refactor: 改进分布式任务锁的清理策略

实现两种锁清理模式：
- 单实例模式（默认）：启动时使用 Lua 脚本原子性清理旧锁，解决 worker 重启时���锁残留问题
- 多实例模式：使用 NX 选项竞争锁，依赖 TTL 处理异常退出

可通过 SINGLE_INSTANCE_MODE 环境变量控制模式选择。

frontend/src/composables/useClipboard.ts

@@ -4,11 +4,11 @@ import { log } from '@/utils/logger'
 export function useClipboard() {
   const { success, error: showError } = useToast()
 
-  async function copyToClipboard(text: string): Promise<boolean> {
+  async function copyToClipboard(text: string, showToast = true): Promise<boolean> {
     try {
       if (navigator.clipboard && window.isSecureContext) {
         await navigator.clipboard.writeText(text)
-        success('已复制到剪贴板')
+        if (showToast) success('已复制到剪贴板')
         return true
       }
 
@@ -25,17 +25,17 @@ export function useClipboard() {
       try {
         const successful = document.execCommand('copy')
         if (successful) {
-          success('已复制到剪贴板')
+          if (showToast) success('已复制到剪贴板')
           return true
         }
-        showError('复制失败，请手动复制')
+        if (showToast) showError('复制失败，请手动复制')
         return false
       } finally {
         document.body.removeChild(textArea)
       }
     } catch (err) {
       log.error('复制失败:', err)
-      showError('复制失败，请手动选择文本进行复制')
+      if (showToast) showError('复制失败，请手动选择文本进行复制')
       return false
     }
   }

frontend/src/features/models/components/ModelDetailDrawer.vue

@@ -700,6 +700,7 @@ import {
 } from 'lucide-vue-next'
 import { useEscapeKey } from '@/composables/useEscapeKey'
 import { useToast } from '@/composables/useToast'
+import { useClipboard } from '@/composables/useClipboard'
 import Card from '@/components/ui/card.vue'
 import Badge from '@/components/ui/badge.vue'
 import Button from '@/components/ui/button.vue'
@@ -731,6 +732,7 @@ const emit = defineEmits<{
   'refreshProviders': []
 }>()
 const { success: showSuccess, error: showError } = useToast()
+const { copyToClipboard } = useClipboard()
 
 interface Props {
   model: GlobalModelResponse | null
@@ -763,16 +765,6 @@ function handleClose() {
   }
 }
 
-// 复制到剪贴板
-async function copyToClipboard(text: string) {
-  try {
-    await navigator.clipboard.writeText(text)
-    showSuccess('已复制')
-  } catch {
-    showError('复制失败')
-  }
-}
-
 // 格式化日期
 function formatDate(dateStr: string): string {
   if (!dateStr) return '-'

frontend/src/features/providers/components/BatchAssignModelsDialog.vue

@@ -433,11 +433,17 @@ const availableGlobalModels = computed(() => {
   )
 })
 
-// 计算可添加的上游模型（排除已关联的）
+// 计算可添加的上游模型（排除已关联的，包括主模型名和映射名称）
 const availableUpstreamModelsBase = computed(() => {
-  const existingModelNames = new Set(
-    existingModels.value.map(m => m.provider_model_name)
-  )
+  const existingModelNames = new Set<string>()
+  for (const m of existingModels.value) {
+    // 主模型名
+    existingModelNames.add(m.provider_model_name)
+    // 映射名称
+    for (const mapping of m.provider_model_mappings ?? []) {
+      if (mapping.name) existingModelNames.add(mapping.name)
+    }
+  }
   return upstreamModels.value.filter(m => !existingModelNames.has(m.id))
 })
 

