backend: confirm a registered update by itself after a delay when auto update is switched on [CI]

The mesh test expects the single line of a pair, dialed by the smaller id. Tests that send at a fixed rate pin adaptive to false, so the admission limit follows that rate.

backend/agent/Directory.Build.props

@@ -8,7 +8,7 @@
     <EventSourceSupport>false</EventSourceSupport>
     <DebuggerSupport>false</DebuggerSupport>
     <HttpActivityPropagationSupport>false</HttpActivityPropagationSupport>
-    <Http3Support>false</Http3Support>
+    <Http3Support>true</Http3Support>
     <MetricsSupport>false</MetricsSupport>
     <UseSizeOptimizedLinq>true</UseSizeOptimizedLinq>
     <JsonSerializerIsReflectionEnabledByDefault>false</JsonSerializerIsReflectionEnabledByDefault>

backend/agent/src/MoShiro.Agent/AgentApp.cs

@@ -28,7 +28,7 @@ public sealed class AgentApp : IDisposable, IAsyncDisposable
     private readonly LoadedNodeIdentity _identity;
     private readonly TimeProvider _time;
     private readonly INodeLog _log;
-    private readonly INodeLogBatchSource? _logBatchSource;
+    private readonly INodeLogSource? _logSource;
     private readonly MonoClock _clock;
     private readonly AgentCounters _counters = new();
     private readonly SessionRegistry _sessions = new();
@@ -45,6 +45,7 @@ public sealed class AgentApp : IDisposable, IAsyncDisposable
     private readonly PeerListener _peers;
     private readonly PeerHub _hub;
     private readonly ChunkAssembler _chunks;
+    private readonly RateChangeLog _rateChanges = new();
     private readonly TaskManager _tasks;
     private readonly TestRunner _tests;
     private readonly FleetLink _link;
@@ -62,7 +63,7 @@ public sealed class AgentApp : IDisposable, IAsyncDisposable
         _identity = identity;
         _time = time;
         _log = log;
-        _logBatchSource = log as INodeLogBatchSource;
+        _logSource = log as INodeLogSource;
         _clock = new MonoClock(time);
         _uplink = new BackendUplink(time);
 
@@ -74,10 +75,16 @@ public sealed class AgentApp : IDisposable, IAsyncDisposable
 
         _ipv6Supported = _listening ? bind.AddressFamily == System.Net.Sockets.AddressFamily.InterNetworkV6 : null;
         _admission = new AgentAdmission(_streams);
-        _datagrams = new QuicDatagramTransport(_sessions, _admission, _clock, _counters.Data, log, bind, config.Listen.QuicPorts, identity.Certificate);
+        QuicSettings quic = config.Quic.ToSettings();
+        if (quic.Validate() is { } invalid)
+        {
+            throw new InvalidOperationException("agent.json quic: " + invalid);
+        }
+
+        _datagrams = new QuicDatagramTransport(_sessions, _admission, _clock, _counters.Data, log, bind, config.Listen.QuicPorts, identity.Certificate, quic);
         // 预握手敲门：控制端口和数据端口共用一个关卡（限速和去重一起算）；名册就是期望状态里的 peers
         _trust = TrustAnchor.Load(config.Fleet.IdentityDir, log);
-        _dialer = new DialerHost(new DialEnv(identity.PeerIdentity, identity.NodeId.Value, config.Limits, new DialDirectory(new ConfigStore(dataDirectory), dataDirectory, log, _trust), _clock, time, log), time, log);
+        _dialer = new DialerHost(new DialEnv(identity.PeerIdentity, identity.NodeId.Value, config.Limits, quic, new DialDirectory(new ConfigStore(dataDirectory), dataDirectory, log, _trust), _clock, time, log, _rateChanges), time, log);
         _knock = new KnockGate(identity.PeerIdentity, RosterKeys, time);
         _tcp = new TcpAcceptor(bind, config.Listen.TcpPorts, identity.Certificate, _sessions, _counters.Data, _knock);
 
@@ -95,7 +102,7 @@ public sealed class AgentApp : IDisposable, IAsyncDisposable
             MaxBulkMbps = config.Limits.MaxTotalMbps,
         };
         _chunks = new ChunkAssembler(_streams, _clock, _counters, _outbox, identity.NodeId, time, log);
-        var targets = new TargetRunners(_chunks, identity.NodeId, _clock, time, log);
+        var targets = new TargetRunners(_chunks, identity.NodeId, _clock, time, log, _rateChanges);
         _tasks = new TaskManager(CreateGuard, _streams, env, targets, () => _datagrams.BoundPorts, () => _tcp.BoundPorts, _trust, acceptLineTasks: _listening);
         _hub = new PeerHub(_sessions, _clock, _chunks, _tasks, _uplink, time, log);
         _tests = new TestRunner(_tasks, _sessions, _streams, env, _uplink, config.Limits.MaxConcurrentTests, transport => transport == "quic_datagram" ? _datagrams.BoundPorts : _tcp.BoundPorts, time, log);
@@ -320,6 +327,23 @@ public sealed class AgentApp : IDisposable, IAsyncDisposable
                 async (_, request, _) => Result<TestRunResult>.Ok(new TestRunResult { Accepted = await _hub.DisconnectAsync(request.DialerId.Value) }));
         }
 
+        if (Allow(MoShiroMethods.LogsFetch))
+        {
+            router.On(
+                MoShiroMethods.LogsFetch,
+                MoShiroJsonContext.Default.LogsFetchParams,
+                MoShiroJsonContext.Default.LogsFetchResult,
+                (_, request, _) =>
+                {
+                    NodeLogPage page = _logSource?.Read(request.AfterId, request.Limit, request.MinLevel) ?? new NodeLogPage([], 0);
+                    return ValueTask.FromResult(Result<LogsFetchResult>.Ok(new LogsFetchResult
+                    {
+                        LastId = page.LastId,
+                        Items = [.. page.Items.Select(e => new LogEntryDto { Id = e.Id, Type = e.Type, AtUtcMs = e.Record.AtUtcMs, Level = e.Record.Level, Message = e.Record.Message, Fields = e.Record.Fields })],
+                    }));
+                });
+        }
+
         if (Allow(MoShiroMethods.LinkRetry))
         {
             router.OnNotify(MoShiroMethods.LinkRetry, MoShiroJsonContext.Default.LinkRetryParams, (_, request, _) =>
@@ -336,6 +360,7 @@ public sealed class AgentApp : IDisposable, IAsyncDisposable
             ServerVerifier = _trust,
             NodeId = _identity.NodeId,
             NodeVersion = Version,
+            MinServerVersion = () => Environment.GetEnvironmentVariable("MOSHIRO_MIN_SERVER_VERSION") is { Length: > 0 } required ? required : _config.Fleet.MinServerVersion,
             Capabilities = [MoShiroCapabilities.Base, MoShiroCapabilities.KindsPrefix + string.Join(',', _listening ? BlockCatalog.AgentKinds : BlockCatalog.TargetKinds)],
             HelloMeta = HelloMeta,
             HeartbeatExtra = HeartbeatExtra,
@@ -407,7 +432,7 @@ public sealed class AgentApp : IDisposable, IAsyncDisposable
         long seconds = Math.Max(1, (nowMs - _lastAtMs) / 1000);
         long packetsIn = _counters.PacketsIn;
         long packetsOut = _counters.PacketsOut;
-        NodeLogBatch logBatch = _logBatchSource?.TakeBatch(16) ?? new NodeLogBatch([], 0);
+        NodeLogSummary? logSummary = _logSource?.TakeSummary();
         UpdateStatus? updateStatus = _nativeUpdate?.Status() ?? _update?.Status();
         var extra = new NodeHeartbeatExtra
         {
@@ -421,8 +446,15 @@ public sealed class AgentApp : IDisposable, IAsyncDisposable
             DroppedRateLimited = _counters.DroppedRateLimited,
             QueueBytes = _outbox.PendingBytes,
             Update = updateStatus,
-            RuntimeLogs = logBatch.Records.Count == 0 ? null : [.. logBatch.Records],
-            DroppedRuntimeLogs = logBatch.Dropped == 0 ? null : logBatch.Dropped,
+            RateChanges = _rateChanges.Take(64),
+            LogSummary = logSummary is null ? null : new LogSummaryDto
+            {
+                LastId = logSummary.LastId,
+                Info = logSummary.Info,
+                Warn = logSummary.Warn,
+                Error = logSummary.Error,
+                Types = [.. logSummary.Types.Select(t => new LogTypeCountDto { Type = t.Type, Level = t.Level, Count = t.Count })],
+            },
         };
         _lastIn = packetsIn;
         _lastOut = packetsOut;

backend/agent/src/MoShiro.Agent/AgentConfig.cs

@@ -15,6 +15,9 @@ public sealed class AgentConfig
     [JsonPropertyName("listen")]
     public ListenSection Listen { get; set; } = new();
 
+    [JsonPropertyName("quic")]
+    public QuicSection Quic { get; set; } = new();
+
     [JsonPropertyName("limits")]
     public LimitsSection Limits { get; set; } = new();
 
@@ -40,6 +43,10 @@ public sealed class FleetSection
     /// <summary>节点自己要求有属主（passkey）：没有就不运行。见 <c>OwnerGuard</c>。</summary>
     [JsonPropertyName("require_owner")]
     public bool RequireOwner { get; set; } = true;
+
+    /// <summary>面板至少要是哪个版本才继续连接（如 <c>0.4.2-dev.80</c>）；空 = 不要求。不够就不发任何东西，5 秒后重新握手（面板可能正在更新）。环境变量 <c>MOSHIRO_MIN_SERVER_VERSION</c> 优先。</summary>
+    [JsonPropertyName("min_server_version")]
+    public string? MinServerVersion { get; set; }
 }
 
 public sealed class ListenSection
@@ -62,6 +69,27 @@ public sealed class ListenSection
     public List<int> TcpPorts { get; set; } = [7444];
 }
 
+/// <summary>数据通道 QUIC 连接的传输参数；不写的项用 MsQuic 默认值。监听和拨出的连接都用这里的值。</summary>
+public sealed class QuicSection
+{
+    [JsonPropertyName("min_mtu")]
+    public int? MinMtu { get; set; }
+
+    [JsonPropertyName("max_mtu")]
+    public int? MaxMtu { get; set; }
+
+    [JsonPropertyName("pacing")]
+    public bool? Pacing { get; set; }
+
+    [JsonPropertyName("idle_timeout_ms")]
+    public int? IdleTimeoutMs { get; set; }
+
+    [JsonPropertyName("keep_alive_ms")]
+    public int? KeepAliveMs { get; set; }
+
+    public QuicSettings ToSettings() => new() { MinMtu = MinMtu, MaxMtu = MaxMtu, Pacing = Pacing, IdleTimeoutMs = IdleTimeoutMs, KeepAliveMs = KeepAliveMs };
+}
+
 public sealed class LimitsSection
 {
     [JsonPropertyName("max_total_mbps")]
@@ -70,7 +98,7 @@ public sealed class LimitsSection
     [JsonPropertyName("max_total_pps")]
     public long MaxTotalPps { get; set; } = 20_000;
 
-    /// <summary>默认为空：不允许执行任何目标任务。</summary>
+    /// <summary>单个 Agent 任务（外部目标）能探测的网段。默认为空：只允许公网地址，内网、回环、链路本地等一律拒绝；写了就只允许列出的网段（可以包含内网）。</summary>
     [JsonPropertyName("allowed_target_cidrs")]
     public List<string> AllowedTargetCidrs { get; set; } = [];
 

backend/agent/src/MoShiro.Agent/DataPlane/Registries.cs

@@ -217,8 +217,8 @@ public sealed class StreamInfo
         KindSpec spec = Kinds.Find(kind)!;
         DeclaredPps = kind switch
         {
-            "udp_echo" or "tcp_echo" => parameters.GetInt("rate_hz"),
-            "udp_train" => parameters.GetNumber("mbps") * 1_000_000 / 8 / Math.Max(1, parameters.GetInt("size")),
+            "quic_ping" or "tcp_ping" => Kinds.PeakRateHz(kind, parameters),
+            "quic_stream" => parameters.GetNumber("mbps") * 1_000_000 / 8 / Math.Max(1, parameters.GetInt("size")),
             _ => 20,
         };
         Port = spec.Params.Any(p => p.Name == "port") ? (int)parameters.GetInt("port") : 0;

backend/agent/src/MoShiro.Agent/Dial/ControlBackoff.cs

@@ -17,6 +17,8 @@ public sealed class ControlBackoff
         TimeSpan.FromSeconds(32),
     ];
 
+    private const int MaxMinutes = 10;
+
     private int _attempt;
 
     public int Attempts => Volatile.Read(ref _attempt);
@@ -24,7 +26,13 @@ public sealed class ControlBackoff
     public TimeSpan Next()
     {
         int attempt = Interlocked.Increment(ref _attempt) - 1;
-        return attempt < s_delays.Length ? s_delays[attempt] : TimeSpan.FromMinutes(1);
+        if (attempt < s_delays.Length)
+        {
+            return s_delays[attempt];
+        }
+
+        // 表走完还连不上（对端关了、这台机器没有这条路由）：一分钟起继续翻倍，最长十分钟，不再每分钟白白重试一次、写三条日志
+        return TimeSpan.FromMinutes(Math.Min(MaxMinutes, 1 << Math.Min(attempt - s_delays.Length, 4)));
     }
 
     public void Reset() => Interlocked.Exchange(ref _attempt, 0);

backend/agent/src/MoShiro.Agent/Dial/DialConnection.cs

@@ -11,7 +11,7 @@ using MoShiro.Protocol;
 namespace MoShiro.Agent;
 
 /// <summary>所有连接共用的东西。</summary>
-public sealed record DialEnv(NodeIdentity Identity, string NodeId, LimitsSection Limits, DialDirectory Directory, MonoClock Clock, TimeProvider Time, INodeLog Log);
+public sealed record DialEnv(NodeIdentity Identity, string NodeId, LimitsSection Limits, QuicSettings Quic, DialDirectory Directory, MonoClock Clock, TimeProvider Time, INodeLog Log, RateChangeLog RateChanges);
 
 /// <summary>
 /// 与一个 Agent 的点对点连接，分两层：
@@ -170,7 +170,8 @@ public sealed class DialConnection : IDisposable
             new DataPlaneCounters(),
             _attemptLog,
             new IPEndPoint(remote.Address, quicPort),
-            agentKey);
+            agentKey,
+            _env.Quic);
         Volatile.Write(ref _activeDatagrams, datagrams);
         using CancellationTokenSource cts = CancellationTokenSource.CreateLinkedTokenSource(ct);
 
@@ -189,6 +190,12 @@ public sealed class DialConnection : IDisposable
             Fragments = shipper,
             MaxPacketsPerSecond = _env.Limits.MaxTotalPps,
             MaxBulkMbps = _env.Limits.MaxTotalMbps,
+            OnRateChange = change =>
+            {
+                change.Listener = Endpoint.NodeId;
+                change.IpVersion = Endpoint.IpVersion;
+                _env.RateChanges.Add(change);
+            },
         };
         var session = new DialSession(blockEnv, clock, _outbox, _env);
         var rpc = new RpcSession<DialSession>(transport, s_router, session, _env.Time);

backend/agent/src/MoShiro.Agent/Dial/DialSession.cs

@@ -55,7 +55,7 @@ public sealed class DialSession
         }
     }
 
-    private static bool IsTcpKind(string kind) => kind is "tcp_echo" or "connect" or "hold" or "tcp_bulk";
+    private static bool IsTcpKind(string kind) => kind is "tcp_ping" or "tcp_connect" or "tls_hold" or "tcp_transfer";
 
     /// <summary>调和线路任务：参数没有变化的积木继续运行，其余启动或停止。返回被拒绝的任务（不认识的 Kind、参数非法、超过上限）。</summary>
     public async Task<List<RejectedItem>> ApplyAsync(LineTaskSet set)
@@ -137,7 +137,7 @@ public sealed class DialSession
             return false;
         }
 
-        if (start.Kind == "udp_train")
+        if (start.Kind == "quic_stream")
         {
             double mbps = start.Params["mbps"].GetDouble();
             long size = start.Params["size"].GetInt64();
@@ -167,7 +167,7 @@ public sealed class DialSession
         }
 
         // 最后一批包（单向数据流）、最后几个回显的回复还在途中
-        await Task.Delay(TimeSpan.FromMilliseconds(phase.Kind == "udp_train" ? 200 : 300), BlockEnv.Time, ct);
+        await Task.Delay(TimeSpan.FromMilliseconds(phase.Kind == "quic_stream" ? 200 : 300), BlockEnv.Time, ct);
         await phase.Running.StopAsync();
         return phase.Running.Block.Flush(FlushMode.All, end.SentCount);
     }

backend/agent/src/MoShiro.Agent/Dial/QuicRedialBackoff.cs

@@ -8,6 +8,8 @@ public sealed class QuicRedialBackoff
 {
     private static readonly TimeSpan[] s_delays = [TimeSpan.FromSeconds(1), TimeSpan.FromSeconds(2), TimeSpan.FromSeconds(3), TimeSpan.FromSeconds(5)];
 
+    private const int ShortAttempts = 12;
+
     private int _attempt;
 
     public int Attempts => _attempt;
@@ -15,6 +17,12 @@ public sealed class QuicRedialBackoff
     public TimeSpan Next(Random? random = null)
     {
         TimeSpan delay = s_delays[Math.Min(_attempt, s_delays.Length - 1)];
+        if (_attempt >= ShortAttempts)
+        {
+            // 短间隔已经连续失败了这么多次：这条路径大概率是死的（对端不通、被丢弃），握手和日志都是白费，翻倍退避，最长五分钟
+            delay = TimeSpan.FromSeconds(Math.Min(300, 5 * (1 << Math.Min(_attempt - ShortAttempts + 1, 6))));
+        }
+
         _attempt++;
         return random is null ? delay : delay * (0.8 + (0.4 * random.NextDouble()));
     }

backend/agent/src/MoShiro.Agent/RateChangeLog.cs

@@ -0,0 +1,40 @@
+using System.Collections.Concurrent;
+using MoShiro.Protocol;
+
+namespace MoShiro.Agent;
+
+/// <summary>
+/// 自适应探测频率的状态变化，等着随下一次心跳上报给 Backend（Backend 存成事件，用于事后审计）。
+/// 和普通日志分开存：日志环形缓冲几分钟到几小时就会被覆盖，而这里的变化要能在几天后回看。有界，满了丢最旧的。
+/// </summary>
+public sealed class RateChangeLog
+{
+    public const int Capacity = 512;
+
+    private readonly ConcurrentQueue<RateChange> _queue = new();
+
+    public void Add(RateChange change)
+    {
+        _queue.Enqueue(change);
+        while (_queue.Count > Capacity && _queue.TryDequeue(out _))
+        {
+        }
+    }
+
+    /// <summary>取走最多 <paramref name="max"/> 条（最旧的在前）；没有返回 null，心跳里就不带这个字段。</summary>
+    public List<RateChange>? Take(int max)
+    {
+        List<RateChange>? taken = null;
+        while ((taken?.Count ?? 0) < max)
+        {
+            if (!_queue.TryDequeue(out RateChange? change))
+            {
+                break;
+            }
+
+            (taken ??= []).Add(change);
+        }
+
+        return taken;
+    }
+}

backend/agent/src/MoShiro.Agent/Tasks/TargetRunners.cs

@@ -7,14 +7,16 @@ using MoShiro.Protocol;
 namespace MoShiro.Agent;
 
 /// <summary>
-/// 目标任务（Agent 自己探测一个地址，没有对端）：用和线路任务同一套积木（<see cref="BlockCatalog"/> 里的拨号方，例如 icmp_echo、connect），
-/// 只是列块不交给 Agent 合并，而是自己盖章、10 秒一块直接上传。目标地址必须在本地 <c>allowed_target_cidrs</c> 内
-/// （由 <see cref="BudgetGuard"/> 在接受任务之前检查）。
+/// 目标任务（Agent 自己探测一个地址，没有对端）：用和线路任务同一套积木（<see cref="BlockCatalog"/> 里的拨号方，例如 icmp_ping、connect），
+/// 只是列块不交给 Agent 合并，而是自己盖章、10 秒一块直接上传。目标可以是 IP、域名或（http）URL；域名在 Agent 上解析，
+/// 每个解析出的地址都必须在本地 <c>allowed_target_cidrs</c> 内（IP 目标由 <see cref="BudgetGuard"/> 在接受任务之前检查，域名在这里检查）。
 /// </summary>
 public sealed class TargetRunners
 {
     private static readonly TimeSpan s_chunkSpan = TimeSpan.FromSeconds(ProtocolLimits.ChunkSeconds);
 
+    private static readonly TimeSpan s_resolveRetry = TimeSpan.FromMinutes(1);
+
     private readonly Dictionary<string, Running> _running = [];
     private readonly object _gate = new();
     private readonly ChunkAssembler _chunks;
@@ -22,9 +24,11 @@ public sealed class TargetRunners
     private readonly MonoClock _clock;
     private readonly TimeProvider _time;
     private readonly INodeLog _log;
+    private readonly RateChangeLog? _rateChanges;
 
-    public TargetRunners(ChunkAssembler chunks, NodeId agent, MonoClock clock, TimeProvider time, INodeLog log)
+    public TargetRunners(ChunkAssembler chunks, NodeId agent, MonoClock clock, TimeProvider time, INodeLog log, RateChangeLog? rateChanges = null)
     {
+        _rateChanges = rateChanges;
         _chunks = chunks;
         _agent = agent;
         _clock = clock;
@@ -33,7 +37,7 @@ public sealed class TargetRunners
     }
 
     /// <summary>让运行中的任务与期望集合一致：参数没有变化的保持，其余启动或停止。</summary>
-    public void Reconcile(IReadOnlyList<(TaskSpec Spec, TaskDecision Decision)> desired)
+    public void Reconcile(IReadOnlyList<(TaskSpec Spec, TaskDecision Decision)> desired, Func<IPAddress, bool>? allow = null)
     {
         lock (_gate)
         {
@@ -56,7 +60,7 @@ public sealed class TargetRunners
 
                 var cts = new CancellationTokenSource();
                 _running[id] = new Running(Signature(spec), cts);
-                _ = Task.Run(() => RunAsync(spec, decision, cts.Token), CancellationToken.None);
+                _ = Task.Run(() => RunAsync(spec, decision, allow, cts.Token), CancellationToken.None);
             }
         }
     }
@@ -64,23 +68,34 @@ public sealed class TargetRunners
     private static string Signature(TaskSpec spec) =>
         spec.Kind + "|" + spec.Target + "|" + string.Join(',', spec.Params.OrderBy(p => p.Key, StringComparer.Ordinal).Select(p => p.Key + "=" + p.Value.GetRawText()));
 
-    private async Task RunAsync(TaskSpec spec, TaskDecision decision, CancellationToken ct)
+    private async Task RunAsync(TaskSpec spec, TaskDecision decision, Func<IPAddress, bool>? allow, CancellationToken ct)
     {
         try
         {
-            if (!TryResolve(spec.Target!, decision.Resolved!, spec.Kind, out IPAddress? address, out int port))
+            if (!TargetHost.TryParse(spec.Target, out string host, out int targetPort, out _))
             {
-                _log.Warn("target is not an address", ("task", spec.Id.Value));
+                _log.Warn("target is not valid", ("task", spec.Id.Value));
                 return;
             }
 
+            // http 自己解析并检查每个地址；其余 Kind 在这里解析出一个允许的地址作为对端
+            IPAddress? address = null;
+            if (spec.Kind != TargetHost.HttpKind)
+            {
+                address = await ResolveAllowedAsync(spec, host, allow, ct);
+            }
+
+            int port = targetPort != 0 ? targetPort : spec.Kind == "tcp_connect" ? (int)decision.Resolved!.GetInt("port") : 0;
             var env = new BlockEnv
             {
                 Clock = _clock,
                 Log = _log,
                 Session = () => null,
                 PeerAddress = address,
-                Fragments = new LocalSink(this, spec, address.AddressFamily == System.Net.Sockets.AddressFamily.InterNetworkV6 ? IpVersions.V6 : IpVersions.V4),
+                Target = spec.Target,
+                AllowAddress = allow,
+                OnRateChange = _rateChanges is null ? null : _rateChanges.Add,
+                Fragments = new LocalSink(this, spec, address?.AddressFamily == System.Net.Sockets.AddressFamily.InterNetworkV6 ? IpVersions.V6 : IpVersions.V4),
             };
             IBlock block = BlockCatalog.Find(spec.Kind)!.Dialer(env, new BlockSpec(decision.Kind!, decision.Resolved!, 0, port, new FragmentScope(spec.Id, null, null)));
             using var cts = CancellationTokenSource.CreateLinkedTokenSource(ct);
@@ -110,21 +125,29 @@ public sealed class TargetRunners
         }
     }
 
-    private static bool TryResolve(string target, ParamValues values, string kind, out IPAddress address, out int port)
+    /// <summary>解析目标，取第一个允许的地址；解析失败或没有允许的地址就每分钟重试（域名的解析结果会变）。</summary>
+    private async Task<IPAddress> ResolveAllowedAsync(TaskSpec spec, string host, Func<IPAddress, bool>? allow, CancellationToken ct)
     {
-        port = kind == "connect" ? (int)values.GetInt("port") : 0;
-        if (IPEndPoint.TryParse(target, out IPEndPoint? endpoint))
+        while (true)
         {
-            address = endpoint.Address;
-            if (endpoint.Port != 0)
+            try
             {
-                port = endpoint.Port;
+                IPAddress[] addresses = IPAddress.TryParse(host, out IPAddress? literal) ? [literal] : await Dns.GetHostAddressesAsync(host, ct);
+                IPAddress? chosen = addresses.FirstOrDefault(a => allow?.Invoke(a) ?? true);
+                if (chosen is not null)
+                {
+                    return chosen;
+                }
+
+                _log.Warn("no address of the target is allowed", ("task", spec.Id.Value), ("host", host));
+            }
+            catch (System.Net.Sockets.SocketException ex)
+            {
+                _log.Warn("target did not resolve", ("task", spec.Id.Value), ("host", host), ("err", ex.Message));
             }
 
-            return true;
+            await Task.Delay(s_resolveRetry, _time, ct);
         }
-
-        return IPAddress.TryParse(target, out address!);
     }
 
     /// <summary>目标任务的行没有拨号方一侧可以合并：积木交出的就是完整的行，Agent 自己盖章（目标、时钟锚点）并放进发件箱。</summary>

backend/agent/src/MoShiro.Agent/Tasks/TaskManager.cs

@@ -15,7 +15,7 @@ namespace MoShiro.Agent;
 /// </summary>
 public sealed class TaskManager
 {
-    // 线路任务 = 有监听方积木、并且不是只用于按需测试的 Kind（udp_train、tcp_bulk 会占满链路）；目标任务 = 可以由 Agent 自己运行的 Kind
+    // 线路任务 = 有监听方积木、并且不是只用于按需测试的 Kind（quic_stream、tcp_transfer 会占满链路）；目标任务 = 可以由 Agent 自己运行的 Kind
     private static readonly HashSet<string> s_lineKinds = [.. BlockCatalog.All.Where(p => p.Listener is not null && !p.OnDemandOnly).Select(p => p.Kind)];
     private static readonly HashSet<string> s_targetKinds = [.. BlockCatalog.All.Where(p => p.RunsAsTarget).Select(p => p.Kind)];
 
