功能: v2.1 可观测性与流控 (#47)

* 功能: v2.1 可观测性与流控 — Prometheus + 节点带宽 + 审计 Webhook 核心能力： - Prometheus /metrics 端点：11 类指标（任务/存储/节点/SLA/验证/恢复/复制） - 节点级带宽限速生效：model.Node.BandwidthLimit 覆盖全局默认 - 审计日志 Webhook 外输：HMAC-SHA256 签名，配合 SIEM 合规留档实现： - server/internal/metrics/ 独立 Registry + 异步 Gauge Collector(30s) - backup/restore/verify/replication 服务注入 metrics 钩子，nil 安全 - resolveProviderForNode() 按 task.NodeID 解析 BandwidthLimit - AuditService.SetWebhook + 动态 settings 推送，无需重启测试： - metrics/registry_test.go: 注册/采集/nil safety/HTTP handler - service/audit_service_webhook_test.go: 签名正确性/异步投递/禁用路径 - go test ./... 全部通过 * chore: 触发 CodeQL 扫描
2026-05-06 20:02:41 +08:00 · 2026-04-20 23:26:04 +08:00
parent f7596bd319
commit 5021fe665e
16 changed files with 970 additions and 14 deletions
--- a/README.md
+++ b/README.md
@@ -46,6 +46,9 @@
 | **Multi-Node Cluster** | Master-Agent mode via HTTP long-polling — Agents run tasks locally, upload straight to storage, no reverse connectivity required |
 | **Security** | JWT + bcrypt + AES-256-GCM encrypted config + optional backup encryption + full audit log |
 | **Notifications** | Email / Webhook / Telegram on success or failure |
+| **Observability** | Prometheus `/metrics` endpoint + `/health` + `/ready` probes + SLA breach gauge |
+| **Audit Webhook** | HMAC-SHA256 signed forwarding to SIEM / WORM storage for compliance (SOC2 / GDPR) |
+| **Flow Control** | Per-node bandwidth cap + per-node concurrency limit — tune big/small nodes independently |
 | **Deployment** | Single binary + embedded SQLite, Docker one-click, zero external dependencies |

 ## Quick Start
--- a/README.zh-CN.md
+++ b/README.zh-CN.md
@@ -46,6 +46,9 @@
 | **多节点集群** | Master-Agent 模式，基于 HTTP 长轮询跨多台服务器管理备份。Agent 本地执行任务并直接上传到存储，无需反向连通性 |
 | **安全** | JWT + bcrypt + AES-256-GCM 加密配置 + 可选备份文件加密 + 完整审计日志 |
 | **通知** | 邮件 / Webhook / Telegram，备份成功或失败时自动推送 |
+| **可观测性** | Prometheus `/metrics` 端点 + `/health` + `/ready` 探针 + SLA 违约监控 |
+| **审计外输** | HMAC-SHA256 签名 Webhook，对接 SIEM / WORM 存储满足 SOC2 / GDPR 合规 |
+| **流控** | 节点级带宽限速 + 节点级并发控制，大小节点分别配置，避免小内存 Agent 被挤爆 |
 | **部署** | 单二进制 + 内嵌 SQLite，Docker 一键启动，零外部依赖 |

