feat(monitor): show backup tunnel latencies (#535)

Closes #508
2026-09-28 07:36:38 +08:00 · 2026-08-03 10:15:22 +08:00
parent ae370382d3
commit cbe2fc492e
6 changed files with 488 additions and 76 deletions
@@ -4,6 +4,7 @@ import (
 	"context"
 	"encoding/json"
 	"errors"
+	"fmt"
 	"log"
 	"sync"
 	"sync/atomic"
@@ -31,6 +32,26 @@ type TunnelQualityHop struct {
 	TargetPort   int     `json:"targetPort,omitempty"`
 }

+type TunnelQualityCandidateHop struct {
+	TunnelQualityHop
+	FromRole     string `json:"fromRole"`
+	ToRole       string `json:"toRole"`
+	HopIndex     int    `json:"hopIndex"`
+	Selected     bool   `json:"selected"`
+	ErrorMessage string `json:"errorMessage,omitempty"`
+}
+
+type tunnelQualityChainDetails struct {
+	PrimaryPath   []TunnelQualityHop          `json:"primaryPath,omitempty"`
+	CandidateHops []TunnelQualityCandidateHop `json:"candidateHops,omitempty"`
+}
+
+type tunnelQualityCandidateGroup struct {
+	role      string
+	roleIndex int
+	nodes     []chainNodeRecord
+}
+
 // tunnelQualitySnapshot is the in-memory latest probe result for a tunnel.
 type tunnelQualitySnapshot struct {
 	TunnelID           int64   `json:"tunnelId"`
@@ -283,16 +304,25 @@ func (p *tunnelQualityProber) probeTunnel(tunnelID int64) {
 		pingCount:      1,
 		timeoutMessage: "探测超时",
 	}
-	p.probeBestExitOwners(tunnelID, inNodes, midNodesGrouped, outNodes, ipPreference, options, probeTarget)
+	roundPinger := newBestExitRoundPinger(p.pingNode)
+	p.probeBestExitOwners(tunnelID, inNodes, midNodesGrouped, outNodes, ipPreference, options, probeTarget, roundPinger)

 	entry, _, entryOnline := p.firstOnlineChainNode(inNodes)
 	exit, _, exitOnline := p.firstOnlineChainNode(outNodes)
+	selectedNodeIDs := make(map[string]int64, 2+len(midNodesGrouped))
+	if entryOnline {
+		selectedNodeIDs[tunnelQualityGroupKey("entry", 0)] = entry.NodeID
+	}
+	if exitOnline {
+		selectedNodeIDs[tunnelQualityGroupKey("exit", 0)] = exit.NodeID
+	}
+	var primaryHops []TunnelQualityHop

 	switch tunnel.Type {
 	case 1:
 		// Port forwarding: entry → public probe target only.
 		if entryOnline {
-			lat, loss, err := p.pingNode(entry.NodeID, probeTarget.Host, probeTarget.Port, options)
+			lat, loss, err := roundPinger(entry.NodeID, probeTarget.Host, probeTarget.Port, options)
 			if err == nil {
 				snap.ExitToBingLatency = lat
 				snap.ExitToBingLoss = loss
@@ -318,13 +348,12 @@ func (p *tunnelQualityProber) probeTunnel(tunnelID int64) {
 			snap.EntryToExitLatency = -1
 			snap.EntryToExitLoss = 100
 		} else {
-			var hops []TunnelQualityHop
 			var totalLat float64
 			remainingSuccessProb := 1.0

 			nodesInPath := make([]chainNodeRecord, 0, 2+len(midNodesGrouped))
 			nodesInPath = append(nodesInPath, entry)
-			for _, midGroup := range midNodesGrouped {
+			for midIndex, midGroup := range midNodesGrouped {
 				mid, _, online := p.firstOnlineChainNode(midGroup)
 				if !online {
 					probeOK = false
@@ -332,6 +361,7 @@ func (p *tunnelQualityProber) probeTunnel(tunnelID int64) {
 					break
 				}
 				nodesInPath = append(nodesInPath, mid)
+				selectedNodeIDs[tunnelQualityGroupKey("middle", midIndex)] = mid.NodeID
 			}
 			if probeOK {
 				nodesInPath = append(nodesInPath, exit)
@@ -354,7 +384,7 @@ func (p *tunnelQualityProber) probeTunnel(tunnelID int64) {
 					probeOK = false
 					hop.Latency = -1
 					hop.Loss = 100
-					hops = append(hops, hop)
+					primaryHops = append(primaryHops, hop)
 					break
 				}

