fix: 회원 한 명의 Slack 사진 동기화를 회원 행 잠금 밖에서 한다

src/main/java/com/bcsdlab/bcsdinternalapiv2/member/controller/AdminMemberController.java

@@ -154,7 +154,7 @@ public ResponseEntity<Void> updatePhotoUrl(@PathVariable Long memberId,
     @Override
     @PostMapping("/{memberId}/photo/slack-sync")
     public ResponseEntity<PhotoUrlResponse> syncPhotoFromSlack(@PathVariable Long memberId) {
-        return ResponseEntity.ok(new PhotoUrlResponse(memberDirectoryService.syncProfileImageFromSlack(memberId)));
+        return ResponseEntity.ok(new PhotoUrlResponse(slackProfileSyncService.syncOne(memberId)));
     }
 
     @Override

src/main/java/com/bcsdlab/bcsdinternalapiv2/member/service/MemberDirectoryService.java

@@ -6,7 +6,6 @@
 import com.bcsdlab.bcsdinternalapiv2.member.controller.dto.response.AdminMemberDirectoryResponse;
 import com.bcsdlab.bcsdinternalapiv2.member.controller.dto.response.MemberDirectoryResponse;
 import com.bcsdlab.bcsdinternalapiv2.member.controller.dto.response.PhotoPresignedUrlResponse;
-import com.bcsdlab.bcsdinternalapiv2.member.client.SlackClient;
 import com.bcsdlab.bcsdinternalapiv2.member.exception.MemberException;
 import com.bcsdlab.bcsdinternalapiv2.member.exception.MemberExceptionType;
 import com.bcsdlab.bcsdinternalapiv2.member.model.AcademicStatus;
@@ -43,7 +42,6 @@ public class MemberDirectoryService {
     private final TrackMasterRepository trackMasterRepository;
     private final PositionRepository positionRepository;
     private final PhotoStorageService photoStorageService;
-    private final SlackClient slackClient;
 
     @Transactional(readOnly = true)
     public MemberDirectoryResponse getDirectory(MemberDirectoryQuery query, Pageable pageable) {
@@ -140,16 +138,6 @@ public void updatePhotoUrl(Long memberId, String photoUrl) {
         member.updateProfileImageUrl(photoUrl);
     }
 
-    @Transactional
-    public String syncProfileImageFromSlack(Long memberId) {
-        Member member = memberRepository.findByIdForUpdate(memberId)
-                .orElseThrow(() -> new MemberException(MemberExceptionType.MEMBER_NOT_FOUND));
-        String imageUrl = slackClient.findProfileImageUrlByEmail(member.getEmail())
-                .orElseThrow(() -> new MemberException(MemberExceptionType.SLACK_PROFILE_NOT_FOUND));
-        member.updateProfileImageUrl(imageUrl);
-        return imageUrl;
-    }
-
     private boolean isBlank(String value) {
         return value == null || value.isBlank();
     }

src/main/java/com/bcsdlab/bcsdinternalapiv2/member/service/SlackProfileSyncService.java

@@ -38,6 +38,19 @@ public class SlackProfileSyncService {
     private final SlackClient slackClient;
     private final MemberDirectoryService memberDirectoryService;
 
+    /**
+     * 한 회원의 프로필 사진을 Slack(이메일 조회)에서 가져와 저장한다. Slack 호출은 트랜잭션과 행 잠금 밖에서 하고,
+     * 저장만 짧은 트랜잭션으로 한다 — 잠금을 쥔 채 외부 호출을 기다리면 같은 회원의 로그인·토큰 갱신이 막힌다.
+     */
+    public String syncOne(Long memberId) {
+        Member member = memberRepository.findById(memberId)
+                .orElseThrow(() -> new MemberException(MemberExceptionType.MEMBER_NOT_FOUND));
+        String imageUrl = slackClient.findProfileImageUrlByEmail(member.getEmail())
+                .orElseThrow(() -> new MemberException(MemberExceptionType.SLACK_PROFILE_NOT_FOUND));
+        memberDirectoryService.updatePhotoUrl(memberId, imageUrl);
+        return imageUrl;
+    }
+
     public SlackProfileSyncResponse syncAll() {
         // 가입 전·잠김 회원도 홈페이지에 노출될 수 있으므로 탈퇴한 회원만 제외한다.
         List<Member> members = memberRepository.findAllByStatusNot(MemberStatus.WITHDRAWN);

src/test/java/com/bcsdlab/bcsdinternalapiv2/member/MemberSlackIdIntegrationTest.java

@@ -27,13 +27,16 @@
 import com.bcsdlab.bcsdinternalapiv2.track.repository.TrackMasterRepository;
 import com.fasterxml.jackson.databind.ObjectMapper;
 import java.util.Optional;
+import java.util.concurrent.atomic.AtomicBoolean;
 import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.DisplayName;
 import org.junit.jupiter.api.Test;
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.http.MediaType;
 import org.springframework.security.crypto.password.PasswordEncoder;
 import org.springframework.test.context.TestPropertySource;
 import org.springframework.test.context.bean.override.mockito.MockitoBean;
+import org.springframework.transaction.support.TransactionSynchronizationManager;
 
 @TestPropertySource(properties = "app.mail.transport=log")
 class MemberSlackIdIntegrationTest extends IntegrationTestSupport {
@@ -343,4 +346,24 @@ private String login(String studentNumber) throws Exception {
                 .getContentAsString();
         return objectMapper.readTree(responseBody).get("accessToken").asText();
     }
+
+    @Test
+    @DisplayName("Slack 사진 동기화는 트랜잭션(회원 행 잠금) 밖에서 Slack을 부르고 사진을 저장한다")
+    void Slack_사진_동기화는_트랜잭션_밖에서_Slack을_부른다() throws Exception {
+        Member member = saveMember("20240021", "윤사진", MemberRole.MEMBER);
+        AtomicBoolean calledInTransaction = new AtomicBoolean(true);
+        when(slackClient.findProfileImageUrlByEmail(member.getEmail())).thenAnswer(invocation -> {
+            calledInTransaction.set(TransactionSynchronizationManager.isActualTransactionActive());
+            return Optional.of("https://avatars.slack-edge.com/photo.png");
+        });
+
+        mockMvc.perform(post("/v1/admin/members/" + member.getId() + "/photo/slack-sync")
+                        .header("Authorization", "Bearer " + adminToken))
+                .andExpect(status().isOk())
+                .andExpect(jsonPath("$.photoUrl").value("https://avatars.slack-edge.com/photo.png"));
+
+        assertThat(calledInTransaction).isFalse();
+        assertThat(memberRepository.findById(member.getId()).orElseThrow().getProfileImageUrl())
+                .isEqualTo("https://avatars.slack-edge.com/photo.png");
+    }
 }