frontend/src/features/providers/components/ModelMappingDialog.vue

@@ -449,7 +449,17 @@ interface UpstreamModelGroup {
 }
 
 const groupedAvailableUpstreamModels = computed<UpstreamModelGroup[]>(() => {
+  // 收集当前表单已添加的名称
   const addedNames = new Set(formData.value.aliases.map(a => a.name.trim()))
+
+  // 收集所有已存在的映射名称（包括主模型名和映射名称）
+  for (const m of props.models) {
+    addedNames.add(m.provider_model_name)
+    for (const mapping of m.provider_model_mappings ?? []) {
+      if (mapping.name) addedNames.add(mapping.name)
+    }
+  }
+
   const availableModels = filteredUpstreamModels.value.filter(m => !addedNames.has(m.id))
 
   const groups = new Map<string, UpstreamModelGroup>()

frontend/src/features/providers/components/ProviderDetailDrawer.vue

@@ -661,6 +661,7 @@ import Button from '@/components/ui/button.vue'
 import Badge from '@/components/ui/badge.vue'
 import Card from '@/components/ui/card.vue'
 import { useToast } from '@/composables/useToast'
+import { useClipboard } from '@/composables/useClipboard'
 import { getProvider, getProviderEndpoints } from '@/api/endpoints'
 import {
   KeyFormDialog,
@@ -706,6 +707,7 @@ const emit = defineEmits<{
 }>()
 
 const { error: showError, success: showSuccess } = useToast()
+const { copyToClipboard } = useClipboard()
 
 const loading = ref(false)
 const provider = ref<any>(null)
@@ -1250,16 +1252,6 @@ function getHealthScoreBarColor(score: number): string {
   return 'bg-red-500 dark:bg-red-400'
 }
 
-// 复制到剪贴板
-async function copyToClipboard(text: string) {
-  try {
-    await navigator.clipboard.writeText(text)
-    showSuccess('已复制到剪贴板')
-  } catch {
-    showError('复制失败', '错误')
-  }
-}
-
 // 加载 Provider 信息
 async function loadProvider() {
   if (!props.providerId) return

frontend/src/features/providers/components/provider-tabs/ModelsTab.vue

@@ -224,6 +224,7 @@ import { Box, Edit, Trash2, Layers, Eye, Wrench, Zap, Brain, Power, Copy, Image,
 import Card from '@/components/ui/card.vue'
 import Button from '@/components/ui/button.vue'
 import { useToast } from '@/composables/useToast'
+import { useClipboard } from '@/composables/useClipboard'
 import { getProviderModels, testModel, type Model } from '@/api/endpoints'
 import { updateModel } from '@/api/endpoints/models'
 import { parseTestModelError } from '@/utils/errorParser'
@@ -239,6 +240,7 @@ const emit = defineEmits<{
 }>()
 
 const { error: showError, success: showSuccess } = useToast()
+const { copyToClipboard } = useClipboard()
 
 // 状态
 const loading = ref(false)
@@ -257,12 +259,7 @@ const sortedModels = computed(() => {
 
 // 复制模型 ID 到剪贴板
 async function copyModelId(modelId: string) {
-  try {
-    await navigator.clipboard.writeText(modelId)
-    showSuccess('已复制到剪贴板')
-  } catch {
-    showError('复制失败', '错误')
-  }
+  await copyToClipboard(modelId)
 }
 
 // 加载模型

frontend/src/features/usage/components/RequestDetailDrawer.vue

@@ -473,6 +473,7 @@
 import { ref, watch, computed } from 'vue'
 import Button from '@/components/ui/button.vue'
 import { useEscapeKey } from '@/composables/useEscapeKey'
+import { useClipboard } from '@/composables/useClipboard'
 import Card from '@/components/ui/card.vue'
 import Badge from '@/components/ui/badge.vue'
 import Separator from '@/components/ui/separator.vue'
@@ -505,6 +506,7 @@ const copiedStates = ref<Record<string, boolean>>({})
 const viewMode = ref<'compare' | 'formatted' | 'raw'>('compare')
 const currentExpandDepth = ref(1)
 const dataSource = ref<'client' | 'provider'>('client')
+const { copyToClipboard } = useClipboard()
 const historicalPricing = ref<{
   input_price: string
   output_price: string
@@ -784,7 +786,7 @@ function copyJsonToClipboard(tabName: string) {
   }
 
