                          MvRankingQueryRepository mvRankingQueryRepository,
                           ExperimentGroupResolver experimentGroupResolver) {
         this.rankingRedisRepository = rankingRedisRepository;
         this.keyResolver = keyResolver;
         this.fallbackAggregator = fallbackAggregator;
+        this.mvRankingQueryRepository = mvRankingQueryRepository;
         this.experimentGroupResolver = experimentGroupResolver;
     }
 
@@ -47,11 +50,18 @@ public long getTotalCount(RankingPeriod period, LocalDate date, String group) {
         String key = keyResolver.resolve(period, date, group);
         try {
             Long count = rankingRedisRepository.getTotalCount(key);
-            return count == null ? 0 : count;
+            if (count != null && count > 0) {
+                return count;
+            }
         } catch (Exception e) {
             log.warn("Redis totalCount 조회 실패: {}", e.getMessage());
-            return 0;
         }
+        // Redis miss 또는 0일 때 MV 카운트 fallback (LAST_7D / LAST_30D 만 해당)
+        return switch (period) {
+            case LAST_7D  -> mvRankingQueryRepository.countLast7d(keyResolver.anchorDateOf(date), group);
+            case LAST_30D -> mvRankingQueryRepository.countLast30d(keyResolver.anchorDateOf(date), group);
+            default       -> 0;
+        };
     }
 
     public Integer getProductRank(Long productId, RankingPeriod period, LocalDate date) {
@@ -67,14 +77,53 @@ private List<RankEntry> loadRankEntries(RankingPeriod period, LocalDate date, in
                 return fromRedis;
             }
         } catch (Exception e) {
-            log.warn("Redis 랭킹 조회 실패, DB fallback. period={}, date={}, group={}: {}",
+            log.warn("Redis 랭킹 조회 실패, fallback. period={}, date={}, group={}: {}",
                     period, date, group, e.getMessage());
         }
 
-        return fallbackFromDb(period, date, page, size);
+        return switch (period) {
+            // 롤링 랭킹: MV 테이블 직접 조회 (확정된 TOP N 을 그대로 투영, bucket SUM 재계산 아님)
+            case LAST_7D, LAST_30D -> fallbackFromMv(period, date, page, size, group);
+            // 실시간/일간: 기존 bucket 집계 재계산 경로
+            case REALTIME, DAILY   -> fallbackFromBucketAggregation(period, date, page, size);
+        };
+    }
+
+    private static final int MV_FALLBACK_MAX_DAYS = 3;
+
+    private List<RankEntry> fallbackFromMv(RankingPeriod period, LocalDate date, int page, int size, String group) {
+        try {
+            LocalDate anchorDate = keyResolver.anchorDateOf(date);
+            int offset = page * size;
+
+            // 현재 anchor 의 MV 가 비어있으면 전일 anchor 로 자동 fallback (최대 3일).
+            // 배치 미실행 또는 해당 anchor 에 데이터가 없으면 비어있을 수 있음.
+            // "잘못된 랭킹" 보다 "어제 랭킹이라도 보여주기" 가 사용자 경험상 나음.
+            for (int retry = 0; retry < MV_FALLBACK_MAX_DAYS; retry++) {
+                List<MvRankEntry> rows = switch (period) {
+                    case LAST_7D  -> mvRankingQueryRepository.findLast7d(anchorDate, group, offset, size);
+                    case LAST_30D -> mvRankingQueryRepository.findLast30d(anchorDate, group, offset, size);
+                    default -> List.of();
+                };
+                if (!rows.isEmpty()) {
+                    if (retry > 0) {
+                        log.info("MV fallback: 현재 anchor 비어있어 전일로 대체. period={}, 원래anchor={}, 사용anchor={}",
+                                period, keyResolver.anchorDateOf(date), anchorDate);
+                    }
+                    return rows.stream()
+                            .map(r -> new RankEntry(r.productId(), r.score(), r.rankPosition()))
+                            .toList();
+                }
+                anchorDate = anchorDate.minusDays(1);
+            }
+            return List.of();
+        } catch (Exception e) {
+            log.error("MV fallback 실패. period={}, date={}, group={}", period, date, group, e);
+            return List.of();
+        }
     }
 