@@ -365,25 +395,25 @@ func (p *tunnelQualityProber) probeTunnel(tunnelID int64) {
 					probeOK = false
 					hop.Latency = -1
 					hop.Loss = 100
-					hops = append(hops, hop)
+					primaryHops = append(primaryHops, hop)
 					break
 				}

 				hop.TargetIP = targetIP
 				hop.TargetPort = targetPort

-				lat, loss, err := p.pingNode(source.NodeID, targetIP, targetPort, options)
+				lat, loss, err := roundPinger(source.NodeID, targetIP, targetPort, options)
 				if err == nil {
 					hop.Latency = lat
 					hop.Loss = loss
 					totalLat += lat
 					remainingSuccessProb *= (1.0 - loss/100.0)
-					hops = append(hops, hop)
+					primaryHops = append(primaryHops, hop)
 				} else {
 					probeOK = false
 					hop.Latency = -1
 					hop.Loss = 100
-					hops = append(hops, hop)
+					primaryHops = append(primaryHops, hop)
 					if snap.ErrorMessage == "" {
 						snap.ErrorMessage = err.Error()
 					}
@@ -398,17 +428,11 @@ func (p *tunnelQualityProber) probeTunnel(tunnelID int64) {
 				snap.EntryToExitLatency = -1
 				snap.EntryToExitLoss = 100
 			}
-
-			if len(hops) > 0 {
-				if b, err := json.Marshal(hops); err == nil {
-					snap.ChainDetails = string(b)
-				}
-			}
 		}

 		// Exit → Bing
 		if exitOnline {
-			lat, loss, err := p.pingNode(exit.NodeID, probeTarget.Host, probeTarget.Port, options)
+			lat, loss, err := roundPinger(exit.NodeID, probeTarget.Host, probeTarget.Port, options)
 			if err == nil {
 				snap.ExitToBingLatency = lat
 				snap.ExitToBingLoss = loss
@@ -424,7 +448,7 @@ func (p *tunnelQualityProber) probeTunnel(tunnelID int64) {
 	default:
 		// Unknown type: entry → public probe target.
 		if entryOnline {
-			lat, loss, err := p.pingNode(entry.NodeID, probeTarget.Host, probeTarget.Port, options)
+			lat, loss, err := roundPinger(entry.NodeID, probeTarget.Host, probeTarget.Port, options)
 			if err == nil {
 				snap.ExitToBingLatency = lat
 				snap.ExitToBingLoss = loss
@@ -437,9 +461,192 @@ func (p *tunnelQualityProber) probeTunnel(tunnelID int64) {
 		}
 	}

+	candidateHops := p.probeTunnelCandidateHops(
+		tunnel.Type,
+		inNodes,
+		midNodesGrouped,
+		outNodes,
+		selectedNodeIDs,
+		ipPreference,
+		options,
+		probeTarget,
+		roundPinger,
+	)
+	if len(primaryHops) > 0 || len(candidateHops) > 0 {
+		details := tunnelQualityChainDetails{
+			PrimaryPath:   primaryHops,
+			CandidateHops: candidateHops,
+		}
+		if b, err := json.Marshal(details); err == nil {
+			snap.ChainDetails = string(b)
+		}
+	}
+
 	p.storeResult(snap)
 }