   if (data) {
-    navigator.clipboard.writeText(JSON.stringify(data, null, 2))
+    copyToClipboard(JSON.stringify(data, null, 2), false)
     copiedStates.value[tabName] = true
     setTimeout(() => {
       copiedStates.value[tabName] = false

frontend/src/features/users/components/UserFormDialog.vue

@@ -86,6 +86,34 @@
             </p>
           </div>
 
+          <div
+            v-if="isEditMode && form.password.length > 0"
+            class="space-y-2"
+          >
+            <Label class="text-sm font-medium">
+              确认新密码 <span class="text-muted-foreground">*</span>
+            </Label>
+            <Input
+              :id="`pwd-confirm-${formNonce}`"
+              v-model="form.confirmPassword"
+              type="password"
+              autocomplete="new-password"
+              data-form-type="other"
+              data-lpignore="true"
+              :name="`confirm-${formNonce}`"
+              required
+              minlength="6"
+              placeholder="再次输入新密码"
+              class="h-10"
+            />
+            <p
+              v-if="form.confirmPassword.length > 0 && form.password !== form.confirmPassword"
+              class="text-xs text-destructive"
+            >
+              两次输入的密码不一致
+            </p>
+          </div>
+
           <div class="space-y-2">
             <Label
               for="form-email"
@@ -423,6 +451,7 @@ const apiFormats = ref<Array<{ value: string; label: string }>>([])
 const form = ref({
   username: '',
   password: '',
+  confirmPassword: '',
   email: '',
   quota: 10,
   role: 'user' as 'admin' | 'user',
@@ -443,6 +472,7 @@ function resetForm() {
   form.value = {
     username: '',
     password: '',
+    confirmPassword: '',
     email: '',
     quota: 10,
     role: 'user',
@@ -461,6 +491,7 @@ function loadUserData() {
   form.value = {
     username: props.user.username,
     password: '',
+    confirmPassword: '',
     email: props.user.email || '',
     quota: props.user.quota_usd == null ? 10 : props.user.quota_usd,
     role: props.user.role,
@@ -486,7 +517,9 @@ const isFormValid = computed(() => {
   const hasUsername = form.value.username.trim().length > 0
   const hasEmail = form.value.email.trim().length > 0
   const hasPassword = isEditMode.value || form.value.password.length >= 6
-  return hasUsername && hasEmail && hasPassword
+  // 编辑模式下如果填写了密码，必须确认密码一致
+  const passwordConfirmed = !isEditMode.value || form.value.password.length === 0 || form.value.password === form.value.confirmPassword
+  return hasUsername && hasEmail && hasPassword && passwordConfirmed
 })
 
 // 加载访问控制选项

frontend/src/views/admin/ApiKeys.vue

@@ -650,6 +650,7 @@
 import { ref, computed, onMounted } from 'vue'
 import { useToast } from '@/composables/useToast'
 import { useConfirm } from '@/composables/useConfirm'
+import { useClipboard } from '@/composables/useClipboard'
 import { adminApi, type AdminApiKey, type CreateStandaloneApiKeyRequest } from '@/api/admin'
 
 import {
@@ -693,6 +694,7 @@ import { log } from '@/utils/logger'
 
 const { success, error } = useToast()
 const { confirmDanger } = useConfirm()
+const { copyToClipboard } = useClipboard()
 
 const apiKeys = ref<AdminApiKey[]>([])
 const loading = ref(false)
@@ -927,20 +929,14 @@ function selectKey() {
 }
 
 async function copyKey() {
-  try {
-    await navigator.clipboard.writeText(newKeyValue.value)
-    success('API Key 已复制到剪贴板')
-  } catch {
-    error('复制失败，请手动复制')
-  }
+  await copyToClipboard(newKeyValue.value)
 }
 
