fix: improve sticky session scheduling

backend/internal/handler/gateway_handler.go

@@ -262,6 +262,12 @@ func (h *GatewayHandler) Messages(c *gin.Context) {
 	}
 	sessionHash := h.gatewayService.GenerateSessionHash(parsedReq)
 
+	// [DEBUG-STICKY] 打印会话 hash 生成结果
+	reqLog.Info("sticky.session_hash_generated",
+		zap.String("session_hash", sessionHash),
+		zap.String("metadata_user_id_raw", parsedReq.MetadataUserID),
+	)
+
 	// 获取平台：优先使用强制平台（/antigravity 路由，中间件已设置 request.Context），否则使用分组平台
 	platform := ""
 	if forcePlatform, ok := middleware2.GetForcePlatformFromContext(c); ok {
@@ -278,6 +284,11 @@ func (h *GatewayHandler) Messages(c *gin.Context) {
 	var sessionBoundAccountID int64
 	if sessionKey != "" {
 		sessionBoundAccountID, _ = h.gatewayService.GetCachedSessionAccountID(c.Request.Context(), apiKey.GroupID, sessionKey)
+		// [DEBUG-STICKY] 打印粘性会话查询结果
+		reqLog.Info("sticky.cache_lookup",
+			zap.String("session_key", sessionKey),
+			zap.Int64("bound_account_id", sessionBoundAccountID),
+		)
 		if sessionBoundAccountID > 0 {
 			prefetchedGroupID := int64(0)
 			if apiKey.GroupID != nil {
@@ -286,6 +297,8 @@ func (h *GatewayHandler) Messages(c *gin.Context) {
 			ctx := service.WithPrefetchedStickySession(c.Request.Context(), sessionBoundAccountID, prefetchedGroupID, h.metadataBridgeEnabled())
 			c.Request = c.Request.WithContext(ctx)
 		}
+	} else {
+		reqLog.Info("sticky.no_session_key", zap.String("session_hash", sessionHash))
 	}
 	// 判断是否真的绑定了粘性会话：有 sessionKey 且已经绑定到某个账号
 	hasBoundSession := sessionKey != "" && sessionBoundAccountID > 0
@@ -536,6 +549,12 @@ func (h *GatewayHandler) Messages(c *gin.Context) {
 
 		for {
 			// 选择支持该模型的账号
+			reqLog.Info("sticky.selecting_account",
+				zap.String("session_key", sessionKey),
+				zap.Int64("sticky_bound_account_id", sessionBoundAccountID),
+				zap.Bool("has_bound_session", hasBoundSession),
+				zap.Int("failed_account_count", len(fs.FailedAccountIDs)),
+			)
 			selection, err := h.gatewayService.SelectAccountWithLoadAwareness(c.Request.Context(), currentAPIKey.GroupID, sessionKey, reqModel, fs.FailedAccountIDs, parsedReq.MetadataUserID, subject.UserID)
 			if err != nil {
 				if len(fs.FailedAccountIDs) == 0 {
@@ -569,6 +588,16 @@ func (h *GatewayHandler) Messages(c *gin.Context) {
 			account := selection.Account
 			setOpsSelectedAccount(c, account.ID, account.Platform)
 