 ## 快速开始
--- a/docs/superpowers/specs/2026-04-19-observability-flow-control-design.md
+++ b/docs/superpowers/specs/2026-04-19-observability-flow-control-design.md
@@ -0,0 +1,142 @@
+# v2.1.0 可观测性与流控设计 (2026-04-19)
+
+## 背景
+
+v2.0.0 交付了 11 项企业能力（RBAC / API Key / 多节点集群 / 3-2-1 复制 / 验证演练等），产品具备"企业级备份管理平台"的完整能力。v2.1.0 聚焦 "**投入生产后运维团队**" 的两类刚需：
+
+1. **可观测性**：SRE 要能把 BackupX 接入 Prometheus/Grafana 做容量规划与告警。
+2. **流控精细化**：不同节点的带宽/并发应该能各自配置，而不是一刀切。
+3. **审计外输**：合规团队需要把审计事件送到 SIEM / WORM 存储，实现集中留档。
+
+## 范围
+
+**In scope：**
+
+- `/metrics` Prometheus 端点（10+ 核心指标）
+- 节点级带宽限速生效（`model.Node.BandwidthLimit` 已存在但未落地）
+- 审计日志 Webhook 外输（HMAC-SHA256 签名）
+
+**Out of scope（放入后续迭代）：**
+
+- Prometheus 鉴权（企业生产可用反向代理做）
+- Grafana Dashboard JSON 预置
+- 节点级并发已在 v2.0 完成，不再重复
+- 审计事件的 Syslog/Kafka 渠道（Webhook 已能衔接 Fluent Bit）
+- 前端 Settings 页 UI（可 API 配置，UI 后续补）
+
+## 架构
+
+### 1. Prometheus /metrics
+
+```
+业务服务                    metrics.Metrics                 /metrics HTTP
+─────────                  ────────────────                ──────────────
+BackupExec  ─ObserveRun──► Counter+Histogram ◄─Scrape── Prometheus
+Restore     ─ObserveRun──►
+Verify      ─ObserveRun──►
+Replication ─ObserveRun──►
+                           Gauge (storage/node/SLA)
+Collector(30s) ─update───► ▲
+                           │
+                           repo.StorageUsage / Node.List / Task.List
+```
+
+- **独立 Registry**：避免与 default registry 中的默认 metrics 混淆，只暴露 backupx_ + go_ + process_
+- **零值安全**：`*Metrics` nil 时所有方法静默退化，不影响未注入 metrics 的单测
+- **Gauge 异步刷新**：30s 后台 goroutine 采集慢查询数据，避免阻塞 /metrics 请求
+- **Counter/Histogram 同步**：任务完成时直接 Observe，延迟 < 1μs
+
+指标清单：
+
+| 指标 | 类型 | 标签 | 含义 |
+|------|------|------|------|
+| `backupx_task_run_total` | Counter | status, task_type | 备份任务运行计数 |
+| `backupx_task_run_duration_seconds` | Histogram | task_type | 任务耗时分布 |
+| `backupx_task_bytes_total` | Counter | task_type | 累计产出字节数 |
+| `backupx_task_running` | Gauge | - | 正在运行任务数 |
+| `backupx_storage_used_bytes` | Gauge | target_name, target_type | 存储目标用量 |
+| `backupx_node_online` | Gauge | node_name, role | 节点在线状态 |
+| `backupx_verify_run_total` | Counter | status | 验证演练计数 |
+| `backupx_restore_run_total` | Counter | status | 恢复操作计数 |
+| `backupx_replication_run_total` | Counter | status | 副本复制计数 |
+| `backupx_sla_breach_tasks` | Gauge | - | 违反 SLA 任务数 |
+| `backupx_app_info` | Gauge | version | 应用版本（恒为 1） |
+
+### 2. 节点级带宽限速
+
+现状：`BackupExecutionService` 在 `resolveProvider()` 中用全局 `s.bandwidthLimit`（来自 `cfg.Backup.BandwidthLimit`）注入 rclone TransferConfig。
+
+改进：新增 `resolveProviderForNode(ctx, targetID, nodeID)`：
+
+```go
+func (s *BackupExecutionService) effectiveBandwidth(ctx context.Context, nodeID uint) string {
+    if nodeID == 0 || s.nodeRepo == nil {
+        return s.bandwidthLimit
+    }
+    node, err := s.nodeRepo.FindByID(ctx, nodeID)
+    if err != nil || node == nil {
+        return s.bandwidthLimit
+    }
+    if strings.TrimSpace(node.BandwidthLimit) != "" {
+        return node.BandwidthLimit
+    }
+    return s.bandwidthLimit
+}
+```
+
+优先级：`Node.BandwidthLimit` > 全局默认。仅 Master 本地执行生效；Agent 使用自身 Node 配置（在 Agent runtime 中独立应用）。
+
+### 3. 审计 Webhook
+
+```
+AuditService.Record(entry)
+   │
+   ├─> repo.Create (写 DB)                     [fire-and-forget]
+   └─> fireWebhook(record)                     [fire-and-forget]
+         │
+         ├─ HTTP POST JSON to webhookURL
+         ├─ Header: X-BackupX-Signature: sha256=<hmac>
+         └─ 失败: log.Printf，不阻塞主流程
+```
+
+Payload schema：
+
+```json
+{
+  "eventType": "audit.log",
+  "occurredAt": "2026-04-19T10:30:00Z",
+  "actor": { "userId": 1, "username": "alice" },
+  "category": "auth",
+  "action": "login_success",
+  "targetType": "user",
+  "targetId": "1",
+  "targetName": "alice",
+  "detail": "admin login",
+  "clientIp": "10.0.0.1"
+}
+```
+
+签名：`HMAC-SHA256(secret, raw_json_body)`，接收方需要验证以防伪造。
+
+配置路径：前端通过 `PUT /api/settings` 写入 `audit_webhook_url` / `audit_webhook_secret`，SettingsService 保存后立即通过 `AuditWebhookConfigurer` 接口同步到 AuditService，无需重启。
+
+## 测试
+
+- `metrics/registry_test.go` — 注册、采集、nil safety、HTTP handler 端到端
+- `service/audit_service_webhook_test.go` — 签名正确性、异步发送、禁用路径
+- 所有现有测试保持通过（backup_execution_service_test / restore_service_test / verification_service_test）
+
+## 风险与应对
+
+| 风险 | 应对 |
+|------|------|
+| Prometheus 采集阻塞 | Gauge 走后台 Collector + Counter/Histogram 是内存操作，无 IO |
+| Webhook 打爆业务 | 3s 超时 + fire-and-forget goroutine，单次 panic 也不影响主流程 |
+| 指标基数爆炸 | task_name 不作为 label（仅 task_type），避免 Prometheus series 失控 |
+| 节点带宽配置错误 | 走 rclone.BwTimetable.Set 校验，解析失败静默沿用全局默认 |
+
+## 部署建议
+
+- Prometheus 抓取配置：`scrape_interval: 30s`，匹配 Collector 间隔
+- Grafana alert 示例：`sum(backupx_sla_breach_tasks) > 0` 触发
+- Webhook 接收侧建议：Fluent Bit HTTP input → Elasticsearch / Loki
--- a/server/go.mod
+++ b/server/go.mod
@@ -7,6 +7,7 @@ require (
 	github.com/glebarez/sqlite v1.11.0
 	github.com/golang-jwt/jwt/v5 v5.3.0
 	github.com/natefinch/lumberjack v2.0.0+incompatible
+	github.com/prometheus/client_golang v1.23.2
 	github.com/rclone/rclone v1.73.3
 	github.com/robfig/cron/v3 v3.0.1
 	github.com/spf13/viper v1.20.0
@@ -181,7 +182,6 @@ require (
 	github.com/pmezard/go-difflib v1.0.1-0.20181226105442-5d4384ee4fb2 // indirect
 	github.com/power-devops/perfstat v0.0.0-20240221224432-82ca36839d55 // indirect
 	github.com/pquerna/otp v1.5.0 // indirect
-	github.com/prometheus/client_golang v1.23.2 // indirect
 	github.com/prometheus/client_model v0.6.2 // indirect
 	github.com/prometheus/common v0.67.2 // indirect
 	github.com/prometheus/procfs v0.19.2 // indirect
--- a/server/internal/app/app.go
+++ b/server/internal/app/app.go
@@ -13,6 +13,7 @@ import (
 	"backupx/server/internal/database"
 	aphttp "backupx/server/internal/http"
 	"backupx/server/internal/logger"
+	"backupx/server/internal/metrics"
 	"backupx/server/internal/notify"
 	"backupx/server/internal/repository"
 	"backupx/server/internal/scheduler"
@@ -109,6 +110,8 @@ func New(ctx context.Context, cfg config.Config, version string) (*Application,
 	auditService := service.NewAuditService(auditLogRepo)
 	authService.SetAuditService(auditService)
 	schedulerService.SetAuditRecorder(auditService)
+	// 审计日志外输：启动时用当前 settings 初始化 webhook，后续前端修改立即生效
+	settingsService.SetAuditWebhookConfigurer(ctx, auditService)

 	// Database discovery（集群依赖在 agentService 创建后注入）
 	databaseDiscoveryService := service.NewDatabaseDiscoveryService(backup.NewOSCommandExecutor())
@@ -226,6 +229,21 @@ func New(ctx context.Context, cfg config.Config, version string) (*Application,
 	// Dashboard 集群概览依赖注入
 	dashboardService.SetClusterDependencies(nodeRepo, version)

+	// Prometheus 指标采集：Counter/Histogram 由业务服务实时写入；
+	// Gauge 类（存储用量、节点在线、SLA 违约）由 Collector 每 30s 异步刷新，
+	// 避免 /metrics 请求路径做慢 IO。
+	appMetrics := metrics.New(version)
+	backupExecutionService.SetMetrics(appMetrics)
+	restoreService.SetMetrics(appMetrics)
+	verificationService.SetMetrics(appMetrics)
+	replicationService.SetMetrics(appMetrics)
+	metricsCollector := metrics.NewCollector(
+		appMetrics,
+		metrics.NewRepoSource(storageTargetRepo, backupRecordRepo, nodeRepo, backupTaskRepo),
+		30*time.Second,
+	)
+	metricsCollector.Start(ctx)
+
 	router := aphttp.NewRouter(aphttp.RouterDependencies{
 		Context:                ctx,
 		Config:                 cfg,
@@ -259,6 +277,7 @@ func New(ctx context.Context, cfg config.Config, version string) (*Application,
 		InstallTokenService:      installTokenService,
 		MasterExternalURL:        "", // 如需覆盖 URL，可扩展 cfg.Server 增字段；目前留空依赖 X-Forwarded-* / Request.Host
 		DB:                       db,
+		Metrics:                  appMetrics,
 	})

 	httpServer := &stdhttp.Server{
--- a/server/internal/http/router.go
+++ b/server/internal/http/router.go
@@ -7,6 +7,7 @@ import (