+func tunnelQualityGroupKey(role string, index int) string {
+	return fmt.Sprintf("%s:%d", role, index)
+}
+
+func (p *tunnelQualityProber) probeTunnelCandidateHops(
+	tunnelType int,
+	inNodes []chainNodeRecord,
+	chainHops [][]chainNodeRecord,
+	outNodes []chainNodeRecord,
+	selectedNodeIDs map[string]int64,
+	ipPreference string,
+	options diagnosisExecOptions,
+	probeTarget tunnelProbeTarget,
+	ping bestExitProbeFunc,
+) []TunnelQualityCandidateHop {
+	if p == nil || p.handler == nil || ping == nil {
+		return nil
+	}
+
+	if tunnelType != 2 {
+		return p.probePublicTargetCandidates("entry", 0, inNodes, selectedNodeIDs, options, probeTarget, ping)
+	}
+
+	groups := make([]tunnelQualityCandidateGroup, 0, 2+len(chainHops))
+	groups = append(groups, tunnelQualityCandidateGroup{role: "entry", roleIndex: 0, nodes: inNodes})
+	for i, hop := range chainHops {
+		groups = append(groups, tunnelQualityCandidateGroup{role: "middle", roleIndex: i, nodes: hop})
+	}
+	groups = append(groups, tunnelQualityCandidateGroup{role: "exit", roleIndex: 0, nodes: outNodes})
+
+	var items []TunnelQualityCandidateHop
+	for i := 0; i < len(groups)-1; i++ {
+		items = append(items, p.probeCandidateGroupLinks(
+			groups[i],
+			groups[i+1],
+			i,
+			selectedNodeIDs,
+			ipPreference,
+			options,
+			ping,
+		)...)
+	}
+	items = append(items, p.probePublicTargetCandidates(
+		"exit",
+		0,
+		outNodes,
+		selectedNodeIDs,
+		options,
+		probeTarget,
+		ping,
+	)...)
+	return items
+}
+
+func (p *tunnelQualityProber) probeCandidateGroupLinks(
+	fromGroup tunnelQualityCandidateGroup,
+	toGroup tunnelQualityCandidateGroup,
+	hopIndex int,
+	selectedNodeIDs map[string]int64,
+	ipPreference string,
+	options diagnosisExecOptions,
+	ping bestExitProbeFunc,
+) []TunnelQualityCandidateHop {
+	items := make([]TunnelQualityCandidateHop, 0, len(fromGroup.nodes)*len(toGroup.nodes))
+	for _, source := range fromGroup.nodes {
+		for _, target := range toGroup.nodes {
+			item := TunnelQualityCandidateHop{
+				TunnelQualityHop: TunnelQualityHop{
+					FromNodeID:   source.NodeID,
+					FromNodeName: source.NodeName,
+					ToNodeID:     target.NodeID,
+					ToNodeName:   target.NodeName,
+					Latency:      -1,
+					Loss:         100,
+				},
+				FromRole: fromGroup.role,
+				ToRole:   toGroup.role,
+				HopIndex: hopIndex,
+				Selected: selectedNodeIDs[tunnelQualityGroupKey(fromGroup.role, fromGroup.roleIndex)] == source.NodeID &&
+					selectedNodeIDs[tunnelQualityGroupKey(toGroup.role, toGroup.roleIndex)] == target.NodeID,
+			}
+
+			sourceNode, sourceErr := p.handler.getNodeRecord(source.NodeID)
+			if sourceErr != nil || !isTunnelProbeNodeOnline(sourceNode) {
+				item.ErrorMessage = "来源节点不在线"
+				items = append(items, item)
+				continue
+			}
+			targetNode, targetErr := p.handler.getNodeRecord(target.NodeID)
+			if targetErr != nil || !isTunnelProbeNodeOnline(targetNode) {
+				item.ErrorMessage = "目标节点不在线"
+				items = append(items, item)
+				continue
+			}
+
+			targetIP, targetPort, resolveErr := resolveChainProbeTarget(sourceNode, targetNode, target.Port, ipPreference, target.ConnectIP)
+			if resolveErr != nil {
+				item.ErrorMessage = resolveErr.Error()
+				items = append(items, item)
+				continue
+			}
+			item.TargetIP = targetIP
+			item.TargetPort = targetPort
+			latency, loss, probeErr := ping(source.NodeID, targetIP, targetPort, options)
+			if probeErr != nil {
+				item.ErrorMessage = probeErr.Error()
+				items = append(items, item)
+				continue
+			}
+			item.Latency = latency
+			item.Loss = loss
+			items = append(items, item)
+		}
+	}
+	return items
+}
+
+func (p *tunnelQualityProber) probePublicTargetCandidates(
+	fromRole string,
+	fromIndex int,
+	nodes []chainNodeRecord,
+	selectedNodeIDs map[string]int64,
+	options diagnosisExecOptions,
+	probeTarget tunnelProbeTarget,
+	ping bestExitProbeFunc,
+) []TunnelQualityCandidateHop {
+	items := make([]TunnelQualityCandidateHop, 0, len(nodes))
+	for _, source := range nodes {
+		item := TunnelQualityCandidateHop{
+			TunnelQualityHop: TunnelQualityHop{
+				FromNodeID:   source.NodeID,
+				FromNodeName: source.NodeName,
+				ToNodeName:   formatTunnelProbeTarget(probeTarget),
+				Latency:      -1,
+				Loss:         100,
+				TargetIP:     probeTarget.Host,
+				TargetPort:   probeTarget.Port,
+			},
+			FromRole: fromRole,
+			ToRole:   "target",
+			HopIndex: fromIndex,
+			Selected: selectedNodeIDs[tunnelQualityGroupKey(fromRole, fromIndex)] == source.NodeID,
+		}
+		sourceNode, sourceErr := p.handler.getNodeRecord(source.NodeID)
+		if sourceErr != nil || !isTunnelProbeNodeOnline(sourceNode) {
+			item.ErrorMessage = "来源节点不在线"
+			items = append(items, item)
+			continue
+		}
+		latency, loss, probeErr := ping(source.NodeID, probeTarget.Host, probeTarget.Port, options)
+		if probeErr != nil {
+			item.ErrorMessage = probeErr.Error()
+			items = append(items, item)
+			continue
+		}
+		item.Latency = latency
+		item.Loss = loss
+		items = append(items, item)
+	}
+	return items
+}
+
 func isTunnelProbeNodeOnline(node *nodeRecord) bool {
 	return node != nil && (node.IsRemote == 1 || node.Status == 1)
 }
@@ -457,7 +664,7 @@ func (p *tunnelQualityProber) firstOnlineChainNode(nodes []chainNodeRecord) (cha
 	return chainNodeRecord{}, nil, false
 }