-    private List<RankEntry> fallbackFromDb(RankingPeriod period, LocalDate date, int page, int size) {
+    private List<RankEntry> fallbackFromBucketAggregation(RankingPeriod period, LocalDate date, int page, int size) {
         try {
             LocalDateTime from = calculateFrom(period, date);
             LocalDateTime to = RankingDateUtils.kstDateToUtcBoundary(date.plusDays(1));
@@ -94,7 +143,7 @@ private List<RankEntry> fallbackFromDb(RankingPeriod period, LocalDate date, int
                     .map(e -> new RankEntry(e.getKey(), e.getValue(), rankCounter.getAndIncrement()))
                     .toList();
         } catch (Exception e) {
-            log.error("DB fallback도 실패. period={}, date={}", period, date, e);
+            log.error("bucket 집계 fallback 실패. period={}, date={}", period, date, e);
             return List.of();
         }
     }
@@ -109,14 +158,9 @@ private LocalDateTime calculateFrom(RankingPeriod period, LocalDate date) {
                         java.time.ZoneOffset.UTC);
             }
             case DAILY -> RankingDateUtils.kstDateToUtcBoundary(date);
-            case WEEKLY -> {
-                LocalDate monday = date.with(TemporalAdjusters.previousOrSame(DayOfWeek.MONDAY));
-                yield RankingDateUtils.kstDateToUtcBoundary(monday);
-            }
-            case MONTHLY -> {
-                LocalDate firstOfMonth = date.withDayOfMonth(1);
-                yield RankingDateUtils.kstDateToUtcBoundary(firstOfMonth);
-            }
+            // LAST_7D / LAST_30D 는 MV fallback 경로라 여기 들어올 일 없음
+            case LAST_7D, LAST_30D -> throw new IllegalStateException(
+                    "rolling period fallback 은 MV 경로로만 처리되어야 한다: " + period);
         };
     }
 }

apps/commerce-api/src/main/java/com/loopers/domain/ranking/RankingPeriod.java

@@ -1,5 +1,16 @@
 package com.loopers.domain.ranking;
 
+/**
+ * 랭킹 조회 기간.
+ *
+ * <p>WEEKLY/MONTHLY 캘린더 경계는 "월요일 오전/매월 1일 오전에 표본이 1일치" 라는 빈약성
+ * 문제가 있고, 실무에선 이커머스 랭킹을 롤링 N일 (오늘 제외) 로 구현하는 것이 일반적이다
+ * (설계.md 프롤로그 + 데빈/케브/앨런 멘토링 결론). 본 API 는 배치가 만드는 롤링 MV 와
+ * 일관되게 LAST_7D / LAST_30D 로 노출한다.</p>
+ */
 public enum RankingPeriod {
-    REALTIME, DAILY, WEEKLY, MONTHLY
+    REALTIME,
+    DAILY,
+    LAST_7D,
+    LAST_30D
 }

apps/commerce-api/src/main/java/com/loopers/domain/ranking/mv/MvProductRankId.java

@@ -0,0 +1,39 @@
+package com.loopers.domain.ranking.mv;
+
+import java.io.Serializable;
+import java.time.LocalDate;
+import java.util.Objects;
+
+/**
+ * mv_product_rank_last_7d / mv_product_rank_last_30d 공통 PK.
+ * commerce-batch 가 생성·적재하는 MV 를 commerce-api 가 읽기 위한 스키마 미러.
+ */
+public class MvProductRankId implements Serializable {
+
+    private LocalDate anchorDate;
+    private String weightGroup;
+    private Long productId;
+
+    public MvProductRankId() {
+    }
+
+    public MvProductRankId(LocalDate anchorDate, String weightGroup, Long productId) {
+        this.anchorDate = anchorDate;
+        this.weightGroup = weightGroup;
+        this.productId = productId;
+    }
+
+    @Override
+    public boolean equals(Object o) {
+        if (this == o) return true;
+        if (!(o instanceof MvProductRankId that)) return false;
+        return Objects.equals(anchorDate, that.anchorDate)
+                && Objects.equals(weightGroup, that.weightGroup)
+                && Objects.equals(productId, that.productId);
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hash(anchorDate, weightGroup, productId);
+    }
+}

apps/commerce-api/src/main/java/com/loopers/domain/ranking/mv/MvProductRankLast30d.java