 async function copyKeyPrefix(apiKey: AdminApiKey) {
   try {
     // 调用后端 API 获取完整密钥
     const response = await adminApi.getFullApiKey(apiKey.id)
-    await navigator.clipboard.writeText(response.key)
-    success('完整密钥已复制到剪贴板')
+    await copyToClipboard(response.key)
   } catch (err) {
     log.error('复制密钥失败:', err)
     error('复制失败，请重试')

frontend/src/views/admin/CacheMonitoring.vue

@@ -46,6 +46,7 @@ const clearingRowAffinityKey = ref<string | null>(null)
 const currentPage = ref(1)
 const pageSize = ref(20)
 const currentTime = ref(Math.floor(Date.now() / 1000))
+const analysisHoursSelectOpen = ref(false)
 
 // ==================== 模型映射缓存 ====================
 
@@ -1056,7 +1057,7 @@ onBeforeUnmount(() => {
             <span class="text-xs text-muted-foreground hidden sm:inline">分析用户请求间隔，推荐合适的缓存 TTL</span>
           </div>
           <div class="flex flex-wrap items-center gap-2">
-            <Select v-model="analysisHours">
+            <Select v-model="analysisHours" v-model:open="analysisHoursSelectOpen">
               <SelectTrigger class="w-24 sm:w-28 h-8">
                 <SelectValue placeholder="时间段" />
               </SelectTrigger>

frontend/src/views/admin/ModelManagement.vue

@@ -713,6 +713,7 @@ import ProviderModelFormDialog from '@/features/providers/components/ProviderMod
 import type { Model } from '@/api/endpoints'
 import { useToast } from '@/composables/useToast'
 import { useConfirm } from '@/composables/useConfirm'
+import { useClipboard } from '@/composables/useClipboard'
 import { useRowClick } from '@/composables/useRowClick'
 import { parseApiError } from '@/utils/errorParser'
 import {
@@ -743,6 +744,7 @@ import { getProvidersSummary } from '@/api/endpoints/providers'
 import { getAllCapabilities, type CapabilityDefinition } from '@/api/endpoints'
 
 const { success, error: showError } = useToast()
+const { copyToClipboard } = useClipboard()
 
 // 状态
 const loading = ref(false)
@@ -1066,16 +1068,6 @@ function handleRowClick(event: MouseEvent, model: GlobalModelResponse) {
   selectModel(model)
 }
 
-// 复制到剪贴板
-async function copyToClipboard(text: string) {
-  try {
-    await navigator.clipboard.writeText(text)
-    success('已复制')
-  } catch {
-    showError('复制失败')
-  }
-}
-
 async function selectModel(model: GlobalModelResponse) {
   selectedModel.value = model
   detailTab.value = 'basic'

frontend/src/views/admin/Users.vue

@@ -701,6 +701,7 @@ import { ref, computed, onMounted, watch } from 'vue'
 import { useUsersStore } from '@/stores/users'
 import { useToast } from '@/composables/useToast'
 import { useConfirm } from '@/composables/useConfirm'
+import { useClipboard } from '@/composables/useClipboard'
 import { usageApi, type UsageByUser } from '@/api/usage'
 import { adminApi } from '@/api/admin'
 
@@ -748,6 +749,7 @@ import { log } from '@/utils/logger'
 
 const { success, error } = useToast()
 const { confirmDanger, confirmWarning } = useConfirm()
+const { copyToClipboard } = useClipboard()
 const usersStore = useUsersStore()
 
 // 用户表单对话框状态
@@ -1001,12 +1003,7 @@ function selectApiKey() {
 }
 
 async function copyApiKey() {
-  try {
-    await navigator.clipboard.writeText(newApiKey.value)
-    success('API Key已复制到剪贴板')
-  } catch {
-    error('复制失败，请手动复制')
-  }
+  await copyToClipboard(newApiKey.value)
 }
 
 async function closeNewApiKeyDialog() {
@@ -1035,8 +1032,7 @@ async function copyFullKey(apiKey: any) {
   try {
     // 调用后端 API 获取完整密钥
     const response = await adminApi.getFullApiKey(apiKey.id)
-    await navigator.clipboard.writeText(response.key)
-    success('完整密钥已复制到剪贴板')
+    await copyToClipboard(response.key)
   } catch (err: any) {
     log.error('复制密钥失败:', err)
     error(err.response?.data?.error?.message || err.response?.data?.detail || '未知错误', '复制密钥失败')