+			// [DEBUG-STICKY] 打印账号选择结果
+			reqLog.Info("sticky.account_selected",
+				zap.Int64("selected_account_id", account.ID),
+				zap.String("account_name", account.Name),
+				zap.Bool("slot_acquired", selection.Acquired),
+				zap.Bool("has_wait_plan", selection.WaitPlan != nil),
+				zap.Int64("sticky_bound_account_id", sessionBoundAccountID),
+				zap.Bool("sticky_honored", sessionBoundAccountID > 0 && sessionBoundAccountID == account.ID),
+			)
+
 			// 检查请求拦截（预热请求、SUGGESTION MODE等）
 			if account.IsInterceptWarmupEnabled() {
 				interceptType := detectInterceptType(body, reqModel, parsedReq.MaxTokens, reqStream, isClaudeCodeClient)
@@ -635,6 +664,10 @@ func (h *GatewayHandler) Messages(c *gin.Context) {
 				}
 				// Slot acquired: no longer waiting in queue.
 				releaseWait()
+				reqLog.Info("sticky.bind_after_wait",
+					zap.String("session_key", sessionKey),
+					zap.Int64("account_id", account.ID),
+				)
 				if err := h.gatewayService.BindStickySession(c.Request.Context(), currentAPIKey.GroupID, sessionKey, account.ID); err != nil {
 					reqLog.Warn("gateway.bind_sticky_session_failed", zap.Int64("account_id", account.ID), zap.Error(err))
 				}
@@ -829,6 +862,17 @@ func (h *GatewayHandler) Messages(c *gin.Context) {
 				}
 			}
 
+			// 绑定粘性会话（成功转发后绑定/刷新）
+			// - 无现有绑定（首次请求）：创建绑定
+			// - 选中账号与粘性账号一致：刷新 TTL
+			// - 粘性账号因负载/RPM 被跳过、选中了其他账号：不覆盖原绑定，
+			//   下次请求粘性账号恢复后仍可命中
+			if sessionKey != "" && (sessionBoundAccountID == 0 || sessionBoundAccountID == account.ID) {
+				if err := h.gatewayService.BindStickySession(c.Request.Context(), currentAPIKey.GroupID, sessionKey, account.ID); err != nil {
+					reqLog.Warn("gateway.bind_sticky_session_failed", zap.Int64("account_id", account.ID), zap.Error(err))
+				}
+			}
+
 			// 捕获请求信息（用于异步记录，避免在 goroutine 中访问 gin.Context）
 			userAgent := c.GetHeader("User-Agent")
 			clientIP := ip.GetClientIP(c)

backend/internal/repository/scheduler_cache.go

@@ -449,11 +449,69 @@ func buildSchedulerMetadataAccount(account service.Account) service.Account {
 		SessionWindowStart:      account.SessionWindowStart,
 		SessionWindowEnd:        account.SessionWindowEnd,
 		SessionWindowStatus:     account.SessionWindowStatus,
+		AccountGroups:           filterSchedulerAccountGroups(account.AccountGroups),
+		GroupIDs:                filterSchedulerGroupIDs(account.GroupIDs, account.AccountGroups),
 		Credentials:             filterSchedulerCredentials(account.Credentials),
 		Extra:                   filterSchedulerExtra(account.Extra),
 	}
 }
 
+func filterSchedulerAccountGroups(accountGroups []service.AccountGroup) []service.AccountGroup {
+	if len(accountGroups) == 0 {
+		return nil
+	}
+
+	filtered := make([]service.AccountGroup, 0, len(accountGroups))
+	for _, ag := range accountGroups {
+		if ag.GroupID <= 0 {
+			continue
+		}
+		filtered = append(filtered, service.AccountGroup{
+			AccountID: ag.AccountID,
+			GroupID:   ag.GroupID,
+			Priority:  ag.Priority,
+			CreatedAt: ag.CreatedAt,
+		})
+	}
+	if len(filtered) == 0 {
+		return nil
+	}
+	return filtered
+}
+
+func filterSchedulerGroupIDs(groupIDs []int64, accountGroups []service.AccountGroup) []int64 {
+	if len(groupIDs) == 0 && len(accountGroups) == 0 {
+		return nil
+	}
+
+	seen := make(map[int64]struct{}, len(groupIDs)+len(accountGroups))
+	filtered := make([]int64, 0, len(groupIDs)+len(accountGroups))
+	for _, id := range groupIDs {
+		if id <= 0 {
+			continue
+		}
+		if _, ok := seen[id]; ok {
+			continue
+		}
+		seen[id] = struct{}{}
+		filtered = append(filtered, id)
+	}
+	for _, ag := range accountGroups {
+		if ag.GroupID <= 0 {
+			continue
+		}
+		if _, ok := seen[ag.GroupID]; ok {
+			continue
+		}
+		seen[ag.GroupID] = struct{}{}
+		filtered = append(filtered, ag.GroupID)
+	}
+	if len(filtered) == 0 {
+		return nil
+	}
+	return filtered
+}
+
 func filterSchedulerCredentials(credentials map[string]any) map[string]any {
 	if len(credentials) == 0 {
 		return nil