-func (p *tunnelQualityProber) probeBestExitOwners(tunnelID int64, inNodes []chainNodeRecord, chainHops [][]chainNodeRecord, outNodes []chainNodeRecord, ipPreference string, options diagnosisExecOptions, probeTarget tunnelProbeTarget) {
+func (p *tunnelQualityProber) probeBestExitOwners(tunnelID int64, inNodes []chainNodeRecord, chainHops [][]chainNodeRecord, outNodes []chainNodeRecord, ipPreference string, options diagnosisExecOptions, probeTarget tunnelProbeTarget, roundPinger bestExitProbeFunc) {
 	if p == nil || p.handler == nil || p.handler.bestExit == nil || len(outNodes) <= 1 {
 		return
 	}
@@ -479,9 +686,6 @@ func (p *tunnelQualityProber) probeBestExitOwners(tunnelID int64, inNodes []chai
 			nodeMap[exit.NodeID] = node
 		}
 	}
-	// This best-exit decision cache is per decision round; the display-oriented
-	// tunnel quality snapshot may still collect its own first-exit public probe.
-	roundPinger := newBestExitRoundPinger(p.pingNode)
 	for _, owner := range owners {
 		if nodeMap[owner.NodeID] == nil {
 			continue
@@ -1,6 +1,7 @@
 package handler

 import (
+	"encoding/json"
 	"fmt"
 	"slices"
 	"testing"
@@ -106,6 +107,57 @@ func TestTunnelQualityProberUsesOnlineBackupExit(t *testing.T) {
 	}
 }