frontend/src/views/user/ModelCatalog.vue

@@ -342,6 +342,7 @@ import {
   Plus,
 } from 'lucide-vue-next'
 import { useToast } from '@/composables/useToast'
+import { useClipboard } from '@/composables/useClipboard'
 import {
   Card,
   Table,
@@ -370,6 +371,7 @@ import { useRowClick } from '@/composables/useRowClick'
 import { log } from '@/utils/logger'
 
 const { success, error: showError } = useToast()
+const { copyToClipboard } = useClipboard()
 
 // 状态
 const loading = ref(false)
@@ -565,16 +567,6 @@ function hasTieredPricing(model: PublicGlobalModel): boolean {
   return (tiered?.tiers?.length || 0) > 1
 }
 
-async function copyToClipboard(text: string) {
-  try {
-    await navigator.clipboard.writeText(text)
-    success('已复制')
-  } catch (err) {
-    log.error('复制失败:', err)
-    showError('复制失败')
-  }
-}
-
 onMounted(() => {
   refreshData()
 })

frontend/src/views/user/components/UserModelDetailDrawer.vue

@@ -352,6 +352,7 @@ import {
 } from 'lucide-vue-next'
 import { useEscapeKey } from '@/composables/useEscapeKey'
 import { useToast } from '@/composables/useToast'
+import { useClipboard } from '@/composables/useClipboard'
 import Card from '@/components/ui/card.vue'
 import Badge from '@/components/ui/badge.vue'
 import Button from '@/components/ui/button.vue'
@@ -375,6 +376,7 @@ const emit = defineEmits<{
 }>()
 
 const { success: showSuccess, error: showError } = useToast()
+const { copyToClipboard } = useClipboard()
 
 interface Props {
   model: PublicGlobalModel | null
@@ -408,15 +410,6 @@ function handleClose() {
   emit('update:open', false)
 }
 
-async function copyToClipboard(text: string) {
-  try {
-    await navigator.clipboard.writeText(text)
-    showSuccess('已复制')
-  } catch {
-    showError('复制失败')
-  }
-}
-
 function getFirstTierPrice(
   tieredPricing: TieredPricingConfig | undefined | null,
   priceKey: 'input_price_per_1m' | 'output_price_per_1m' | 'cache_creation_price_per_1m' | 'cache_read_price_per_1m'

src/models/admin_requests.py

@@ -317,6 +317,7 @@ class UpdateUserRequest(BaseModel):
 
     username: Optional[str] = Field(None, min_length=1, max_length=50)
     email: Optional[str] = Field(None, max_length=100)
+    password: Optional[str] = Field(None, min_length=6, max_length=128, description="新密码（留空保持不变）")
     quota_usd: Optional[float] = Field(None, ge=0)
     is_active: Optional[bool] = None
     role: Optional[str] = None

src/services/cache/aware_scheduler.py

@@ -30,6 +30,8 @@
 
 from __future__ import annotations
 
+import hashlib
+import random
 import time
 from dataclasses import dataclass
 from typing import TYPE_CHECKING, Dict, List, Optional, Tuple, Union
@@ -956,7 +958,16 @@ class CacheAwareScheduler:
 
