fix: Notification 重连 + Social 修复 + Following 缓存失效

- Notification Worker 加重连循环，Channel 断开不再静默死亡
- Social: 先写 DB 再发 MQ，修复 DB 失败产生幽灵通知的问题
- Social: MQ 发布失败记日志，不再静默忽略
- 关注/取关后失效该用户的 Following Feed 缓存（24h TTL）
- Redis Client 新增 DelByPattern 按模式批量删除缓存

backend/internal/http/router.go

@@ -127,7 +127,7 @@ func SetRouter(db *gorm.DB, cache *rediscache.Client, rmq *rabbitmq.RabbitMQ) *g
 		socialMQ = nil
 	}
 	socialRepository := social.NewSocialRepository(db)
-	socialService := social.NewSocialService(socialRepository, accountRepository, socialMQ)
+	socialService := social.NewSocialService(socialRepository, accountRepository, socialMQ, cache)
 	socialHandler := social.NewSocialHandler(socialService)
 	socialGroup := r.Group("/social")
 	protectedSocialGroup := socialGroup.Group("")
@@ -227,43 +227,25 @@ func SetRouter(db *gorm.DB, cache *rediscache.Client, rmq *rabbitmq.RabbitMQ) *g
 		if rmq != nil {
 			hub := sseHub
 			ctx := context.Background()
-			// consume from like queue
-			go func() {
-				ch, err := rmq.NewChannel()
-				if err != nil {
-					log.Printf("notification-like channel: %v", err)
-					return
-				}
-				defer ch.Close()
-				w := worker.NewNotificationWorker(ch, db, "notification.like", hub)
-				if err := w.Run(ctx); err != nil {
-					log.Printf("notification-like worker: %v", err)
-				}
-			}()
-			go func() {
-				ch, err := rmq.NewChannel()
-				if err != nil {
-					log.Printf("notification-comment channel: %v", err)
-					return
-				}
-				defer ch.Close()
-				w := worker.NewNotificationWorker(ch, db, "notification.comment", hub)
-				if err := w.Run(ctx); err != nil {
-					log.Printf("notification-comment worker: %v", err)
-				}
-			}()
-			go func() {
-				ch, err := rmq.NewChannel()
-				if err != nil {
-					log.Printf("notification-social channel: %v", err)
-					return
-				}
-				defer ch.Close()
-				w := worker.NewNotificationWorker(ch, db, "notification.social", hub)
-				if err := w.Run(ctx); err != nil {
-					log.Printf("notification-social worker: %v", err)
-				}
-			}()
+			// 每个 notification worker 独立 Channel + 自动重连
+			for _, q := range []string{"notification.like", "notification.comment", "notification.social"} {
+				go func(queue string) {
+					for {
+						ch, err := rmq.NewChannel()
+						if err != nil {
+							log.Printf("notification-%s: 创建 Channel 失败: %v, 5秒后重试", queue, err)
+							time.Sleep(5 * time.Second)
+							continue
+						}
+						w := worker.NewNotificationWorker(ch, db, queue, hub)
+						if err := w.Run(ctx); err != nil {
+							log.Printf("notification-%s: %v, 5秒后重连...", queue, err)
+						}
+						ch.Close()
+						time.Sleep(5 * time.Second)
+					}
+				}(q)
+			}
 		} else {
 			log.Printf("Notification SSE disabled (MQ not available)")
 		}

backend/internal/middleware/redis/cache.go

@@ -27,6 +27,17 @@ func (c *Client) Del(ctx context.Context, key string) error {
 	return c.rdb.Del(ctx, key).Err()
 }
 