backend/internal/repository/scheduler_cache_integration_test.go

@@ -56,6 +56,15 @@ func TestSchedulerCacheSnapshotUsesSlimMetadataButKeepsFullAccount(t *testing.T)
 		SessionWindowStart:     &now,
 		SessionWindowEnd:       &windowEnd,
 		SessionWindowStatus:    "active",
+		GroupIDs:               []int64{bucket.GroupID},
+		AccountGroups: []service.AccountGroup{
+			{
+				AccountID: 101,
+				GroupID:   bucket.GroupID,
+				Priority:  5,
+				Group:     &service.Group{ID: bucket.GroupID, Name: "gemini-group"},
+			},
+		},
 	}
 
 	require.NoError(t, cache.SetSnapshot(ctx, bucket, []service.Account{account}))
@@ -79,10 +88,17 @@ func TestSchedulerCacheSnapshotUsesSlimMetadataButKeepsFullAccount(t *testing.T)
 	require.Equal(t, 4, got.GetMaxSessions())
 	require.Equal(t, 11, got.GetSessionIdleTimeoutMinutes())
 	require.Nil(t, got.Extra["unused_large_field"])
+	require.Equal(t, []int64{bucket.GroupID}, got.GroupIDs)
+	require.Len(t, got.AccountGroups, 1)
+	require.Equal(t, account.ID, got.AccountGroups[0].AccountID)
+	require.Equal(t, bucket.GroupID, got.AccountGroups[0].GroupID)
+	require.Nil(t, got.AccountGroups[0].Group)
 
 	full, err := cache.GetAccount(ctx, account.ID)
 	require.NoError(t, err)
 	require.NotNil(t, full)
 	require.Equal(t, "secret-access-token", full.GetCredential("access_token"))
 	require.Equal(t, strings.Repeat("x", 4096), full.GetCredential("huge_blob"))
+	require.Len(t, full.AccountGroups, 1)
+	require.NotNil(t, full.AccountGroups[0].Group)
 }

backend/internal/repository/scheduler_cache_unit_test.go

@@ -31,3 +31,43 @@ func TestBuildSchedulerMetadataAccount_KeepsOpenAIWSFlags(t *testing.T) {
 	require.Equal(t, true, got.Extra["mixed_scheduling"])
 	require.Nil(t, got.Extra["unused_large_field"])
 }
+
+func TestBuildSchedulerMetadataAccount_KeepsSlimGroupMembership(t *testing.T) {
+	account := service.Account{
+		ID:       42,
+		Platform: service.PlatformAnthropic,
+		GroupIDs: []int64{7, 9, 7, 0},
+		AccountGroups: []service.AccountGroup{
+			{
+				AccountID: 42,
+				GroupID:   7,
+				Priority:  2,
+				Account:   &service.Account{ID: 42, Name: "drop-from-metadata"},
+				Group:     &service.Group{ID: 7, Name: "drop-from-metadata"},
+			},
+			{
+				AccountID: 42,
+				GroupID:   11,
+				Priority:  3,
+				Group:     &service.Group{ID: 11, Name: "drop-from-metadata"},
+			},
+			{
+				AccountID: 42,
+				GroupID:   0,
+				Priority:  4,
+			},
+		},
+	}
+
+	got := buildSchedulerMetadataAccount(account)
+
+	require.Equal(t, []int64{7, 9, 11}, got.GroupIDs)
+	require.Len(t, got.AccountGroups, 2)
+	require.Equal(t, int64(42), got.AccountGroups[0].AccountID)
+	require.Equal(t, int64(7), got.AccountGroups[0].GroupID)
+	require.Equal(t, 2, got.AccountGroups[0].Priority)
+	require.Nil(t, got.AccountGroups[0].Account)
+	require.Nil(t, got.AccountGroups[0].Group)
+	require.Equal(t, int64(11), got.AccountGroups[1].GroupID)
+	require.Nil(t, got.Groups)
+}

backend/internal/service/gateway_service.go

@@ -654,15 +654,31 @@ func (s *GatewayService) GenerateSessionHash(parsed *ParsedRequest) string {
 
