[fix] 좋아요 수 동시성 이슈 처리

build.gradle

@@ -72,6 +72,9 @@ dependencies {
 
 	// Discord Webhook
 	implementation 'com.github.napstr:logback-discord-appender:1.0.0'
+
+	// aop
+	implementation 'org.springframework.boot:spring-boot-starter-aop'
 }
 
 tasks.named('test') {
@@ -93,4 +96,4 @@ tasks.register('copyYml', Copy) {
 		include "*.yml"
 		into 'src/main/resources'
 	}
-}
+}

src/main/java/org/hankki/hankkiserver/api/common/annotation/Retry.java

@@ -0,0 +1,15 @@
+package org.hankki.hankkiserver.api.common.annotation;
+
+import java.lang.annotation.ElementType;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.lang.annotation.Target;
+
+@Target(ElementType.METHOD)
+@Retention(RetentionPolicy.RUNTIME)
+public @interface Retry {
+
+    int maxAttempts() default 3;
+
+    int backoff() default 100;
+}

src/main/java/org/hankki/hankkiserver/api/store/service/HeartCommandService.java

@@ -2,6 +2,7 @@
 
 import lombok.RequiredArgsConstructor;
 import org.hankki.hankkiserver.api.auth.service.UserFinder;
+import org.hankki.hankkiserver.api.common.annotation.Retry;
 import org.hankki.hankkiserver.api.store.service.command.HeartDeleteCommand;
 import org.hankki.hankkiserver.api.store.service.command.HeartPostCommand;
 import org.hankki.hankkiserver.api.store.service.response.HeartCreateResponse;
@@ -16,7 +17,6 @@
 
 @Service
 @RequiredArgsConstructor
-@Transactional
 public class HeartCommandService {
 
     private final HeartUpdater heartUpdater;
@@ -25,6 +25,8 @@ public class HeartCommandService {
     private final UserFinder userFinder;
     private final StoreFinder storeFinder;
 
+    @Retry
+    @Transactional
     public HeartCreateResponse createHeart(final HeartPostCommand heartPostCommand) {
         User user = userFinder.getUserReference(heartPostCommand.userId());
         Store store = storeFinder.findByIdWhereDeletedIsFalse(heartPostCommand.storeId());
@@ -34,6 +36,8 @@ public HeartCreateResponse createHeart(final HeartPostCommand heartPostCommand)
         return HeartCreateResponse.of(store);
     }
 
+    @Retry
+    @Transactional
     public HeartDeleteResponse deleteHeart(final HeartDeleteCommand heartDeleteCommand) {
         User user = userFinder.getUserReference(heartDeleteCommand.userId());
         Store store = storeFinder.findByIdWhereDeletedIsFalse(heartDeleteCommand.storeId());

src/main/java/org/hankki/hankkiserver/common/aspect/RetryAspect.java

@@ -0,0 +1,30 @@
+package org.hankki.hankkiserver.common.aspect;
+
+import org.aspectj.lang.ProceedingJoinPoint;
+import org.aspectj.lang.annotation.Around;
+import org.aspectj.lang.annotation.Aspect;
+import org.hankki.hankkiserver.api.common.annotation.Retry;
+import org.hankki.hankkiserver.common.code.HeartErrorCode;
+import org.hankki.hankkiserver.common.exception.ConflictException;
+import org.springframework.core.Ordered;
+import org.springframework.core.annotation.Order;
+import org.springframework.orm.ObjectOptimisticLockingFailureException;
+import org.springframework.stereotype.Component;
+
+@Order(Ordered.LOWEST_PRECEDENCE - 1)
+@Aspect
+@Component
+public class RetryAspect {
+
+    @Around("@annotation(retry)")
+    public Object retryOptimisticLock(final ProceedingJoinPoint joinPoint, final Retry retry) throws Throwable {
+        for (int attempt = 0; attempt < retry.maxAttempts(); attempt++) {
+            try {
+                return joinPoint.proceed();
+            } catch (ObjectOptimisticLockingFailureException e) {
+                Thread.sleep(retry.backoff());
+            }
+        }
+        throw new ConflictException(HeartErrorCode.HEART_COUNT_CONCURRENCY_ERROR);
+    }
+}

src/main/java/org/hankki/hankkiserver/common/code/HeartErrorCode.java

@@ -8,9 +8,11 @@
 @RequiredArgsConstructor
 public enum HeartErrorCode implements ErrorCode {
 
-    ALREADY_EXISTED_HEART(HttpStatus.CONFLICT, "이미 좋아요 한 가게입니다."),
-    ALREADY_NO_HEART(HttpStatus.CONFLICT, "이미 좋아요를 취소한 가게입니다.");
+    ALREADY_EXISTED_HEART(HttpStatus.CONFLICT, "이미 좋아요를 누른 식당이에요"),
+    ALREADY_NO_HEART(HttpStatus.CONFLICT, "이미 좋아요를 취소한 식당이에요"),
+    HEART_COUNT_CONCURRENCY_ERROR(HttpStatus.CONFLICT, "오류가 발생했어요" + System.lineSeparator() + "좋아요를 다시 눌러주세요");
 
     private final HttpStatus httpStatus;
     private final String message;
 }
+

src/main/java/org/hankki/hankkiserver/domain/store/model/Store.java

@@ -1,6 +1,17 @@
 package org.hankki.hankkiserver.domain.store.model;
 
-import jakarta.persistence.*;
+import jakarta.persistence.Column;
+import jakarta.persistence.Embedded;
+import jakarta.persistence.Entity;
+import jakarta.persistence.EnumType;
+import jakarta.persistence.Enumerated;
+import jakarta.persistence.GeneratedValue;
+import jakarta.persistence.GenerationType;
+import jakarta.persistence.Id;
+import jakarta.persistence.OneToMany;
+import jakarta.persistence.Version;
+import java.util.ArrayList;
+import java.util.List;
 import lombok.AccessLevel;
 import lombok.Builder;
 import lombok.Getter;
@@ -11,9 +22,6 @@
 import org.hankki.hankkiserver.domain.universitystore.model.UniversityStore;
 import org.hibernate.annotations.BatchSize;
 
-import java.util.ArrayList;
-import java.util.List;
-
 @Entity
 @Getter
 @BatchSize(size = 100)
@@ -57,6 +65,9 @@ public class Store extends BaseTimeEntity {
     @Column(nullable = false)
     private boolean isDeleted;
 
+    @Version
+    private Long version = 0L;
+
     @Builder
     private Store (String name, Point point, String address, StoreCategory category, int lowestPrice, int heartCount, boolean isDeleted) {
         this.name = name;