@@ -0,0 +1,72 @@
+package com.loopers.domain.ranking.mv;
+
+import jakarta.persistence.Column;
+import jakarta.persistence.Entity;
+import jakarta.persistence.Id;
+import jakarta.persistence.IdClass;
+import jakarta.persistence.Index;
+import jakarta.persistence.Table;
+import lombok.Getter;
+
+import java.time.LocalDate;
+import java.time.LocalDateTime;
+
+@Entity
+@Table(
+        name = "mv_product_rank_last_30d",
+        indexes = @Index(
+                name = "idx_last_30d_rank",
+                columnList = "anchor_date, weight_group, rank_position"
+        )
+)
+@IdClass(MvProductRankId.class)
+@Getter
+public class MvProductRankLast30d {
+
+    @Id
+    @Column(name = "anchor_date", nullable = false)
+    private LocalDate anchorDate;
+
+    @Id
+    @Column(name = "weight_group", length = 32, nullable = false)
+    private String weightGroup;
+
+    @Id
+    @Column(name = "product_id", nullable = false)
+    private Long productId;
+
+    @Column(name = "view_count", nullable = false)
+    private long viewCount;
+
+    @Column(name = "like_count", nullable = false)
+    private long likeCount;
+
+    @Column(name = "sales_amount", nullable = false)
+    private long salesAmount;
+
+    @Column(name = "score", nullable = false)
+    private double score;
+
+    @Column(name = "rank_position", nullable = false)
+    private int rankPosition;
+
+    @Column(name = "created_at", nullable = false)
+    private LocalDateTime createdAt;
+
+    protected MvProductRankLast30d() {
+    }
+
+    public MvProductRankLast30d(LocalDate anchorDate, String weightGroup, Long productId,
+                                long viewCount, long likeCount, long salesAmount,
+                                double score, int rankPosition, LocalDateTime createdAt) {
+        this.anchorDate = anchorDate;
+        this.weightGroup = weightGroup;
+        this.productId = productId;
+        this.viewCount = viewCount;
+        this.likeCount = likeCount;
+        this.salesAmount = salesAmount;
+        this.score = score;
+        this.rankPosition = rankPosition;
+        this.createdAt = createdAt;
+    }
+}

apps/commerce-api/src/main/java/com/loopers/domain/ranking/mv/MvProductRankLast7d.java

@@ -0,0 +1,76 @@
+package com.loopers.domain.ranking.mv;
+
+import jakarta.persistence.Column;
+import jakarta.persistence.Entity;
+import jakarta.persistence.Id;
+import jakarta.persistence.IdClass;
+import jakarta.persistence.Index;
+import jakarta.persistence.Table;
+import lombok.Getter;
+
+import java.time.LocalDate;
+import java.time.LocalDateTime;
+
+/**
+ * 롤링 7일 랭킹 확정 MV 의 commerce-api 측 읽기 모델.
+ * commerce-batch 가 쓰기 소유자이며, 여기서는 조회만 한다.
+ */
+@Entity
+@Table(
+        name = "mv_product_rank_last_7d",
+        indexes = @Index(
+                name = "idx_last_7d_rank",
+                columnList = "anchor_date, weight_group, rank_position"
+        )
+)
+@IdClass(MvProductRankId.class)
+@Getter
+public class MvProductRankLast7d {
+
+    @Id
+    @Column(name = "anchor_date", nullable = false)
+    private LocalDate anchorDate;
+
+    @Id
+    @Column(name = "weight_group", length = 32, nullable = false)
+    private String weightGroup;
+
+    @Id
+    @Column(name = "product_id", nullable = false)
+    private Long productId;
+
+    @Column(name = "view_count", nullable = false)
+    private long viewCount;
+
+    @Column(name = "like_count", nullable = false)
+    private long likeCount;
+
+    @Column(name = "sales_amount", nullable = false)
+    private long salesAmount;
+
+    @Column(name = "score", nullable = false)
+    private double score;
+
+    @Column(name = "rank_position", nullable = false)
+    private int rankPosition;
+
+    @Column(name = "created_at", nullable = false)
+    private LocalDateTime createdAt;
+
+    protected MvProductRankLast7d() {
+    }
+
+    public MvProductRankLast7d(LocalDate anchorDate, String weightGroup, Long productId,
+                               long viewCount, long likeCount, long salesAmount,
+                               double score, int rankPosition, LocalDateTime createdAt) {
+        this.anchorDate = anchorDate;
+        this.weightGroup = weightGroup;
+        this.productId = productId;
+        this.viewCount = viewCount;
+        this.likeCount = likeCount;
+        this.salesAmount = salesAmount;
+        this.score = score;
+        this.rankPosition = rankPosition;
+        this.createdAt = createdAt;
+    }
+}