 	// 1. 最高优先级：从 metadata.user_id 提取 session_xxx
 	if parsed.MetadataUserID != "" {
-		if uid := ParseMetadataUserID(parsed.MetadataUserID); uid != nil && uid.SessionID != "" {
+		uid := ParseMetadataUserID(parsed.MetadataUserID)
+		if uid != nil && uid.SessionID != "" {
+			slog.Info("sticky.hash_source",
+				"source", "metadata_user_id",
+				"session_id", uid.SessionID,
+				"device_id", uid.DeviceID,
+				"is_new_format", uid.IsNewFormat,
+			)
 			return uid.SessionID
 		}
+		slog.Info("sticky.hash_metadata_parse_failed",
+			"metadata_user_id", parsed.MetadataUserID,
+			"parsed_nil", uid == nil,
+		)
 	}
 
 	// 2. 提取带 cache_control: {type: "ephemeral"} 的内容
 	cacheableContent := s.extractCacheableContent(parsed)
 	if cacheableContent != "" {
-		return s.hashContent(cacheableContent)
+		hash := s.hashContent(cacheableContent)
+		slog.Info("sticky.hash_source",
+			"source", "cacheable_content",
+			"hash", hash,
+		)
+		return hash
 	}
 
 	// 3. 最后 fallback: 使用 session上下文 + system + 所有消息的完整摘要串
@@ -702,7 +718,13 @@ func (s *GatewayService) GenerateSessionHash(parsed *ParsedRequest) string {
 		}
 	}
 	if combined.Len() > 0 {
-		return s.hashContent(combined.String())
+		hash := s.hashContent(combined.String())
+		slog.Info("sticky.hash_source",
+			"source", "message_content_fallback",
+			"hash", hash,
+			"content_len", combined.Len(),
+		)
+		return hash
 	}
 
 	return ""
@@ -1406,14 +1428,29 @@ func (s *GatewayService) SelectAccountWithLoadAwareness(ctx context.Context, gro
 	}
 
 	var stickyAccountID int64
+	var stickySource string
 	if prefetch := prefetchedStickyAccountIDFromContext(ctx, groupID); prefetch > 0 {
 		stickyAccountID = prefetch
+		stickySource = "prefetch"
 	} else if sessionHash != "" && s.cache != nil {
 		if accountID, err := s.cache.GetSessionAccountID(ctx, derefGroupID(groupID), sessionHash); err == nil {
 			stickyAccountID = accountID
+			stickySource = "cache"
 		}
 	}
 