@@ -151,7 +151,7 @@ public sealed class TaskManager
             }
         }
 
-        _targets.Reconcile(targets);
+        _targets.Reconcile(targets, guard.AddressAllowed);
 
         // 参数没有变化的任务沿用原来的流和积木，数据面上的会话（重放窗口、记录）不被打断
         var retired = new List<LineEntry>();

backend/agent/src/MoShiro.Agent/Tests/TestRunner.cs

@@ -206,7 +206,7 @@ public sealed class TestRunner
             }
 
             // 单向数据流的发送端自己运行到结束（或失败）；其他积木是反应式的，等够时长即可
-            if (phase.Kind == "udp_train")
+            if (phase.Kind == "quic_stream")
             {
                 try
                 {

backend/agent/tests/MoShiro.Agent.Tests/ControlBackoffTests.cs

@@ -4,7 +4,7 @@ namespace MoShiro.Agent.Tests;
 public sealed class ControlBackoffTests
 {
     [Fact]
-    public void Next_UsesRequestedEscalationThenCapsAtOneMinute()
+    public void Next_UsesRequestedEscalationThenKeepsDoublingToTenMinutes()
     {
         var backoff = new ControlBackoff();
         TimeSpan[] expected =
@@ -13,7 +13,8 @@ public sealed class ControlBackoffTests
             TimeSpan.FromSeconds(8), TimeSpan.FromSeconds(16),
             TimeSpan.FromSeconds(32), TimeSpan.FromSeconds(32), TimeSpan.FromSeconds(32),
             TimeSpan.FromSeconds(32), TimeSpan.FromSeconds(32),
-            TimeSpan.FromMinutes(1), TimeSpan.FromMinutes(1),
+            TimeSpan.FromMinutes(1), TimeSpan.FromMinutes(2), TimeSpan.FromMinutes(4),
+            TimeSpan.FromMinutes(8), TimeSpan.FromMinutes(10), TimeSpan.FromMinutes(10),
         ];
 
         Assert.Equal(expected, expected.Select(_ => backoff.Next()));

backend/agent/tests/MoShiro.Agent.Tests/LinkStateTests.cs

@@ -16,6 +16,10 @@ public sealed class LinkStateTests
         int[] seconds = [1, 2, 3, 5, 5, 5];
         Assert.Equal(seconds, seconds.Select(_ => (int)backoff.Next().TotalSeconds));
 
+        // 连续失败很多次（路径是死的）：翻倍退避，最长五分钟
+        int[] later = [.. Enumerable.Range(0, 12).Select(_ => (int)backoff.Next().TotalSeconds)];
+        Assert.Equal([5, 5, 5, 10, 20, 40, 80, 160, 300], later[3..]);
+
         backoff.Reset();
 
         Assert.Equal(TimeSpan.FromSeconds(1), backoff.Next());

backend/fleet/src/Fleet.Core/ErrorCode.cs

@@ -27,4 +27,7 @@ public static class FleetErrors
     public static readonly ErrorCode JoinTokenExpired = new("fleet_join_token_expired");
     public static readonly ErrorCode ProofInvalid = new("fleet_proof_invalid");
     public static readonly ErrorCode FrameTooLarge = new("fleet_frame_too_large");
+
+    /// <summary>对方的版本低于要求的最低版本：等一会儿（对方可能正在更新）再握手。</summary>
+    public static readonly ErrorCode VersionRequired = new("fleet_version_required");
 }

backend/fleet/src/Fleet.Core/NodeSupport.cs

@@ -15,15 +15,27 @@ public interface INodeLog
     void Write(NodeLogLevel level, string message, params (string Key, object? Value)[] fields);
 }
 
-/// <summary>One structured node log line queued for delivery to the control plane.</summary>
+/// <summary>One structured node log line.</summary>
 public sealed record NodeLogRecord(long AtUtcMs, string Level, string Message, Dictionary<string, string> Fields);
 
-public sealed record NodeLogBatch(IReadOnlyList<NodeLogRecord> Records, long Dropped);
+/// <summary>A retained log line: <paramref name="Id"/> grows with every line, <paramref name="Type"/> is a stable hash of the message text (the template), so counters can be sent without the text.</summary>
+public sealed record NodeLogEntry(long Id, uint Type, NodeLogRecord Record);
 
-/// <summary>Optional bounded log source used by node heartbeats to upload recent local logs.</summary>
-public interface INodeLogBatchSource
+/// <summary>How many lines of one type and level were written since the last summary.</summary>
+public sealed record NodeLogTypeCount(uint Type, string Level, long Count);
+
+/// <summary>What a node tells the control plane about its logs without sending any text: counters since the last summary and the newest line id.</summary>
+public sealed record NodeLogSummary(long LastId, long Info, long Warn, long Error, IReadOnlyList<NodeLogTypeCount> Types);
+
+public sealed record NodeLogPage(IReadOnlyList<NodeLogEntry> Items, long LastId);
+
+/// <summary>Bounded local log retention. The control plane gets counters in heartbeats and pulls the text when it needs it.</summary>
+public interface INodeLogSource
 {
-    NodeLogBatch TakeBatch(int maxRecords);
+    NodeLogSummary TakeSummary();
+
+    /// <summary>Lines with an id above <paramref name="afterId"/>, oldest first, at most <paramref name="limit"/>, at or above <paramref name="minLevel"/> (info, warn or error).</summary>
+    NodeLogPage Read(long afterId, int limit, string? minLevel);
 }
 
 public sealed class NullNodeLog : INodeLog

backend/fleet/src/Fleet.Core/NodeVersions.cs

@@ -0,0 +1,87 @@
+using System.Globalization;
+
+namespace Fleet.Core;
+
+/// <summary>
+/// 版本号比较，给「要求的最低版本」用。认得 <c>主.次.修订</c>，可以带预发布后缀；开发构建 <c>0.4.2-dev.73-5245f03</c> 按 <c>dev.73</c> 的序号比较，
+/// 提交哈希不参与比较。同一个主次修订里，正式版高于任何预发布版。认不出来的版本号不拒绝（返回 false），免得一个奇怪的版本字符串把节点挡在门外。
+/// </summary>
+public static class NodeVersions
+{
+    private readonly record struct Parsed(int Major, int Minor, int Patch, bool Prerelease, long Dev, string Suffix);
+
+    /// <summary><paramref name="actual"/> 低于 <paramref name="required"/> 返回 true；任何一个为空或无法解析返回 false。</summary>
+    public static bool IsBelow(string? actual, string? required)
+    {
+        if (string.IsNullOrWhiteSpace(required) || string.IsNullOrWhiteSpace(actual))
+        {
+            return false;
+        }
+
+        if (!TryParse(actual, out Parsed have) || !TryParse(required, out Parsed need))
+        {
+            return false;
+        }
+
+        return Compare(have, need) < 0;
+    }
+
+    private static int Compare(Parsed a, Parsed b)
+    {
+        int core = (a.Major, a.Minor, a.Patch).CompareTo((b.Major, b.Minor, b.Patch));
+        if (core != 0)
+        {
+            return core;
+        }
+
+        if (a.Prerelease != b.Prerelease)
+        {
+            return a.Prerelease ? -1 : 1; // 正式版高于预发布版
+        }
+
+        if (!a.Prerelease)
+        {
+            return 0;
+        }
+
+        int dev = a.Dev.CompareTo(b.Dev);
+        return dev != 0 ? dev : 0;
+    }
+
+    private static bool TryParse(string text, out Parsed parsed)
+    {
+        parsed = default;
+        string value = text.Trim().TrimStart('v');
+        int plus = value.IndexOf('+', StringComparison.Ordinal);
+        if (plus >= 0)
+        {
+            value = value[..plus];
+        }
+
+        int dash = value.IndexOf('-', StringComparison.Ordinal);
+        string core = dash < 0 ? value : value[..dash];
+        string suffix = dash < 0 ? "" : value[(dash + 1)..];
+        string[] parts = core.Split('.');
+        if (parts.Length != 3
+            || !int.TryParse(parts[0], NumberStyles.None, CultureInfo.InvariantCulture, out int major)
+            || !int.TryParse(parts[1], NumberStyles.None, CultureInfo.InvariantCulture, out int minor)
+            || !int.TryParse(parts[2], NumberStyles.None, CultureInfo.InvariantCulture, out int patch))
+        {
+            return false;
+        }
+
+        long dev = 0;
+        if (suffix.StartsWith("dev.", StringComparison.Ordinal))
+        {
+            string number = suffix[4..];
+            int end = number.IndexOf('-', StringComparison.Ordinal);
+            if (!long.TryParse(end < 0 ? number : number[..end], NumberStyles.None, CultureInfo.InvariantCulture, out dev))
+            {
+                return false;
+            }
+        }
+
+        parsed = new Parsed(major, minor, patch, suffix.Length > 0, dev, suffix);
+        return true;
+    }
+}

backend/fleet/src/Fleet.Hosting/BufferedNodeLog.cs

@@ -3,20 +3,28 @@ using Fleet.Core;
 
 namespace Fleet.Hosting;
 
-/// <summary>Writes logs locally and keeps a bounded copy for the next authenticated heartbeat.</summary>
-public sealed class BufferedNodeLog : INodeLog, INodeLogBatchSource
+/// <summary>
+/// Writes logs locally and keeps a bounded ring of recent lines. Heartbeats carry only counters (see <see cref="TakeSummary"/>);
+/// the text leaves the node when the control plane asks for it (see <see cref="Read"/>).
+/// </summary>
+public sealed class BufferedNodeLog : INodeLog, INodeLogSource
 {
-    private const int Capacity = 256;
+    private const int Capacity = 2048;
     private const int MaxFields = 20;
     private const int MaxMessageLength = 512;
     private const int MaxFieldValueLength = 256;
-    private const int MaxBatchBytes = 8 << 10;
+    private const int MaxPageBytes = 96 << 10;
+    private const int MaxSummaryTypes = 8;
 
     private readonly object _gate = new();
-    private readonly Queue<NodeLogRecord> _pending = [];
+    private readonly LinkedList<NodeLogEntry> _ring = [];
+    private readonly Dictionary<(uint Type, string Level), long> _counts = [];
     private readonly INodeLog _local;
     private readonly TimeProvider _time;
-    private long _dropped;
+    private long _lastId;
+    private long _info;
+    private long _warn;
+    private long _error;
 
     public BufferedNodeLog(INodeLog local, TimeProvider time)
     {
@@ -35,50 +43,93 @@ public sealed class BufferedNodeLog : INodeLog, INodeLogBatchSource
             safeFields[key.Length <= 64 ? key : key[..64]] = Truncate(safeValue, MaxFieldValueLength);
         }
 
-        var record = new NodeLogRecord(
-            _time.GetUtcNow().ToUnixTimeMilliseconds(),
-            level.ToString().ToLowerInvariant(),
-            Truncate(message, MaxMessageLength),
-            safeFields);
-
+        string levelName = level.ToString().ToLowerInvariant();
+        var record = new NodeLogRecord(_time.GetUtcNow().ToUnixTimeMilliseconds(), levelName, Truncate(message, MaxMessageLength), safeFields);
+        uint type = TypeOf(record.Message);
         lock (_gate)
         {
-            if (_pending.Count == Capacity)
+            _ring.AddLast(new NodeLogEntry(++_lastId, type, record));
+            if (_ring.Count > Capacity)
             {
-                _pending.Dequeue();
-                _dropped++;
+                _ring.RemoveFirst();
             }
 
-            _pending.Enqueue(record);
+            _counts[(type, levelName)] = _counts.GetValueOrDefault((type, levelName)) + 1;
+            switch (level)
+            {
+                case NodeLogLevel.Error:
+                    _error++;
+                    break;
+                case NodeLogLevel.Warn:
+                    _warn++;
+                    break;
+                default:
+                    _info++;
+                    break;
+            }
         }
     }
 
-    public NodeLogBatch TakeBatch(int maxRecords)
+    public NodeLogSummary TakeSummary()
     {
-        int count = Math.Clamp(maxRecords, 0, 32);
         lock (_gate)
         {
-            var records = new List<NodeLogRecord>(Math.Min(count, _pending.Count));
+            var summary = new NodeLogSummary(
+                _lastId, _info, _warn, _error,
+                [.. _counts.OrderByDescending(pair => pair.Value).Take(MaxSummaryTypes).Select(pair => new NodeLogTypeCount(pair.Key.Type, pair.Key.Level, pair.Value))]);
+            _counts.Clear();
+            _info = _warn = _error = 0;
+            return summary;
+        }
+    }
+
+    public NodeLogPage Read(long afterId, int limit, string? minLevel)
+    {
+        int rank = LevelRank(minLevel);
+        lock (_gate)
+        {
+            var items = new List<NodeLogEntry>(Math.Min(Math.Max(limit, 0), 200));
             int bytes = 0;
-            while (records.Count < count && _pending.TryPeek(out NodeLogRecord? record))
+            foreach (NodeLogEntry entry in _ring)
             {
-                int recordBytes = 64 + record.Message.Length + record.Fields.Sum(pair => pair.Key.Length + pair.Value.Length + 8);
-                if (records.Count > 0 && bytes + recordBytes > MaxBatchBytes)
+                if (entry.Id <= afterId || LevelRank(entry.Record.Level) < rank)
+                {
+                    continue;
+                }
+
+                int entryBytes = 64 + entry.Record.Message.Length + entry.Record.Fields.Sum(pair => pair.Key.Length + pair.Value.Length + 8);
+                if (items.Count >= Math.Clamp(limit, 0, 200) || (items.Count > 0 && bytes + entryBytes > MaxPageBytes))
                 {
                     break;
                 }
 
-                _pending.Dequeue();
-                records.Add(record);
-                bytes += recordBytes;
+                items.Add(entry);
+                bytes += entryBytes;
             }
 
-            long dropped = _dropped;
-            _dropped = 0;
-            return new NodeLogBatch(records, dropped);
+            return new NodeLogPage(items, _lastId);
         }
     }
 
+    /// <summary>The line's type: a stable 32-bit FNV-1a hash of its message text, so the same template always maps to the same number.</summary>
+    public static uint TypeOf(string message)
+    {
+        uint hash = 2166136261;
+        foreach (char c in message)
+        {
+            hash = (hash ^ c) * 16777619;
+        }
+
+        return hash;
+    }
+
+    private static int LevelRank(string? level) => level switch
+    {
+        "error" => 2,
+        "warn" => 1,
+        _ => 0,
+    };
+
     private static bool IsSensitiveKey(string key)
     {
         string lower = key.ToLowerInvariant();

backend/fleet/src/Fleet.Link/FleetLink.cs

@@ -52,7 +52,10 @@ public sealed class FleetLinkOptions
 
     public string NodeVersion { get; init; } = "0.0.0";
 
-    /// <summary>框架之外的能力，例如 <c>moshiro.v1</c> 与 <c>moshiro.kinds:udp_echo,tcp_echo</c>。</summary>
+    /// <summary>服务端至少要是哪个版本（每次握手重新取）；空表示不要求。不够就关掉这条连接，等 <see cref="VersionRetry"/> 再握手，服务端可能正在更新。</summary>
+    public Func<string?>? MinServerVersion { get; init; }
+
+    /// <summary>框架之外的能力，例如 <c>moshiro.v1</c> 与 <c>moshiro.kinds:quic_ping,tcp_ping</c>。</summary>
     public IReadOnlyList<string> Capabilities { get; init; } = [];
 
     /// <summary>附加到 <c>fleet.hello</c> 的产品元数据。</summary>
@@ -100,7 +103,11 @@ public sealed class FleetLink
     private volatile RpcSession<LinkContext>? _session;
     private volatile bool _stopped;
 
+    /// <summary>版本不够时重新握手的间隔：固定，不退避（对方更新完马上就能连上）。</summary>
+    public static readonly TimeSpan VersionRetry = TimeSpan.FromSeconds(5);
+
     private static readonly TimeSpan s_tcpTimeout = TimeSpan.FromSeconds(4);
+    private TimeSpan? _fixedRetry;
     private int _failedConnects;
 
     public FleetLink(FleetLinkOptions options, RpcRouter<LinkContext> router, IEnumerable<IStateHandler> handlers, Outbox outbox, TimeProvider time, INodeLog log)
@@ -166,7 +173,8 @@ public sealed class FleetLink
                 return;
             }
 
-            TimeSpan delay = _options.Backoff.Next();
+            TimeSpan delay = _fixedRetry ?? _options.Backoff.Next();
+            _fixedRetry = null;
             _log.Warn("link down, retrying", ("err", reason), ("retry_ms", (long)delay.TotalMilliseconds));
             await Task.Delay(delay, _time, ct);
         }
@@ -263,7 +271,19 @@ public sealed class FleetLink
             Result<HelloResult> helloResult = await session.RequestAsync(FleetMethods.Hello, hello, FleetRpcContext.Default.HelloParams, FleetRpcContext.Default.HelloResult, ct);
             if (!helloResult.IsSuccess)
             {
-                return "hello failed: " + helloResult.Error.Code;
+                if (helloResult.Error.Code == FleetErrors.VersionRequired)
+                {
+                    _fixedRetry = VersionRetry; // 我们的版本低于服务端要求的：等自己更新，每 5 秒再试一次
+                }
+
+                return "hello failed: " + helloResult.Error.Code + (_fixedRetry is null ? "" : ": " + helloResult.Error.Message);
+            }
+
+            string? requiredServer = _options.MinServerVersion?.Invoke();
+            if (NodeVersions.IsBelow(helloResult.Value.ServerVersion, requiredServer))
+            {
+                _fixedRetry = VersionRetry; // 服务端版本低于我们要求的（它可能正在更新）：不发任何东西，5 秒后重新握手
+                return $"server version {helloResult.Value.ServerVersion} is below the required {requiredServer}";
             }
 
             Outbox.ResetSent();

backend/fleet/src/Fleet.Link/Peer.cs

@@ -27,7 +27,15 @@ public sealed class PeerListenerOptions
 
     public int MaxFrameBytes { get; init; } = 8 << 20;
 
-    public int MaxSessions { get; init; } = 8;
+    /// <summary>
+    /// 同时在线的会话数上限，只数已经通过敲门的对端。每个拨号方每个地址族一个会话，所以要容得下「名册里的节点数 × 2」。
+    /// 之前这个上限连还没敲门的连接一起数：节点多起来之后，已建立的会话把名额占满，后到的拨号方（哪怕在名册里）一连上就被断开，
+    /// 而且一直连不上，重试只会得到同样的结果。
+    /// </summary>
+    public int MaxSessions { get; init; } = 64;
+
+    /// <summary>还没通过敲门的连接数上限（陌生人、扫描器、还在握手的）：敲门有读超时，占着名额的时间有限，但它们不能挤占已通过敲门的会话。</summary>
+    public int MaxPending { get; init; } = 64;
 
     /// <summary>敲门、TLS、挑战应答整个握手的上限。线路差的时候（RTT 好几秒、还丢包）握手本来就要很久，10 秒做不完就会一直连不上；敲门已经挡住了不认识的连接，放宽不会放大被占连接的风险。</summary>
     public TimeSpan HandshakeTimeout { get; init; } = PeerTimings.Handshake;
@@ -44,6 +52,7 @@ public sealed class PeerListener
     private readonly INodeLog _log;
     private readonly TimeProvider _time;
     private int _sessions;
+    private int _pending;
 
     public PeerListener(PeerListenerOptions options, Func<PeerSessionInfo, IRpcTransport, CancellationToken, Task> onSession, INodeLog log, TimeProvider time)
     {
@@ -74,9 +83,9 @@ public sealed class PeerListener
             while (!ct.IsCancellationRequested)
             {
                 TcpClient client = await listener.AcceptTcpClientAsync(ct);
-                if (Interlocked.Increment(ref _sessions) > _options.MaxSessions)
+                if (Interlocked.Increment(ref _pending) > _options.MaxPending)
                 {
-                    Interlocked.Decrement(ref _sessions);
+                    Interlocked.Decrement(ref _pending);
                     client.Dispose();
                     continue;
                 }
@@ -97,6 +106,7 @@ public sealed class PeerListener
     private async Task HandleAsync(TcpClient client, CancellationToken ct)
     {
         bool admitted = false;
+        bool counted = false;
         string phase = "knock";
         long started = _time.GetTimestamp();
         EndPoint? remote = client.Client.RemoteEndPoint;
@@ -113,6 +123,15 @@ public sealed class PeerListener
             }
 
             admitted = true;
+            Interlocked.Decrement(ref _pending);
+            if (Interlocked.Increment(ref _sessions) > _options.MaxSessions)
+            {
+                Interlocked.Decrement(ref _sessions);
+                _log.Warn("peer session limit reached", ("remote", remote), ("limit", _options.MaxSessions));
+                return;
+            }
+
+            counted = true;
             phase = "tls";
             _log.Info("peer knock accepted", ("remote", remote), ("phase", phase));
             var tls = new SslStream(stream, leaveInnerStreamOpen: false);
@@ -152,7 +171,15 @@ public sealed class PeerListener
         finally
         {
             client.Dispose();
-            Interlocked.Decrement(ref _sessions);
+            if (!admitted)
+            {
+                Interlocked.Decrement(ref _pending);
+            }
+
+            if (counted)
+            {
+                Interlocked.Decrement(ref _sessions);
+            }
         }
     }
 

backend/fleet/src/Fleet.Rpc/FleetMethods.cs

@@ -104,6 +104,10 @@ public sealed class HelloResult
     /// <summary>节点时钟 − 服务端时钟（毫秒，未扣除网络往返）。</summary>
     [JsonPropertyName("clock_offset_ms")]
     public long ClockOffsetMs { get; set; }
+
+    /// <summary>服务端的版本：节点要求了最低服务端版本时，用它判断。</summary>
+    [JsonPropertyName("server_version")]
+    public string? ServerVersion { get; set; }
 }
 
 public sealed class HeartbeatParams

backend/fleet/src/Fleet.Server.Abstractions/FleetServerOptions.cs

@@ -22,3 +22,12 @@ public sealed class FleetServerOptions
     /// <summary>节点违反协议（方法没有声明、方向、类型或角色不对）的次数上限；超过就断开这条连接。</summary>
     public int MaxViolations { get; set; } = 20;
 }
+
+/// <summary>握手时的版本要求：服务端的版本（告诉节点），以及节点至少要是哪个版本。每次握手都重新取，所以改配置不用重启。</summary>
+public interface IFleetVersionPolicy
+{
+    string? ServerVersion { get; }
+
+    /// <summary>空表示不要求。</summary>
+    string? MinNodeVersion { get; }
+}

backend/fleet/src/Fleet.Server.Link/FleetLinkHost.cs

@@ -24,8 +24,10 @@ public sealed class FleetLinkHost : IFleetConnections, IStateNotifier
         IEnumerable<IInbox> inboxes,
         IEnumerable<INodeEventSink> sinks,
         FleetRouter router,
-        IServerIdentity? serverIdentity = null)
+        IServerIdentity? serverIdentity = null,
+        IFleetVersionPolicy? versionPolicy = null)
     {
+        VersionPolicy = versionPolicy;
         ServerIdentity = serverIdentity;
         Store = store;
         Options = options;
@@ -43,6 +45,8 @@ public sealed class FleetLinkHost : IFleetConnections, IStateNotifier
     /// <summary>服务器的身份密钥；没有时节点连接用旧的明文认证。</summary>
     internal IServerIdentity? ServerIdentity { get; }
 
+    internal IFleetVersionPolicy? VersionPolicy { get; }
+
     internal FleetServerOptions Options { get; }
 
     internal TimeProvider Time { get; }

backend/fleet/src/Fleet.Server.Link/FleetLog.cs

@@ -10,6 +10,9 @@ internal static partial class FleetLog
     [LoggerMessage(Level = LogLevel.Information, Message = "node disconnected node={Node} reason={Reason}")]
     public static partial void Disconnected(ILogger logger, string node, string reason);
 
+    [LoggerMessage(Level = LogLevel.Warning, Message = "node below the required version node={Node} version={Version} required={Required}")]
+    public static partial void VersionTooOld(ILogger logger, string node, string version, string required);
+
     [LoggerMessage(Level = LogLevel.Warning, Message = "node auth rejected err={Err}")]
     public static partial void AuthRejected(ILogger logger, string err);
 

backend/fleet/src/Fleet.Server.Link/FleetServerBuilder.cs

@@ -110,7 +110,8 @@ public static class FleetServerExtensions
             provider.GetServices<IInbox>(),
             provider.GetServices<INodeEventSink>(),
             provider.GetRequiredService<FleetRouter>(),
-            provider.GetService<IServerIdentity>()));
+            provider.GetService<IServerIdentity>(),
+            provider.GetService<IFleetVersionPolicy>()));
         services.AddSingleton<IFleetConnections>(provider => provider.GetRequiredService<FleetLinkHost>());
         services.AddSingleton<IStateNotifier>(provider => provider.GetRequiredService<FleetLinkHost>());
         return builder;

backend/fleet/src/Fleet.Server.Link/NodeConnection.Receive.cs

@@ -151,6 +151,20 @@ internal sealed partial class NodeConnection
             return;
         }
 