 	"backupx/server/internal/apperror"
 	"backupx/server/internal/config"
+	"backupx/server/internal/metrics"
 	"backupx/server/internal/repository"
 	"backupx/server/internal/security"
 	"backupx/server/internal/service"
@@ -52,6 +53,8 @@ type RouterDependencies struct {
 	MasterExternalURL        string
 	// DB 注入给健康检查端点做 liveness/readiness 探测。
 	DB *gorm.DB
+	// Metrics 注入给 /metrics 端点；为 nil 时端点返回 503。
+	Metrics *metrics.Metrics
 }

 func NewRouter(deps RouterDependencies) *gin.Engine {
@@ -311,6 +314,12 @@ func NewRouter(deps RouterDependencies) *gin.Engine {
 	engine.GET("/api/health", healthHandler.Live)
 	engine.GET("/api/ready", healthHandler.Ready)

+	// Prometheus /metrics 端点（公开、无认证；内网/反向代理授权即可）。
+	// 业内通行做法：/metrics 通常由 Prometheus pull 抓取，不走 API Key。
+	if deps.Metrics != nil {
+		engine.GET("/metrics", gin.WrapH(deps.Metrics.Handler()))
+	}
+
 	// 公开安装路由（不走 JWT 中间件）
 	if deps.InstallTokenService != nil {
 		gcCtx := deps.Context
--- a/server/internal/metrics/collector.go
+++ b/server/internal/metrics/collector.go
@@ -0,0 +1,152 @@
+package metrics
+
+import (
+	"context"
+	"time"
+
+	"backupx/server/internal/model"
+	"backupx/server/internal/repository"
+)
+
+// SampleSource 抽象 Collector 需要的仓储访问，便于单测替换。
+type SampleSource interface {
+	ListStorageTargets(ctx context.Context) ([]model.StorageTarget, error)
+	StorageUsage(ctx context.Context) ([]repository.BackupStorageUsageItem, error)
+	ListNodes(ctx context.Context) ([]model.Node, error)
+	CountSLABreach(ctx context.Context) (int, error)
+}
+
+// repoSource 把 repository 适配到 SampleSource。
+type repoSource struct {
+	targets repository.StorageTargetRepository
+	records repository.BackupRecordRepository
+	nodes   repository.NodeRepository
+	tasks   repository.BackupTaskRepository
+	now     func() time.Time
+}
+
+// NewRepoSource 用仓储实例构造 SampleSource。
+func NewRepoSource(
+	targets repository.StorageTargetRepository,
+	records repository.BackupRecordRepository,
+	nodes repository.NodeRepository,
+	tasks repository.BackupTaskRepository,
+) SampleSource {
+	return &repoSource{
+		targets: targets,
+		records: records,
+		nodes:   nodes,
+		tasks:   tasks,
+		now:     func() time.Time { return time.Now().UTC() },
+	}
+}
+
+func (s *repoSource) ListStorageTargets(ctx context.Context) ([]model.StorageTarget, error) {
+	return s.targets.List(ctx)
+}
+
+func (s *repoSource) StorageUsage(ctx context.Context) ([]repository.BackupStorageUsageItem, error) {
+	return s.records.StorageUsage(ctx)
+}
+
+func (s *repoSource) ListNodes(ctx context.Context) ([]model.Node, error) {
+	return s.nodes.List(ctx)
+}
+
+// CountSLABreach 统计当前违反 RPO 的任务：
+//   - 任务启用且配置了 SLAHoursRPO > 0
+//   - 最近一次成功备份距今超出 SLA 时间窗，或从未成功过
+func (s *repoSource) CountSLABreach(ctx context.Context) (int, error) {
+	tasks, err := s.tasks.List(ctx, repository.BackupTaskListOptions{})
+	if err != nil {
+		return 0, err
+	}
+	now := s.now()
+	count := 0
+	for i := range tasks {
+		task := &tasks[i]
+		if task.SLAHoursRPO <= 0 || !task.Enabled {
+			continue
+		}
+		threshold := now.Add(-time.Duration(task.SLAHoursRPO) * time.Hour)
+		if task.LastRunAt == nil || task.LastRunAt.Before(threshold) {
+			count++
+		}
+	}
+	return count, nil
+}
+
+// Collector 周期性采集 gauge 类指标（存储用量、节点在线、SLA 违约）。
+// 用后台 goroutine 驱动，避免在 /metrics 请求路径做慢 IO。
+type Collector struct {
+	metrics  *Metrics
+	source   SampleSource
+	interval time.Duration
+}
+
+// NewCollector 创建周期采集器。interval=0 走默认 30s。
+func NewCollector(m *Metrics, source SampleSource, interval time.Duration) *Collector {
+	if interval <= 0 {
+		interval = 30 * time.Second
+	}
+	return &Collector{metrics: m, source: source, interval: interval}
+}
+
+// Start 在后台运行采集循环；随 ctx 取消而终止。
+// 启动时立即采一次，之后按 interval 轮询。
+func (c *Collector) Start(ctx context.Context) {
+	if c == nil || c.metrics == nil || c.source == nil {
+		return
+	}
+	go func() {
+		c.collect(ctx)
+		ticker := time.NewTicker(c.interval)
+		defer ticker.Stop()
+		for {
+			select {
+			case <-ctx.Done():
+				return
+			case <-ticker.C:
+				c.collect(ctx)
+			}
+		}
+	}()
+}
+
+// collect 执行一次采样；单轮失败不影响下次。
+func (c *Collector) collect(ctx context.Context) {
+	// 存储用量：按 StorageTargetID 聚合 file_size，对应 target name/type
+	if targets, err := c.source.ListStorageTargets(ctx); err == nil {
+		nameByID := make(map[uint]string, len(targets))
+		typeByID := make(map[uint]string, len(targets))
+		for i := range targets {
+			nameByID[targets[i].ID] = targets[i].Name
+			typeByID[targets[i].ID] = targets[i].Type
+		}
+		if usage, uerr := c.source.StorageUsage(ctx); uerr == nil {
+			c.metrics.ResetStorageUsed()
+			for _, item := range usage {
+				name := nameByID[item.StorageTargetID]
+				if name == "" {
+					continue
+				}
+				c.metrics.SetStorageUsed(name, typeByID[item.StorageTargetID], item.TotalSize)
+			}
+		}
+	}
+	// 节点在线状态：role 约定为 master / agent
+	if nodes, err := c.source.ListNodes(ctx); err == nil {
+		c.metrics.ResetNodeOnline()
+		for i := range nodes {
+			n := &nodes[i]
+			role := "agent"
+			if n.IsLocal {
+				role = "master"
+			}
+			c.metrics.SetNodeOnline(n.Name, role, n.Status == model.NodeStatusOnline)
+		}
+	}
+	if breach, err := c.source.CountSLABreach(ctx); err == nil {
+		c.metrics.SetSLABreach(breach)
+	}
+}
--- a/server/internal/metrics/registry.go
+++ b/server/internal/metrics/registry.go
@@ -0,0 +1,225 @@
+// Package metrics 暴露 BackupX 的 Prometheus 采集器。
+//
+// 设计要点：
+//   - 使用独立 Registry，避免与 default registry 中的 Go runtime metrics 混淆
+//   - Counter/Gauge/Histogram 全部以 backupx_ 为前缀，遵循 Prometheus 命名规范
+//   - 所有指标都支持零值：未注入时调用方法是 no-op，不会 panic
+//   - 组件只依赖本包，不反向引用 service/repository，避免循环
+package metrics
+
+import (
+	"net/http"
+
+	"github.com/prometheus/client_golang/prometheus"
+	"github.com/prometheus/client_golang/prometheus/collectors"
+	"github.com/prometheus/client_golang/prometheus/promhttp"
+)
+
+// Metrics 聚合所有采集器，由 app 层组装一次并按需注入到 service。
+type Metrics struct {
+	registry *prometheus.Registry
+
+	// 任务执行计数（labels: status, task_type）
+	TaskRunTotal *prometheus.CounterVec
+	// 任务耗时分布（labels: task_type）
+	TaskRunDuration *prometheus.HistogramVec
+	// 任务产出字节数（labels: task_type）
+	TaskBytesTotal *prometheus.CounterVec
+	// 正在运行的任务数
+	TaskRunningGauge prometheus.Gauge
+	// 存储目标用量（labels: target_name, target_type）
+	StorageUsedBytes *prometheus.GaugeVec
+	// 节点在线状态（labels: node_name, role；value: 0/1）
+	NodeOnline *prometheus.GaugeVec
+	// 验证演练结果（labels: status）
+	VerifyRunTotal *prometheus.CounterVec
+	// 恢复操作结果（labels: status）
+	RestoreRunTotal *prometheus.CounterVec
+	// 副本复制结果（labels: status）
+	ReplicationRunTotal *prometheus.CounterVec
+	// SLA 违约数（gauge）
+	SLABreachGauge prometheus.Gauge
+	// 应用信息（label: version）
+	AppInfo *prometheus.GaugeVec
+}
+
+// New 构造并注册所有采集器。
+// 失败时 panic：采集器注册失败属于启动期编程错误，没有合理 fallback。
+func New(version string) *Metrics {
+	reg := prometheus.NewRegistry()
+	// 注入标准 Go runtime + process 指标
+	reg.MustRegister(collectors.NewGoCollector())
+	reg.MustRegister(collectors.NewProcessCollector(collectors.ProcessCollectorOpts{}))
+
+	m := &Metrics{
+		registry: reg,
+		TaskRunTotal: prometheus.NewCounterVec(prometheus.CounterOpts{