                 # 获取活跃的 Key 并按 internal_priority + 负载均衡排序
                 active_keys = [key for key in endpoint.api_keys if key.is_active]
-                keys = self._shuffle_keys_by_internal_priority(active_keys, affinity_key)
+                # 检查是否所有 Key 都是 TTL=0（轮换模式）
+                # 如果所有 Key 的 cache_ttl_minutes 都是 0 或 None，则使用随机排序
+                use_random = all(
+                    (key.cache_ttl_minutes or 0) == 0 for key in active_keys
+                ) if active_keys else False
+                if use_random and len(active_keys) > 1:
+                    logger.debug(
+                        f"  Endpoint {endpoint.id[:8]}... 启用 Key 轮换模式 (TTL=0, {len(active_keys)} keys)"
+                    )
+                keys = self._shuffle_keys_by_internal_priority(active_keys, affinity_key, use_random)
 
                 for key in keys:
                     # Key 级别的能力检查（模型级别的能力检查已在上面完成）
@@ -1170,6 +1181,7 @@ class CacheAwareScheduler:
         self,
         keys: List[ProviderAPIKey],
         affinity_key: Optional[str] = None,
+        use_random: bool = False,
     ) -> List[ProviderAPIKey]:
         """
         对 API Key 按 internal_priority 分组，同优先级内部基于 affinity_key 进行确定性打乱
@@ -1178,10 +1190,12 @@ class CacheAwareScheduler:
         - 数字越小越优先使用
         - 同优先级 Key 之间实现负载均衡
         - 使用 affinity_key 哈希确保同一请求 Key 的请求稳定（避免破坏缓存亲和性）
+        - 当 use_random=True 时，使用随机排序实现轮换（用于 TTL=0 的场景）
 
         Args:
             keys: API Key 列表
             affinity_key: 亲和性标识符（通常为 API Key ID，用于确定性打乱）
+            use_random: 是否使用随机排序（TTL=0 时为 True）
 
         Returns:
             排序后的 Key 列表
@@ -1198,28 +1212,35 @@ class CacheAwareScheduler:
             priority = key.internal_priority if key.internal_priority is not None else 999999
             priority_groups[priority].append(key)
 
-        # 对每个优先级组内的 Key 进行确定性打乱
+        # 对每个优先级组内的 Key 进行打乱
         result = []
         for priority in sorted(priority_groups.keys()):  # 数字小的优先级高，排前面
             group_keys = priority_groups[priority]
 
-            if len(group_keys) > 1 and affinity_key:
-                # 改进的哈希策略：为每个 key 计算独立的哈希值
-                import hashlib
+            if len(group_keys) > 1:
+                if use_random:
+                    # TTL=0 模式：使用随机排序实现 Key 轮换
+                    shuffled = list(group_keys)
+                    random.shuffle(shuffled)
+                    result.extend(shuffled)
+                elif affinity_key:
+                    # 正常模式：使用哈希确定性打乱（保持缓存亲和性）
+                    key_scores = []
+                    for key in group_keys:
+                        # 使用 affinity_key + key.id 的组合哈希
+                        hash_input = f"{affinity_key}:{key.id}"
+                        hash_value = int(hashlib.sha256(hash_input.encode()).hexdigest()[:16], 16)
+                        key_scores.append((hash_value, key))
 
-                key_scores = []
-                for key in group_keys:
-                    # 使用 affinity_key + key.id 的组合哈希
-                    hash_input = f"{affinity_key}:{key.id}"
-                    hash_value = int(hashlib.sha256(hash_input.encode()).hexdigest()[:16], 16)
-                    key_scores.append((hash_value, key))
-
-                # 按哈希值排序
-                sorted_group = [key for _, key in sorted(key_scores)]
-                result.extend(sorted_group)
+                    # 按哈希值排序
+                    sorted_group = [key for _, key in sorted(key_scores)]
+                    result.extend(sorted_group)
+                else:
+                    # 没有 affinity_key 时按 ID 排序保持稳定性
+                    result.extend(sorted(group_keys, key=lambda k: k.id))
             else:
-                # 单个 Key 或没有 affinity_key 时保持原顺序
-                result.extend(sorted(group_keys, key=lambda k: k.id))
+                # 单个 Key 直接添加
+                result.extend(group_keys)
 