+        string? minVersion = _host.VersionPolicy?.MinNodeVersion;
+        if (NodeVersions.IsBelow(hello.NodeVersion, minVersion))
+        {
+            // 版本不够：不登记在线，告诉节点要求的版本，关闭连接。节点等几秒（它可能正在更新）再握手。
+            FleetLog.VersionTooOld(_host.Logger, _node!.Id.Value, hello.NodeVersion, minVersion!);
+            if (message.Id is not null)
+            {
+                await SendAsync(RpcMessage.Failure(message.Id, new FleetError(FleetErrors.VersionRequired, $"node version {hello.NodeVersion} is below the required {minVersion}")), ct);
+            }
+
+            await CloseAsync("version required");
+            return;
+        }
+
         long nowMs = _host.Time.GetUtcNow().ToUnixTimeMilliseconds();
         _session = _session! with
         {
@@ -169,7 +183,7 @@ internal sealed partial class NodeConnection
             await SendAsync(
                 RpcMessage.Success(
                     message.Id.Value,
-                    new HelloResult { ServerTimeMs = nowMs, ClockOffsetMs = hello.NowUtcMs - nowMs },
+                    new HelloResult { ServerTimeMs = nowMs, ClockOffsetMs = hello.NowUtcMs - nowMs, ServerVersion = _host.VersionPolicy?.ServerVersion },
                     FleetRpcContext.Default.HelloResult),
                 ct);
         }

backend/fleet/tests/Fleet.Tests/BufferedNodeLogTests.cs

@@ -0,0 +1,65 @@
+using Fleet.Core;
+using Fleet.Hosting;
+
+namespace Fleet.Tests;
+
+public sealed class BufferedNodeLogTests
+{
+    [Fact]
+    public void Summary_CountsByLevelAndTypeWithoutText_AndResetsAfterEachTake()
+    {
+        var log = new BufferedNodeLog(NullNodeLog.Instance, TimeProvider.System);
+        for (int i = 0; i < 5; i++)
+        {
+            log.Warn("peer control handshake failed", ("attempt", i));
+        }
+
+        log.Info("link up");
+        log.Error("MsQuic QUIC transport shutdown");
+
+        NodeLogSummary first = log.TakeSummary();
+        Assert.Equal((1L, 5L, 1L), (first.Info, first.Warn, first.Error));
+        Assert.Equal(7, first.LastId);
+        NodeLogTypeCount top = first.Types[0];
+        Assert.Equal((BufferedNodeLog.TypeOf("peer control handshake failed"), "warn", 5L), (top.Type, top.Level, top.Count));
+
+        NodeLogSummary second = log.TakeSummary();
+        Assert.Equal((0L, 0L, 0L), (second.Info, second.Warn, second.Error));
+        Assert.Empty(second.Types);
+        Assert.Equal(7, second.LastId);
+    }
+
+    [Fact]
+    public void Read_ReturnsLinesAfterAnIdAtOrAboveALevel_OldestFirst_AndTheRingKeepsTheNewest()
+    {
+        var log = new BufferedNodeLog(NullNodeLog.Instance, TimeProvider.System);
+        log.Info("one");
+        log.Warn("two");
+        log.Error("three");
+        log.Info("four");
+
+        Assert.Equal(["two", "three"], log.Read(1, 2, null).Items.Select(e => e.Record.Message));
+        Assert.Equal(["three"], log.Read(0, 10, "error").Items.Select(e => e.Record.Message));
+        Assert.Equal(["two", "three"], log.Read(0, 10, "warn").Items.Select(e => e.Record.Message));
+
+        for (int i = 0; i < 3000; i++)
+        {
+            log.Info("filler", ("n", i));
+        }
+
+        NodeLogPage page = log.Read(0, 200, null);
+        Assert.Equal(200, page.Items.Count);
+        Assert.True(page.Items[0].Id > 4); // 最早的几条已经被环挤掉
+        Assert.Equal(3004, page.LastId);
+    }
+
+    [Fact]
+    public void SensitiveFieldsAreRedacted()
+    {
+        var log = new BufferedNodeLog(NullNodeLog.Instance, TimeProvider.System);
+        log.Info("auth", ("token", "abc"), ("agent", "agt_x"));
+        NodeLogEntry entry = Assert.Single(log.Read(0, 10, null).Items);
+        Assert.Equal("[redacted]", entry.Record.Fields["token"]);
+        Assert.Equal("agt_x", entry.Record.Fields["agent"]);
+    }
+}

backend/fleet/tests/Fleet.Tests/LinkTests.cs

@@ -303,7 +303,7 @@ public sealed class LinkTests
         private readonly CancellationTokenSource _stop = new();
         private readonly NodeIdentity _identity;
 
-        public PeerFixture(Func<string, byte[]?> lookup, Func<PeerSessionInfo, IRpcTransport, CancellationToken, Task>? onSession = null)
+        public PeerFixture(Func<string, byte[]?> lookup, Func<PeerSessionInfo, IRpcTransport, CancellationToken, Task>? onSession = null, int maxSessions = 64)
         {
             Certificate = NodeCertificate.LoadPfx(NodeCertificate.CreateSelfSignedPfx("agent", TimeSpan.FromDays(30), TimeProvider.System));
             _identity = NodeIdentity.FromPkcs8(Certificate.GetECDsaPrivateKey()!.ExportPkcs8PrivateKey());
@@ -314,6 +314,7 @@ public sealed class LinkTests
                     Certificate = Certificate,
                     LookupPeerKey = lookup,
                     Knock = new KnockGate(_identity, () => KnockPeers, TimeProvider.System),
+                    MaxSessions = maxSessions,
                 },
                 onSession ?? ((_, transport, ct) => KeepOpenAsync(transport, ct)),
                 NullNodeLog.Instance, TimeProvider.System);
@@ -373,9 +374,9 @@ public sealed class LinkTests
             Assert.Equal("dlr_1", server.PeerId);
             Assert.Equal(client.Credentials.Key, server.Credentials.Key);
             Assert.Equal(client.Credentials.SessionId, server.Credentials.SessionId);
-            NodeLogBatch batch = logs.TakeBatch(32);
-            Assert.Equal(new[] { "tcp_connect", "tls", "peer_auth" }, batch.Records.Select(x => x.Fields["phase"]));
-            Assert.All(batch.Records, entry => Assert.Equal("test-attempt", entry.Fields["attempt_id"]));
+            NodeLogPage page = logs.Read(0, 32, null);
+            Assert.Equal(new[] { "tcp_connect", "tls", "peer_auth" }, page.Items.Select(x => x.Record.Fields["phase"]));
+            Assert.All(page.Items, entry => Assert.Equal("test-attempt", entry.Record.Fields["attempt_id"]));
         }
     }
 
@@ -391,7 +392,7 @@ public sealed class LinkTests
         var logs = new Fleet.Hosting.BufferedNodeLog(NullNodeLog.Instance, TimeProvider.System);
         InvalidOperationException unknown = await Assert.ThrowsAsync<InvalidOperationException>(async () =>
             await PeerConnector.ConnectAsync("127.0.0.1", agent.Listener.Port, agent.PublicKey, dialer, "dlr_unknown", null, 1 << 20, TimeProvider.System, logs, default));
-        NodeLogRecord failure = Assert.Single(logs.TakeBatch(32).Records, entry => entry.Message == "peer control handshake failed");
+        NodeLogRecord failure = Assert.Single(logs.Read(0, 32, null).Items, entry => entry.Record.Message == "peer control handshake failed").Record;
         Assert.Equal("peer_auth", failure.Fields["phase"]);
         Assert.Equal("InvalidOperationException", failure.Fields["exception"]);
         InvalidOperationException forged = await Assert.ThrowsAsync<InvalidOperationException>(async () =>
@@ -462,6 +463,65 @@ public sealed class LinkTests
         await ok.DisposeAsync();
     }
 
+    /// <summary>名额只数通过敲门的会话：一堆还没敲门的连接占着，名册里的拨号方照样连得上（之前它们共用一个上限，节点多了之后后到的拨号方被永远拒绝）。</summary>
+    [Fact]
+    public async Task PeerListener_SessionLimitCountsOnlyAdmittedPeers_SoSilentConnectionsCannotLockOutTheRoster()
+    {
+        using NodeIdentity first = NodeIdentity.Generate();
+        using NodeIdentity second = NodeIdentity.Generate();
+        using NodeIdentity third = NodeIdentity.Generate();
+        await using var agent = new PeerFixture(id => id == "dlr_1" ? first.PublicKeySpki : id == "dlr_2" ? second.PublicKeySpki : third.PublicKeySpki, maxSessions: 2);
+        agent.KnockPeers.AddRange([first.PublicKeySpki, second.PublicKeySpki, third.PublicKeySpki]);
+        await agent.Listener.Started.Task;
+
+        // 20 个什么都不说的连接：占着待敲门的名额，但不占会话名额
+        var silent = new List<TcpClient>();
+        try
+        {
+            for (int i = 0; i < 20; i++)
+            {
+                var client = new TcpClient();
+                await client.ConnectAsync(IPAddress.Loopback, agent.Listener.Port);
+                silent.Add(client);
+            }
+
+            (_, TlsFrameTransport a) = await PeerConnector.ConnectAsync("127.0.0.1", agent.Listener.Port, agent.PublicKey, first, "dlr_1", null, 1 << 20, TimeProvider.System, default);
+            (_, TlsFrameTransport b) = await PeerConnector.ConnectAsync("127.0.0.1", agent.Listener.Port, agent.PublicKey, second, "dlr_2", null, 1 << 20, TimeProvider.System, default);
+
+            // 会话名额（2）满了：第三个在名册里的拨号方被拒绝，一个会话结束之后又能连上
+            await Assert.ThrowsAnyAsync<Exception>(async () =>
+            {
+                (_, TlsFrameTransport refused) = await PeerConnector.ConnectAsync("127.0.0.1", agent.Listener.Port, agent.PublicKey, third, "dlr_3", null, 1 << 20, TimeProvider.System, default);
+                await refused.DisposeAsync();
+            });
+            await a.DisposeAsync();
+            bool reconnected = false;
+            for (int attempt = 0; attempt < 50 && !reconnected; attempt++)
+            {
+                try
+                {
+                    (_, TlsFrameTransport again) = await PeerConnector.ConnectAsync("127.0.0.1", agent.Listener.Port, agent.PublicKey, third, "dlr_3", null, 1 << 20, TimeProvider.System, default);
+                    await again.DisposeAsync();
+                    reconnected = true;
+                }
+                catch (Exception ex) when (ex is IOException or System.Security.Authentication.AuthenticationException or InvalidOperationException)
+                {
+                    await Task.Delay(100);
+                }
+            }
+
+            Assert.True(reconnected);
+            await b.DisposeAsync();
+        }
+        finally
+        {
+            foreach (TcpClient client in silent)
+            {
+                client.Dispose();
+            }
+        }
+    }
+
     [Fact]
     public async Task PeerListener_WritesNothingToStrangers_NotEvenATlsServerHello()
     {

backend/fleet/tests/Fleet.Tests/NodeVersionsTests.cs

@@ -0,0 +1,21 @@
+using Fleet.Core;
+
+namespace Fleet.Tests;
+
+public sealed class NodeVersionsTests
+{
+    [Theory]
+    [InlineData("0.4.2-dev.73-5245f03", "0.4.2-dev.74", true)]
+    [InlineData("0.4.2-dev.73-5245f03", "0.4.2-dev.73-abcdef0", false)] // 哈希不参与比较
+    [InlineData("0.4.2-dev.100-aaaaaaa", "0.4.2-dev.99", false)] // 序号按数字比，不是按字符串
+    [InlineData("0.4.2-dev.999", "0.4.2", true)] // 正式版高于预发布版
+    [InlineData("0.4.2", "0.4.2-dev.5", false)]
+    [InlineData("0.4.1", "0.4.2-dev.1", true)]
+    [InlineData("v0.5.0", "0.4.9", false)]
+    [InlineData("0.4.2-dev.73-5245f03", "", false)] // 没有要求
+    [InlineData("", "0.4.2", false)] // 认不出来的版本号不拒绝
+    [InlineData("not-a-version", "0.4.2", false)]
+    [InlineData("0.4.2", "garbage", false)]
+    public void IsBelow_ComparesCoreThenReleaseThenTheDevCounter(string actual, string required, bool expected) =>
+        Assert.Equal(expected, NodeVersions.IsBelow(actual, required));
+}

backend/openapi/v1.json

@@ -1897,7 +1897,7 @@
         "tags": [
           "admin-nodes"
         ],
-        "summary": "Recent runtime logs of a node",
+        "summary": "Recent runtime logs of a node: pulled from the node when it is online, otherwise what the backend kept",
         "operationId": "node_runtime_logs",
         "parameters": [
           {
@@ -8774,7 +8774,8 @@
           "control_state": {
             "type": "string",
             "default": "dialing"
-          }
+          },
+          "control_down_since": {}
         }
       },
       "RawChunkMetaDto": {

backend/shared/MoShiro.Measurement/Blocks/BlockBase.cs

@@ -1,4 +1,5 @@
 using System.Net;
+using Fleet.Core;
 using MoShiro.Protocol;
 
 namespace MoShiro.Measurement;
@@ -41,6 +42,107 @@ public abstract class BlockBase : IBlock
         Env.Fragments!.Ship(Spec.KindId, Spec.Scope, streams, parameters ?? Spec.Params.Values, Env.Clock.UtcMsAt(first), (int)((last - first) / 1000), Spec.Port);
     }
 
+    /// <summary>
+    /// 按自适应的节奏发包：下一个包的时刻按绝对时间排（不累积误差），每秒评估一次状态，状态变化记进日志（供审计）。
+    /// 落后了就从现在重新排，不补发。
+    /// </summary>
+    protected async Task PaceAsync(AdaptiveRate rate, Func<ValueTask> sendOne, CancellationToken ct)
+    {
+        long due = Env.Clock.NowUs();
+        long lastEvaluation = due;
+        while (!ct.IsCancellationRequested)
+        {
+            due += (long)(rate.NextDelay().TotalMilliseconds * 1000);
+            long wait = due - Env.Clock.NowUs();
+            if (wait > 0)
+            {
+                await Task.Delay(TimeSpan.FromMicroseconds(wait), Env.Time, ct);
+            }
+            else
+            {
+                due = Env.Clock.NowUs();
+            }
+
+            await sendOne();
+            long now = Env.Clock.NowUs();
+            if (now - lastEvaluation >= 1_000_000 || rate.State == ProbeState.Dead)
+            {
+                lastEvaluation = now;
+                if (rate.Evaluate(now) is { } change)
+                {
+                    LogTransition(change);
+                }
+            }
+        }
+    }
+
+    /// <summary>读这个任务的自适应频率参数（<c>quic_ping</c> 和 <c>tcp_ping</c> 共用）。</summary>
+    protected AdaptiveRate? CreateAdaptiveRate()
+    {
+        if (!Spec.Bool("adaptive"))
+        {
+            return null;
+        }
+
+        double max = Math.Max(Spec.Int("rate_max_hz"), Spec.Int("rate_min_hz"));
+        ReportStart(max);
+        return new AdaptiveRate(new AdaptiveRateOptions
+        {
+            MinHz = Spec.Int("rate_min_hz"),
+            MaxHz = max,
+            TauPct = Spec.Number("tau_pct"),
+            RttTolPct = Spec.Number("rtt_tol_pct"),
+            Prior = Env.LossPrior,
+        });
+    }
+
+    /// <summary>
+    /// 自适应开始：记一条「start → watch」（从最高频率起步）。审计据此知道这个任务从什么时候起在自适应，
+    /// 没有这条之前的时段是「没有记录」，不是某个状态。
+    /// </summary>
+    protected void ReportStart(double hz) =>
+        Env.OnRateChange?.Invoke(new RateChange
+        {
+            AtMs = Env.Time.GetUtcNow().ToUnixTimeMilliseconds(),
+            Task = Spec.Scope.Task?.Value,
+            Kind = Spec.KindId,
+            From = "start",
+            To = "watch",
+            Hz = Math.Round(hz, 3),
+            Reason = "start",
+        });
+
+    private void LogTransition(ProbeTransition change)
+    {
+        Env.OnRateChange?.Invoke(new RateChange
+        {
+            AtMs = Env.Time.GetUtcNow().ToUnixTimeMilliseconds(),
+            Task = Spec.Scope.Task?.Value,
+            Kind = Spec.KindId,
+            From = change.From.ToString().ToLowerInvariant(),
+            To = change.To.ToString().ToLowerInvariant(),
+            Hz = Math.Round(change.Hz, 3),
+            Reason = change.Reason,
+            LossPct = Math.Round(change.LossPct, 4),
+            Sent = change.Sent,
+            Lost = change.Lost,
+        });
+
+        var fields = new (string, object?)[]
+        {
+            ("stream", Spec.StreamId), ("kind", Spec.KindId), ("from", change.From.ToString().ToLowerInvariant()), ("to", change.To.ToString().ToLowerInvariant()), ("hz", Math.Round(change.Hz, 1)),
+            ("reason", change.Reason), ("loss_pct", Math.Round(change.LossPct, 3)), ("sent", change.Sent), ("lost", change.Lost),
+        };
+        if (change.To == ProbeState.Dead)
+        {
+            Env.Log.Warn("probe rate changed", fields);
+        }
+        else
+        {
+            Env.Log.Info("probe rate changed", fields);
+        }
+    }
+
     /// <summary>什么也不做、一直等到取消（监听方里不需要自己运行逻辑的积木）。</summary>
     protected async Task WaitUntilCancelledAsync(CancellationToken ct)
     {

backend/shared/MoShiro.Measurement/Blocks/BlockCatalog.cs

@@ -26,13 +26,14 @@ public static class BlockCatalog
 {
     public static readonly IReadOnlyList<BlockPair> All =
     [
-        new("udp_echo", (e, s) => new DatagramEchoDialer(e, s), (e, s) => new DatagramEchoListener(e, s)),
-        new("tcp_echo", (e, s) => new TcpEchoDialer(e, s), (e, s) => new TcpEchoListener(e, s)),
-        new("udp_train", (e, s) => new TrainDialer(e, s), (e, s) => new TrainListener(e, s), OnDemandOnly: true, Directions: ["rev"]),
-        new("tcp_bulk", (e, s) => new TcpBulkDialer(e, s), (e, s) => new TcpBulkListener(e, s), OnDemandOnly: true, Directions: ["fwd", "rev"]),
-        new("connect", (e, s) => new ConnectDialer(e, s), (e, s) => new IdleListener(e, s), RunsAsTarget: true),
-        new("hold", (e, s) => new HoldDialer(e, s), (e, s) => new TcpEchoListener(e, s, record: false)),
-        new("icmp_echo", (e, s) => new IcmpEchoSolo(e, s), null, RunsAsTarget: true),
+        new("quic_ping", (e, s) => new DatagramEchoDialer(e, s), (e, s) => new DatagramEchoListener(e, s)),
+        new("tcp_ping", (e, s) => new TcpEchoDialer(e, s), (e, s) => new TcpEchoListener(e, s)),
+        new("quic_stream", (e, s) => new TrainDialer(e, s), (e, s) => new TrainListener(e, s), OnDemandOnly: true, Directions: ["rev"]),
+        new("tcp_transfer", (e, s) => new TcpBulkDialer(e, s), (e, s) => new TcpBulkListener(e, s), OnDemandOnly: true, Directions: ["fwd", "rev"]),
+        new("tcp_connect", (e, s) => new ConnectDialer(e, s), (e, s) => new IdleListener(e, s), RunsAsTarget: true),
+        new("tls_hold", (e, s) => new HoldDialer(e, s), (e, s) => new TcpEchoListener(e, s, record: false)),
+        new("http_request", (e, s) => new HttpDialer(e, s), null, RunsAsTarget: true),
+        new("icmp_ping", (e, s) => new IcmpEchoSolo(e, s), null, RunsAsTarget: true),
     ];
 
     public static BlockPair? Find(string kind) => All.FirstOrDefault(p => p.Kind == kind);

backend/shared/MoShiro.Measurement/Blocks/Echo.cs

@@ -23,6 +23,7 @@ internal sealed class EchoRows
 
     private readonly DriverLog _log;
     private readonly int _size;
+    private readonly int _w;
     private readonly int _t1;
     private readonly int _t4;
     private readonly long _graceUs;
@@ -36,26 +37,36 @@ internal sealed class EchoRows
         StreamSpec spec = kind.FindStream("msg")!;
         _log = new DriverLog(spec, Side.Dialer, capacity);
         _size = _log.Store.ColumnIndex("size");
+        _w = _log.Store.ColumnIndex("w");
         _t1 = _log.Store.ColumnIndex("t1");
         _t4 = _log.Store.ColumnIndex("t4");
     }
 
     public long Count => _log.Count - Interlocked.Read(ref _discarded);
 
-    public uint Add(int size, long t1Us)
+    /// <summary><paramref name="weight"/>：这个包代表多少个基础网格间隔（频率变化时分析按它累计，丢包率和分位数仍是按时间平均的）。</summary>
+    public uint Add(int size, long t1Us, int weight = 1)
     {
         long key = _log.Store.Append();
         _log.Store.Set(key, _size, size);
+        _log.Store.Set(key, _w, weight);
         _log.Store.Set(key, _t1, t1Us);
         return (uint)key;
     }
 
-    public void Reply(uint seq, long t4Us)
+    public bool Reply(uint seq, long t4Us) => Reply(seq, t4Us, out _);
+
+    /// <summary>回填 t4；第一次回复才算，<paramref name="t1Us"/> 是这个包的发出时间。</summary>
+    public bool Reply(uint seq, long t4Us, out long t1Us)
     {
-        if (_log.Store.Contains(seq) && !_log.Store.IsSet(seq, _t4))
+        t1Us = 0;
+        if (_log.Store.Contains(seq) && !_log.Store.IsSet(seq, _t4) && _log.Store.TryGet(seq, _t1, out t1Us))
         {
             _log.Store.Set(seq, _t4, t4Us);
+            return true;
         }
+
+        return false;
     }
 
     public bool Discard(uint seq)
@@ -83,6 +94,7 @@ public sealed class DatagramEchoDialer : BlockBase
     private readonly EchoRows _rows;
     private readonly object _gate = new();
     private long _nextSendFailureWarningUs;
+    private AdaptiveRate? _rate;
 
     public DatagramEchoDialer(BlockEnv env, BlockSpec spec)
         : base(env, spec)
@@ -100,29 +112,50 @@ public sealed class DatagramEchoDialer : BlockBase
         IPEndPoint target = PeerEndpoint(Spec.Port);
         int size = (int)Spec.Int("size");
         byte[] packet = new byte[size];
+        _rate = CreateAdaptiveRate();
+
+        void SendOne()
+        {
+            long t1 = Env.Clock.NowUs();
+            lock (_gate)
+            {
+                uint seq = _rows.Add(size, t1, _rate?.Weight ?? 1);
+                MeasurementDatagram.Write(packet, new MeasurementDatagramHeader(MeasurementDatagramType.EchoRequest, session.SessionId, Spec.StreamId, seq, t1), session.Key);
+                if (datagrams.Send(session, target, packet))
+                {
+                    _rate?.OnSend(t1);
+                    return;
+                }
+
+                _rows.Discard(seq);
+                if (t1 >= _nextSendFailureWarningUs)
+                {
+                    Env.Log.Warn("QUIC echo datagram was not queued; omitted from loss samples",
+                        ("stream", Spec.StreamId), ("seq", seq), ("bytes", size));
+                    _nextSendFailureWarningUs = t1 + 5_000_000;
+                }
+            }
+        }
+
         datagrams.Register(Spec.StreamId, OnPacket);
         try
         {
-            using var timer = new PeriodicTimer(TimeSpan.FromSeconds(1.0 / Spec.Int("rate_hz")), Env.Time);
-            while (await timer.WaitForNextTickAsync(ct))
+            if (_rate is null)
             {
-                long t1 = Env.Clock.NowUs();
-                lock (_gate)
+                using var timer = new PeriodicTimer(TimeSpan.FromSeconds(1.0 / Spec.Int("rate_hz")), Env.Time);
+                while (await timer.WaitForNextTickAsync(ct))
                 {
-                    uint seq = _rows.Add(size, t1);
-                    MeasurementDatagram.Write(packet, new MeasurementDatagramHeader(MeasurementDatagramType.EchoRequest, session.SessionId, Spec.StreamId, seq, t1), session.Key);
-                    if (!datagrams.Send(session, target, packet))
-                    {
-                        _rows.Discard(seq);
-                        if (t1 >= _nextSendFailureWarningUs)
-                        {
-                            Env.Log.Warn("QUIC echo datagram was not queued; omitted from loss samples",
-                                ("stream", Spec.StreamId), ("seq", seq), ("bytes", size));
-                            _nextSendFailureWarningUs = t1 + 5_000_000;
-                        }
-                    }
+                    SendOne();
                 }
             }
+            else
+            {
+                await PaceAsync(_rate, () =>
+                {
+                    SendOne();
+                    return ValueTask.CompletedTask;
+                }, ct);
+            }
         }
         catch (OperationCanceledException)
         {
@@ -157,7 +190,10 @@ public sealed class DatagramEchoDialer : BlockBase
         {
             lock (_gate)
             {
-                _rows.Reply(delivery.Header.Seq, delivery.ReceiveUs);
+                if (_rows.Reply(delivery.Header.Seq, delivery.ReceiveUs, out long t1))
+                {
+                    _rate?.OnReply(t1, delivery.ReceiveUs, (delivery.ReceiveUs - t1) / 1000.0);
+                }
             }
         }
     }
@@ -211,6 +247,7 @@ public sealed class TcpEchoDialer : BlockBase
 {
     private readonly EchoRows _rows;
     private readonly TcpInfoRecorder _info;
+    private AdaptiveRate? _rate;
 
     public TcpEchoDialer(BlockEnv env, BlockSpec spec)
         : base(env, spec)
@@ -224,12 +261,14 @@ public sealed class TcpEchoDialer : BlockBase
     public override async Task RunAsync(CancellationToken ct)
     {
         var backoff = new Fleet.Core.Backoff(TimeSpan.FromSeconds(1), TimeSpan.FromSeconds(30));
+        _rate = CreateAdaptiveRate();
         while (!ct.IsCancellationRequested)
         {
             try
             {
                 using TcpLink link = await TcpLink.OpenAsync(Env, Spec.Port, Spec.Bool("tls"), Spec.StreamId, sendAuth: true, ct);
                 backoff.Reset();
+                _rate?.Reconnected(Env.Clock.NowUs());
                 await ExchangeAsync(link, ct);
             }
             catch (OperationCanceledException) when (ct.IsCancellationRequested)
@@ -300,16 +339,29 @@ public sealed class TcpEchoDialer : BlockBase
         int min = (int)Spec.Int("min");
         int max = (int)Spec.Int("max");
         byte[] body = new byte[Math.Max(max, min)];
-        using var timer = new PeriodicTimer(TimeSpan.FromSeconds(1.0 / Spec.Int("rate_hz")), Env.Time);
-        while (await timer.WaitForNextTickAsync(ct))
+
+        async ValueTask SendOneAsync()
         {
             int size = Math.Max(TcpWire.MinEchoBody, max > min ? Random.Shared.Next(min, max + 1) : min);
             long t1 = Env.Clock.NowUs();
-            uint seq = _rows.Add(size, t1);
+            uint seq = _rows.Add(size, t1, _rate?.Weight ?? 1);
             body.AsSpan(0, size).Clear();
             TcpWire.WriteEchoBody(body, seq, t1);
             await TcpWire.WriteMessageAsync(stream, body.AsMemory(0, size), ct);
             await stream.FlushAsync(ct);
+            _rate?.OnSend(t1);
+        }
+
+        if (_rate is not null)
+        {
+            await PaceAsync(_rate, SendOneAsync, ct);
+            return;
+        }
+
+        using var timer = new PeriodicTimer(TimeSpan.FromSeconds(1.0 / Spec.Int("rate_hz")), Env.Time);
+        while (await timer.WaitForNextTickAsync(ct))
+        {
+            await SendOneAsync();
         }
     }
 