+	// [DEBUG-STICKY] 调度器入口日志
+	slog.Info("sticky.scheduler_entry",
+		"group_id", derefGroupID(groupID),
+		"session_hash", shortSessionHash(sessionHash),
+		"sticky_account_id", stickyAccountID,
+		"sticky_source", stickySource,
+		"model", requestedModel,
+		"load_batch", cfg.LoadBatchEnabled,
+		"has_concurrency_svc", s.concurrencyService != nil,
+		"excluded_count", len(excludedIDs),
+	)
+
 	if s.debugModelRoutingEnabled() && requestedModel != "" {
 		groupPlatform := ""
 		if group != nil {
@@ -1589,6 +1626,13 @@ func (s *GatewayService) SelectAccountWithLoadAwareness(ctx context.Context, gro
 		if len(routingCandidates) > 0 {
 			// 1.5. 在路由账号范围内检查粘性会话
 			if sessionHash != "" && stickyAccountID > 0 {
+				slog.Debug("sticky.layer1_5_checking",
+					"sticky_account_id", stickyAccountID,
+					"in_routing_list", containsInt64(routingAccountIDs, stickyAccountID),
+					"is_excluded", isExcluded(stickyAccountID),
+					"in_account_map", func() bool { _, ok := accountByID[stickyAccountID]; return ok }(),
+					"session", shortSessionHash(sessionHash),
+				)
 				if containsInt64(routingAccountIDs, stickyAccountID) && !isExcluded(stickyAccountID) {
 					// 粘性账号在路由列表中，优先使用
 					if stickyAccount, ok := accountByID[stickyAccountID]; ok {
@@ -1612,6 +1656,11 @@ func (s *GatewayService) SelectAccountWithLoadAwareness(ctx context.Context, gro
 									stickyCacheMissReason = "session_limit"
 									// 继续到负载感知选择
 								} else {
+									slog.Debug("sticky.layer1_5_hit",
+										"account_id", stickyAccountID,
+										"session", shortSessionHash(sessionHash),
+										"result", "slot_acquired",
+									)
 									if s.debugModelRoutingEnabled() {
 										logger.LegacyPrintf("service.gateway", "[ModelRoutingDebug] routed sticky hit: group_id=%v model=%s session=%s account=%d", derefGroupID(groupID), requestedModel, shortSessionHash(sessionHash), stickyAccountID)
 									}
@@ -1762,27 +1811,65 @@ func (s *GatewayService) SelectAccountWithLoadAwareness(ctx context.Context, gro
 				// 检查账户是否需要清理粘性会话绑定
 				clearSticky := shouldClearStickySession(account, requestedModel)
 				if clearSticky {
+					slog.Debug("sticky.layer1_5_no_routing_clear",
+						"account_id", accountID,
+						"reason", "should_clear_sticky_session",
+						"session", shortSessionHash(sessionHash),
+					)
 					_ = s.cache.DeleteSessionAccountID(ctx, derefGroupID(groupID), sessionHash)
 				}
-				if !clearSticky && s.isAccountInGroup(account, groupID) &&
-					s.isAccountAllowedForPlatform(account, platform, useMixed) &&
-					(requestedModel == "" || s.isModelSupportedByAccountWithContext(ctx, account, requestedModel)) &&
-					s.isAccountSchedulableForModelSelection(ctx, account, requestedModel) &&
-					s.isAccountSchedulableForQuota(account) &&
-					s.isAccountSchedulableForWindowCost(ctx, account, true) &&
 