+func TestTunnelQualityProberReportsAllExitCandidateLatencies(t *testing.T) {
+	h := setupProbeTargetTunnelHandler(t)
+	seedQualityForwardTunnel(t, h, 83, []int{1, 1})
+
+	p := newTunnelQualityProber(h)
+	p.probeNode = func(nodeID int64, ip string, port int, options diagnosisExecOptions) (float64, float64, error) {
+		switch fmt.Sprintf("%d|%s|%d", nodeID, ip, port) {
+		case "10|10.0.0.30|30030":
+			return 20, 0, nil
+		case "10|10.0.0.31|30031":
+			return 35, 0, nil
+		case "30|www.bing.com|443":
+			return 50, 0, nil
+		case "31|www.bing.com|443":
+			return 65, 0, nil
+		default:
+			return 0, 100, fmt.Errorf("unexpected probe node=%d target=%s:%d", nodeID, ip, port)
+		}
+	}
+	p.probeTunnel(83)
+
+	snaps := p.GetAll()
+	if len(snaps) != 1 {
+		t.Fatalf("expected one quality snapshot, got %+v", snaps)
+	}
+	if snaps[0].EntryToExitLatency != 20 || snaps[0].ExitToBingLatency != 50 {
+		t.Fatalf("expected primary path metrics to remain unchanged, got %+v", snaps[0])
+	}
+
+	var details tunnelQualityChainDetails
+	if err := json.Unmarshal([]byte(snaps[0].ChainDetails), &details); err != nil {
+		t.Fatalf("decode chain details: %v", err)
+	}
+	assertCandidateHop := func(fromID, toID int64, latency float64, selected bool) {
+		t.Helper()
+		for _, hop := range details.CandidateHops {
+			if hop.FromNodeID == fromID && hop.ToNodeID == toID {
+				if hop.Latency != latency || hop.Selected != selected || hop.ErrorMessage != "" {
+					t.Fatalf("unexpected candidate hop: %+v", hop)
+				}
+				return
+			}
+		}
+		t.Fatalf("candidate hop %d -> %d not found in %+v", fromID, toID, details.CandidateHops)
+	}
+	assertCandidateHop(10, 30, 20, true)
+	assertCandidateHop(10, 31, 35, false)
+	assertCandidateHop(30, 0, 50, true)
+	assertCandidateHop(31, 0, 65, false)
+}
+
 func TestTunnelQualityProberStoresProbeTargetWhenChainIncomplete(t *testing.T) {
 	h := setupProbeTargetTunnelHandler(t)
 	seedProbeTargetTunnel(t, h, 78, "quality-target-incomplete", "speed.example.com", 8443)
@@ -132,3 +132,31 @@ func TestUpsertTunnelMetricBucketsIsSafeUnderConcurrency(t *testing.T) {
 		t.Fatalf("expected bytesOut %d, got %d", wantOut, rows[0].BytesOut)
 	}
 }
+
+func TestGetLatestTunnelQualitiesIncludesChainDetails(t *testing.T) {
+	r, err := Open(":memory:")
+	if err != nil {
+		t.Fatalf("open repo: %v", err)
+	}
+	defer r.Close()
+
+	if err := r.InsertTunnelQuality(&model.TunnelQuality{
+		TunnelID:     7,
+		Timestamp:    time.Now().UnixMilli(),
+		Success:      1,
+		ChainDetails: `{"primaryPath":[],"candidateHops":[{"fromNodeId":10,"toNodeId":31}]}`,
+	}); err != nil {
+		t.Fatalf("insert tunnel quality: %v", err)
+	}
+
+	items, err := r.GetLatestTunnelQualities()
+	if err != nil {
+		t.Fatalf("get latest tunnel qualities: %v", err)
+	}
+	if len(items) != 1 {
+		t.Fatalf("expected one latest tunnel quality, got %+v", items)
+	}
+	if items[0].ChainDetails == "" {
+		t.Fatalf("expected chain details in latest quality row, got %+v", items[0])
+	}
+}
@@ -44,7 +44,8 @@ func (r *Repository) GetLatestTunnelQualities() ([]model.TunnelQuality, error) {
 	// Use window function (works on modern SQLite 3.25+ and PostgreSQL).
 	q := `
 		SELECT id, tunnel_id, entry_to_exit_latency, exit_to_bing_latency,
-		       entry_to_exit_loss, exit_to_bing_loss, success, error_message, timestamp
+		       entry_to_exit_loss, exit_to_bing_loss, success, error_message, timestamp,
+		       chain_details
 		FROM (
 			SELECT *, ROW_NUMBER() OVER (PARTITION BY tunnel_id ORDER BY timestamp DESC, id DESC) AS rn
 			FROM tunnel_quality
@@ -595,6 +595,20 @@ export interface TunnelQualityHopApiItem {
  targetPort?: number;
 }

+export interface TunnelQualityCandidateHopApiItem
+  extends TunnelQualityHopApiItem {
+  fromRole: "entry" | "middle" | "exit";
+  toRole: "middle" | "exit" | "target";
+  hopIndex: number;
+  selected: boolean;
+  errorMessage?: string;
+}
+
+export interface TunnelQualityChainDetailsApiItem {
+  primaryPath?: TunnelQualityHopApiItem[];
+  candidateHops?: TunnelQualityCandidateHopApiItem[];
+}
+
 export interface TunnelQualityApiItem {
  tunnelId: number;
  entryToExitLatency: number;
@@ -2,6 +2,8 @@ import type {
  MonitorTunnelApiItem,
  TunnelMetricApiItem,
  TunnelQualityApiItem,
+  TunnelQualityCandidateHopApiItem,
+  TunnelQualityChainDetailsApiItem,
  TunnelQualityHopApiItem,
 } from "@/api/types";

@@ -468,18 +470,59 @@ const TrafficChartCard = React.memo(function TrafficChartCard({
  );
 });