+func (c *Client) DelByPattern(ctx context.Context, pattern string) error {
+	if c == nil || c.rdb == nil {
+		return nil
+	}
+	iter := c.rdb.Scan(ctx, 0, pattern, 0).Iterator()
+	for iter.Next(ctx) {
+		_ = c.rdb.Del(ctx, iter.Val())
+	}
+	return iter.Err()
+}
+
 func (c *Client) MGet(cacheCtx context.Context, cacheKeys ...string) ([]interface{}, error) {
 	if c == nil || c.rdb == nil {
 		return nil, errors.New("redis client not initialized")

backend/internal/social/service.go

@@ -5,16 +5,19 @@ import (
 	"errors"
 	"feedsystem_video_go/internal/account"
 	"feedsystem_video_go/internal/middleware/rabbitmq"
+	rediscache "feedsystem_video_go/internal/middleware/redis"
+	"log"
 )
 
 type SocialService struct {
 	repo        *SocialRepository
 	accountrepo *account.AccountRepository
 	socialMQ    *rabbitmq.SocialMQ
+	cache       *rediscache.Client
 }
 
-func NewSocialService(repo *SocialRepository, accountrepo *account.AccountRepository, socialMQ *rabbitmq.SocialMQ) *SocialService {
-	return &SocialService{repo: repo, accountrepo: accountrepo, socialMQ: socialMQ}
+func NewSocialService(repo *SocialRepository, accountrepo *account.AccountRepository, socialMQ *rabbitmq.SocialMQ, cache *rediscache.Client) *SocialService {
+	return &SocialService{repo: repo, accountrepo: accountrepo, socialMQ: socialMQ, cache: cache}
 }
 
 func (s *SocialService) Follow(ctx context.Context, social *Social) error {
@@ -36,10 +39,22 @@ func (s *SocialService) Follow(ctx context.Context, social *Social) error {
 	if isFollowed {
 		return errors.New("already followed")
 	}
-	if s.socialMQ != nil {
-		s.socialMQ.Follow(ctx, social.FollowerID, social.VloggerID)
+
+	// 先写 DB，确保数据持久化
+	if err := s.repo.Follow(ctx, social); err != nil {
+		return err
 	}
-	return s.repo.Follow(ctx, social)
+
+	// DB 成功后，失效该用户的关注列表缓存
+	s.invalidateFollowingFeedCache(context.Background(), social.FollowerID)
+
+	// 最后发 MQ（用于通知），失败只记日志不影响业务
+	if s.socialMQ != nil {
+		if err := s.socialMQ.Follow(ctx, social.FollowerID, social.VloggerID); err != nil {
+			log.Printf("social MQ Follow 发布失败: %v", err)
+		}
+	}
+	return nil
 }
 
 func (s *SocialService) Unfollow(ctx context.Context, social *Social) error {
@@ -58,10 +73,32 @@ func (s *SocialService) Unfollow(ctx context.Context, social *Social) error {
 	if !isFollowed {
 		return errors.New("not followed")
 	}
-	if s.socialMQ != nil {
-		s.socialMQ.UnFollow(ctx, social.FollowerID, social.VloggerID)
+
+	// 先写 DB
+	if err := s.repo.Unfollow(ctx, social); err != nil {
+		return err
+	}
+
+	// 失效缓存
+	s.invalidateFollowingFeedCache(context.Background(), social.FollowerID)
+
+	// 最后发 MQ
+	if s.socialMQ != nil {
+		if err := s.socialMQ.UnFollow(ctx, social.FollowerID, social.VloggerID); err != nil {
+			log.Printf("social MQ UnFollow 发布失败: %v", err)
+		}
+	}
+	return nil
+}
+
+func (s *SocialService) invalidateFollowingFeedCache(ctx context.Context, accountID uint) {
+	if s.cache == nil {
+		return
+	}
+	pattern := s.cache.Key("feed:listByFollowing:*:accountID=%d:*", accountID)
+	if err := s.cache.DelByPattern(ctx, pattern); err != nil {
+		log.Printf("失效 Following 缓存失败: accountID=%d, err=%v", accountID, err)
 	}
-	return s.repo.Unfollow(ctx, social)
 }
 
 func (s *SocialService) GetAllFollowers(ctx context.Context, VloggerID uint) ([]*account.Account, error) {