+			Name: "backupx_task_run_total",
+			Help: "备份任务执行总数，按状态和任务类型细分",
+		}, []string{"status", "task_type"}),
+		TaskRunDuration: prometheus.NewHistogramVec(prometheus.HistogramOpts{
+			Name:    "backupx_task_run_duration_seconds",
+			Help:    "备份任务耗时分布",
+			Buckets: []float64{1, 5, 15, 30, 60, 120, 300, 600, 1800, 3600, 7200},
+		}, []string{"task_type"}),
+		TaskBytesTotal: prometheus.NewCounterVec(prometheus.CounterOpts{
+			Name: "backupx_task_bytes_total",
+			Help: "备份任务累计产出字节数",
+		}, []string{"task_type"}),
+		TaskRunningGauge: prometheus.NewGauge(prometheus.GaugeOpts{
+			Name: "backupx_task_running",
+			Help: "当前正在执行的备份任务数",
+		}),
+		StorageUsedBytes: prometheus.NewGaugeVec(prometheus.GaugeOpts{
+			Name: "backupx_storage_used_bytes",
+			Help: "存储目标已用字节数",
+		}, []string{"target_name", "target_type"}),
+		NodeOnline: prometheus.NewGaugeVec(prometheus.GaugeOpts{
+			Name: "backupx_node_online",
+			Help: "集群节点在线状态（1 在线 / 0 离线）",
+		}, []string{"node_name", "role"}),
+		VerifyRunTotal: prometheus.NewCounterVec(prometheus.CounterOpts{
+			Name: "backupx_verify_run_total",
+			Help: "备份验证演练执行总数",
+		}, []string{"status"}),
+		RestoreRunTotal: prometheus.NewCounterVec(prometheus.CounterOpts{
+			Name: "backupx_restore_run_total",
+			Help: "恢复操作执行总数",
+		}, []string{"status"}),
+		ReplicationRunTotal: prometheus.NewCounterVec(prometheus.CounterOpts{
+			Name: "backupx_replication_run_total",
+			Help: "备份副本复制执行总数",
+		}, []string{"status"}),
+		SLABreachGauge: prometheus.NewGauge(prometheus.GaugeOpts{
+			Name: "backupx_sla_breach_tasks",
+			Help: "当前违反 SLA/RPO 的任务数",
+		}),
+		AppInfo: prometheus.NewGaugeVec(prometheus.GaugeOpts{
+			Name: "backupx_app_info",
+			Help: "BackupX 应用元信息（恒为 1，通过 label 暴露版本号）",
+		}, []string{"version"}),
+	}
+	reg.MustRegister(
+		m.TaskRunTotal,
+		m.TaskRunDuration,
+		m.TaskBytesTotal,
+		m.TaskRunningGauge,
+		m.StorageUsedBytes,
+		m.NodeOnline,
+		m.VerifyRunTotal,
+		m.RestoreRunTotal,
+		m.ReplicationRunTotal,
+		m.SLABreachGauge,
+		m.AppInfo,
+	)
+	m.AppInfo.WithLabelValues(version).Set(1)
+	return m
+}
+
+// Handler 返回 /metrics 的 HTTP handler。
+// 使用本包专属 registry，避免混入其他组件的默认 metrics。
+func (m *Metrics) Handler() http.Handler {
+	if m == nil {
+		return http.HandlerFunc(func(w http.ResponseWriter, _ *http.Request) {
+			http.Error(w, "metrics disabled", http.StatusServiceUnavailable)
+		})
+	}
+	return promhttp.HandlerFor(m.registry, promhttp.HandlerOpts{
+		EnableOpenMetrics: false,
+	})
+}
+
+// ObserveTaskRun 记录一次任务执行结果。
+// status 常用值：success / failed / cancelled。nil 接收器安全。
+func (m *Metrics) ObserveTaskRun(taskType, status string, durationSec float64, bytes int64) {
+	if m == nil {
+		return
+	}
+	m.TaskRunTotal.WithLabelValues(status, taskType).Inc()
+	m.TaskRunDuration.WithLabelValues(taskType).Observe(durationSec)
+	if bytes > 0 {
+		m.TaskBytesTotal.WithLabelValues(taskType).Add(float64(bytes))
+	}
+}
+
+// IncTaskRunning / DecTaskRunning 配套使用，反映并发中任务数。
+func (m *Metrics) IncTaskRunning() {
+	if m == nil {
+		return
+	}
+	m.TaskRunningGauge.Inc()
+}
+
+func (m *Metrics) DecTaskRunning() {
+	if m == nil {
+		return
+	}
+	m.TaskRunningGauge.Dec()
+}
+
+// ObserveRestore / ObserveVerify / ObserveReplication 记录子动作结果。
+// 所有方法对 nil 接收器安全：未注入 Metrics 时静默降级，不 panic。
+func (m *Metrics) ObserveRestore(status string) {
+	if m == nil {
+		return
+	}
+	m.RestoreRunTotal.WithLabelValues(status).Inc()
+}
+
+func (m *Metrics) ObserveVerify(status string) {
+	if m == nil {
+		return
+	}
+	m.VerifyRunTotal.WithLabelValues(status).Inc()
+}
+
+func (m *Metrics) ObserveReplication(status string) {
+	if m == nil {
+		return
+	}
+	m.ReplicationRunTotal.WithLabelValues(status).Inc()
+}
+
+// SetStorageUsed 刷新某存储目标的用量。调用方负责周期采集。
+func (m *Metrics) SetStorageUsed(name, targetType string, bytes int64) {
+	if m == nil {
+		return
+	}
+	m.StorageUsedBytes.WithLabelValues(name, targetType).Set(float64(bytes))
+}
+
+// SetNodeOnline 刷新节点在线状态。
+func (m *Metrics) SetNodeOnline(name, role string, online bool) {
+	if m == nil {
+		return
+	}
+	val := 0.0
+	if online {
+		val = 1
+	}
+	m.NodeOnline.WithLabelValues(name, role).Set(val)
+}
+
+// ResetNodeOnline 清空节点 gauge（当节点被删除时避免残留指标）。
+func (m *Metrics) ResetNodeOnline() {
+	if m == nil {
+		return
+	}
+	m.NodeOnline.Reset()
+}
+
+// ResetStorageUsed 清空存储目标 gauge。
+func (m *Metrics) ResetStorageUsed() {
+	if m == nil {
+		return
+	}
+	m.StorageUsedBytes.Reset()
+}
+
+// SetSLABreach 刷新 SLA 违约任务数。
+func (m *Metrics) SetSLABreach(count int) {
+	if m == nil {
+		return
+	}
+	m.SLABreachGauge.Set(float64(count))
+}
--- a/server/internal/metrics/registry_test.go
+++ b/server/internal/metrics/registry_test.go
@@ -0,0 +1,76 @@
+package metrics
+
+import (
+	"io"
+	"net/http/httptest"
+	"strings"
+	"testing"
+
+	"github.com/prometheus/client_golang/prometheus/testutil"
+)
+
+func TestNew_AppInfoVersionLabel(t *testing.T) {
+	m := New("2.1.0")
+	if got := testutil.ToFloat64(m.AppInfo.WithLabelValues("2.1.0")); got != 1 {
+		t.Fatalf("app_info(version=2.1.0) expected 1, got %v", got)
+	}
+}
+
+func TestObserveTaskRun_IncrementsCounterAndHistogram(t *testing.T) {
+	m := New("test")
+	m.ObserveTaskRun("mysql", "success", 12.5, 1024)
+	m.ObserveTaskRun("mysql", "failed", 3.0, 0)
+	if got := testutil.ToFloat64(m.TaskRunTotal.WithLabelValues("success", "mysql")); got != 1 {
+		t.Fatalf("task_run_total{status=success,task_type=mysql}: expected 1, got %v", got)
+	}
+	if got := testutil.ToFloat64(m.TaskRunTotal.WithLabelValues("failed", "mysql")); got != 1 {
+		t.Fatalf("task_run_total{status=failed,task_type=mysql}: expected 1, got %v", got)
+	}
+	if got := testutil.ToFloat64(m.TaskBytesTotal.WithLabelValues("mysql")); got != 1024 {
+		t.Fatalf("task_bytes_total{task_type=mysql}: expected 1024, got %v", got)
+	}
+}
+
+func TestObserveTaskRun_NilReceiverIsSafe(t *testing.T) {
+	var m *Metrics // nil
+	m.ObserveTaskRun("file", "success", 1, 1)
+	m.ObserveRestore("success")
+	m.ObserveVerify("failed")
+	m.ObserveReplication("success")
+	m.IncTaskRunning()
+	m.DecTaskRunning()
+	m.SetStorageUsed("a", "s3", 1)
+	m.SetNodeOnline("n1", "master", true)
+	m.SetSLABreach(3)
+	m.ResetNodeOnline()
+	m.ResetStorageUsed()
+	// no panic -> pass
+}
+
+func TestHandler_ExposesBackupxMetrics(t *testing.T) {
+	m := New("0.0.0-test")
+	m.ObserveTaskRun("file", "success", 1.0, 2048)
+	m.SetNodeOnline("n1", "master", true)
+	m.SetSLABreach(1)
+
+	recorder := httptest.NewRecorder()
+	req := httptest.NewRequest("GET", "/metrics", nil)
+	m.Handler().ServeHTTP(recorder, req)
+
+	body, err := io.ReadAll(recorder.Result().Body)
+	if err != nil {
+		t.Fatalf("read body: %v", err)
+	}
+	content := string(body)
+	for _, keyword := range []string{
+		"backupx_task_run_total",
+		"backupx_task_run_duration_seconds",
+		"backupx_node_online",
+		"backupx_sla_breach_tasks",
+		"backupx_app_info",
+	} {
+		if !strings.Contains(content, keyword) {
+			t.Errorf("expected /metrics to contain %q", keyword)
+		}
+	}
+}
--- a/server/internal/service/audit_service.go
+++ b/server/internal/service/audit_service.go
@@ -1,9 +1,18 @@
 package service