-function ForwardingChainTopology({ hopsStr }: { hopsStr?: string }) {
-  if (!hopsStr) return null;
-
-  let hops: TunnelQualityHopApiItem[] = [];
-
+const parseTunnelQualityChainDetails = (
+  raw?: string,
+): TunnelQualityChainDetailsApiItem => {
+  if (!raw) return {};
  try {
-    hops = JSON.parse(hopsStr);
+    const parsed: unknown = JSON.parse(raw);
+
+    // Backward-compatible with historical rows that stored the primary path
+    // directly as a JSON array.
+    if (Array.isArray(parsed)) {
+      return { primaryPath: parsed as TunnelQualityHopApiItem[] };
+    }
+    if (parsed && typeof parsed === "object") {
+      return parsed as TunnelQualityChainDetailsApiItem;
+    }
  } catch {
-    return null;
+    return {};
  }

-  if (!Array.isArray(hops) || hops.length === 0) return null;
+  return {};
+};
+
+const candidateRoleLabel = (role: string) => {
+  switch (role) {
+    case "entry":
+      return "入口";
+    case "middle":
+      return "中转";
+    case "exit":
+      return "出口";
+    case "target":
+      return "测试目标";
+    default:
+      return role;
+  }
+};
+
+const ForwardingChainTopology = React.memo(function ForwardingChainTopology({
+  hopsStr,
+}: {
+  hopsStr?: string;
+}) {
+  const details = useMemo(
+    () => parseTunnelQualityChainDetails(hopsStr),
+    [hopsStr],
+  );
+  const primaryHops = details.primaryPath ?? [];
+  const alternativeHops = useMemo(
+    () => (details.candidateHops ?? []).filter((hop) => !hop.selected),
+    [details.candidateHops],
+  );
+
+  if (primaryHops.length === 0 && alternativeHops.length === 0) return null;

  return (
    <Card className="border border-divider/60 shadow-sm transition-shadow bg-gradient-to-br from-background to-default-50/50 mt-4">
@@ -490,61 +533,131 @@ function ForwardingChainTopology({ hopsStr }: { hopsStr?: string }) {
        </h3>
      </CardHeader>
      <CardBody className="py-2 px-4 pb-4">
-        <div className="flex items-center overflow-x-auto pb-2 py-2">
-          {hops.map((hop, index) => {
-            const hasError = hop.latency < 0 || hop.loss > 0;
-            const colorClass =
-              hop.latency < 0
-                ? "text-danger"
-                : hop.loss > 0
-                  ? "text-warning"
-                  : "text-success";
-            const borderColor = hasError ? "border-danger" : "";
+        {primaryHops.length > 0 ? (
+          <div className="flex items-center overflow-x-auto pb-2 py-2">
+            {primaryHops.map((hop, index) => {
+              const hasError = hop.latency < 0 || hop.loss > 0;
+              const colorClass =
+                hop.latency < 0
+                  ? "text-danger"
+                  : hop.loss > 0
+                    ? "text-warning"
+                    : "text-success";
+              const borderColor = hasError ? "border-danger" : "";