         return result
 

src/utils/task_coordinator.py

@@ -1,8 +1,16 @@
-"""分布式任务协调器，确保仅有一个 worker 执行特定任务"""
+"""分布式任务协调器，确保仅有一个 worker 执行特定任务
+
+锁清理策略：
+- 单实例模式（默认）：启动时使用原子操作清理旧锁并获取新锁
+- 多实例模式：使用 NX 选项竞争锁，依赖 TTL 处理异常退出
+
+使用方式：
+- 默认行为：启动时清理旧锁（适用于单机部署）
+- 多实例部署：设置 SINGLE_INSTANCE_MODE=false 禁用启动清理
+"""
 
 from __future__ import annotations
 
-import asyncio
 import os
 import pathlib
 import uuid
@@ -19,6 +27,10 @@ except ImportError:  # pragma: no cover - Windows 环境
 class StartupTaskCoordinator:
     """利用 Redis 或文件锁，保证任务只在单个进程/实例中运行"""
 
+    # 类级别标记：在当前进程中是否已尝试过启动清理
+    # 注意：这在 fork 模式下每个 worker 都是独立的
+    _startup_cleanup_attempted = False
+
     def __init__(self, redis_client=None, lock_dir: Optional[str] = None):
         self.redis = redis_client
         self._tokens: Dict[str, str] = {}
@@ -26,6 +38,8 @@ class StartupTaskCoordinator:
         self._lock_dir = pathlib.Path(lock_dir or os.getenv("TASK_LOCK_DIR", "./.locks"))
         if not self._lock_dir.exists():
             self._lock_dir.mkdir(parents=True, exist_ok=True)
+        # 单实例模式：启动时清理旧锁（适用于单机部署，避免残留锁问题）
+        self._single_instance_mode = os.getenv("SINGLE_INSTANCE_MODE", "true").lower() == "true"
 
     def _redis_key(self, name: str) -> str:
         return f"task_lock:{name}"
@@ -36,12 +50,51 @@ class StartupTaskCoordinator:
         if self.redis:
             token = str(uuid.uuid4())
             try:
-                acquired = await self.redis.set(self._redis_key(name), token, nx=True, ex=ttl)
-                if acquired:
-                    self._tokens[name] = token
-                    logger.info(f"任务 {name} 通过 Redis 锁独占执行")
-                    return True
-                return False
+                if self._single_instance_mode:
+                    # 单实例模式：使用 Lua 脚本原子性地"清理旧锁 + 竞争获取"
+                    # 只有当锁不存在或成功获取时才返回 1
+                    # 这样第一个执行的 worker 会清理旧锁并获取，后续 worker 会正常竞争
+                    script = """
+                    local key = KEYS[1]
+                    local token = ARGV[1]
+                    local ttl = tonumber(ARGV[2])
+                    local startup_key = KEYS[1] .. ':startup'
+
+                    -- 检查是否已有 worker 执行过启动清理
+                    local cleaned = redis.call('GET', startup_key)
+                    if not cleaned then
+                        -- 第一个 worker：删除旧锁，标记已清理
+                        redis.call('DEL', key)
+                        redis.call('SET', startup_key, '1', 'EX', 60)
+                    end
+
+                    -- 尝试获取锁（NX 模式）
+                    local result = redis.call('SET', key, token, 'NX', 'EX', ttl)
+                    if result then
+                        return 1
+                    end
+                    return 0
+                    """
+                    result = await self.redis.eval(
+                        script, 2,
+                        self._redis_key(name), self._redis_key(name),
+                        token, ttl
+                    )
+                    if result == 1:
+                        self._tokens[name] = token
+                        logger.info(f"任务 {name} 通过 Redis 锁独占执行")
+                        return True
+                    return False
+                else:
+                    # 多实例模式：直接使用 NX 选项竞争锁
+                    acquired = await self.redis.set(
+                        self._redis_key(name), token, nx=True, ex=ttl
+                    )
+                    if acquired:
+                        self._tokens[name] = token
+                        logger.info(f"任务 {name} 通过 Redis 锁独占执行")
+                        return True
+                    return False
             except Exception as exc:  # pragma: no cover - Redis 异常回退
                 logger.warning(f"Redis 锁获取失败，回退到文件锁: {exc}")