-					s.isAccountSchedulableForRPM(ctx, account, true) { // 粘性会话窗口费用+RPM 检查
+				// 注意：不再检查 isAccountInGroup，因为 accountByID 已经从按分组过滤的
+				// accounts 列表构建，账号一定在分组内。而 scheduler snapshot 缓存
+				// 反序列化后 AccountGroups 字段为空，导致 isAccountInGroup 永远返回 false。
+				platformOK := s.isAccountAllowedForPlatform(account, platform, useMixed)
+				modelSupported := requestedModel == "" || s.isModelSupportedByAccountWithContext(ctx, account, requestedModel)
+				modelSchedulable := s.isAccountSchedulableForModelSelection(ctx, account, requestedModel)
+				quotaOK := s.isAccountSchedulableForQuota(account)
+				windowCostOK := s.isAccountSchedulableForWindowCost(ctx, account, true)
+				rpmOK := s.isAccountSchedulableForRPM(ctx, account, true)
+				schedulable := s.isAccountSchedulableForSelection(account)
+
+				slog.Debug("sticky.layer1_5_no_routing_checks",
+					"account_id", accountID,
+					"session", shortSessionHash(sessionHash),
+					"clear_sticky", clearSticky,
+					"schedulable", schedulable,
+					"platform_ok", platformOK,
+					"model_supported", modelSupported,
+					"model_schedulable", modelSchedulable,
+					"quota_ok", quotaOK,
+					"window_cost_ok", windowCostOK,
+					"rpm_ok", rpmOK,
+				)
+
+				if !clearSticky && platformOK && modelSupported && modelSchedulable && quotaOK && windowCostOK && rpmOK && schedulable {
 					result, err := s.tryAcquireAccountSlot(ctx, accountID, account.Concurrency)
 					if err == nil && result.Acquired {
 						// 会话数量限制检查
 						if !s.checkAndRegisterSession(ctx, account, sessionHash) {
 							result.ReleaseFunc() // 释放槽位，继续到 Layer 2
+							slog.Debug("sticky.layer1_5_no_routing_miss",
+								"account_id", accountID,
+								"reason", "session_limit",
+								"session", shortSessionHash(sessionHash),
+							)
 						} else {
+							slog.Debug("sticky.layer1_5_no_routing_hit",
+								"account_id", accountID,
+								"session", shortSessionHash(sessionHash),
+								"result", "slot_acquired",
+							)
 							if s.cache != nil {
 								_ = s.cache.RefreshSessionTTL(ctx, derefGroupID(groupID), sessionHash, stickySessionTTL)
 							}
 							return s.newSelectionResult(ctx, account, true, result.ReleaseFunc, nil)
 						}
+					} else {
+						slog.Debug("sticky.layer1_5_no_routing_slot_busy",
+							"account_id", accountID,
+							"session", shortSessionHash(sessionHash),
+						)
 					}
 
 					waitingCount, _ := s.concurrencyService.GetAccountWaitingCount(ctx, accountID)
@@ -1791,6 +1878,11 @@ func (s *GatewayService) SelectAccountWithLoadAwareness(ctx context.Context, gro
 						if !s.checkAndRegisterSession(ctx, account, sessionHash) {
 							// 会话限制已满，继续到 Layer 2
 						} else {
+							slog.Debug("sticky.layer1_5_no_routing_hit",
+								"account_id", accountID,
+								"session", shortSessionHash(sessionHash),
+								"result", "wait_plan",
+							)
 							return s.newSelectionResult(ctx, account, false, nil, &AccountWaitPlan{
 								AccountID:      accountID,
 								MaxConcurrency: account.Concurrency,
@@ -1799,12 +1891,42 @@ func (s *GatewayService) SelectAccountWithLoadAwareness(ctx context.Context, gro
 							})
 						}
 					}
+				} else if !clearSticky {
+					slog.Debug("sticky.layer1_5_no_routing_miss",
+						"account_id", accountID,
+						"reason", "gate_check_failed",
+						"session", shortSessionHash(sessionHash),
+					)
 				}
+			} else {
+				slog.Debug("sticky.layer1_5_no_routing_miss",
+					"account_id", accountID,
+					"reason", "account_not_in_map",
+					"session", shortSessionHash(sessionHash),
+				)
 			}
 		}
+	} else if len(routingAccountIDs) == 0 && sessionHash != "" {
+		slog.Debug("sticky.layer1_5_no_routing_skip",
+			"sticky_account_id", stickyAccountID,
+			"is_excluded", func() bool { return stickyAccountID > 0 && isExcluded(stickyAccountID) }(),
+			"session", shortSessionHash(sessionHash),
+			"reason", func() string {
+				if stickyAccountID == 0 {
+					return "no_sticky_binding"
+				}
+				return "sticky_account_excluded"
+			}(),
+		)
 	}
 
 	// ============ Layer 2: 负载感知选择 ============
+	slog.Debug("sticky.layer2_fallback",
+		"session", shortSessionHash(sessionHash),
+		"sticky_account_id", stickyAccountID,
+		"reason", "sticky_not_used_falling_back_to_load_balance",
+		"total_accounts", len(accounts),
+	)
 	candidates := make([]*Account, 0, len(accounts))
 	for i := range accounts {
 		acc := &accounts[i]