 import (
+	"bytes"
 	"context"
+	"crypto/hmac"
+	"crypto/sha256"
+	"encoding/hex"
+	"encoding/json"
 	"fmt"
 	"log"
+	"net/http"
+	"strings"
+	"sync"
+	"time"

 	"backupx/server/internal/apperror"
 	"backupx/server/internal/model"
@@ -25,10 +34,39 @@ type AuditEntry struct {

 type AuditService struct {
 	repo repository.AuditLogRepository
+
+	// webhook 外输配置（可选）
+	webhookMu     sync.RWMutex
+	webhookURL    string
+	webhookSecret string
+	httpClient    *http.Client
 }

 func NewAuditService(repo repository.AuditLogRepository) *AuditService {
-	return &AuditService{repo: repo}
+	return &AuditService{
+		repo: repo,
+		httpClient: &http.Client{
+			Timeout: 3 * time.Second, // 短超时：审计 webhook 不应拖慢业务
+		},
+	}
+}
+
+// SetWebhook 动态配置审计事件转发 URL 与签名密钥。
+//   - url 为空字符串时禁用转发
+//   - secret 非空时对 payload 计算 HMAC-SHA256，作为 X-BackupX-Signature header
+//
+// 适用场景：
+//   - 企业 SIEM 集成（Splunk HEC、ELK、Loki）
+//   - 安全审计留痕到第三方 WORM 存储
+//   - 合规日志归档（GDPR / SOC2）
+func (s *AuditService) SetWebhook(url, secret string) {
+	if s == nil {
+		return
+	}
+	s.webhookMu.Lock()
+	defer s.webhookMu.Unlock()
+	s.webhookURL = strings.TrimSpace(url)
+	s.webhookSecret = strings.TrimSpace(secret)
 }