@@ -324,9 +376,9 @@ public sealed class TcpEchoDialer : BlockBase
             }
 
             long now = Env.Clock.NowUs();
-            if (TcpWire.TryReadEchoBody(reply, out uint seq, out _))
+            if (TcpWire.TryReadEchoBody(reply, out uint seq, out _) && _rows.Reply(seq, now, out long t1))
             {
-                _rows.Reply(seq, now);
+                _rate?.OnReply(t1, now, (now - t1) / 1000.0);
             }
         }
     }

backend/shared/MoShiro.Measurement/Blocks/Http.cs

@@ -0,0 +1,383 @@
+using System.Net;
+using System.Net.Http;
+using System.Net.Quic;
+using System.Net.Security;
+using System.Net.Sockets;
+using System.Security.Authentication;
+using Fleet.Core;
+using MoShiro.Protocol;
+
+namespace MoShiro.Measurement;
+
+/// <summary>http 请求的结果，编码与 Backend 的 <c>HttpOutcome</c> 一致。</summary>
+internal static class HttpOutcomes
+{
+    public const int Ok = 0;
+    public const int Timeout = 1;
+    public const int Reset = 2;
+    public const int Tls = 3;
+    public const int Other = 4;
+    public const int Dns = 5;
+    public const int BadStatus = 6;
+    public const int Unsupported = 7;
+    public const int NotAllowed = 8;
+}
+
+/// <summary>解析出的地址都不在本地允许的网段内。</summary>
+internal sealed class TargetNotAllowedException : Exception
+{
+    public TargetNotAllowedException(string host)
+        : base("no address of " + host + " is allowed by allowed_target_cidrs")
+    {
+    }
+}
+
+/// <summary>
+/// 单个 Agent 去请求一个 URL（HTTP/1.1、HTTP/2 或 HTTP/3，不回退），记录 DNS、TCP 建连、首字节、总耗时和状态码。
+/// 每次请求新建连接，所以每次都包含完整的建连过程；频率按失败率自适应：目标一直应答就降到证明得了成功率的最低频率，
+/// 出现失败升到最高频率，全部失败时指数退避。
+/// </summary>
+public sealed class HttpDialer : BlockBase
+{
+    private readonly DriverLog _log;
+    private readonly int _attempt;
+    private readonly int _ts;
+    private readonly int _w;
+    private readonly int _dns;
+    private readonly int _tcp;
+    private readonly int _ttfb;
+    private readonly int _total;
+    private readonly int _status;
+    private readonly int _proto;
+    private readonly int _outcome;
+    private readonly HashSet<int> _loggedOutcomes = [];
+    private long _next;
+
+    public HttpDialer(BlockEnv env, BlockSpec spec)
+        : base(env, spec)
+    {
+        _log = new DriverLog(spec.Kind.FindStream("req")!, Side.Dialer, 1024);
+        _attempt = _log.Store.ColumnIndex("attempt");
+        _ts = _log.Store.ColumnIndex("ts");
+        _w = _log.Store.ColumnIndex("w");
+        _dns = _log.Store.ColumnIndex("dns_us");
+        _tcp = _log.Store.ColumnIndex("tcp_us");
+        _ttfb = _log.Store.ColumnIndex("ttfb_us");
+        _total = _log.Store.ColumnIndex("total_us");
+        _status = _log.Store.ColumnIndex("status");
+        _proto = _log.Store.ColumnIndex("proto");
+        _outcome = _log.Store.ColumnIndex("outcome");
+    }
+
+    public override long Produced => _log.Count;
+
+    public override async Task RunAsync(CancellationToken ct)
+    {
+        if (!TargetHost.TryParse(Env.Target, out _, out _, out Uri? url) || url is null)
+        {
+            Env.Log.Warn("http target is not a URL", ("task", Spec.Scope.Task?.Value));
+            await WaitUntilCancelledAsync(ct);
+            return;
+        }
+
+        AdaptiveRate? rate = CreateRequestRate();
+        try
+        {
+            if (rate is not null)
+            {
+                await PaceAsync(rate, async () =>
+                {
+                    int weight = rate.Weight;
+                    long sent = Env.Clock.NowUs();
+                    rate.OnSend(sent);
+                    bool ok = await RequestAsync(url, weight, ct);
+                    if (ok)
+                    {
+                        long now = Env.Clock.NowUs();
+                        rate.OnReply(sent, now, (now - sent) / 1000.0);
+                    }
+                }, ct);
+            }
+            else
+            {
+                TimeSpan interval = TimeSpan.FromSeconds(60.0 / Spec.Int("per_minute"));
+                while (!ct.IsCancellationRequested)
+                {
+                    long start = Env.Clock.NowUs();
+                    await RequestAsync(url, 1, ct);
+                    TimeSpan wait = interval - TimeSpan.FromMicroseconds(Env.Clock.NowUs() - start);
+                    if (wait > TimeSpan.Zero)
+                    {
+                        await Task.Delay(wait, Env.Time, ct);
+                    }
+                }
+            }
+        }
+        catch (OperationCanceledException)
+        {
+            // 积木被停止
+        }
+    }
+
+    public override int Flush(FlushMode mode, long peerProduced = 0)
+    {
+        RawStream? stream = _log.Take(null, all: true);
+        if (stream is null)
+        {
+            return 0;
+        }
+
+        Ship(stream, "ts");
+        return 1;
+    }
+
+    /// <summary>
+    /// 频率以「次/分钟」声明，换算成 Hz 交给 <see cref="AdaptiveRate"/>。请求间隔以秒到分钟计，所以窗口按分钟级放宽，
+    /// 并且不用 RTT 分位数的精度保护（样本太少，估计不出来）：平稳时只由成功率的上界决定频率。
+    /// </summary>
+    private AdaptiveRate? CreateRequestRate()
+    {
+        if (!Spec.Bool("adaptive"))
+        {
+            return null;
+        }
+
+        double max = Math.Max(Spec.Int("rate_max_per_min"), Spec.Int("rate_min_per_min")) / 60.0;
+        ReportStart(max);
+        return new AdaptiveRate(new AdaptiveRateOptions
+        {
+            MinHz = Spec.Int("rate_min_per_min") / 60.0,
+            MaxHz = max,
+            TauPct = Spec.Number("tau_pct"),
+            RttGuard = false,
+            CertifySeconds = 900,
+            QuietCertifySeconds = 1200,
+            GraceSeconds = Math.Ceiling(Spec.Int("timeout_ms") / 1000.0) + 1,
+            DeadWindowSeconds = 120,
+            DeadMinSent = 3,
+            DeadMaxIntervalSeconds = 300,
+            ActiveLossCount = 2,
+            Prior = Env.LossPrior,
+        });
+    }
+
+    /// <summary>发一次请求并记一行；返回这次算不算成功（有应答且状态码合格）。</summary>
+    private async Task<bool> RequestAsync(Uri url, int weight, CancellationToken ct)
+    {
+        string version = Spec.Text("version");
+        bool verify = Spec.Bool("tls_verify");
+        TimeSpan timeout = TimeSpan.FromMilliseconds(Spec.Int("timeout_ms"));
+        var phases = new Phases();
+        long start = Env.Clock.NowUs();
+        int outcome = HttpOutcomes.Other;
+        int status = 0;
+        int proto = 0;
+        long? ttfb = null;
+        long? total = null;
+        using var timeoutCts = new CancellationTokenSource(timeout, Env.Time);
+        using CancellationTokenSource linked = CancellationTokenSource.CreateLinkedTokenSource(ct, timeoutCts.Token);
+        try
+        {
+            if (version == "h3" && !QuicConnection.IsSupported)
+            {
+                outcome = HttpOutcomes.Unsupported;
+                LogFirstFailure(outcome, url, version, null);
+            }
+            else
+            {
+                if (version == "h3")
+                {
+                    await ResolveForQuicAsync(url.IdnHost, phases, linked.Token);
+                }
+
+                using HttpMessageInvoker invoker = CreateInvoker(version, verify, phases);
+                using var request = new HttpRequestMessage(new HttpMethod(Spec.Text("method")), url)
+                {
+                    Version = version switch { "h1" => HttpVersion.Version11, "h2" => HttpVersion.Version20, _ => HttpVersion.Version30 },
+                    VersionPolicy = HttpVersionPolicy.RequestVersionExact,
+                };
+                using HttpResponseMessage response = await invoker.SendAsync(request, linked.Token);
+                ttfb = Env.Clock.NowUs() - start;
+                status = (int)response.StatusCode;
+                proto = response.Version.Major switch { 3 => 3, 2 => 2, _ => 1 };
+                await ReadBodyAsync(response, (int)Spec.Int("read_kb") * 1024, linked.Token);
+                total = Env.Clock.NowUs() - start;
+                long expected = Spec.Int("ok_status");
+                outcome = (expected == 0 ? status < 400 : status == expected) ? HttpOutcomes.Ok : HttpOutcomes.BadStatus;
+            }
+        }
+        catch (OperationCanceledException) when (!ct.IsCancellationRequested)
+        {
+            outcome = HttpOutcomes.Timeout;
+        }
+        catch (OperationCanceledException)
+        {
+            return false;
+        }
+        catch (Exception ex) when (ex is HttpRequestException or IOException or SocketException or AuthenticationException or TargetNotAllowedException or QuicException)
+        {
+            outcome = Classify(ex);
+            LogFirstFailure(outcome, url, version, ex);
+        }
+
+        Record(start, weight, phases, ttfb, total, status, proto, outcome);
+        return outcome == HttpOutcomes.Ok;
+    }
+
+    private HttpMessageInvoker CreateInvoker(string version, bool verify, Phases phases)
+    {
+        var handler = new SocketsHttpHandler
+        {
+            UseProxy = false,
+            AllowAutoRedirect = false,
+            UseCookies = false,
+            AutomaticDecompression = DecompressionMethods.None,
+        };
+
+        // 设置了 ConnectCallback 的处理器不能用 HTTP/3（运行时用自己的 QUIC 连接，不经过回调）：h3 只能靠请求前的解析和网段检查
+        if (version != "h3")
+        {
+            handler.ConnectCallback = (context, token) => ConnectAsync(context.DnsEndPoint, phases, token);
+        }
+
+        if (!verify)
+        {
+#pragma warning disable CA5359 // 操作员明确关闭证书校验（tls_verify=false）：只测可达性和耗时
+            handler.SslOptions = new SslClientAuthenticationOptions { RemoteCertificateValidationCallback = (_, _, _, _) => true };
+#pragma warning restore CA5359
+        }
+
+        return new HttpMessageInvoker(handler, disposeHandler: true);
+    }
+
+    /// <summary>自己解析和连接：每个地址都要在允许的网段里，DNS 和 TCP 建连的耗时分别记下来。</summary>
+    private async ValueTask<Stream> ConnectAsync(DnsEndPoint endpoint, Phases phases, CancellationToken ct)
+    {
+        IPAddress[] addresses = await ResolveAsync(endpoint.Host, phases, ct);
+        long start = Env.Clock.NowUs();
+        Exception? last = null;
+        foreach (IPAddress address in addresses)
+        {
+            var socket = new Socket(address.AddressFamily, SocketType.Stream, ProtocolType.Tcp) { NoDelay = true };
+            try
+            {
+                await socket.ConnectAsync(new IPEndPoint(address, endpoint.Port), ct);
+                phases.TcpUs = Env.Clock.NowUs() - start;
+                return new NetworkStream(socket, ownsSocket: true);
+            }
+            catch (SocketException ex)
+            {
+                socket.Dispose();
+                last = ex;
+            }
+        }
+
+        throw last ?? new SocketException((int)SocketError.HostNotFound);
+    }
+
+    /// <summary>HTTP/3 由运行时自己建 UDP 连接，没法接管；先解析并检查一遍，再让它去连。</summary>
+    private async Task ResolveForQuicAsync(string host, Phases phases, CancellationToken ct) => _ = await ResolveAsync(host, phases, ct);
+
+    private async Task<IPAddress[]> ResolveAsync(string host, Phases phases, CancellationToken ct)
+    {
+        long start = Env.Clock.NowUs();
+        IPAddress[] all = IPAddress.TryParse(host, out IPAddress? literal) ? [literal] : await Dns.GetHostAddressesAsync(host, ct);
+        phases.DnsUs = Env.Clock.NowUs() - start;
+        IPAddress[] allowed = [.. all.Where(a => Env.AllowAddress?.Invoke(a) ?? true)];
+        return allowed.Length > 0 ? allowed : throw new TargetNotAllowedException(host);
+    }
+
+    private static async Task ReadBodyAsync(HttpResponseMessage response, int limit, CancellationToken ct)
+    {
+        if (limit <= 0)
+        {
+            return;
+        }
+
+        await using Stream body = await response.Content.ReadAsStreamAsync(ct);
+        byte[] buffer = new byte[Math.Min(limit, 16 * 1024)];
+        int read = 0;
+        while (read < limit)
+        {
+            int n = await body.ReadAsync(buffer.AsMemory(0, Math.Min(buffer.Length, limit - read)), ct);
+            if (n == 0)
+            {
+                break;
+            }
+
+            read += n;
+        }
+    }
+
+    /// <summary>每种失败结果只记第一次（带原因），保留给事后审计，不会随请求频率刷屏。</summary>
+    private void LogFirstFailure(int outcome, Uri url, string version, Exception? ex)
+    {
+        if (!_loggedOutcomes.Add(outcome))
+        {
+            return;
+        }
+
+        Env.Log.Warn("http request failed", ("task", Spec.Scope.Task?.Value), ("outcome", outcome), ("version", version), ("host", url.Host),
+            ("quic_supported", version == "h3" ? QuicConnection.IsSupported : null), ("err", ex is null ? "System.Net.Quic is not available" : ex.GetType().Name + ": " + (ex.InnerException?.Message ?? ex.Message)));
+    }
+
+    private static int Classify(Exception ex)
+    {
+        for (Exception? e = ex; e is not null; e = e.InnerException)
+        {
+            switch (e)
+            {
+                case TargetNotAllowedException:
+                    return HttpOutcomes.NotAllowed;
+                case AuthenticationException:
+                    return HttpOutcomes.Tls;
+                case SocketException { SocketErrorCode: SocketError.HostNotFound or SocketError.TryAgain or SocketError.NoData }:
+                    return HttpOutcomes.Dns;
+                case SocketException { SocketErrorCode: SocketError.ConnectionRefused or SocketError.ConnectionReset }:
+                    return HttpOutcomes.Reset;
+                case HttpRequestException { HttpRequestError: HttpRequestError.NameResolutionError }:
+                    return HttpOutcomes.Dns;
+                case HttpRequestException { HttpRequestError: HttpRequestError.SecureConnectionError }:
+                    return HttpOutcomes.Tls;
+                case HttpRequestException { HttpRequestError: HttpRequestError.VersionNegotiationError }:
+                    return HttpOutcomes.Unsupported;
+            }
+        }
+
+        return HttpOutcomes.Other;
+    }
+
+    private void Record(long startUs, int weight, Phases phases, long? ttfb, long? total, int status, int proto, int outcome)
+    {
+        long key = _log.Store.Append();
+        _log.Store.Set(key, _attempt, _next++);
+        _log.Store.Set(key, _ts, startUs);
+        _log.Store.Set(key, _w, Math.Clamp(weight, 1, 65535));
+        _log.Store.Set(key, _outcome, outcome);
+        SetIf(key, _dns, phases.DnsUs);
+        SetIf(key, _tcp, phases.TcpUs);
+        SetIf(key, _ttfb, ttfb);
+        SetIf(key, _total, total);
+        if (status != 0)
+        {
+            _log.Store.Set(key, _status, status);
+            _log.Store.Set(key, _proto, proto);
+        }
+    }
+
+    private void SetIf(long key, int column, long? value)
+    {
+        if (value is { } v)
+        {
+            _log.Store.Set(key, column, Math.Clamp(v, 0, uint.MaxValue));
+        }
+    }
+
+    /// <summary>一次请求里 DNS 和 TCP 建连用了多久（连接回调里填）。</summary>
+    private sealed class Phases
+    {
+        public long? DnsUs { get; set; }
+
+        public long? TcpUs { get; set; }
+    }
+}

backend/shared/MoShiro.Measurement/Blocks/Train.cs

@@ -219,7 +219,7 @@ public sealed class TrainDialer : BlockBase
                 [FragmentKeys.SeqTo] = Number(to),
             };
             Env.Fragments!.Ship(
-                "udp_train",
+                "quic_stream",
                 Spec.Scope,
                 fragments == 0 ? [pkt, _step.Cut(0, 1, includeKey: false)] : [pkt],
                 parameters,

backend/shared/MoShiro.Measurement/Core/AdaptiveRate.cs

@@ -0,0 +1,452 @@
+namespace MoShiro.Measurement;
+
+/// <summary>探测节奏的状态。<see cref="Dead"/> 是线路几乎全丢：不再按正常频率白白发包，指数退避着探测，等到有回包再恢复。</summary>
+public enum ProbeState : byte
+{
+    Quiet = 0,
+    Watch = 1,
+    Active = 2,
+    Dead = 3,
+}
+
+/// <summary>自适应探测频率的参数。频率范围、精度目标和各状态的保持时间都在这里。</summary>
+public sealed record AdaptiveRateOptions
+{
+    /// <summary>平稳时的最低频率（Hz）。</summary>
+    public double MinHz { get; init; } = 2;
+
+    /// <summary>
+    /// 最高频率（Hz），也是权重的参考网格：每个探测包的权重是它代表的时间除以 <c>1/MaxHz</c>，
+    /// 分析时丢包率和 RTT 分位数按权重累计，所以频率怎么变，得到的仍是按时间平均的值，不会偏向探测更密的时段。
+    /// </summary>
+    public double MaxHz { get; init; } = 10;
+
+    /// <summary>平稳时 RTT 分位数（p99）的 95% 置信区间半宽容差：取 max(下限毫秒, 百分比 × p99)。样本多到超出这个精度才会降频。</summary>
+    public double RttTolPct { get; init; } = 2;
+
+    public double RttTolFloorMs { get; init; } = 0.3;
+
+    /// <summary>平稳线路要能证明的丢包上界（百分比，95% 置信）。三法则：零丢包需要 3 / τ 个样本。</summary>
+    public double TauPct { get; init; } = 0.2;
+
+    /// <summary>证明窗口（秒）：平稳频率 = 3 / (τ × 窗口)。</summary>
+    public double CertifySeconds { get; init; } = 300;
+
+    /// <summary>历史上一直平稳的时段可以拉长证明窗口，同样的精度用更少的包。</summary>
+    public double QuietCertifySeconds { get; init; } = 900;
+
+    /// <summary>回包等多久算丢（秒）。</summary>
+    public double GraceSeconds { get; init; } = 3;
+
+    /// <summary>刚启动没有历史：先按 Watch 频率跑这么久（秒）。</summary>
+    public double WarmupSeconds { get; init; } = 300;
+
+    /// <summary>一次丢包事件之后，Watch 至少保持多久（秒）。</summary>
+    public double WatchHoldSeconds { get; init; } = 1800;
+
+    /// <summary>进入 Active 之后，没有新的丢包事件要保持多久才降到 Watch（秒）。</summary>
+    public double ActiveHoldSeconds { get; init; } = 900;
+
+    /// <summary>证明窗口内有这么多个不同的秒出现丢包，就算持续丢包，升到 Active。</summary>
+    public int ActiveLossCount { get; init; } = 3;
+
+    /// <summary>判断线路全丢的窗口（秒）和最少样本数、丢包比例。</summary>
+    public double DeadWindowSeconds { get; init; } = 10;
+
+    public int DeadMinSent { get; init; } = 10;
+
+    public double DeadLossRatio { get; init; } = 0.95;
+
+    /// <summary>Dead 状态的探测间隔：从 1 秒起翻倍，最长这么久（秒），带 ±20% 抖动。</summary>
+    public double DeadMaxIntervalSeconds { get; init; } = 30;
+
+    /// <summary>RTT 比长期水平高出这个倍数（再加下面的绝对值）持续几秒，就当作链路在变差，至少升到 Watch。</summary>
+    public double RttFactor { get; init; } = 1.5;
+
+    public double RttFloorMs { get; init; } = 5;
+
+    /// <summary>用 RTT p99 的置信区间限制降频。样本稀少的任务（每分钟几次）估不出区间，关掉后平稳频率只由丢包上界决定。</summary>
+    public bool RttGuard { get; init; } = true;
+
+    /// <summary>先验：时间 → 这个时刻丢包的历史概率（0 到 1）；null 表示没有历史。</summary>
+    public Func<long, double?>? Prior { get; init; }
+
+    /// <summary>先验里的"丢包高发"阈值：达到它在到来之前 <see cref="PriorLeadSeconds"/> 提前预热。</summary>
+    public double PriorWatchAt { get; init; } = 0.15;
+
+    public double PriorActiveAt { get; init; } = 0.5;
+
+    public double PriorLeadSeconds { get; init; } = 1800;
+}
+
+/// <summary>状态或频率变了：<see cref="Reason"/> 是给日志和审计看的固定短语。</summary>
+public sealed record ProbeTransition(ProbeState From, ProbeState To, double Hz, string Reason, double LossPct, int Sent, int Lost);
+
+/// <summary>
+/// 自适应探测频率：按"要证明的精度"决定频率，丢包多了自动升频，线路全丢就指数退避。
+/// 平稳线路只需要能证明丢包低于 τ 的样本数（三法则 N = 3/τ），有丢包的线路用满频率保精度和丢包的细节（连续丢包、乱序）。
+/// 状态靠丢包事件的频率升降，带滞回，不会在阈值附近来回跳；时间画像可以让高发时段提前预热。
+/// 纯逻辑：时间由调用方传入，不依赖时钟，方便测试。
+/// </summary>
+public sealed class AdaptiveRate
+{
+    private const long UsPerSecond = 1_000_000;
+    private const int Buckets = 1200; // 20 分钟，够覆盖最长的统计窗口
+
+    private readonly AdaptiveRateOptions _options;
+    private readonly Random _random;
+    private readonly object _gate = new();
+    private readonly long[] _second = new long[Buckets];
+    private readonly int[] _sent = new int[Buckets];
+    private readonly int[] _replied = new int[Buckets];
+
+    private long _startUs = -1;
+    private long _lastLossUs = long.MinValue;
+    private long _activeUntilUs = long.MinValue;
+    private long _lastReplyUs = long.MinValue;
+    private long _deadSinceUs = long.MinValue;
+    private int _deadProbes;
+    private readonly Queue<(long Second, double Ms)> _rtts = new();
+    private long _lastGuardSecond = long.MinValue;
+    private double _guardHz = double.NaN;
+    private TimeSpan _lastDelay = TimeSpan.Zero;
+    private double _rttFast = double.NaN;
+    private double _rttSlow = double.NaN;
+    private int _rttHighSeconds;
+    private long _lastRttSecond = long.MinValue;
+
+    public AdaptiveRate(AdaptiveRateOptions options, Random? random = null)
+    {
+        _options = options;
+        _random = random ?? Random.Shared;
+        State = ProbeState.Watch;
+        Hz = _options.MaxHz;
+    }
+
+    public ProbeState State { get; private set; }
+
+    /// <summary>当前的探测频率（Hz）。Dead 时是退避后的近似频率。</summary>
+    public double Hz { get; private set; }
+
+    /// <summary>发出一个探测包。</summary>
+    public void OnSend(long nowUs)
+    {
+        lock (_gate)
+        {
+            if (_startUs < 0)
+            {
+                _startUs = nowUs;
+            }
+
+            long second = nowUs / UsPerSecond;
+            int slot = Slot(second);
+            if (_second[slot] != second)
+            {
+                _second[slot] = second;
+                _sent[slot] = 0;
+                _replied[slot] = 0;
+            }
+
+            _sent[slot]++;
+            if (State == ProbeState.Dead)
+            {
+                _deadProbes++;
+            }
+        }
+    }
+
+    /// <summary>收到回包：<paramref name="sentUs"/> 是它发出的时间，<paramref name="rttMs"/> 是往返时延。</summary>
+    public void OnReply(long sentUs, long nowUs, double rttMs)
+    {
+        lock (_gate)
+        {
+            long second = sentUs / UsPerSecond;
+            int slot = Slot(second);
+            if (_second[slot] == second && _replied[slot] < _sent[slot])
+            {
+                _replied[slot]++;
+            }
+
+            if (double.IsNaN(_rttSlow))
+            {
+                _rttSlow = _rttFast = rttMs;
+            }
+            else
+            {
+                // 时间常数：快的 5 秒，慢的 15 分钟（按时间而不是按包数，频率变了也一样）
+                double dt = Math.Max(0, (nowUs - Math.Max(_lastReplyUs, 0)) / (double)UsPerSecond);
+                _rttFast += (1 - Math.Exp(-dt / 5)) * (rttMs - _rttFast);
+                _rttSlow += (1 - Math.Exp(-dt / 900)) * (rttMs - _rttSlow);
+            }
+
+            _lastReplyUs = nowUs;
+            _rtts.Enqueue((nowUs / UsPerSecond, rttMs));
+            while (_rtts.Count > 6000)
+            {
+                _rtts.Dequeue();
+            }
+        }
+    }
+
+    /// <summary>连接（重新）建立了：之前线路不通退避着的话，马上恢复探测，不用等退避间隔。</summary>
+    public void Reconnected(long nowUs)
+    {
+        lock (_gate)
+        {
+            if (State == ProbeState.Dead)
+            {
+                _lastReplyUs = nowUs;
+            }
+        }
+    }
+
+    /// <summary>距离下一个探测包还有多久（带抖动，平均值等于频率的倒数）。</summary>
+    public TimeSpan NextDelay()
+    {
+        lock (_gate)
+        {
+            if (State == ProbeState.Dead)
+            {
+                double seconds = Math.Min(_options.DeadMaxIntervalSeconds, Math.Pow(2, Math.Min(_deadProbes, 10)));
+                return _lastDelay = TimeSpan.FromSeconds(seconds * (0.8 + 0.4 * _random.NextDouble()));
+            }
+
+            // 平稳时间隔精确（不加抖动）：发包时刻规整，列块里的时间戳差分更小；抖动只用在退避里避免多条线路同步重试
+            return _lastDelay = TimeSpan.FromSeconds(1.0 / Hz);
+        }
+    }
+
+    /// <summary>刚刚等过的那个间隔所代表的权重（以 1/MaxHz 为单位）：下一个发出的包用它。平稳时是 MaxHz/Hz，退避时是几十到几百。</summary>
+    public int Weight
+    {
+        get
+        {
+            lock (_gate)
+            {
+                return (int)Math.Clamp(Math.Round(_lastDelay.TotalSeconds * _options.MaxHz), 1, 65535);
+            }
+        }
+    }
+
+    /// <summary>重新评估状态，大约每秒调用一次；状态或频率变了就返回变化。</summary>
+    public ProbeTransition? Evaluate(long nowUs)
+    {
+        lock (_gate)
+        {
+            if (_startUs < 0)
+            {
+                return null;
+            }
+
+            long finalSecond = nowUs / UsPerSecond - (long)Math.Ceiling(_options.GraceSeconds);
+            (int sent, int replied, int _) shortWindow = Window(finalSecond, (int)_options.DeadWindowSeconds);
+            (int sent, int replied, int lossSeconds) certify = Window(finalSecond, (int)_options.CertifySeconds);
+            int lostCertify = certify.sent - certify.replied;
+            double lossPct = certify.sent == 0 ? 0 : 100.0 * lostCertify / certify.sent;
+
+            // 最近一次有丢包的时间：用最近 CertifySeconds 里最晚一个有丢包的整秒
+            for (long second = finalSecond; second > finalSecond - (long)_options.CertifySeconds; second--)
+            {
+                int slot = Slot(second);
+                if (_second[slot] == second && _sent[slot] > _replied[slot])
+                {
+                    _lastLossUs = Math.Max(_lastLossUs, second * UsPerSecond);
+                    break;
+                }
+            }
+
+            UpdateRttTrend(nowUs);
+
+            ProbeState next;
+            string reason;
+            if (State == ProbeState.Dead)
+            {
+                if (_lastReplyUs > _deadSinceUs)
+                {
+                    next = ProbeState.Watch;
+                    reason = "reply received";
+                    _deadProbes = 0;
+                    _lastLossUs = nowUs;
+                }
+                else
+                {
+                    return null;
+                }
+            }
+            else if (shortWindow.sent >= _options.DeadMinSent && shortWindow.replied <= shortWindow.sent * (1 - _options.DeadLossRatio))
+            {
+                next = ProbeState.Dead;
+                reason = "line unreachable";
+                _deadSinceUs = nowUs;
+                _deadProbes = 0;
+            }
+            else
+            {
+                (next, reason) = Decide(nowUs, certify.lossSeconds, lostCertify, lossPct);
+            }
+
+            UpdateGuard(nowUs);
+            double hz = next switch
+            {
+                ProbeState.Quiet => Quantize(Math.Max(QuietHz(QuietWindowSeconds(nowUs)), !_options.RttGuard ? _options.MinHz : double.IsNaN(_guardHz) ? _options.MaxHz : _guardHz)),
+                ProbeState.Watch or ProbeState.Active => _options.MaxHz,
+                _ => Math.Max(_options.MinHz / 4, 1.0 / _options.DeadMaxIntervalSeconds),
+            };
+            hz = Math.Min(_options.MaxHz, hz);
+
+            if (next == State && Math.Abs(hz - Hz) / Hz < 0.05)
+            {
+                return null;
+            }
+
+            ProbeTransition result = new(State, next, hz, reason, lossPct, certify.sent, lostCertify);
+            State = next;
+            Hz = hz;
+            return result;
+        }
+    }
+
+    private (ProbeState State, string Reason) Decide(long nowUs, int lossSeconds, int lostCertify, double lossPct)
+    {
+        ProbeState state = ProbeState.Quiet;
+        string reason = "quiet";
+
+        double sinceLoss = _lastLossUs == long.MinValue ? double.PositiveInfinity : (nowUs - _lastLossUs) / (double)UsPerSecond;
+        if (lossSeconds >= _options.ActiveLossCount || (lossPct >= _options.TauPct * 2 && lossSeconds >= 2))
+        {
+            _activeUntilUs = nowUs + (long)(_options.ActiveHoldSeconds * UsPerSecond);
+        }
+
+        if (nowUs < _activeUntilUs)
+        {
+            return (ProbeState.Active, "sustained loss");
+        }
+
+        if (sinceLoss <= _options.WatchHoldSeconds)
+        {
+            state = ProbeState.Watch;
+            reason = "recent loss";
+        }
+
+        if (_rttHighSeconds >= 3)
+        {
+            state = ProbeState.Watch;
+            reason = "rtt above baseline";
+        }
+
+        double? prior = _options.Prior?.Invoke(nowUs);
+        double? ahead = _options.Prior?.Invoke(nowUs + (long)(_options.PriorLeadSeconds * UsPerSecond));
+        double expected = Math.Max(prior ?? 0, ahead ?? 0);
+        if (expected >= _options.PriorActiveAt)
+        {
+            return (ProbeState.Active, "expected peak");
+        }
+
+        if (expected >= _options.PriorWatchAt && state == ProbeState.Quiet)
+        {
+            state = ProbeState.Watch;
+            reason = "expected loss window";
+        }
+
+        if (state == ProbeState.Quiet && _options.Prior is null && nowUs - _startUs < (long)(_options.WarmupSeconds * UsPerSecond))
+        {
+            state = ProbeState.Watch;
+            reason = "warm-up";
+        }
+
+        return (state, reason);
+    }
+
+    /// <summary>历史上这个时段（现在和将要到来的一段时间）都平稳时，证明窗口可以更长，频率更低。</summary>
+    private double QuietWindowSeconds(long nowUs)
+    {
+        if (_options.Prior is null)
+        {
+            return _options.CertifySeconds;
+        }
+
+        double now = _options.Prior(nowUs) ?? 1;
+        double ahead = _options.Prior(nowUs + (long)(_options.PriorLeadSeconds * UsPerSecond)) ?? 1;
+        return Math.Max(now, ahead) <= 0.02 ? _options.QuietCertifySeconds : _options.CertifySeconds;
+    }
+
+    /// <summary>频率取 MaxHz/k（k 为整数）：每个包的权重正好是整数 k，分析时没有舍入误差。</summary>
+    private double Quantize(double hz)
+    {
+        double k = Math.Max(1, Math.Floor(_options.MaxHz / Math.Max(hz, 1e-9)));
+        return _options.MaxHz / k;
+    }
+
+    /// <summary>
+    /// 分位数精度保护：用最近一个证明窗口里的 RTT 样本估计 p99 的 95% 置信区间（次序统计量），
+    /// 半宽超过容差就升频，远小于容差才降频（单步最多减半），使平稳线路的 RTT 分位数始终保持在设定的精度内。
+    /// </summary>
+    private void UpdateGuard(long nowUs)
+    {
+        long second = nowUs / UsPerSecond;
+        if (_lastGuardSecond != long.MinValue && second - _lastGuardSecond < 10)
+        {
+            return;
+        }
+
+        _lastGuardSecond = second;
+        long from = second - (long)_options.CertifySeconds;
+        double[] window = [.. _rtts.Where(r => r.Second >= from).Select(r => r.Ms).Order()];
+        if (window.Length < 200)
+        {
+            _guardHz = double.NaN; // 样本不够估计精度：按最高频率
+            return;
+        }
+
+        int n = window.Length;
+        double rank = n * 0.99;
+        double half = 1.96 * Math.Sqrt(n * 0.99 * 0.01);
+        int lo = Math.Clamp((int)Math.Floor(rank - half), 0, n - 1);
+        int hi = Math.Clamp((int)Math.Ceiling(rank + half), 0, n - 1);
+        double halfWidth = (window[hi] - window[lo]) / 2;
+        double tolerance = Math.Max(_options.RttTolFloorMs, _options.RttTolPct / 100.0 * window[Math.Min(n - 1, (int)rank)]);
+        double ratio = Math.Clamp(halfWidth / tolerance, 0.7, 2.0); // 单步变化有限，避免来回跳
+        double current = Hz;
+        _guardHz = Math.Clamp(current * ratio * ratio, _options.MinHz, _options.MaxHz);
+    }
+
+    private double QuietHz(double windowSeconds) => Math.Min(_options.MaxHz, Math.Max(_options.MinHz, 3.0 / (_options.TauPct / 100.0 * windowSeconds)));
+
+    /// <summary>窗口内发出、回来的包数，以及有丢包的整秒数（一次连续丢包只算一个"事件"，不会因为一次短暂中断就判成持续丢包）。</summary>
+    private (int Sent, int Replied, int LossSeconds) Window(long finalSecond, int seconds)
+    {
+        int sent = 0;
+        int replied = 0;
+        int lossSeconds = 0;
+        for (long second = finalSecond; second > finalSecond - seconds; second--)
+        {
+            int slot = Slot(second);
+            if (_second[slot] == second)
+            {
+                sent += _sent[slot];
+                replied += _replied[slot];
+                if (_sent[slot] > _replied[slot])
+                {
+                    lossSeconds++;
+                }
+            }
+        }
+
+        return (sent, replied, lossSeconds);
+    }
+
+    private void UpdateRttTrend(long nowUs)
+    {
+        long second = nowUs / UsPerSecond;
+        if (second == _lastRttSecond || double.IsNaN(_rttFast) || double.IsNaN(_rttSlow))
+        {
+            return;
+        }
+
+        _lastRttSecond = second;
+        bool high = _rttFast > _rttSlow * _options.RttFactor + _options.RttFloorMs;
+        _rttHighSeconds = high ? _rttHighSeconds + 1 : 0;
+    }
+
+    private static int Slot(long second) => (int)(((second % Buckets) + Buckets) % Buckets);
+}