-            return (
-              <React.Fragment key={index}>
-                {index === 0 && (
+              return (
+                <React.Fragment
+                  key={`${hop.fromNodeId}-${hop.toNodeId}-${index}`}
+                >
+                  {index === 0 ? (
+                    <Chip
+                      className="shrink-0 font-mono shadow-sm"
+                      size="sm"
+                      variant="flat"
+                    >
+                      {hop.fromNodeName}
+                    </Chip>
+                  ) : null}
+                  <div className="flex flex-col items-center justify-center min-w-[70px] mx-1 shrink-0 relative">
+                    <span
+                      className={`text-[10px] font-mono leading-none mb-1 ${colorClass}`}
+                    >
+                      {hop.latency >= 0
+                        ? `${hop.latency.toFixed(0)}ms`
+                        : "超时"}
+                    </span>
+                    <div
+                      className={`h-[2px] w-full relative flex items-center justify-end bg-default-200 ${hop.latency < 0 ? "!bg-danger" : ""}`}
+                    >
+                      <ArrowRight
+                        className={`w-3.5 h-3.5 absolute -right-2 ${colorClass} bg-background rounded-full p-[1px] z-10`}
+                      />
+                    </div>
+                    <span
+                      className={`text-[10px] font-mono leading-none mt-1.5 ${hop.loss > 0 ? "text-warning" : "text-default-400"}`}
+                    >
+                      {hop.loss.toFixed(0)}% 丢包
+                    </span>
+                  </div>
                  <Chip
-                    className="shrink-0 font-mono shadow-sm"
+                    className={`shrink-0 font-mono shadow-sm ${borderColor}`}
                    size="sm"
                    variant="flat"
                  >
-                    {hop.fromNodeName}
+                    {hop.toNodeName}
                  </Chip>
-                )}
-                <div className="flex flex-col items-center justify-center min-w-[70px] mx-1 shrink-0 relative">
-                  <span
-                    className={`text-[10px] font-mono leading-none mb-1 ${colorClass}`}
-                  >
-                    {hop.latency >= 0 ? `${hop.latency.toFixed(0)}ms` : "超时"}
-                  </span>
-                  <div
-                    className={`h-[2px] w-full relative flex items-center justify-end bg-default-200 ${hop.latency < 0 ? "!bg-danger" : ""}`}
-                  >
-                    <ArrowRight
-                      className={`w-3.5 h-3.5 absolute -right-2 ${colorClass} bg-background rounded-full p-[1px] z-10`}
-                    />
-                  </div>
-                  <span
-                    className={`text-[10px] font-mono leading-none mt-1.5 ${hop.loss > 0 ? "text-warning" : "text-default-400"}`}
-                  >
-                    {hop.loss.toFixed(0)}% 丢包
-                  </span>
-                </div>
-                <Chip
-                  className={`shrink-0 font-mono shadow-sm ${borderColor}`}
-                  size="sm"
-                  variant="flat"
-                >
-                  {hop.toNodeName}
-                </Chip>
-              </React.Fragment>
-            );
-          })}
-        </div>
+                </React.Fragment>
+              );
+            })}
+          </div>
+        ) : null}
+
+        {alternativeHops.length > 0 ? (
+          <div
+            className={`${primaryHops.length > 0 ? "mt-3 border-t border-divider/60 pt-3" : ""}`}
+          >
+            <div className="mb-2 flex items-center justify-between gap-2">
+              <span className="text-xs font-semibold text-default-600">
+                备选节点实时延迟
+              </span>
+              <span className="text-[10px] text-default-400">
+                {alternativeHops.length} 条候选链路
+              </span>
+            </div>
+            <div className="grid max-h-72 grid-cols-1 gap-2 overflow-y-auto pr-1 md:grid-cols-2">
+              {alternativeHops.map((hop) => (
+                <CandidateHopLatency
+                  key={`${hop.hopIndex}-${hop.fromNodeId}-${hop.toRole}-${hop.toNodeId || hop.toNodeName}`}
+                  hop={hop}
+                />
+              ))}
+            </div>
+          </div>
+        ) : null}
      </CardBody>
    </Card>
  );
+});
+
+function CandidateHopLatency({
+  hop,
+}: {
+  hop: TunnelQualityCandidateHopApiItem;
+}) {
+  const hasError = Boolean(hop.errorMessage) || hop.latency < 0;
+
+  return (
+    <div className="rounded-xl border border-divider/60 bg-default-50/50 px-3 py-2.5">
+      <div className="flex items-center gap-2 text-xs">
+        <span className="min-w-0 truncate font-medium text-foreground">
+          {hop.fromNodeName}
+        </span>
+        <ArrowRight className="h-3.5 w-3.5 shrink-0 text-default-400" />
+        <span className="min-w-0 truncate font-medium text-foreground">
+          {hop.toNodeName}
+        </span>
+        <span className="ml-auto shrink-0">
+          <LatencyDisplay value={hop.latency} />
+        </span>
+      </div>
+      <div className="mt-1.5 flex items-center gap-2 text-[10px] text-default-400">
+        <span>
+          {candidateRoleLabel(hop.fromRole)} → {candidateRoleLabel(hop.toRole)}
+        </span>
+        {hasError ? (
+          <span className="ml-auto truncate text-danger">
+            {hop.errorMessage || "探测失败"}
+          </span>
+        ) : (
+          <span
+            className={`ml-auto font-mono ${hop.loss > 0 ? "text-warning" : "text-default-500"}`}
+          >
+            {hop.loss.toFixed(0)}% 丢包
+          </span>
+        )}
+      </div>
+    </div>
+  );
 }

 export function TunnelMonitorView({