 // Record 异步 fire-and-forget 写入审计日志，不阻塞业务逻辑
@@ -51,9 +89,65 @@ func (s *AuditService) Record(entry AuditEntry) {
 		if err := s.repo.Create(context.Background(), record); err != nil {
 			log.Printf("[audit] failed to write audit log: %v", err)
 		}
+		s.fireWebhook(record)
 	}()
 }

+// fireWebhook 异步向外部系统转发审计事件。失败降级到本地日志，永不影响主流程。
+func (s *AuditService) fireWebhook(record *model.AuditLog) {
+	if s == nil {
+		return
+	}
+	s.webhookMu.RLock()
+	url := s.webhookURL
+	secret := s.webhookSecret
+	s.webhookMu.RUnlock()
+	if url == "" {
+		return
+	}
+	payload := map[string]any{
+		"eventType":  "audit.log",
+		"occurredAt": record.CreatedAt.UTC().Format(time.RFC3339),
+		"actor": map[string]any{
+			"userId":   record.UserID,
+			"username": record.Username,
+		},
+		"category":   record.Category,
+		"action":     record.Action,
+		"targetType": record.TargetType,
+		"targetId":   record.TargetID,
+		"targetName": record.TargetName,
+		"detail":     record.Detail,
+		"clientIp":   record.ClientIP,
+	}
+	body, err := json.Marshal(payload)
+	if err != nil {
+		log.Printf("[audit] webhook marshal failed: %v", err)
+		return
+	}
+	req, err := http.NewRequestWithContext(context.Background(), http.MethodPost, url, bytes.NewReader(body))
+	if err != nil {
+		log.Printf("[audit] webhook build request failed: %v", err)
+		return
+	}
+	req.Header.Set("Content-Type", "application/json")
+	req.Header.Set("User-Agent", "BackupX-Audit/1.0")
+	if secret != "" {
+		mac := hmac.New(sha256.New, []byte(secret))
+		mac.Write(body)
+		req.Header.Set("X-BackupX-Signature", "sha256="+hex.EncodeToString(mac.Sum(nil)))
+	}
+	resp, err := s.httpClient.Do(req)
+	if err != nil {
+		log.Printf("[audit] webhook POST failed: %v", err)
+		return
+	}
+	defer resp.Body.Close()
+	if resp.StatusCode >= 400 {
+		log.Printf("[audit] webhook returned status %d", resp.StatusCode)
+	}
+}
+
 // List 分页查询审计日志
 func (s *AuditService) List(ctx context.Context, category string, limit, offset int) (*repository.AuditLogListResult, error) {
 	result, err := s.repo.List(ctx, repository.AuditLogListOptions{
--- a/server/internal/service/audit_service_webhook_test.go
+++ b/server/internal/service/audit_service_webhook_test.go
@@ -0,0 +1,129 @@
+package service
+
+import (
+	"context"
+	"crypto/hmac"
+	"crypto/sha256"
+	"encoding/hex"
+	"encoding/json"
+	"io"
+	"net/http"
+	"net/http/httptest"
+	"sync"
+	"sync/atomic"
+	"testing"
+	"time"
+
+	"backupx/server/internal/model"
+	"backupx/server/internal/repository"
+)
+
+// fakeAuditRepo 用通道同步等待异步写入，避免 sleep。
+type fakeAuditRepo struct {
+	mu      sync.Mutex
+	logs    []model.AuditLog
+	created chan struct{}
+}
+
+func newFakeAuditRepo() *fakeAuditRepo {
+	return &fakeAuditRepo{created: make(chan struct{}, 4)}
+}
+
+func (r *fakeAuditRepo) Create(_ context.Context, log *model.AuditLog) error {
+	r.mu.Lock()
+	log.CreatedAt = time.Now().UTC()
+	r.logs = append(r.logs, *log)
+	r.mu.Unlock()
+	r.created <- struct{}{}
+	return nil
+}
+
+func (r *fakeAuditRepo) List(context.Context, repository.AuditLogListOptions) (*repository.AuditLogListResult, error) {
+	return &repository.AuditLogListResult{}, nil
+}
+
+func (r *fakeAuditRepo) ListAll(context.Context, repository.AuditLogListOptions) ([]model.AuditLog, error) {
+	return nil, nil
+}
+
+func TestAuditService_WebhookDeliversSignedPayload(t *testing.T) {
+	var hits atomic.Int32
+	var got struct {
+		sig      string
+		payload  map[string]any
+		received chan struct{}
+	}
+	got.received = make(chan struct{}, 1)
+
+	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		hits.Add(1)
+		body, _ := io.ReadAll(r.Body)
+		got.sig = r.Header.Get("X-BackupX-Signature")
+		_ = json.Unmarshal(body, &got.payload)
+
+		// 验证 HMAC 正确
+		mac := hmac.New(sha256.New, []byte("s3cret"))
+		mac.Write(body)
+		expected := "sha256=" + hex.EncodeToString(mac.Sum(nil))
+		if got.sig != expected {
+			t.Errorf("signature mismatch: expected %s, got %s", expected, got.sig)
+		}
+		w.WriteHeader(http.StatusOK)
+		got.received <- struct{}{}
+	}))
+	defer server.Close()
+
+	repo := newFakeAuditRepo()
+	svc := NewAuditService(repo)
+	svc.SetWebhook(server.URL, "s3cret")
+
+	svc.Record(AuditEntry{
+		Username: "alice",
+		Category: "auth",
+		Action:   "login_success",
+		ClientIP: "10.0.0.1",
+		Detail:   "admin login",
+	})
+
+	// 等待异步写入 + webhook
+	select {
+	case <-repo.created:
+	case <-time.After(time.Second):
+		t.Fatal("audit log not written within 1s")
+	}
+	select {
+	case <-got.received:
+	case <-time.After(time.Second):
+		t.Fatal("webhook not invoked within 1s")
+	}
+
+	if hits.Load() != 1 {
+		t.Fatalf("expected 1 webhook hit, got %d", hits.Load())
+	}
+	if got.payload["eventType"] != "audit.log" {
+		t.Errorf("eventType wrong: %v", got.payload["eventType"])
+	}
+	actor, ok := got.payload["actor"].(map[string]any)
+	if !ok || actor["username"] != "alice" {
+		t.Errorf("actor.username mismatch: %v", got.payload["actor"])
+	}
+	if got.payload["action"] != "login_success" {
+		t.Errorf("action mismatch: %v", got.payload["action"])
+	}
+}
+
+func TestAuditService_WebhookDisabledWhenURLEmpty(t *testing.T) {
+	repo := newFakeAuditRepo()
+	svc := NewAuditService(repo)
+	// 不调用 SetWebhook：应该不发送任何请求
+	svc.Record(AuditEntry{Username: "bob", Action: "logout"})
+
+	select {
+	case <-repo.created:
+	case <-time.After(time.Second):
+		t.Fatal("audit log not written within 1s")
+	}
+	// 给 webhook 一些时间（即便它不会被调用）
+	time.Sleep(100 * time.Millisecond)
+	// 无显式断言：能不 panic 即算通过
+}
--- a/server/internal/service/backup_execution_service.go
+++ b/server/internal/service/backup_execution_service.go
@@ -17,6 +17,7 @@ import (
 	"backupx/server/internal/apperror"
 	"backupx/server/internal/backup"
 	backupretention "backupx/server/internal/backup/retention"
+	"backupx/server/internal/metrics"
 	"backupx/server/internal/model"
 	"backupx/server/internal/repository"
 	"backupx/server/internal/storage"
@@ -93,7 +94,13 @@ type BackupExecutionService struct {
 	// 没命中的 NodeID 走全局 semaphore，节点配置 MaxConcurrent>0 时按该节点独立排队。
 	nodeSemaphores sync.Map
 	retries        int           // rclone 底层重试次数
-	bandwidthLimit string // rclone 带宽限制
+	bandwidthLimit string        // rclone 带宽限制（全局默认，节点配置可覆盖）
+	metrics        *metrics.Metrics
+}
+
+// SetMetrics 注入 Prometheus 采集器。nil 时所有埋点退化为 no-op。
+func (s *BackupExecutionService) SetMetrics(m *metrics.Metrics) {
+	s.metrics = m
 }