backend/shared/MoShiro.Measurement/Core/Contracts.cs

@@ -186,8 +186,12 @@ public sealed class BlockSpec
 
     public long Int(string name) => Params.GetInt(name);
 
+    public double Number(string name) => Params.GetNumber(name);
+
     public bool Bool(string name) => Params.GetBool(name);
 
+    public string Text(string name) => Params.GetString(name);
+
     /// <summary>参数或端口变化时调和器重启这个积木（不含流编号：Agent 的流编号每次重建都会重新分配）。</summary>
     public string ConfigSignature => KindId + "|" + Port + "|" +
         string.Join(',', Params.Values.OrderBy(p => p.Key, StringComparer.Ordinal).Select(p => p.Key + "=" + p.Value.GetRawText()));
@@ -221,6 +225,9 @@ public sealed class BlockEnv
 
     public QuicDatagramTransport? Datagrams { get; init; }
 
+    /// <summary>拨号方：这条线路在每个时刻（单调时钟，微秒）丢包的历史概率（0 到 1），自适应探测用它在高发时段提前升频；没有历史为 null。</summary>
+    public Func<long, double?>? LossPrior { get; init; }
+
     /// <summary>监听方的准入策略（限速等）；拨号方为 null。</summary>
     public IAdmission? Admission { get; init; }
 
@@ -232,6 +239,15 @@ public sealed class BlockEnv
     /// <summary>拨号方：对端（Agent，或目标任务的目标地址）。</summary>
     public IPAddress? PeerAddress { get; init; }
 
+    /// <summary>单个 Agent 任务的目标原文（http 是 URL，其余是主机[:端口]）；线路任务为 null。</summary>
+    public string? Target { get; init; }
+
+    /// <summary>单个 Agent 任务：解析出来的地址能不能连（本地 <c>allowed_target_cidrs</c>）；null 表示不限制。</summary>
+    public Func<IPAddress, bool>? AllowAddress { get; init; }
+
+    /// <summary>自适应频率的状态变化（用于审计）；null 表示不记录。</summary>
+    public Action<RateChange>? OnRateChange { get; init; }
+
     /// <summary>拨号方：对端 TLS 证书的 SPKI 指纹；null 表示不校验证书（目标任务，目标是任意地址）。</summary>
     public byte[]? PeerSpkiSha256 { get; init; }
 
@@ -241,7 +257,7 @@ public sealed class BlockEnv
     /// <summary>拨号方：列块出口。</summary>
     public IFragmentSink? Fragments { get; init; }
 
-    /// <summary>本地硬上限：批量传输（tcp_bulk）发送端的码率（Mbit/s）。批量传输会尽可能占满链路，这是防止把小机器打满的保险。</summary>
+    /// <summary>本地硬上限：批量传输（tcp_transfer）发送端的码率（Mbit/s）。批量传输会尽可能占满链路，这是防止把小机器打满的保险。</summary>
     public double MaxBulkMbps { get; init; } = 100;
 
     /// <summary>本地硬上限：单向数据流接收缓冲的包速率上界。</summary>
@@ -257,10 +273,14 @@ public sealed class BlockEnv
             Log = Log,
             Session = () => session,
             Datagrams = Datagrams,
+            LossPrior = LossPrior,
             Admission = Admission,
             Counters = Counters,
             TcpListen = TcpListen,
             PeerAddress = PeerAddress,
+            Target = Target,
+            AllowAddress = AllowAddress,
+            OnRateChange = OnRateChange,
             PeerSpkiSha256 = PeerSpkiSha256,
             KnockKey = KnockKey,
             Fragments = Fragments,

backend/shared/MoShiro.Measurement/Execution/BudgetGuard.cs

@@ -106,22 +106,34 @@ public sealed class BudgetGuard
         return Check(new TaskSpec { Id = new TaskId("tsk_phase"), Scope = "line", Kind = kindId, Params = new Dictionary<string, JsonElement>(parameters) }, ref mbps, ref pps);
     }
 
+    /// <summary>
+    /// 目标在静态上可不可以接受：IP 字面量直接用 <see cref="AddressAllowed"/> 判断；域名（包括 URL 里的）要解析之后才知道，
+    /// 这里先接受，运行时每次解析出的地址再逐个检查。
+    /// </summary>
     public bool TargetAllowed(string? target)
     {
-        if (target is null)
+        if (!TargetHost.TryParse(target, out string? host, out _, out _))
         {
             return false;
         }
 
-        string host = target;
-        if (IPEndPoint.TryParse(target, out IPEndPoint? endpoint))
+        return !IPAddress.TryParse(host, out IPAddress? address) || AddressAllowed(address);
+    }
+
+    /// <summary>
+    /// 这个地址能不能作为单个 Agent 任务的目标。<c>allowed_target_cidrs</c> 没配置时只允许公网地址（内网、回环、链路本地、组播等一律拒绝），
+    /// 防止被攻破的 Backend 借 Agent 探测它所在的内网；配置了就只允许列出的网段（包括内网段，由节点所有者显式决定）。
+    /// </summary>
+    public bool AddressAllowed(IPAddress address)
+    {
+        if (address.IsIPv4MappedToIPv6)
         {
-            host = endpoint.Address.ToString();
+            address = address.MapToIPv4();
         }
 
-        if (!IPAddress.TryParse(host, out IPAddress? address))
+        if (_limits.AllowedTargetCidrs.Count == 0)
         {
-            return false;
+            return IsPublic(address);
         }
 
         foreach ((IPAddress network, int prefix) in _cidrs)
@@ -135,6 +147,28 @@ public sealed class BudgetGuard
         return false;
     }
 
+    private static readonly (IPAddress Network, int Prefix)[] s_nonPublic =
+    [
+        (IPAddress.Parse("0.0.0.0"), 8), (IPAddress.Parse("10.0.0.0"), 8), (IPAddress.Parse("100.64.0.0"), 10), (IPAddress.Parse("127.0.0.0"), 8),
+        (IPAddress.Parse("169.254.0.0"), 16), (IPAddress.Parse("172.16.0.0"), 12), (IPAddress.Parse("192.0.0.0"), 24), (IPAddress.Parse("192.168.0.0"), 16),
+        (IPAddress.Parse("198.18.0.0"), 15), (IPAddress.Parse("224.0.0.0"), 3),
+        (IPAddress.Parse("::"), 128), (IPAddress.Parse("::1"), 128), (IPAddress.Parse("fc00::"), 7), (IPAddress.Parse("fe80::"), 10), (IPAddress.Parse("ff00::"), 8),
+    ];
+
+    /// <summary>不是公网：私有、回环、链路本地、运营商级 NAT、组播、保留地址。</summary>
+    private static bool IsPublic(IPAddress address)
+    {
+        foreach ((IPAddress network, int prefix) in s_nonPublic)
+        {
+            if (InCidr(address, network, prefix))
+            {
+                return false;
+            }
+        }
+
+        return true;
+    }
+
     private bool PortAllowed(KindSpec kind, ParamValues values)
     {
         if (!kind.Params.Any(p => p.Name == "port"))
@@ -148,10 +182,11 @@ public sealed class BudgetGuard
 
     private static long EstimatePps(string kindId, ParamValues values) => kindId switch
     {
-        "udp_echo" or "tcp_echo" => values.GetInt("rate_hz") * 2,
-        "icmp_echo" => values.GetInt("rate_hz") * 2,
-        "udp_train" => (long)(values.GetNumber("mbps") * 1_000_000 / 8 / Math.Max(1, values.GetInt("size"))),
-        "connect" => values.GetInt("per_minute") * 6 / 60,
+        "quic_ping" or "tcp_ping" => Kinds.PeakRateHz(kindId, values) * 2,
+        "icmp_ping" => values.GetInt("rate_hz") * 2,
+        "quic_stream" => (long)(values.GetNumber("mbps") * 1_000_000 / 8 / Math.Max(1, values.GetInt("size"))),
+        "tcp_connect" => values.GetInt("per_minute") * 6 / 60,
+        "http_request" => Math.Max(1, values.GetInt("rate_max_per_min") * 20 / 60),
         _ => 1,
     };
 

backend/shared/MoShiro.Measurement/Net/MsQuicApi.cs

@@ -109,14 +109,16 @@ internal static unsafe class MsQuicApi
 
     public static void RegistrationClose(nint handle) => s_registrationClose(handle);
 
-    public static nint ConfigurationOpen(nint registration, byte[] alpn)
+    public static nint ConfigurationOpen(nint registration, byte[] alpn, QuicSettings? settings = null)
     {
+        byte[] native = settings is { IsDefault: false } ? settings.ToNative() : [];
         unsafe
         {
             fixed (byte* alpnBytes = alpn)
+            fixed (byte* settingsBytes = native)
             {
                 var buffer = new QuicBuffer { Length = (uint)alpn.Length, Buffer = (nint)alpnBytes };
-                uint status = s_configurationOpen(registration, ref buffer, 1, 0, 0, 0, out nint configuration);
+                uint status = s_configurationOpen(registration, ref buffer, 1, native.Length == 0 ? 0 : (nint)settingsBytes, (uint)native.Length, 0, out nint configuration);
                 Check(status, "ConfigurationOpen");
                 return configuration;
             }

backend/shared/MoShiro.Measurement/Net/MsQuicConnection.cs

@@ -156,7 +156,8 @@ internal sealed class MsQuicConnection : IAsyncDisposable, IDatagramConnection
         byte[] expectedPeerSpki,
         MsQuicDatagramCallback datagramHandler,
         INodeLog log,
-        CancellationToken ct)
+        CancellationToken ct,
+        QuicSettings? settings = null)
     {
         nint registration = 0;
         nint configuration = 0;
@@ -165,7 +166,7 @@ internal sealed class MsQuicConnection : IAsyncDisposable, IDatagramConnection
         try
         {
             registration = MsQuicApi.RegistrationOpen("moshiro-dialer");
-            configuration = MsQuicApi.ConfigurationOpen(registration, QuicAlpn.Value);
+            configuration = MsQuicApi.ConfigurationOpen(registration, QuicAlpn.Value, settings);
             LoadClientCredentials(configuration);
             var endpoint = new IPEndPoint(address.AddressFamily == AddressFamily.InterNetworkV6 ? IPAddress.IPv6Any : IPAddress.Any, localPort);
             SocketAddress serialized = endpoint.Serialize();

backend/shared/MoShiro.Measurement/Net/MsQuicListener.cs

@@ -21,6 +21,7 @@ internal sealed class MsQuicListener : IAsyncDisposable
     private readonly INodeLog _log;
     private readonly Action<IPEndPoint>? _peerAddressChanged;
     private readonly X509Certificate2 _certificate;
+    private readonly QuicSettings? _settings;
     private readonly GCHandle _self;
     private readonly ConcurrentDictionary<nint, MsQuicConnection> _connections = new();
     private readonly List<nint> _listeners = [];
@@ -34,8 +35,10 @@ internal sealed class MsQuicListener : IAsyncDisposable
         X509Certificate2 certificate,
         MsQuicDatagramCallback datagramHandler,
         INodeLog log,
-        Action<IPEndPoint>? peerAddressChanged)
+        Action<IPEndPoint>? peerAddressChanged,
+        QuicSettings? settings = null)
     {
+        _settings = settings;
         // MsQuic opens dual-mode wildcard sockets, but filters incoming connections using
         // the address family supplied to ListenerStart. An IPv6Any listener alone rejects
         // IPv4-mapped connections with TLS alert 120 (no_application_protocol).
@@ -62,7 +65,7 @@ internal sealed class MsQuicListener : IAsyncDisposable
         _registration = MsQuicApi.RegistrationOpen("moshiro-agent");
         try
         {
-            _configuration = MsQuicApi.ConfigurationOpen(_registration, QuicAlpn.Value);
+            _configuration = MsQuicApi.ConfigurationOpen(_registration, QuicAlpn.Value, _settings);
             MsQuicConnection.LoadServerCredentials(_configuration, _certificate);
             var bound = new List<int>(_ports.Count * _bindAddresses.Count);
             foreach (int port in _ports)

backend/shared/MoShiro.Measurement/Net/QuicDatagramTransport.cs

@@ -21,6 +21,7 @@ public sealed class QuicDatagramTransport : IDisposable, IAsyncDisposable
     private readonly DataSession? _clientSession;
     private readonly IPEndPoint? _remote;
     private readonly byte[]? _peerSpki;
+    private readonly QuicSettings? _settings;
     private int _previousSourcePort;
     private readonly TaskCompletionSource _clientReady = new(TaskCreationOptions.RunContinuationsAsynchronously);
     private MsQuicListener? _listener;
@@ -28,8 +29,9 @@ public sealed class QuicDatagramTransport : IDisposable, IAsyncDisposable
     private int _disposed;
 
     /// <summary>Constructs an Agent-side QUIC listener.</summary>
-    public QuicDatagramTransport(IDataSessions sessions, IAdmission? admission, MonoClock clock, DataPlaneCounters counters, INodeLog log, IPAddress bind, IReadOnlyList<int> ports, X509Certificate2 serverCertificate)
+    public QuicDatagramTransport(IDataSessions sessions, IAdmission? admission, MonoClock clock, DataPlaneCounters counters, INodeLog log, IPAddress bind, IReadOnlyList<int> ports, X509Certificate2 serverCertificate, QuicSettings? settings = null)
     {
+        _settings = settings;
         _router = new MeasurementDatagramRouter(sessions, admission, clock, counters, log);
         _log = log;
         _onDatagram = _router.Dispatch;
@@ -39,8 +41,9 @@ public sealed class QuicDatagramTransport : IDisposable, IAsyncDisposable
     }
 
     /// <summary>Constructs a 拨号方-side QUIC dialer for one Agent session.</summary>
-    public QuicDatagramTransport(DataSession session, MonoClock clock, DataPlaneCounters counters, INodeLog log, IPEndPoint remote, byte[] peerSpki)
+    public QuicDatagramTransport(DataSession session, MonoClock clock, DataPlaneCounters counters, INodeLog log, IPEndPoint remote, byte[] peerSpki, QuicSettings? settings = null)
     {
+        _settings = settings;
         _router = new MeasurementDatagramRouter(new SingleSession(session), null, clock, counters, log);
         _log = log;
         _onDatagram = _router.Dispatch;
@@ -73,7 +76,7 @@ public sealed class QuicDatagramTransport : IDisposable, IAsyncDisposable
             throw new InvalidOperationException("QUIC listener is already bound.");
         }
 
-        _listener = new MsQuicListener(_bind, _ports, _serverCertificate!, _onDatagram, _log, null);
+        _listener = new MsQuicListener(_bind, _ports, _serverCertificate!, _onDatagram, _log, null, _settings);
         _listener.Start();
         BoundPorts = _listener.BoundPorts;
     }
@@ -92,7 +95,7 @@ public sealed class QuicDatagramTransport : IDisposable, IAsyncDisposable
         ObjectDisposedException.ThrowIf(Volatile.Read(ref _disposed) != 0, this);
         await CloseClientAsync().ConfigureAwait(false);
         int sourcePort = SelectSourcePort(_remote.AddressFamily, _previousSourcePort);
-        MsQuicConnection client = await MsQuicConnection.ConnectAsync(_remote.Address, _remote.Port, sourcePort, _peerSpki, _onDatagram, _log, ct).ConfigureAwait(false);
+        MsQuicConnection client = await MsQuicConnection.ConnectAsync(_remote.Address, _remote.Port, sourcePort, _peerSpki, _onDatagram, _log, ct, _settings).ConfigureAwait(false);
         _client = client;
         _clientSession.BindDatagramConnection(client);
         BoundPorts = client.LocalEndPoint is { } local ? [local.Port] : [sourcePort];

backend/shared/MoShiro.Measurement/Net/QuicSettings.cs

@@ -0,0 +1,110 @@
+using System.Buffers.Binary;
+
+namespace MoShiro.Measurement;
+
+/// <summary>
+/// 数据通道 QUIC 连接的传输参数（<c>agent.json</c> 的 <c>quic</c> 段）；null 的项用 MsQuic 默认值。
+/// 一条 QUIC 连接由这个 Agent 与对端之间的所有任务共用，所以这些参数属于节点，不属于某个任务。
+/// 监听方用它接受连接，拨号方用它发起连接，两边各自生效。
+/// </summary>
+public sealed record QuicSettings
+{
+    /// <summary>MsQuic 默认的最小、最大 MTU 是 1248 和 1500（IP 包大小，含 IP 和 UDP 头）。</summary>
+    public const int MinAllowedMtu = 1200;
+
+    public const int MaxAllowedMtu = 65535;
+
+    /// <summary>路径 MTU 探测的起点；链路的真实 MTU 更小时探测会往下收缩，更大时往上探测到 <see cref="MaxMtu"/>。</summary>
+    public int? MinMtu { get; init; }
+
+    /// <summary>路径 MTU 探测的上限。设成链路的真实 MTU 可以省掉探测，设小可以避开会丢大包的路径。</summary>
+    public int? MaxMtu { get; init; }
+
+    public bool? Pacing { get; init; }
+
+    public int? IdleTimeoutMs { get; init; }
+
+    public int? KeepAliveMs { get; init; }
+
+    public bool IsDefault => MinMtu is null && MaxMtu is null && Pacing is null && IdleTimeoutMs is null && KeepAliveMs is null;
+
+    /// <summary>参数是否合法；不合法返回原因。</summary>
+    public string? Validate()
+    {
+        if (MinMtu is { } min && min is < MinAllowedMtu or > MaxAllowedMtu)
+        {
+            return $"min_mtu must be {MinAllowedMtu}..{MaxAllowedMtu}";
+        }
+
+        if (MaxMtu is { } max && max is < MinAllowedMtu or > MaxAllowedMtu)
+        {
+            return $"max_mtu must be {MinAllowedMtu}..{MaxAllowedMtu}";
+        }
+
+        if (MinMtu is { } lo && MaxMtu is { } hi && lo > hi)
+        {
+            return "min_mtu must not exceed max_mtu";
+        }
+
+        if (IdleTimeoutMs is < 0)
+        {
+            return "idle_timeout_ms must not be negative";
+        }
+
+        return KeepAliveMs is < 0 ? "keep_alive_ms must not be negative" : null;
+    }
+
+    // QUIC_SETTINGS（msquic.h）的布局：IsSetFlags(u64) 后面依次是 u64、u32、u16 各一组字段，再是位域字节。
+    // 这里只写用到的几项，其余字段保持 0 且不置位。长度只算到 MtuDiscoveryMissingProbeCount，更靠后的字段 MsQuic 不会读。
+    private const int Size = 112;
+    private const int IdleTimeoutOffset = 24;
+    private const int KeepAliveOffset = 88;
+    private const int MinMtuOffset = 102;
+    private const int MaxMtuOffset = 104;
+    private const int BitFieldOffset = 106;
+    private const int PacingBit = 1 << 1;
+
+    private const int IdleTimeoutFlag = 2;
+    private const int KeepAliveFlag = 16;
+    private const int MinMtuFlag = 22;
+    private const int MaxMtuFlag = 23;
+    private const int PacingFlag = 25;
+
+    internal byte[] ToNative()
+    {
+        byte[] native = new byte[Size];
+        ulong isSet = 0;
+        if (IdleTimeoutMs is { } idle)
+        {
+            BinaryPrimitives.WriteUInt64LittleEndian(native.AsSpan(IdleTimeoutOffset), (ulong)idle);
+            isSet |= 1UL << IdleTimeoutFlag;
+        }
+
+        if (KeepAliveMs is { } keepAlive)
+        {
+            BinaryPrimitives.WriteUInt32LittleEndian(native.AsSpan(KeepAliveOffset), (uint)keepAlive);
+            isSet |= 1UL << KeepAliveFlag;
+        }
+
+        if (MinMtu is { } min)
+        {
+            BinaryPrimitives.WriteUInt16LittleEndian(native.AsSpan(MinMtuOffset), (ushort)min);
+            isSet |= 1UL << MinMtuFlag;
+        }
+
+        if (MaxMtu is { } max)
+        {
+            BinaryPrimitives.WriteUInt16LittleEndian(native.AsSpan(MaxMtuOffset), (ushort)max);
+            isSet |= 1UL << MaxMtuFlag;
+        }
+
+        if (Pacing is { } pacing)
+        {
+            native[BitFieldOffset] = (byte)(pacing ? PacingBit : 0);
+            isSet |= 1UL << PacingFlag;
+        }
+
+        BinaryPrimitives.WriteUInt64LittleEndian(native, isSet);
+        return native;
+    }
+}

backend/shared/MoShiro.Protocol/Catalog/Kinds/Kinds.cs

@@ -8,10 +8,14 @@ public static class Kinds
 {
     private static readonly string[] s_directions = ["fwd", "rev", "bidir"];
 
+    /// <summary>这个任务可能达到的最高探测频率（Hz）：自适应时是 <c>rate_max_hz</c>，否则是固定的 <c>rate_hz</c>。预算、限速和准入都按它算。</summary>
+    public static long PeakRateHz(string kindId, ParamValues values) =>
+        (kindId is "quic_ping" or "tcp_ping") && values.GetBool("adaptive") ? Math.Max(values.GetInt("rate_max_hz"), values.GetInt("rate_min_hz")) : values.GetInt("rate_hz");
+
     private static readonly StreamSpec s_echoMsg = new(
         "msg",
         [
-            Col.Seq("seq"), Col.U16("size"),
+            Col.Seq("seq"), Col.U16("size"), Col.U16("w"),
             Col.TsDialer("t1"), Col.TsListener("t2", nullable: true), Col.TsListener("t3", nullable: true), Col.TsDialer("t4", nullable: true),
         ],
         Side.Dialer,
@@ -26,22 +30,27 @@ public static class Kinds
         ],
         Union: true);
 
-    public static readonly KindSpec UdpEcho = new(
-        "udp_echo",
+    public static readonly KindSpec QuicPing = new(
+        "quic_ping",
         "QUIC Datagram echo",
         "Fixed-rate QUIC Datagram echo with four timestamps per packet.",
         Scope.Line,
         new BlockSet("quic_datagram", "fixed", "fixed", "echo", []),
         [
-            P.Int("rate_hz", 10, 1, 200, "Hz"),
+            P.Bool("adaptive", true, "Adapt the probe rate to the loss rate: low when the line is quiet, up to rate_max_hz when it loses packets, exponential back-off when it is unreachable."),
+            P.Int("rate_hz", 10, 1, 200, "Hz", "Fixed rate, used when adaptive is false."),
+            P.Int("rate_min_hz", 2, 1, 200, "Hz"),
+            P.Int("rate_max_hz", 10, 1, 200, "Hz", "Highest rate, and the reference grid for sample weights."),
+            P.Number("tau_pct", 0.2, 0.01, 5, "%", "Loss rate a quiet line has to be able to prove below, at 95% confidence."),
+            P.Number("rtt_tol_pct", 2, 0.1, 20, "%", "Half-width of the 95% confidence interval of the RTT p99 a quiet line has to keep, as a share of p99 (never below 0.3 ms)."),
             P.Int("size", 64, 44, 1400, "B"),
             P.Int("port", 7443, 1, 65535),
         ],
         [s_echoMsg],
-        p => Bandwidth.UdpEcho(p.GetInt("rate_hz"), p.GetInt("size")));
+        p => Bandwidth.UdpEcho(PeakRateHz("quic_ping", p), p.GetInt("size")));
 
-    public static readonly KindSpec UdpTrain = new(
-        "udp_train",
+    public static readonly KindSpec QuicStream = new(
+        "quic_stream",
         "QUIC Datagram train",
         "Fixed-rate or laddered one-way QUIC Datagram stream (Agent to 拨号方) for loss and delay variation under load.",
         Scope.Line,
@@ -59,25 +68,30 @@ public static class Kinds
         ],
         p => (long)(p.GetNumber("mbps") * 1_000_000));
 
-    public static readonly KindSpec TcpEcho = new(
-        "tcp_echo",
+    public static readonly KindSpec TcpPing = new(
+        "tcp_ping",
         "TCP echo",
         "Small TCP messages echoed with four timestamps, plus periodic kernel tcp_info samples.",
         Scope.Line,
         new BlockSet("tcp", "fixed", "uniform", "echo", ["tcp_info"]),
         [
-            P.Int("rate_hz", 20, 1, 200, "Hz"),
+            P.Bool("adaptive", true, "Adapt the echo rate: as low as the loss bound and the RTT percentile precision allow when the line is quiet, the maximum when it is not, back-off when it stalls."),
+            P.Int("rate_hz", 20, 1, 200, "Hz", "Fixed rate, used when adaptive is false."),
+            P.Int("rate_min_hz", 2, 1, 200, "Hz"),
+            P.Int("rate_max_hz", 20, 1, 200, "Hz", "Highest rate, and the reference grid for sample weights."),
+            P.Number("tau_pct", 0.2, 0.01, 5, "%", "Share of retransmitted segments a quiet line has to be able to prove below, at 95% confidence."),
+            P.Number("rtt_tol_pct", 2, 0.1, 20, "%", "Half-width of the 95% confidence interval of the RTT p99 a quiet line has to keep, as a share of p99 (never below 0.3 ms)."),
             P.Int("min", 32, 16, 1400, "B"),
             P.Int("max", 64, 16, 1400, "B"),
-            P.Int("tcp_info_ms", 100, 10, 1000, "ms"),
+            P.Int("tcp_info_ms", 1000, 10, 1000, "ms"),
             P.Int("port", 7444, 1, 65535),
             P.Bool("tls", false),
         ],
         [s_echoMsg, s_tcpInfo],
-        p => Bandwidth.TcpEcho(p.GetInt("rate_hz"), p.GetInt("max")));
+        p => Bandwidth.TcpEcho(PeakRateHz("tcp_ping", p), p.GetInt("max")));
 
-    public static readonly KindSpec TcpBulk = new(
-        "tcp_bulk",
+    public static readonly KindSpec TcpTransfer = new(
+        "tcp_transfer",
         "TCP bulk",
         "Bulk TCP transfer on several streams with periodic byte counters and tcp_info.",
         Scope.Line,
@@ -96,8 +110,8 @@ public static class Kinds
         ],
         _ => 0);
 
-    public static readonly KindSpec Connect = new(
-        "connect",
+    public static readonly KindSpec TcpConnect = new(
+        "tcp_connect",
         "Connect",
         "Repeated TCP and TLS connection establishment with per-phase timings and outcome.",
         Scope.Line | Scope.Target,
@@ -115,8 +129,8 @@ public static class Kinds
         ],
         p => p.GetInt("per_minute") * 4000 / 60);
 
-    public static readonly KindSpec Hold = new(
-        "hold",
+    public static readonly KindSpec TlsHold = new(
+        "tls_hold",
         "Hold",
         "A long-lived TLS connection with periodic heartbeats; records resets and lifetime.",
         Scope.Line,
@@ -130,8 +144,38 @@ public static class Kinds
         ],
         p => 2000 / Math.Max(1, p.GetInt("heartbeat_s")) * 8);
 
-    public static readonly KindSpec IcmpEcho = new(
-        "icmp_echo",
+    public static readonly KindSpec HttpRequest = new(
+        "http_request",
+        "HTTP request",
+        "One Agent requests a URL over HTTP/1.1, HTTP/2 or HTTP/3 and records DNS, TCP, time to first byte, total time and status. Target is the URL.",
+        Scope.Target,
+        new BlockSet("http", "fixed", "fixed", "request", []),
+        [
+            P.Enum("version", "h2", ["h1", "h2", "h3"], "HTTP version; the request fails instead of falling back."),
+            P.Enum("method", "GET", ["GET", "HEAD"]),
+            P.Bool("adaptive", true, "Adapt the request rate to the failure rate: low while the target answers, up to rate_max_per_min when it fails, exponential back-off while it is unreachable."),
+            P.Int("per_minute", 6, 1, 120, "/min", "Fixed rate, used when adaptive is false."),
+            P.Int("rate_min_per_min", 1, 1, 120, "/min"),
+            P.Int("rate_max_per_min", 12, 1, 120, "/min", "Highest rate, and the reference grid for sample weights."),
+            P.Number("tau_pct", 5, 0.1, 50, "%", "Failure rate a quiet target has to be able to prove below, at 95% confidence."),
+            P.Int("timeout_ms", 10000, 500, 60000, "ms"),
+            P.Int("read_kb", 16, 0, 1024, "KiB", "Body bytes to read before the request counts as finished (0: headers only)."),
+            P.Int("ok_status", 0, 0, 599, null, "Status that counts as success; 0 means any status below 400."),
+            P.Bool("tls_verify", true),
+        ],
+        [
+            new StreamSpec(
+                "req",
+                [
+                    Col.Seq("attempt"), Col.TsDialer("ts"), Col.U16("w"),
+                    Col.U32("dns_us", nullable: true), Col.U32("tcp_us", nullable: true), Col.U32("ttfb_us", nullable: true), Col.U32("total_us", nullable: true),
+                    Col.U16("status", nullable: true), Col.U8("proto", nullable: true), Col.U8("outcome"),
+                ]),
+        ],
+        p => p.GetInt("rate_max_per_min") * (2000 + p.GetInt("read_kb") * 1024) * 8 / 60);
+
+    public static readonly KindSpec IcmpPing = new(
+        "icmp_ping",
         "ICMP echo",
         "拨号方 or Agent side ICMP echo to a target address.",
         Scope.Target,
@@ -145,7 +189,7 @@ public static class Kinds
         ],
         p => Bandwidth.UdpEcho(p.GetInt("rate_hz"), p.GetInt("size")));
 
-    public static readonly IReadOnlyList<KindSpec> All = [UdpEcho, UdpTrain, TcpEcho, TcpBulk, Connect, Hold, IcmpEcho];
+    public static readonly IReadOnlyList<KindSpec> All = [QuicPing, QuicStream, TcpPing, TcpTransfer, TcpConnect, TlsHold, HttpRequest, IcmpPing];
 
     public static KindSpec? Find(string id)
     {

backend/shared/MoShiro.Protocol/Rpc/MoShiroMethodTable.cs

@@ -19,6 +19,7 @@ public static class MoShiroMethodTable
                 MethodSpec.Request(MoShiroMethods.TestRun, RpcSide.Server),
                 MethodSpec.Request(MoShiroMethods.TestCancel, RpcSide.Server),
                 MethodSpec.Request(MoShiroMethods.DialerDisconnect, RpcSide.Server),
+                MethodSpec.Request(MoShiroMethods.LogsFetch, RpcSide.Server),
                 MethodSpec.Notification(MoShiroMethods.LinkRetry, RpcSide.Server),
                 MethodSpec.Notification(MoShiroMethods.UpdateOffer, RpcSide.Server),
                 MethodSpec.Notification(MoShiroMethods.UpdateApply, RpcSide.Server),

backend/shared/MoShiro.Protocol/Rpc/MoShiroRpc.cs

@@ -17,6 +17,7 @@ public static class MoShiroMethods
     public const string UpdateOffer = "moshiro.update.offer";
     public const string UpdateApply = "moshiro.update.apply";
     public const string Schedule = "moshiro.schedule";
+    public const string LogsFetch = "moshiro.logs.fetch";
 
     // 拨号方 ↔ 监听方（点对点会话）
     public const string Clock = "moshiro.clock";
@@ -338,11 +339,138 @@ public sealed class NodeHeartbeatExtra
     [JsonPropertyName("update")]
     public UpdateStatus? Update { get; set; }
 
-    [JsonPropertyName("runtime_logs")]
-    public List<NodeLogRecord>? RuntimeLogs { get; set; }
+    /// <summary>日志只报计数（不带文本）：自上次心跳以来各级别的条数、最多几个出现最多的类型，以及最新一条的编号；文本由 Backend 用 <c>moshiro.logs.fetch</c> 按需拉取。</summary>
+    [JsonPropertyName("log_summary")]
+    public LogSummaryDto? LogSummary { get; set; }
 
-    [JsonPropertyName("dropped_runtime_logs")]
-    public long? DroppedRuntimeLogs { get; set; }
+    /// <summary>自上次心跳以来自适应探测频率的状态变化（节点上限 512 条，超出丢最旧的）。</summary>
+    [JsonPropertyName("rate_changes")]
+    public List<RateChange>? RateChanges { get; set; }
+}
+
+/// <summary>某一类日志（消息文本的稳定哈希）在一个级别上出现了多少次。</summary>
+public sealed class LogTypeCountDto
+{
+    [JsonPropertyName("type")]
+    public uint Type { get; set; }
+
+    [JsonPropertyName("level")]
+    public string Level { get; set; } = "info";
+
+    [JsonPropertyName("count")]
+    public long Count { get; set; }
+}
+
+/// <summary>
+/// 自适应探测频率的一次状态变化（Quiet / Watch / Active / Dead）：节点随心跳上报，Backend 存成事件（<c>rate_change</c>），
+/// 事后可以回看每条线路、每个时段的探测频率为什么升降（例如晚高峰）。线路任务带 <c>listener</c>（对端）和 <c>ip_version</c>，目标任务带 <c>task</c>。
+/// </summary>
+public sealed class RateChange
+{
+    [JsonPropertyName("at_ms")]
+    public long AtMs { get; set; }
+
+    /// <summary>这条线路的监听方节点 id（线路任务）。</summary>
+    [JsonPropertyName("listener")]
+    public string? Listener { get; set; }
+
+    /// <summary>拨号方节点 id：节点上报时不填，由 Backend 按上报者补上。</summary>
+    [JsonPropertyName("dialer")]
+    public string? Dialer { get; set; }
+
+    [JsonPropertyName("ip_version")]
+    public string? IpVersion { get; set; }
+
+    /// <summary>单个 Agent 任务的任务 id。</summary>
+    [JsonPropertyName("task")]
+    public string? Task { get; set; }
+
+    [JsonPropertyName("kind")]
+    public string Kind { get; set; } = "";
+
+    [JsonPropertyName("from")]
+    public string From { get; set; } = "";
+
+    [JsonPropertyName("to")]
+    public string To { get; set; } = "";
+
+    [JsonPropertyName("hz")]
+    public double Hz { get; set; }
+
+    [JsonPropertyName("reason")]
+    public string Reason { get; set; } = "";
+
+    /// <summary>变化时刻证明窗口内的丢包率（百分比）和发出、丢失的包数。</summary>
+    [JsonPropertyName("loss_pct")]
+    public double LossPct { get; set; }
+
+    [JsonPropertyName("sent")]
+    public int Sent { get; set; }
+
+    [JsonPropertyName("lost")]
+    public int Lost { get; set; }
+}
+
+public sealed class LogSummaryDto
+{
+    [JsonPropertyName("last_id")]
+    public long LastId { get; set; }
+
+    [JsonPropertyName("info")]
+    public long Info { get; set; }
+
+    [JsonPropertyName("warn")]
+    public long Warn { get; set; }
+
+    [JsonPropertyName("error")]
+    public long Error { get; set; }
+
+    [JsonPropertyName("types")]
+    public List<LogTypeCountDto> Types { get; set; } = [];
+}
+
+/// <summary>Backend → 节点：拉取编号大于 <c>after_id</c> 的日志（最旧的在前），级别不低于 <c>min_level</c>。</summary>
+public sealed class LogsFetchParams
+{
+    [JsonPropertyName("after_id")]
+    public long AfterId { get; set; }
+
+    [JsonPropertyName("limit")]
+    public int Limit { get; set; } = 100;
+
+    [JsonPropertyName("min_level")]
+    public string? MinLevel { get; set; }
+}
+
+public sealed class LogEntryDto
+{
+    [JsonPropertyName("id")]
+    public long Id { get; set; }
+
+    [JsonPropertyName("type")]
+    public uint Type { get; set; }
+
+    [JsonPropertyName("at_utc_ms")]
+    public long AtUtcMs { get; set; }
+
+    [JsonPropertyName("level")]
+    public string Level { get; set; } = "info";
+
+    [JsonPropertyName("message")]
+    public string Message { get; set; } = "";
+
+    [JsonPropertyName("fields")]
+    public Dictionary<string, string> Fields { get; set; } = [];
+}
+
+public sealed class LogsFetchResult
+{
+    [JsonPropertyName("items")]
+    public List<LogEntryDto> Items { get; set; } = [];
+
+    /// <summary>节点上最新一条的编号：比 <c>after_id</c> 小说明节点重启过，编号从头开始。</summary>
+    [JsonPropertyName("last_id")]
+    public long LastId { get; set; }
 }
 
 /// <summary>
@@ -414,7 +542,7 @@ public sealed class ControlHealth
 /// <summary>任务层：测量自己使用的链路。TCP 类积木自带套接字和重拨，QUIC 数据通道由拨号方单独维护。</summary>
 public sealed class TaskHealth
 {
-    /// <summary>正在运行的 TCP 类线路积木数（tcp_echo、connect、hold、tcp_bulk）。</summary>
+    /// <summary>正在运行的 TCP 类线路积木数（tcp_ping、connect、hold、tcp_transfer）。</summary>
     [JsonPropertyName("tcp_blocks")]
     public int TcpBlocks { get; set; }
 
@@ -422,7 +550,7 @@ public sealed class TaskHealth
     public QuicHealth Quic { get; set; } = new();
 }
 
-/// <summary>QUIC 数据通道（udp_echo、udp_train 使用）的状态、握手统计和传输层统计。</summary>
+/// <summary>QUIC 数据通道（quic_ping、quic_stream 使用）的状态、握手统计和传输层统计。</summary>
 public sealed class QuicHealth
 {
     [JsonPropertyName("state")]
@@ -749,6 +877,10 @@ public static class FragmentKeys
 [JsonSerializable(typeof(DialTargets))]
 [JsonSerializable(typeof(UpdateOfferParams))]
 [JsonSerializable(typeof(ScheduleParams))]
+[JsonSerializable(typeof(LogsFetchParams))]
+[JsonSerializable(typeof(LogsFetchResult))]
+[JsonSerializable(typeof(LogSummaryDto))]
+[JsonSerializable(typeof(RateChange))]
 [JsonSerializable(typeof(UpdateStatus))]
 [JsonSerializable(typeof(NodeHeartbeatExtra))]
 [JsonSerializable(typeof(NodeHelloMeta))]

backend/shared/MoShiro.Protocol/Tasks/TargetHost.cs

@@ -0,0 +1,104 @@
+using System.Globalization;
+using System.Net;
+
+namespace MoShiro.Protocol;
+
+/// <summary>
+/// 单个 Agent 任务的目标：<c>http</c> 是 <c>http(s)://主机[:端口][/路径]</c>，其余 Kind 是 <c>主机[:端口]</c>（IP 或域名，IPv6 带端口时用方括号）。
+/// Backend 只检查格式，不做 DNS 解析；解析在 Agent 上进行，每个解析出的地址都要在 <c>allowed_target_cidrs</c> 里。
+/// </summary>
+public static class TargetHost
+{
+    public const string HttpKind = "http_request";
+
+    /// <summary>解析目标；<paramref name="port"/> 为 0 表示没有写端口，<paramref name="url"/> 只在 http(s) URL 时有值。</summary>
+    public static bool TryParse(string? target, out string host, out int port, out Uri? url)
+    {
+        host = "";
+        port = 0;
+        url = null;
+        if (string.IsNullOrWhiteSpace(target) || target.Length > 2048 || target.Any(char.IsWhiteSpace))
+        {
+            return false;
+        }
+
+        if (target.Contains("://", StringComparison.Ordinal))
+        {
+            if (!Uri.TryCreate(target, UriKind.Absolute, out Uri? uri) || uri.Scheme is not ("http" or "https") || uri.UserInfo.Length > 0 || !ValidHost(uri.IdnHost))
+            {
+                return false;
+            }
+
+            url = uri;
+            host = uri.IdnHost.Trim('[', ']');
+            port = uri.IsDefaultPort ? 0 : uri.Port;
+            return true;
+        }
+
+        // IPAddress.TryParse 会把「[v6]:端口」的端口丢掉，带方括号的先按端点解析
+        if (!target.StartsWith('[') && IPAddress.TryParse(target, out IPAddress? ip))
+        {
+            host = ip.ToString();
+            return true;
+        }
+
+        if (IPEndPoint.TryParse(target, out IPEndPoint? endpoint))
+        {
+            if (endpoint.Port is 0)
+            {
+                return false;
+            }
+
+            host = endpoint.Address.ToString();
+            port = endpoint.Port;
+            return true;
+        }
+
+        int colon = target.LastIndexOf(':');
+        string name = colon < 0 ? target : target[..colon];
+        if (colon >= 0 && (!int.TryParse(target.AsSpan(colon + 1), NumberStyles.None, CultureInfo.InvariantCulture, out port) || port is < 1 or > 65535))
+        {
+            return false;
+        }
+
+        if (!ValidHost(name))
+        {
+            return false;
+        }
+
+        host = name.ToLowerInvariant();
+        return true;
+    }
+
+    /// <summary>按 Kind 检查并规范化：<c>http</c> 必须是 http(s) URL，其余 Kind 必须是主机[:端口]；不合格返回 null。</summary>
+    public static string? Normalize(string kindId, string? target)
+    {
+        if (!TryParse(target, out string host, out int port, out Uri? url) || (url is not null) != (kindId == HttpKind))
+        {
+            return null;
+        }
+
+        if (url is not null)
+        {
+            return url.AbsoluteUri;
+        }
+
+        string shown = IPAddress.TryParse(host, out IPAddress? ip) && ip.AddressFamily == System.Net.Sockets.AddressFamily.InterNetworkV6 && port != 0 ? "[" + host + "]" : host;
+        return port == 0 ? host : shown + ":" + port.ToString(CultureInfo.InvariantCulture);
+    }
+
+    private static bool ValidHost(string name)
+    {
+        if (IPAddress.TryParse(name.Trim('[', ']'), out _))
+        {
+            return true;
+        }
+
+        if (name.Length is 0 or > 253 || name[^1] == '-' || name[0] is '-' or '.')
+        {
+            return false;
+        }
+
+        return name.TrimEnd('.').Split('.').All(label => label.Length is > 0 and <= 63 && label.All(c => char.IsAsciiLetterOrDigit(c) || c == '-'));
+    }
+}

backend/shared/MoShiro.Protocol/Wire/MeasurementDatagram.cs

@@ -8,7 +8,7 @@ public enum MeasurementDatagramType : byte
     EchoRequest = 1,
     EchoReply = 2,
 