 // ReplicationTrigger 抽象备份成功后的副本派发（实现者：ReplicationService）。
@@ -407,6 +414,22 @@ func (s *BackupExecutionService) shouldNotify(ctx context.Context, task *model.B
 	return true
 }

+// effectiveBandwidth 返回当前上下文应用的带宽限速字符串。
+// 优先级：Node.BandwidthLimit（非空） > 全局 s.bandwidthLimit。
+func (s *BackupExecutionService) effectiveBandwidth(ctx context.Context, nodeID uint) string {
+	if nodeID == 0 || s.nodeRepo == nil {
+		return s.bandwidthLimit
+	}
+	node, err := s.nodeRepo.FindByID(ctx, nodeID)
+	if err != nil || node == nil {
+		return s.bandwidthLimit
+	}
+	if strings.TrimSpace(node.BandwidthLimit) != "" {
+		return node.BandwidthLimit
+	}
+	return s.bandwidthLimit
+}
+
 // acquireNodeSemaphore 返回节点级并发通道。懒初始化：第一次为某节点排队时创建。
 // 如果节点未配置 MaxConcurrent 或 nodeRepo 未注入，返回 nil（调用方走全局 semaphore）。
 // 节点容量仅在首次创建时采用，后续变更需重启服务才生效（避免运行时 resize 通道的复杂度）。
@@ -456,6 +479,10 @@ func (s *BackupExecutionService) executeTask(ctx context.Context, task *model.Ba
 	s.semaphore <- struct{}{}
 	defer func() { <-s.semaphore }()

+	// Prometheus: running gauge + 完成时 observe 耗时/字节/状态
+	s.metrics.IncTaskRunning()
+	defer s.metrics.DecTaskRunning()
+
 	logger := backup.NewExecutionLogger(recordID, s.logHub)
 	status := "failed"
 	errMessage := ""
@@ -468,6 +495,8 @@ func (s *BackupExecutionService) executeTask(ctx context.Context, task *model.Ba
 		if finalizeErr := s.finalizeRecord(ctx, task, recordID, startedAt, status, errMessage, logger.String(), fileName, fileSize, checksum, storagePath); finalizeErr != nil {
 			logger.Errorf("写回备份记录失败：%v", finalizeErr)
 		}
+		// 采集任务执行结果到 Prometheus（耗时 + 产出字节 + 状态计数）
+		s.metrics.ObserveTaskRun(task.Type, status, time.Since(startedAt).Seconds(), fileSize)
 		// 写入多目标上传结果
 		if len(uploadResults) > 0 {
 			if resultsJSON, marshalErr := json.Marshal(uploadResults); marshalErr == nil {
@@ -559,7 +588,8 @@ func (s *BackupExecutionService) executeTask(ctx context.Context, task *model.Ba
 			if findErr == nil && target != nil {
 				targetName = target.Name
 			}
-			provider, resolveErr := s.resolveProvider(ctx, targetID)
+			// 节点级带宽覆盖：若 task 绑定节点并配置了 BandwidthLimit，覆盖全局限速
+			provider, resolveErr := s.resolveProviderForNode(ctx, targetID, task.NodeID)
 			if resolveErr != nil {
 				uploadResults[index] = StorageUploadResultItem{StorageTargetID: targetID, StorageTargetName: targetName, Status: "failed", Error: resolveErr.Error()}
 				logger.Warnf("存储目标 %s 创建客户端失败：%v", targetName, resolveErr)
@@ -742,10 +772,17 @@ func (s *BackupExecutionService) finalizeRecord(ctx context.Context, task *model
 }

 func (s *BackupExecutionService) resolveProvider(ctx context.Context, targetID uint) (storage.StorageProvider, error) {
-	// 注入 rclone 传输配置（重试、带宽限制）
+	return s.resolveProviderForNode(ctx, targetID, 0)
+}
+
+// resolveProviderForNode 根据节点的 BandwidthLimit 覆盖全局默认。
+// nodeID=0 或节点未配置时退化为全局默认。
+// 仅在 Master 本地执行生效；Agent 会收到自身 Node 配置，并在独立 runtime 中应用。
+func (s *BackupExecutionService) resolveProviderForNode(ctx context.Context, targetID uint, nodeID uint) (storage.StorageProvider, error) {
+	// 注入 rclone 传输配置（重试、节点级带宽覆盖全局）
 	ctx = rclone.ConfiguredContext(ctx, rclone.TransferConfig{
 		LowLevelRetries: s.retries,
-		BandwidthLimit:  s.bandwidthLimit,
+		BandwidthLimit:  s.effectiveBandwidth(ctx, nodeID),
 	})
 	target, err := s.targets.FindByID(ctx, targetID)
 	if err != nil {
--- a/server/internal/service/replication_service.go
+++ b/server/internal/service/replication_service.go
@@ -10,6 +10,7 @@ import (
 	"time"