-    /// <summary>单向数据（udp_train），以及 拨号方 为了保持 NAT 映射和让 Agent 学到源地址而发的探活包。</summary>
+    /// <summary>单向数据（quic_stream），以及 拨号方 为了保持 NAT 映射和让 Agent 学到源地址而发的探活包。</summary>
     Data = 3,
 }
 

backend/shared/tests/MoShiro.Measurement.Tests/AdaptiveRateTests.cs

@@ -0,0 +1,175 @@
+using MoShiro.Measurement;
+
+namespace MoShiro.Measurement.Tests;
+
+public sealed class AdaptiveRateTests
+{
+    private const long Second = 1_000_000;
+
+    /// <summary>按当前频率发包、按 <paramref name="lost"/> 决定回不回，每秒评估一次；返回结束时的秒数。</summary>
+    private static long Run(AdaptiveRate rate, long fromSecond, int seconds, Func<long, bool> lost, double rttMs = 20, List<ProbeTransition>? log = null, bool stopAtDead = false)
+    {
+        long second = fromSecond;
+        for (int i = 0; i < seconds; i++, second++)
+        {
+            int probes = Math.Max(1, (int)Math.Round(rate.Hz));
+            if (rate.State == ProbeState.Dead)
+            {
+                probes = i % 4 == 0 ? 1 : 0; // 退避：几秒才发一个
+            }
+
+            for (int k = 0; k < probes; k++)
+            {
+                long sent = second * Second + k * Second / probes;
+                rate.OnSend(sent);
+                if (!lost(second))
+                {
+                    rate.OnReply(sent, sent + (long)(rttMs * 1000), rttMs);
+                }
+            }
+
+            if (rate.Evaluate((second + 1) * Second) is { } change)
+            {
+                log?.Add(change);
+                if (stopAtDead && change.To == ProbeState.Dead)
+                {
+                    return second + 1;
+                }
+            }
+        }
+
+        return second;
+    }
+
+    [Fact]
+    public void QuietLine_AfterWarmUp_ProbesJustEnoughToProveTheLossBound()
+    {
+        var rate = new AdaptiveRate(new AdaptiveRateOptions());
+        long at = Run(rate, 0, 600, _ => false);
+        Assert.Equal(ProbeState.Quiet, rate.State);
+        Assert.Equal(5, rate.Hz, 0.01); // 3 / (0.2% × 300 s)
+        Assert.True(at > 0);
+    }
+
+    [Fact]
+    public void SustainedLoss_RaisesToTheMaximum_AndComesBackOnlyAfterTheHoldTimes()
+    {
+        var rate = new AdaptiveRate(new AdaptiveRateOptions());
+        long at = Run(rate, 0, 600, _ => false);
+        at = Run(rate, at, 60, second => second % 10 == 0); // 每 10 秒丢一整秒的包
+        Assert.Equal(ProbeState.Active, rate.State);
+        Assert.Equal(10, rate.Hz);
+
+        at = Run(rate, at, 800, _ => false); // 不到 15 分钟：还在 Active
+        Assert.Equal(ProbeState.Active, rate.State);
+        at = Run(rate, at, 400, _ => false); // 超过 15 分钟：降到 Watch
+        Assert.Equal(ProbeState.Watch, rate.State);
+        Run(rate, at, 1900, _ => false); // 最后一次丢包 30 分钟之后：回到 Quiet
+        Assert.Equal(ProbeState.Quiet, rate.State);
+    }
+
+    [Fact]
+    public void AnIsolatedLoss_OnlyRaisesToWatch()
+    {
+        var rate = new AdaptiveRate(new AdaptiveRateOptions());
+        long at = Run(rate, 0, 600, _ => false);
+        var log = new List<ProbeTransition>();
+        Run(rate, at, 120, second => second == at + 10, log: log);
+        Assert.Equal(ProbeState.Watch, rate.State);
+        Assert.DoesNotContain(log, change => change.To == ProbeState.Active);
+    }
+
+    [Fact]
+    public void Unreachable_BacksOffExponentially_AndRecoversOnTheFirstReply()
+    {
+        var rate = new AdaptiveRate(new AdaptiveRateOptions(), new Random(1));
+        long at = Run(rate, 0, 600, _ => false);
+        at = Run(rate, at, 60, _ => true, stopAtDead: true);
+        Assert.Equal(ProbeState.Dead, rate.State);
+
+        var delays = new List<double>();
+        long now = at * Second;
+        for (int i = 0; i < 8; i++)
+        {
+            double delay = rate.NextDelay().TotalSeconds;
+            delays.Add(delay);
+            now += (long)(delay * Second);
+            rate.OnSend(now);
+        }
+
+        Assert.InRange(delays[0], 0.8, 1.2); // 从 1 秒开始
+        Assert.True(delays[3] > delays[0] * 4, string.Join(",", delays)); // 翻倍增长（有抖动）
+        Assert.All(delays, delay => Assert.InRange(delay, 0.8, 36.0)); // 最长 30 秒，抖动 ±20%
+
+        rate.OnReply(now, now + 30_000, 30);
+        Assert.Equal(ProbeState.Watch, rate.Evaluate(now + 2 * Second)!.To);
+    }
+
+    [Fact]
+    public void QuietLineWithTightRtt_MayDropBelowTheGrid_ButAJitteryOneStaysAtTheMaximum()
+    {
+        var tight = new AdaptiveRate(new AdaptiveRateOptions());
+        Run(tight, 0, 1200, _ => false, rttMs: 20); // RTT 恒定：p99 的置信区间几乎为零，降到丢包下界 5 Hz
+        Assert.Equal(ProbeState.Quiet, tight.State);
+        Assert.Equal(5, tight.Hz, 0.01);
+
+        var jittery = new AdaptiveRate(new AdaptiveRateOptions());
+        var random = new Random(7);
+        long second = 0;
+        for (int i = 0; i < 1200; i++, second++)
+        {
+            int probes = Math.Max(1, (int)Math.Round(jittery.Hz));
+            for (int k = 0; k < probes; k++)
+            {
+                long sent = second * Second + k * Second / probes;
+                double rtt = 20 + random.NextDouble() * random.NextDouble() * 60; // 长尾 20 到 80 ms
+                jittery.OnSend(sent);
+                jittery.OnReply(sent, sent + (long)(rtt * 1000), rtt);
+            }
+
+            jittery.Evaluate((second + 1) * Second);
+        }
+
+        Assert.Equal(10, jittery.Hz, 0.01); // 分位数精度保护：抖动大，样本不能少
+    }
+
+    [Fact]
+    public void Weight_IsTheTimeAProbeStandsFor_InUnitsOfTheGrid()
+    {
+        var rate = new AdaptiveRate(new AdaptiveRateOptions());
+        Run(rate, 0, 1200, _ => false);
+        Assert.Equal(5, rate.Hz, 0.01);
+        rate.NextDelay();
+        Assert.Equal(2, rate.Weight); // 5 Hz 的一个包代表 2 个 10 Hz 网格间隔
+    }
+
+    [Fact]
+    public void RttWellAboveTheBaseline_RaisesToWatch()
+    {
+        var rate = new AdaptiveRate(new AdaptiveRateOptions());
+        long at = Run(rate, 0, 900, _ => false, rttMs: 20);
+        Assert.Equal(ProbeState.Quiet, rate.State);
+        Run(rate, at, 30, _ => false, rttMs: 120);
+        Assert.Equal(ProbeState.Watch, rate.State);
+    }
+
+    [Fact]
+    public void Prior_WarmsUpBeforeTheEveningPeak_AndLetsHistoricallyQuietHoursUseTheLowestRate()
+    {
+        const long peakStart = 1_000 * 3600; // 秒
+        double? Prior(long us)
+        {
+            long second = us / Second;
+            return second >= peakStart && second < peakStart + 4 * 3600 ? 0.8 : 0.0;
+        }
+
+        var rate = new AdaptiveRate(new AdaptiveRateOptions { Prior = Prior });
+        long at = Run(rate, 100_000, 1200, _ => false); // 远离高峰，历史平稳：证明窗口拉长，2 Hz
+        Assert.Equal(ProbeState.Quiet, rate.State);
+        Assert.Equal(2, rate.Hz, 0.01);
+
+        Run(rate, peakStart - 1500, 120, _ => false); // 距离高峰不到半小时：提前升到 Active
+        Assert.Equal(ProbeState.Active, rate.State);
+        Assert.True(at > 0);
+    }
+}

backend/shared/tests/MoShiro.Measurement.Tests/MeasurementTests.cs

@@ -1,3 +1,4 @@
+using System.Net;
 using System.Text.Json;
 using Fleet.Core;
 using MoShiro.Protocol;
@@ -24,11 +25,11 @@ public sealed class MeasurementTests
         BudgetGuard guard = Guard();
         double mbps = 0;
         long pps = 0;
-        Assert.True(guard.Check(Line("udp_echo"), ref mbps, ref pps).Accepted);
+        Assert.True(guard.Check(Line("quic_ping"), ref mbps, ref pps).Accepted);
         Assert.Equal(RejectReasons.Unsupported, guard.Check(Line("no_such_kind"), ref mbps, ref pps).Reason);
-        Assert.Equal(RejectReasons.InvalidParams, guard.Check(Line("udp_echo", ("rate_hz", "100000")), ref mbps, ref pps).Reason);
-        Assert.Equal(RejectReasons.InvalidParams, guard.Check(Line("udp_echo", ("nope", "1")), ref mbps, ref pps).Reason);
-        Assert.Equal(RejectReasons.PolicyDenied, guard.Check(Line("udp_echo", ("port", "9999")), ref mbps, ref pps).Reason);
+        Assert.Equal(RejectReasons.InvalidParams, guard.Check(Line("quic_ping", ("rate_hz", "100000")), ref mbps, ref pps).Reason);
+        Assert.Equal(RejectReasons.InvalidParams, guard.Check(Line("quic_ping", ("nope", "1")), ref mbps, ref pps).Reason);
+        Assert.Equal(RejectReasons.PolicyDenied, guard.Check(Line("quic_ping", ("port", "9999")), ref mbps, ref pps).Reason);
     }
 
     [Fact]
@@ -37,25 +38,45 @@ public sealed class MeasurementTests
         BudgetGuard guard = Guard(new NodeLimits { MaxTotalMbps = 15, AllowedQuicPorts = [7443] });
         double mbps = 0;
         long pps = 0;
-        Assert.True(guard.CheckPhase("udp_train", new Dictionary<string, JsonElement> { ["mbps"] = Json("10") }).Accepted);
-        Assert.Equal(RejectReasons.BudgetExceeded, guard.CheckPhase("udp_train", new Dictionary<string, JsonElement> { ["mbps"] = Json("20") }).Reason);
+        Assert.True(guard.CheckPhase("quic_stream", new Dictionary<string, JsonElement> { ["mbps"] = Json("10") }).Accepted);
+        Assert.Equal(RejectReasons.BudgetExceeded, guard.CheckPhase("quic_stream", new Dictionary<string, JsonElement> { ["mbps"] = Json("20") }).Reason);
 
-        Assert.True(guard.Check(Line("udp_train", ("mbps", "10")), ref mbps, ref pps).Accepted);
-        Assert.Equal(RejectReasons.BudgetExceeded, guard.Check(Line("udp_train", ("mbps", "10")), ref mbps, ref pps).Reason);
+        Assert.True(guard.Check(Line("quic_stream", ("mbps", "10")), ref mbps, ref pps).Accepted);
+        Assert.Equal(RejectReasons.BudgetExceeded, guard.Check(Line("quic_stream", ("mbps", "10")), ref mbps, ref pps).Reason);
     }
 
     [Fact]
-    public void BudgetGuard_TargetTasks_AreDeniedUnlessTheAddressIsInAnAllowedRange()
+    public void BudgetGuard_TargetTasks_DefaultToPublicAddressesOnly_AndAnExplicitListIsExactly_WhatItSays()
     {
-        Assert.False(Guard().TargetAllowed("1.1.1.1"));
+        // 没配置白名单：公网地址允许，内网、回环、链路本地、运营商 NAT、组播一律拒绝；域名要解析后逐个地址检查
+        BudgetGuard open = Guard();
+        foreach (string allowed in new[] { "1.1.1.1", "1.1.1.1:443", "2606:4700::1111", "example.com:443", "https://example.com/health", "::ffff:8.8.8.8" })
+        {
+            Assert.True(open.TargetAllowed(allowed), allowed);
+        }
 
-        BudgetGuard some = Guard(new NodeLimits { AllowedTargetCidrs = ["192.0.2.0/24", "2001:db8::/32"] });
-        Assert.True(some.TargetAllowed("192.0.2.17"));
+        foreach (string denied in new[] { "10.1.2.3", "172.16.0.1", "172.31.255.255", "192.168.1.1:80", "127.0.0.1", "169.254.169.254", "100.64.0.1", "224.0.0.1", "0.0.0.0", "::1", "fe80::1", "fd00::1", "::ffff:10.0.0.1", "http://192.168.1.1/" })
+        {
+            Assert.False(open.TargetAllowed(denied), denied);
+        }
+
+        Assert.False(open.TargetAllowed(null));
+        Assert.True(open.AddressAllowed(IPAddress.Parse("172.32.0.1"))); // 172.16/12 的外面是公网
+
+        // 配置了白名单：只允许列出的网段，可以包含内网，其余（包括公网）都不允许
+        BudgetGuard some = Guard(new NodeLimits { AllowedTargetCidrs = ["192.0.2.0/24", "2001:db8::/32", "10.0.0.0/8"] });
         Assert.True(some.TargetAllowed("192.0.2.17:443"));
         Assert.True(some.TargetAllowed("2001:db8::1"));
+        Assert.True(some.TargetAllowed("10.9.9.9"));
+        Assert.False(some.TargetAllowed("1.1.1.1"));
         Assert.False(some.TargetAllowed("192.0.3.1"));
-        Assert.False(some.TargetAllowed("example.com"));
-        Assert.False(some.TargetAllowed(null));
+        Assert.True(some.TargetAllowed("example.com"));
+        Assert.True(some.AddressAllowed(IPAddress.Parse("192.0.2.9")));
+        Assert.False(some.AddressAllowed(IPAddress.Parse("8.8.8.8")));
+        Assert.False(some.AddressAllowed(IPAddress.Parse("::ffff:8.8.8.8")));
+
+        // 写了但一条也解析不出来：当成「什么都不允许」，不退回到默认
+        Assert.False(Guard(new NodeLimits { AllowedTargetCidrs = ["not-a-network"] }).AddressAllowed(IPAddress.Parse("1.1.1.1")));
     }
 
     // ---- RowStore ----
@@ -63,9 +84,9 @@ public sealed class MeasurementTests
     [Fact]
     public void RowStore_RecordsOnlyItsOwnSidesColumns_AndCutsExistingRowsInKeyOrder()
     {
-        StreamSpec msg = Kinds.UdpEcho.FindStream("msg")!;
+        StreamSpec msg = Kinds.QuicPing.FindStream("msg")!;
         var dialer = new RowStore(msg, Side.Dialer, 64);
-        Assert.Equal(["size", "t1", "t4"], msg.ColumnsOf(Side.Dialer).Select(c => c.Name));
+        Assert.Equal(["size", "w", "t1", "t4"], msg.ColumnsOf(Side.Dialer).Select(c => c.Name));
         Assert.Equal(["t2", "t3"], msg.ColumnsOf(Side.Listener).Select(c => c.Name));
 
         for (int i = 0; i < 4; i++)
@@ -78,7 +99,7 @@ public sealed class MeasurementTests
         dialer.Set(2, dialer.ColumnIndex("t4"), 5000);
         RawStream cut = dialer.Cut(1, 4, includeKey: true);
         Assert.Equal(3, cut.Count);
-        Assert.Equal(["seq", "size", "t1", "t4"], cut.Columns.Select(c => c.Name));
+        Assert.Equal(["seq", "size", "w", "t1", "t4"], cut.Columns.Select(c => c.Name));
         Assert.Equal([1L, 2L, 3L], cut.Find("seq")!.Values);
         Assert.Equal([false, true, false], cut.Find("t4")!.Valid!);
 
@@ -88,7 +109,7 @@ public sealed class MeasurementTests
     [Fact]
     public void RowStore_RingOverwritesOldRows_AndNeverReturnsAStaleOne()
     {
-        var store = new RowStore(Kinds.UdpEcho.FindStream("msg")!, Side.Listener, 16);
+        var store = new RowStore(Kinds.QuicPing.FindStream("msg")!, Side.Listener, 16);
         store.SetRow(3, [30, 31]);
         Assert.True(store.TryGet(3, 0, out long t2));
         Assert.Equal(30, t2);
@@ -111,27 +132,27 @@ public sealed class MeasurementTests
 
     private static RawChunk EchoFragment(params (uint Seq, long T1, long? T4)[] rows)
     {
-        var msg = new StreamBuilder(new StreamSpec("msg", [Col.Seq("seq"), Col.U16("size"), Col.TsDialer("t1"), Col.TsDialer("t4", nullable: true)]));
+        var msg = new StreamBuilder(new StreamSpec("msg", [Col.Seq("seq"), Col.U16("size"), Col.U16("w"), Col.TsDialer("t1"), Col.TsDialer("t4", nullable: true)]));
         foreach ((uint seq, long t1, long? t4) in rows)
         {
-            msg.Add(seq, 64, t1, t4);
+            msg.Add(seq, 64, 1, t1, t4);
         }
 
-        return new RawChunk(new RawChunkHeader { Kind = "udp_echo", Clock = new ChunkClock { DialerOffsetUs = 1000 } }, [msg.Build()]);
+        return new RawChunk(new RawChunkHeader { Kind = "quic_ping", Clock = new ChunkClock { DialerOffsetUs = 1000 } }, [msg.Build()]);
     }
 
     [Fact]
     public void FragmentMerger_DialerDriven_AddsTheAgentColumnsByKey_AndLeavesMissingRowsEmpty()
     {
-        var agent = new RowStore(Kinds.UdpEcho.FindStream("msg")!, Side.Listener, 64);
+        var agent = new RowStore(Kinds.QuicPing.FindStream("msg")!, Side.Listener, 64);
         agent.SetRow(0, [2000, 2050]);
         agent.SetRow(2, [4000, 4040]);
         var source = new Source { Stores = { ["msg"] = agent } };
         RawChunk fragment = EchoFragment((0, 1000, 3000), (1, 2000, null), (2, 3000, 5000));
 
-        Result<IReadOnlyList<RawStream>> merged = FragmentMerger.Merge(Kinds.UdpEcho, fragment, 1, source);
+        Result<IReadOnlyList<RawStream>> merged = FragmentMerger.Merge(Kinds.QuicPing, fragment, 1, source);
         RawStream msg = Assert.Single(merged.Value);
-        Assert.Equal(["seq", "size", "t1", "t2", "t3", "t4"], msg.Columns.Select(c => c.Name));
+        Assert.Equal(["seq", "size", "w", "t1", "t2", "t3", "t4"], msg.Columns.Select(c => c.Name));
         Assert.Equal([true, false, true], Enumerable.Range(0, 3).Select(i => msg.Find("t2")!.IsValid(i)));
         Assert.Equal(2050, msg.Find("t3")!.Values[0]);
         Assert.False(msg.Find("t4")!.IsValid(1));
@@ -141,7 +162,7 @@ public sealed class MeasurementTests
     public void FragmentMerger_DialerDriven_WithoutAnyAgentRecords_KeepsTheDialerRows()
     {
         RawChunk fragment = EchoFragment((0, 1000, 3000), (1, 2000, null));
-        RawStream msg = Assert.Single(FragmentMerger.Merge(Kinds.UdpEcho, fragment, 1, new Source()).Value);
+        RawStream msg = Assert.Single(FragmentMerger.Merge(Kinds.QuicPing, fragment, 1, new Source()).Value);
         Assert.Equal(2, msg.Count);
         Assert.False(msg.Find("t2")!.IsValid(0));
         Assert.Equal(3000, msg.Find("t4")!.Values[0]);
@@ -152,14 +173,14 @@ public sealed class MeasurementTests
     {
         var bad = new StreamBuilder(new StreamSpec("msg", [Col.Seq("seq")]));
         bad.Add(0);
-        var fragment = new RawChunk(new RawChunkHeader { Kind = "udp_echo" }, [bad.Build()]);
-        Assert.False(FragmentMerger.Merge(Kinds.UdpEcho, fragment, 1, new Source()).IsSuccess);
+        var fragment = new RawChunk(new RawChunkHeader { Kind = "quic_ping" }, [bad.Build()]);
+        Assert.False(FragmentMerger.Merge(Kinds.QuicPing, fragment, 1, new Source()).IsSuccess);
     }
 
     [Fact]
     public void FragmentMerger_AgentDriven_TakesRowsFromTheAgent_AndMarksUnreceivedPacketsAsLost()
     {
-        var agent = new RowStore(Kinds.UdpTrain.FindStream("pkt")!, Side.Listener, 64);
+        var agent = new RowStore(Kinds.QuicStream.FindStream("pkt")!, Side.Listener, 64);
         for (uint seq = 0; seq < 5; seq++)
         {
             agent.SetRow(seq, [1000, 100 + seq]);
@@ -167,12 +188,12 @@ public sealed class MeasurementTests
 
         var pkt = new StreamBuilder(new StreamSpec("pkt", [Col.Seq("seq"), Col.TsDialer("t_recv")]));
         pkt.Add(1, 5000).Add(1, 9999).Add(3, 6000); // sequence 1 arrives twice (the first one counts); 0, 2 and 4 are lost
-        var header = new RawChunkHeader { Kind = "udp_train" };
+        var header = new RawChunkHeader { Kind = "quic_stream" };
         header.Params[FragmentKeys.SeqFrom] = Json("0");
         header.Params[FragmentKeys.SeqTo] = Json("5");
         var source = new Source { Stores = { ["pkt"] = agent } };
 
-        RawStream merged = Assert.Single(FragmentMerger.Merge(Kinds.UdpTrain, new RawChunk(header, [pkt.Build()]), 1, source).Value);
+        RawStream merged = Assert.Single(FragmentMerger.Merge(Kinds.QuicStream, new RawChunk(header, [pkt.Build()]), 1, source).Value);
         Assert.Equal(5, merged.Count);
         Assert.Equal(["seq", "size", "t_send", "t_recv"], merged.Columns.Select(c => c.Name));
         RawColumn recv = merged.Find("t_recv")!;
@@ -181,7 +202,7 @@ public sealed class MeasurementTests
         Assert.Equal(103, merged.Find("t_send")!.Values[3]);
 
         // A one-way fragment that does not declare its sequence range is invalid
-        Assert.False(FragmentMerger.Merge(Kinds.UdpTrain, new RawChunk(new RawChunkHeader { Kind = "udp_train" }, [pkt.Build()]), 1, source).IsSuccess);
+        Assert.False(FragmentMerger.Merge(Kinds.QuicStream, new RawChunk(new RawChunkHeader { Kind = "quic_stream" }, [pkt.Build()]), 1, source).IsSuccess);
     }
 
     [Fact]
@@ -189,9 +210,9 @@ public sealed class MeasurementTests
     {
         var conn = new StreamBuilder(new StreamSpec("conn", [Col.U8("outcome"), Col.Seq("attempt"), Col.TsDialer("ts")]));
         conn.Add(0, 0, 100);
-        var fragment = new RawChunk(new RawChunkHeader { Kind = "connect" }, [conn.Build()]);
+        var fragment = new RawChunk(new RawChunkHeader { Kind = "tcp_connect" }, [conn.Build()]);
 
-        RawStream merged = Assert.Single(FragmentMerger.Merge(Kinds.Connect, fragment, 1, new Source()).Value);
+        RawStream merged = Assert.Single(FragmentMerger.Merge(Kinds.TcpConnect, fragment, 1, new Source()).Value);
         Assert.Equal(["attempt", "ts", "tcp_us", "tls_us", "outcome"], merged.Columns.Select(c => c.Name));
         Assert.False(merged.Find("tcp_us")!.IsValid(0));
     }
@@ -212,7 +233,7 @@ public sealed class MeasurementTests
     [Fact]
     public void FragmentMerger_UnionStreams_ConcatenateBothSidesRows_AndEachAgentRowIsDeliveredOnce()
     {
-        StreamSpec info = Kinds.TcpEcho.FindStream("tcp_info")!;
+        StreamSpec info = Kinds.TcpPing.FindStream("tcp_info")!;
         Assert.Equal(info.Columns.Count, info.ColumnsOf(Side.Listener).Count); // each side owns every column
         var agent = new RowStore(info, Side.Listener, 64);
         var recorder = new Source { Stores = { ["tcp_info"] = agent } };
@@ -222,7 +243,7 @@ public sealed class MeasurementTests
         var msg = EchoFragment((0, 1000, 3000));
         var fragment = new RawChunk(msg.Header, [msg.Streams[0], InfoRows(info, (100, 0, 1))]);
 
-        IReadOnlyList<RawStream> first = FragmentMerger.Merge(Kinds.TcpEcho, fragment, 1, recorder).Value;
+        IReadOnlyList<RawStream> first = FragmentMerger.Merge(Kinds.TcpPing, fragment, 1, recorder).Value;
         RawStream merged = first.Single(x => x.Name == "tcp_info");
         Assert.Equal(3, merged.Count);
         Assert.Equal([0L, 1L, 1L], merged.Find("side")!.Values);
@@ -231,20 +252,20 @@ public sealed class MeasurementTests
         Assert.Equal(1, merged.Find("conn")!.Values[1]);
 
         // The agent's rows were consumed: the next chunk carries only the dialer's own rows
-        IReadOnlyList<RawStream> second = FragmentMerger.Merge(Kinds.TcpEcho, fragment, 1, recorder).Value;
+        IReadOnlyList<RawStream> second = FragmentMerger.Merge(Kinds.TcpPing, fragment, 1, recorder).Value;
         Assert.Equal(1, second.Single(x => x.Name == "tcp_info").Count);
     }
 
     [Fact]
     public void FragmentMerger_UnionStreams_AgentRowsAreDeliveredEvenWhenTheDialerHasNone()
     {
-        StreamSpec info = Kinds.TcpEcho.FindStream("tcp_info")!;
+        StreamSpec info = Kinds.TcpPing.FindStream("tcp_info")!;
         var agent = new RowStore(info, Side.Listener, 64);
         agent.SetRow(agent.Append(), [500, 1, 40_000, 5_000, 10, 7, 100, 1_000, 1]);
 
         // A dialer on a platform without kernel sampling sends the echo rows only
         RawChunk fragment = EchoFragment((0, 1000, 3000));
-        IReadOnlyList<RawStream> merged = FragmentMerger.Merge(Kinds.TcpEcho, fragment, 1, new Source { Stores = { ["tcp_info"] = agent } }).Value;
+        IReadOnlyList<RawStream> merged = FragmentMerger.Merge(Kinds.TcpPing, fragment, 1, new Source { Stores = { ["tcp_info"] = agent } }).Value;
         RawStream rows = merged.Single(x => x.Name == "tcp_info");
         Assert.Equal(1, rows.Count);
         Assert.Equal(7, rows.Find("retrans_total")!.Values[0]);
@@ -253,11 +274,11 @@ public sealed class MeasurementTests
     [Fact]
     public void FragmentMerger_LegacyTcpSamples_KeepConnectionIdentityUnknown()
     {
-        StreamSpec info = Kinds.TcpEcho.FindStream("tcp_info")!;
+        StreamSpec info = Kinds.TcpPing.FindStream("tcp_info")!;
         RawStream sample = InfoRows(info, (100, 0, 1));
         var legacy = new RawStream(sample.Name, sample.Count, sample.Columns.Where(c => c.Name != "conn").ToArray());
-        var fragment = new RawChunk(new RawChunkHeader { Kind = "tcp_echo" }, [legacy]);
-        RawStream merged = Assert.Single(FragmentMerger.Merge(Kinds.TcpEcho, fragment, 1, new Source()).Value);
+        var fragment = new RawChunk(new RawChunkHeader { Kind = "tcp_ping" }, [legacy]);
+        RawStream merged = Assert.Single(FragmentMerger.Merge(Kinds.TcpPing, fragment, 1, new Source()).Value);
         Assert.False(merged.Find("conn")!.IsValid(0));
         Assert.Equal(1, merged.Find("retrans_total")!.Values[0]);
     }
@@ -282,7 +303,7 @@ public sealed class MeasurementTests
     [Fact]
     public void EchoRows_Tcp_WaitsForTheReplyInsteadOfCallingASeveralSecondStallALoss()
     {
-        var rows = new EchoRows(Kinds.TcpEcho, 64, EchoRows.TcpGraceUs, settleOnReply: true);
+        var rows = new EchoRows(Kinds.TcpPing, 64, EchoRows.TcpGraceUs, settleOnReply: true);
         uint a = rows.Add(64, 0);
         uint b = rows.Add(64, 100_000);
         uint c = rows.Add(64, 200_000);
@@ -312,7 +333,7 @@ public sealed class MeasurementTests
     [Fact]
     public void EchoRows_Udp_GivesUpOnAMissingReplyAfterTwoSeconds()
     {
-        var rows = new EchoRows(Kinds.UdpEcho, 64, EchoRows.DatagramGraceUs, settleOnReply: false);
+        var rows = new EchoRows(Kinds.QuicPing, 64, EchoRows.DatagramGraceUs, settleOnReply: false);
         rows.Add(64, 0);
         rows.Add(64, 1_000_000);
         RawStream cut = rows.Take(2_500_000, all: false)!;
@@ -324,7 +345,7 @@ public sealed class MeasurementTests
     [Fact]
     public void EchoRows_DiscardedLocalSendIsNotReportedAsNetworkLoss()
     {
-        var rows = new EchoRows(Kinds.UdpEcho, 64, EchoRows.DatagramGraceUs, settleOnReply: false);
+        var rows = new EchoRows(Kinds.QuicPing, 64, EchoRows.DatagramGraceUs, settleOnReply: false);
         uint unsent = rows.Add(64, 0);
         Assert.True(rows.Discard(unsent));
 