 	"backupx/server/internal/apperror"
+	"backupx/server/internal/metrics"
 	"backupx/server/internal/model"
 	"backupx/server/internal/repository"
 	"backupx/server/internal/storage"
@@ -37,6 +38,12 @@ type ReplicationService struct {
 	semaphore       chan struct{}
 	async           func(func())
 	now             func() time.Time
+	metrics         *metrics.Metrics
+}
+
+// SetMetrics 注入 Prometheus 采集器。
+func (s *ReplicationService) SetMetrics(m *metrics.Metrics) {
+	s.metrics = m
 }

 func NewReplicationService(
@@ -193,6 +200,7 @@ func (s *ReplicationService) executeReplication(ctx context.Context, repID uint)
 		rep.DurationSeconds = int(completedAt.Sub(rep.StartedAt).Seconds())
 		rep.CompletedAt = &completedAt
 		_ = s.replications.Update(ctx, rep)
+		s.metrics.ObserveReplication(status)
 		if status == model.ReplicationStatusFailed {
 			s.dispatchFailed(ctx, rep, errMessage)
 		}
--- a/server/internal/service/restore_service.go
+++ b/server/internal/service/restore_service.go
@@ -11,6 +11,7 @@ import (

 	"backupx/server/internal/apperror"
 	"backupx/server/internal/backup"
+	"backupx/server/internal/metrics"
 	"backupx/server/internal/model"
 	"backupx/server/internal/repository"
 	"backupx/server/internal/storage"
@@ -41,6 +42,12 @@ type RestoreService struct {
 	semaphore       chan struct{}
 	async           func(func())
 	now             func() time.Time
+	metrics         *metrics.Metrics
+}
+
+// SetMetrics 注入 Prometheus 采集器。
+func (s *RestoreService) SetMetrics(m *metrics.Metrics) {
+	s.metrics = m
 }

 // NewRestoreService 构造恢复服务。maxConcurrent 控制本地并发恢复数。
@@ -432,6 +439,7 @@ func (s *RestoreService) finalizeWithLog(ctx context.Context, restoreID uint, st
 	}
 	record.DurationSeconds = int(completedAt.Sub(record.StartedAt).Seconds())
 	record.CompletedAt = &completedAt
+	s.metrics.ObserveRestore(status)
 	return s.restores.Update(ctx, record)
 }

--- a/server/internal/service/settings_service.go
+++ b/server/internal/service/settings_service.go
@@ -8,21 +8,55 @@ import (
 	"backupx/server/internal/repository"
 )

+// AuditWebhookConfigurer 抽象审计 webhook 配置接口，由 AuditService 实现。
+// 用接口解耦避免 settings_service 直接依赖 AuditService 具体类型。
+type AuditWebhookConfigurer interface {
+	SetWebhook(url, secret string)
+}
+
 type SettingsService struct {
 	configs      repository.SystemConfigRepository
+	auditWebhook AuditWebhookConfigurer
 }

 func NewSettingsService(configs repository.SystemConfigRepository) *SettingsService {
 	return &SettingsService{configs: configs}
 }

-// settingsKeys lists all user-editable setting keys.
+// SetAuditWebhookConfigurer 注入 audit webhook 配置接收方。
+// 启动时立即用当前 DB 中的设置调用一次，后续每次 Update 变更 webhook key 时同步推送。
+func (s *SettingsService) SetAuditWebhookConfigurer(ctx context.Context, configurer AuditWebhookConfigurer) {
+	if s == nil || configurer == nil {
+		return
+	}
+	s.auditWebhook = configurer
+	// 启动时同步一次，保证重启后配置不丢失
+	all, err := s.GetAll(ctx)
+	if err == nil {
+		configurer.SetWebhook(all[SettingKeyAuditWebhookURL], all[SettingKeyAuditWebhookSecret])
+	}
+}
+
+// 可被前端写入的系统设置键。新增键必须同步加入此清单，
+// 否则 Update 会忽略（安全原则：显式 allow-list）。
+const (
+	SettingKeySiteName                  = "site_name"
+	SettingKeyLanguage                  = "language"
+	SettingKeyTimezone                  = "timezone"
+	SettingKeyBackupNotificationEnabled = "backup_notification_enabled"
+	SettingKeyBandwidthLimit            = "bandwidth_limit"
+	SettingKeyAuditWebhookURL           = "audit_webhook_url"
+	SettingKeyAuditWebhookSecret        = "audit_webhook_secret"
+)
+
 var settingsKeys = []string{
-	"site_name",
-	"language",
-	"timezone",
-	"backup_notification_enabled",
-	"bandwidth_limit",
+	SettingKeySiteName,
+	SettingKeyLanguage,
+	SettingKeyTimezone,
+	SettingKeyBackupNotificationEnabled,
+	SettingKeyBandwidthLimit,
+	SettingKeyAuditWebhookURL,
+	SettingKeyAuditWebhookSecret,
 }

 func (s *SettingsService) GetAll(ctx context.Context) (map[string]string, error) {
@@ -42,6 +76,7 @@ func (s *SettingsService) Update(ctx context.Context, settings map[string]string
 	for _, key := range settingsKeys {
 		allowed[key] = true
 	}
+	auditWebhookTouched := false
 	for key, value := range settings {
 		if !allowed[key] {
 			continue
@@ -50,6 +85,14 @@ func (s *SettingsService) Update(ctx context.Context, settings map[string]string
 		if err := s.configs.Upsert(ctx, item); err != nil {
 			return nil, apperror.Internal("SETTINGS_UPDATE_FAILED", "无法更新系统设置", err)
 		}
+		if key == SettingKeyAuditWebhookURL || key == SettingKeyAuditWebhookSecret {
+			auditWebhookTouched = true
+		}
+	}
+	// audit webhook 配置变化：立即同步到 AuditService，避免重启才生效
+	if auditWebhookTouched && s.auditWebhook != nil {
+		all, _ := s.GetAll(ctx)
+		s.auditWebhook.SetWebhook(all[SettingKeyAuditWebhookURL], all[SettingKeyAuditWebhookSecret])
 	}
 	return s.GetAll(ctx)
 }
--- a/server/internal/service/verification_service.go
+++ b/server/internal/service/verification_service.go
@@ -10,6 +10,7 @@ import (

 	"backupx/server/internal/apperror"
 	"backupx/server/internal/backup"
+	"backupx/server/internal/metrics"
 	"backupx/server/internal/model"
 	"backupx/server/internal/repository"
 	"backupx/server/internal/storage"
@@ -42,6 +43,12 @@ type VerificationService struct {
 	semaphore       chan struct{}
 	async           func(func())
 	now             func() time.Time
+	metrics         *metrics.Metrics
+}
+
+// SetMetrics 注入 Prometheus 采集器。
+func (s *VerificationService) SetMetrics(m *metrics.Metrics) {
+	s.metrics = m
 }

 // VerificationNotifier 给用户推送验证完成/失败通知。
@@ -413,6 +420,7 @@ func (s *VerificationService) finalize(ctx context.Context, verID uint, status,
 	}
 	record.DurationSeconds = int(completedAt.Sub(record.StartedAt).Seconds())
 	record.CompletedAt = &completedAt
+	s.metrics.ObserveVerify(status)
 	return s.verifications.Update(ctx, record)
 }