@@ -369,7 +390,7 @@ public sealed class MeasurementTests
     public void BlockSpec_ConfigSignatureIgnoresTheStreamId_ButSignatureDoesNot()
     {
         BlockSpec Create(string json, uint stream = 1, int port = 7443) => BlockSpec.Create(
-            "udp_echo",
+            "quic_ping",
             JsonDocument.Parse(json).RootElement.EnumerateObject().ToDictionary(p => p.Name, p => p.Value.Clone()),
             stream,
             port,
@@ -381,7 +402,7 @@ public sealed class MeasurementTests
         Assert.NotEqual(baseline.Signature, Create("""{"rate_hz":10,"size":64}""", stream: 2).Signature);
         Assert.Equal(baseline.ConfigSignature, Create("""{"rate_hz":10,"size":64}""", stream: 2).ConfigSignature);
         Assert.NotEqual(baseline.ConfigSignature, Create("""{"rate_hz":10,"size":64}""", port: 9000).ConfigSignature);
-        Assert.Null(BlockSpec.Create("udp_echo", new Dictionary<string, JsonElement> { ["rate_hz"] = Json("100000") }, 1, 7443, new FragmentScope(null, null, null)));
+        Assert.Null(BlockSpec.Create("quic_ping", new Dictionary<string, JsonElement> { ["rate_hz"] = Json("100000") }, 1, 7443, new FragmentScope(null, null, null)));
     }
 
     // ---- 起止时间 ----
@@ -389,13 +410,13 @@ public sealed class MeasurementTests
     [Fact]
     public void ChunkFinalizer_TakesStartAndDurationFromTheDataTimestamps_NotFromTheDeliveryTime()
     {
-        var agent = new RowStore(Kinds.UdpEcho.FindStream("msg")!, Side.Listener, 64);
+        var agent = new RowStore(Kinds.QuicPing.FindStream("msg")!, Side.Listener, 64);
         agent.SetRow(0, [2000, 2050]);
         RawChunk fragment = EchoFragment((0, 1000, 3000));
-        IReadOnlyList<RawStream> streams = FragmentMerger.Merge(Kinds.UdpEcho, fragment, 1, new Source { Stores = { ["msg"] = agent } }).Value;
+        IReadOnlyList<RawStream> streams = FragmentMerger.Merge(Kinds.QuicPing, fragment, 1, new Source { Stores = { ["msg"] = agent } }).Value;
 
         var anchor = new ClockAnchor(ListenerMonoUs: 1_000_000, UtcMs: 1_700_000_000_000);
-        RawChunk chunk = ChunkFinalizer.Finalize(Kinds.UdpEcho, fragment, streams, new NodeId("agt_x"), anchor, new Dictionary<string, JsonElement> { ["port"] = Json("7443") }, 7443, new ChunkId(Guid.NewGuid()));
+        RawChunk chunk = ChunkFinalizer.Finalize(Kinds.QuicPing, fragment, streams, new NodeId("agt_x"), anchor, new Dictionary<string, JsonElement> { ["port"] = Json("7443") }, 7443, new ChunkId(Guid.NewGuid()));
 
         // t1 = 1000 us (拨号方 clock) + offset 1000 = 2000 us on the Agent clock, which is 998 ms before the anchor
         Assert.Equal(1_700_000_000_000 - 998, chunk.Header.StartUtcMs);

backend/shared/tests/MoShiro.Measurement.Tests/QuicSettingsTests.cs

@@ -0,0 +1,57 @@
+using System.Net;
+using System.Security.Cryptography;
+using System.Security.Cryptography.X509Certificates;
+using Fleet.Core;
+
+namespace MoShiro.Measurement.Tests;
+
+public sealed class QuicSettingsTests
+{
+    [Theory]
+    [InlineData(1100, null, false)]
+    [InlineData(null, 70_000, false)]
+    [InlineData(1400, 1300, false)]
+    [InlineData(1280, 1500, true)]
+    [InlineData(null, null, true)]
+    public void Validate_RejectsMtuOutsideTheSupportedRangeOrOutOfOrder(int? min, int? max, bool valid) =>
+        Assert.Equal(valid, new QuicSettings { MinMtu = min, MaxMtu = max }.Validate() is null);
+
+    /// <summary>设置真的写进了 MsQuic：最大 MTU 压低后数据报上限随之变小，最小 MTU 抬高后一连上就是大包（不用等路径探测）。</summary>
+    [Theory]
+    [InlineData(1200, 1280, 1200, 1280)]
+    [InlineData(1500, 1500, 1400, 1500)]
+    public async Task Settings_ChangeTheDatagramLimitOfTheConnection(int min, int max, int atLeast, int atMost)
+    {
+        var settings = new QuicSettings { MinMtu = min, MaxMtu = max };
+        var log = new NullLog();
+        using ECDsa key = ECDsa.Create(ECCurve.NamedCurves.nistP256);
+        var request = new CertificateRequest("CN=localhost", key, HashAlgorithmName.SHA256);
+        using X509Certificate2 certificate = request.CreateSelfSigned(DateTimeOffset.UnixEpoch, DateTimeOffset.UnixEpoch.AddYears(100));
+        await using var listener = new MsQuicListener(IPAddress.Loopback, [0], certificate, (_, _) => { }, log, null, settings);
+        listener.Start();
+        using var timeout = new CancellationTokenSource(TimeSpan.FromSeconds(15));
+        MsQuicConnection client = await MsQuicConnection.ConnectAsync(IPAddress.Loopback, listener.BoundPorts[0], 0, key.ExportSubjectPublicKeyInfo(), (_, _) => { }, log, timeout.Token, settings);
+        try
+        {
+            while (!client.IsReady)
+            {
+                await Task.Delay(10, timeout.Token);
+            }
+
+            // 路径 MTU 探测还可能在往上走，给它一点时间；上限始终不能超过设置的最大 MTU
+            await Task.Delay(1500, timeout.Token);
+            Assert.InRange(client.MaxDatagramBytes, atLeast - 100, atMost);
+        }
+        finally
+        {
+            await client.DisposeAsync().AsTask().WaitAsync(TimeSpan.FromSeconds(3));
+        }
+    }
+
+    private sealed class NullLog : INodeLog
+    {
+        public void Write(NodeLogLevel level, string message, params (string Key, object? Value)[] fields)
+        {
+        }
+    }
+}

backend/shared/tests/MoShiro.Protocol.Tests/CatalogTests.cs

@@ -35,7 +35,7 @@ public sealed class CatalogTests
     public void DefaultLineTemplates_StayWithinTheLineBudget()
     {
         long total = 0;
-        foreach (KindSpec kind in new[] { Kinds.UdpEcho, Kinds.TcpEcho })
+        foreach (KindSpec kind in new[] { Kinds.QuicPing, Kinds.TcpPing })
         {
             total += kind.BudgetBitsPerSecond(ParamResolver.Resolve(kind.Params, null).Values!);
         }
@@ -52,7 +52,7 @@ public sealed class CatalogTests
             ["size"] = Json("\"big\""),
             ["bogus"] = Json("1"),
         };
-        ParamResolution result = ParamResolver.Resolve(Kinds.UdpEcho.Params, input);
+        ParamResolution result = ParamResolver.Resolve(Kinds.QuicPing.Params, input);
 
         Assert.False(result.IsValid);
         Assert.Contains("between 1 and 200", result.Errors["rate_hz"]);
@@ -64,13 +64,13 @@ public sealed class CatalogTests
     [Fact]
     public void Resolve_AcceptsBoundariesAndRejectsJustOutside()
     {
-        Assert.True(ParamResolver.Resolve(Kinds.UdpEcho.Params, new Dictionary<string, JsonElement> { ["rate_hz"] = Json("1") }).IsValid);
-        Assert.True(ParamResolver.Resolve(Kinds.UdpEcho.Params, new Dictionary<string, JsonElement> { ["rate_hz"] = Json("200") }).IsValid);
-        Assert.False(ParamResolver.Resolve(Kinds.UdpEcho.Params, new Dictionary<string, JsonElement> { ["rate_hz"] = Json("0") }).IsValid);
-        Assert.False(ParamResolver.Resolve(Kinds.UdpEcho.Params, new Dictionary<string, JsonElement> { ["rate_hz"] = Json("201") }).IsValid);
-        Assert.False(ParamResolver.Resolve(Kinds.UdpEcho.Params, new Dictionary<string, JsonElement> { ["rate_hz"] = Json("1.5") }).IsValid);
-        Assert.False(ParamResolver.Resolve(Kinds.UdpTrain.Params, new Dictionary<string, JsonElement> { ["direction"] = Json("\"sideways\"") }).IsValid);
-        Assert.False(ParamResolver.Resolve(Kinds.TcpEcho.Params, new Dictionary<string, JsonElement> { ["tls"] = Json("1") }).IsValid);
+        Assert.True(ParamResolver.Resolve(Kinds.QuicPing.Params, new Dictionary<string, JsonElement> { ["rate_hz"] = Json("1") }).IsValid);
+        Assert.True(ParamResolver.Resolve(Kinds.QuicPing.Params, new Dictionary<string, JsonElement> { ["rate_hz"] = Json("200") }).IsValid);
+        Assert.False(ParamResolver.Resolve(Kinds.QuicPing.Params, new Dictionary<string, JsonElement> { ["rate_hz"] = Json("0") }).IsValid);
+        Assert.False(ParamResolver.Resolve(Kinds.QuicPing.Params, new Dictionary<string, JsonElement> { ["rate_hz"] = Json("201") }).IsValid);
+        Assert.False(ParamResolver.Resolve(Kinds.QuicPing.Params, new Dictionary<string, JsonElement> { ["rate_hz"] = Json("1.5") }).IsValid);
+        Assert.False(ParamResolver.Resolve(Kinds.QuicStream.Params, new Dictionary<string, JsonElement> { ["direction"] = Json("\"sideways\"") }).IsValid);
+        Assert.False(ParamResolver.Resolve(Kinds.TcpPing.Params, new Dictionary<string, JsonElement> { ["tls"] = Json("1") }).IsValid);
     }
 
     [Fact]
@@ -98,7 +98,7 @@ public sealed class CatalogTests
         var set = new TaskSet
         {
             Version = 7,
-            Tasks = [new TaskSpec { Id = new TaskId("tsk_1"), Kind = "udp_echo", Params = new Dictionary<string, JsonElement> { ["rate_hz"] = Json("10") } }],
+            Tasks = [new TaskSpec { Id = new TaskId("tsk_1"), Kind = "quic_ping", Params = new Dictionary<string, JsonElement> { ["rate_hz"] = Json("10") } }],
             Peers = [new PeerSpec { NodeId = new Fleet.Core.NodeId("agt_1"), PublicKey = "AAAA" }],
         };
         string text = JsonSerializer.Serialize(set, MoShiroJsonContext.Default.TaskSet);
@@ -114,9 +114,9 @@ public sealed class CatalogTests
     [Fact]
     public void NodeEnrollMeta_ToleratesUnknownFields_AndKeepsDefaults()
     {
-        NodeEnrollMeta meta = JsonSerializer.Deserialize("{\"kinds\":[\"udp_echo\"],\"future\":1}", MoShiroJsonContext.Default.NodeEnrollMeta)!;
+        NodeEnrollMeta meta = JsonSerializer.Deserialize("{\"kinds\":[\"quic_ping\"],\"future\":1}", MoShiroJsonContext.Default.NodeEnrollMeta)!;
         Assert.Equal(0, meta.TcpPort); // 没有端口表示这个节点不监听
-        Assert.Equal(["udp_echo"], meta.Kinds);
+        Assert.Equal(["quic_ping"], meta.Kinds);
     }
 
     [Fact]

backend/shared/tests/MoShiro.Protocol.Tests/RawChunkCodecTests.cs

@@ -28,7 +28,7 @@ public sealed class RawChunkCodecTests
     private static RawChunk SampleChunk()
     {
         RawChunk chunk = ChunkFactory.Echo(
-            s_agent, "udp_echo", 1_700_000_000_000, 6, 100,
+            s_agent, "quic_ping", 1_700_000_000_000, 6, 100,
             i => new EchoPacket(LostUp: i == 2, LostDown: i == 4, 20_000 + (i * 100), 21_000));
         chunk.Header.ChunkId = new ChunkId(Guid.Parse("01890000-0000-7000-8000-000000000001"));
         return chunk;
@@ -41,7 +41,7 @@ public sealed class RawChunkCodecTests
         RawChunk decoded = RawChunkCodec.Decode(RawChunkCodec.Encode(original)).Value;
 
         Assert.Equal(original.Header.ChunkId, decoded.Header.ChunkId);
-        Assert.Equal("udp_echo", decoded.Header.Kind);
+        Assert.Equal("quic_ping", decoded.Header.Kind);
         Assert.Equal(original.Header.Clock.DialerOffsetUs, decoded.Header.Clock.DialerOffsetUs);
         RawStream before = original.Find("msg")!;
         RawStream after = decoded.Find("msg")!;
@@ -92,6 +92,7 @@ public sealed class RawChunkCodecTests
     public void GoldenBody_LayoutIsStable()
     {
         // 布局变化（列编码、头部字段、字节序）会让这个测试失败：必须同时升级 container_version 并更新黄金字节。
+        // 只是回显流多了一列权重 w（块头自描述新增列，不用升级 container_version），黄金字节里多出六个 01。
         RawChunk chunk = SampleChunk();
         chunk.Header.Clock = new ChunkClock { ListenerMonoUs = 1000, UtcMs = 1_700_000_000_000, DialerOffsetUs = 500 };
         byte[] body = RawChunkCodec.EncodeBody(chunk);
@@ -99,12 +100,12 @@ public sealed class RawChunkCodecTests
         string columns = Convert.ToHexStringLower(body.AsSpan(4 + (int)headerLength));
         string header = System.Text.Encoding.UTF8.GetString(body.AsSpan(4, (int)headerLength));
 
-        Assert.StartsWith("{\"chunk_id\":\"01890000-0000-7000-8000-000000000001\",\"container_version\":1,\"kind\":\"udp_echo\"", header);
+        Assert.StartsWith("{\"chunk_id\":\"01890000-0000-7000-8000-000000000001\",\"container_version\":1,\"kind\":\"quic_ping\"", header);
         Assert.Contains("\"streams\":[{\"name\":\"msg\",\"count\":6,\"columns\":[{\"name\":\"seq\",\"type\":\"u32\",\"enc\":\"delta\",\"nullable\":false},", header);
         Assert.Equal(GoldenColumns, columns);
     }
 
-    private const string GoldenColumns = "00020202020240404040404080fbf3b407c09a0cc09a0cc09a0cc09a0cc09a0c3bc0e0d8b907889c0c90b818889c0c889c0c3ba4e1d8b907889c0c90b818889c0c889c0c2bb4fcf8b407889c0c90b81890b818";
+    private const string GoldenColumns = "00020202020240404040404001010101010180fbf3b407c09a0cc09a0cc09a0cc09a0cc09a0c3bc0e0d8b907889c0c90b818889c0c889c0c3ba4e1d8b907889c0c90b818889c0c889c0c2bb4fcf8b407889c0c90b81890b818";
 
     [Fact]
     public void Decode_RejectsBadMagicVersionCrcAndTruncation()
@@ -180,7 +181,7 @@ public sealed class RawChunkCodecTests
     [Fact]
     public void Encode_IsSmallerThanTheNaiveRepresentation()
     {
-        // 10 Hz 的 udp_echo 一个 10 秒块应当远小于每行 6×8 字节
+        // 10 Hz 的 quic_ping 一个 10 秒块应当远小于每行 6×8 字节
         RawChunk chunk = ChunkFactory.UdpEchoClean(s_agent, 1_700_000_000_000);
         Assert.True(RawChunkCodec.Encode(chunk).Length < 100 * 6 * 8 / 4);
     }

backend/shared/tests/MoShiro.Protocol.Tests/TargetHostTests.cs

@@ -0,0 +1,28 @@
+using MoShiro.Protocol;
+
+namespace MoShiro.Protocol.Tests;
+
+public sealed class TargetHostTests
+{
+    [Theory]
+    [InlineData("http_request", "https://Example.com/health?x=1", "https://example.com/health?x=1")]
+    [InlineData("http_request", "http://192.0.2.1:8080", "http://192.0.2.1:8080/")]
+    [InlineData("tcp_connect", "Example.com:443", "example.com:443")]
+    [InlineData("tcp_connect", "192.0.2.1", "192.0.2.1")]
+    [InlineData("tcp_connect", "[2001:db8::1]:443", "[2001:db8::1]:443")]
+    [InlineData("icmp_ping", "2001:db8::1", "2001:db8::1")]
+    public void Normalize_AcceptsTheTargetFormOfTheKind(string kind, string target, string expected) =>
+        Assert.Equal(expected, TargetHost.Normalize(kind, target));
+
+    [Theory]
+    [InlineData("http_request", "example.com")]            // http 必须是 URL
+    [InlineData("http_request", "ftp://example.com/")]
+    [InlineData("http_request", "https://user:pw@example.com/")]
+    [InlineData("tcp_connect", "https://example.com/")]    // 其余 Kind 不能是 URL
+    [InlineData("tcp_connect", "example.com:0")]
+    [InlineData("tcp_connect", "exa mple.com")]
+    [InlineData("tcp_connect", "-bad.example.com")]
+    [InlineData("tcp_connect", "")]
+    public void Normalize_RejectsTheWrongFormForTheKind(string kind, string target) =>
+        Assert.Null(TargetHost.Normalize(kind, target));
+}

backend/src/MoShiro.Backend.Analysis/Engine/ChunkView.cs

@@ -33,5 +33,8 @@ public sealed class ChunkView
     public double ParamNumber(string name, double fallback) =>
         Header.Params.TryGetValue(name, out JsonElement v) && v.ValueKind == JsonValueKind.Number && v.TryGetDouble(out double d) ? d : fallback;
 
+    public bool ParamBool(string name, bool fallback) =>
+        Header.Params.TryGetValue(name, out JsonElement v) && v.ValueKind is JsonValueKind.True or JsonValueKind.False ? v.GetBoolean() : fallback;
+
     private static long FloorDiv(long a, long b) => (a / b) - ((a % b != 0 && (a < 0) != (b < 0)) ? 1 : 0);
 }

backend/src/MoShiro.Backend.Analysis/Engine/TestEvaluator.cs

@@ -31,7 +31,7 @@ public sealed class TestResult
 
 /// <summary>
 /// 测试结果的计算：所有阶段的块到达之后，按方案算出指标和曲线。
-/// udp_train 的各个阶段作为码率阶梯：可持续码率、有效吞吐、限速开始的位置。
+/// quic_stream 的各个阶段作为码率阶梯：可持续码率、有效吞吐、限速开始的位置。
 /// </summary>
 public static class TestEvaluator
 {
@@ -43,7 +43,7 @@ public static class TestEvaluator
     {
         var result = new TestResult();
         EvaluateMetrics(chunks, result);
-        if (chunks.Any(c => c.Header.Kind == Kinds.UdpTrain.Id))
+        if (chunks.Any(c => c.Header.Kind == Kinds.QuicStream.Id))
         {
             EvaluateLadder(chunks, result);
         }
@@ -95,7 +95,7 @@ public static class TestEvaluator
 
         // 一个阶段（一档码率）可能被切成好几个块（一个块最多 50000 条记录，100 Mbit/s 的 10 秒要切 3～4 块）：
         // 阶梯里的一步是一个阶段，不是一个块——同一阶段的块先合并，再算丢包、抖动和实际吞吐。
-        foreach (IGrouping<int, RawChunk> phase in chunks.Where(c => c.Header.Kind == Kinds.UdpTrain.Id).GroupBy(c => c.Header.Phase ?? 0).OrderBy(g => g.Key))
+        foreach (IGrouping<int, RawChunk> phase in chunks.Where(c => c.Header.Kind == Kinds.QuicStream.Id).GroupBy(c => c.Header.Phase ?? 0).OrderBy(g => g.Key))
         {
             RawChunk[] parts = [.. phase.Where(c => c.Find("pkt") is not null).OrderBy(c => c.Header.StartUtcMs)];
             if (parts.Length == 0)

backend/src/MoShiro.Backend.Analysis/Metrics/HttpMetrics.cs

@@ -0,0 +1,48 @@
+namespace MoShiro.Backend.Analysis;
+
+/// <summary>http 任务（单个 Agent 请求一个 URL）的指标。耗时只统计成功的请求。</summary>
+public static class HttpMetrics
+{
+    private static readonly string[] s_req = ["http_request.req"];
+
+    public static readonly MetricDef Success = new(
+        "http.success", AccKind.Ratio, s_req, Ops.HttpSuccess, "HTTP success", "Share of requests that got an answer with an accepted status.", Better.Higher,
+        [new MetricExport("http.success", Stat.Pct, Unit.Pct, 99, 90)]);
+
+    public static readonly MetricDef Dns = Metric.Histogram(
+        "http.dns_ms", s_req, Ops.HttpPhaseMs("dns_us"), "DNS time", "Time to resolve the target host name.", Unit.Ms, [Stat.P95], good: 50, poor: 300);
+
+    public static readonly MetricDef Tcp = Metric.Histogram(
+        "http.tcp_ms", s_req, Ops.HttpPhaseMs("tcp_us"), "TCP connect time", "Time to establish the TCP connection (HTTP/1.1 and HTTP/2).", Unit.Ms, [Stat.P95], good: 100, poor: 400);
+
+    public static readonly MetricDef Ttfb = Metric.Histogram(
+        "http.ttfb_ms", s_req, Ops.HttpPhaseMs("ttfb_us"), "Time to first byte", "Time from starting the request until the response headers arrive, including connection setup.", Unit.Ms,
+        [Stat.P50, Stat.P95, Stat.P99], good: 300, poor: 1000);
+
+    public static readonly MetricDef Total = Metric.Histogram(
+        "http.total_ms", s_req, Ops.HttpPhaseMs("total_us"), "Total time", "Time until the response body was read.", Unit.Ms, [Stat.P50, Stat.P95, Stat.P99], good: 500, poor: 2000);
+
+    public static readonly MetricDef FailTimeout = Metric.Counter(
+        "http.fail.timeout", s_req, Ops.HttpOutcomeCount(HttpOutcome.Timeout), "HTTP timeouts", "Requests that timed out.", new MetricExport("http.fail.timeout", Stat.Count, Unit.Count));
+
+    public static readonly MetricDef FailDns = Metric.Counter(
+        "http.fail.dns", s_req, Ops.HttpOutcomeCount(HttpOutcome.Dns), "DNS failures", "Requests whose host name did not resolve.", new MetricExport("http.fail.dns", Stat.Count, Unit.Count));
+
+    public static readonly MetricDef FailReset = Metric.Counter(
+        "http.fail.rst", s_req, Ops.HttpOutcomeCount(HttpOutcome.Reset), "HTTP resets", "Requests answered with a reset or refused.", new MetricExport("http.fail.rst", Stat.Count, Unit.Count));
+
+    public static readonly MetricDef FailTls = Metric.Counter(
+        "http.fail.tls", s_req, Ops.HttpOutcomeCount(HttpOutcome.Tls), "TLS failures", "Requests that ended in a TLS error.", new MetricExport("http.fail.tls", Stat.Count, Unit.Count));
+
+    public static readonly MetricDef FailStatus = Metric.Counter(
+        "http.fail.status", s_req, Ops.HttpOutcomeCount(HttpOutcome.BadStatus), "Bad status", "Requests that got an answer with an unaccepted status.", new MetricExport("http.fail.status", Stat.Count, Unit.Count));
+
+    public static readonly MetricDef FailUnsupported = Metric.Counter(
+        "http.fail.unsupported", s_req, Ops.HttpOutcomeCount(HttpOutcome.Unsupported), "Unsupported version", "Requests that could not use the requested HTTP version (for HTTP/3: no QUIC library, or the server does not offer it).", new MetricExport("http.fail.unsupported", Stat.Count, Unit.Count));
+
+    public static readonly MetricDef FailOther = Metric.Counter(
+        "http.fail.other", s_req, Ops.HttpOutcomeCount(HttpOutcome.Other), "Other failures", "Requests that failed for a reason not listed separately.", new MetricExport("http.fail.other", Stat.Count, Unit.Count));
+
+    public static readonly MetricDef Samples = Metric.Counter(
+        "n.http", s_req, Ops.RowCount, "http samples", "Number of http requests.", new MetricExport("n.http", Stat.Count, Unit.Count), Better.None);
+}

backend/src/MoShiro.Backend.Analysis/Metrics/LinkMetrics.cs

@@ -1,10 +1,10 @@
 namespace MoShiro.Backend.Analysis;
 
-/// <summary>线路基础指标（udp_echo / icmp_echo 的回显流）。新增指标 = 加一行声明。</summary>
+/// <summary>线路基础指标（quic_ping / icmp_ping 的回显流）。新增指标 = 加一行声明。</summary>
 public static class LinkMetrics
 {
-    private static readonly string[] s_udpMsg = ["udp_echo.msg"];
-    private static readonly string[] s_udpOrIcmpMsg = ["udp_echo.msg", "icmp_echo.msg"];
+    private static readonly string[] s_udpMsg = ["quic_ping.msg"];
+    private static readonly string[] s_udpOrIcmpMsg = ["quic_ping.msg", "icmp_ping.msg"];
 
     public static readonly MetricDef Rtt = Metric.Histogram(
         "rtt", s_udpOrIcmpMsg, Ops.Rtt, "RTT", "Round-trip time with the Agent processing time removed.", Unit.Ms,
@@ -45,5 +45,5 @@ public static class LinkMetrics
         "dup", s_udpMsg, Ops.Dup, "Duplicates", "Replies received more than once.", new MetricExport("dup", Stat.Count, Unit.Count));
 
     public static readonly MetricDef SamplesUdp = Metric.Counter(
-        "n.udp_echo", s_udpMsg, Ops.RowCount, "udp_echo samples", "Number of udp_echo records.", new MetricExport("n.udp_echo", Stat.Count, Unit.Count), Better.None);
+        "n.quic_ping", s_udpMsg, Ops.RowCount, "quic_ping samples", "Number of quic_ping records.", new MetricExport("n.quic_ping", Stat.Count, Unit.Count), Better.None);
 }

backend/src/MoShiro.Backend.Analysis/Metrics/MetricRegistry.cs

@@ -15,6 +15,8 @@ public static class MetricRegistry
         TcpMetrics.Rtt, TcpMetrics.Slow, TcpMetrics.Stall, TcpMetrics.StallMax, TcpMetrics.Retrans, TcpMetrics.RetransUp, TcpMetrics.RetransDown, TcpMetrics.Srtt, TcpMetrics.BulkRate, TcpMetrics.BulkPeak, TcpMetrics.SamplesTcp,
         SessionMetrics.ConnectSuccess, SessionMetrics.ConnectTcp, SessionMetrics.ConnectTls,
         SessionMetrics.FailTimeout, SessionMetrics.FailReset, SessionMetrics.FailTls,
+        HttpMetrics.Success, HttpMetrics.Dns, HttpMetrics.Tcp, HttpMetrics.Ttfb, HttpMetrics.Total,
+        HttpMetrics.FailTimeout, HttpMetrics.FailDns, HttpMetrics.FailReset, HttpMetrics.FailTls, HttpMetrics.FailStatus, HttpMetrics.FailUnsupported, HttpMetrics.FailOther, HttpMetrics.Samples,
         SessionMetrics.HoldResets, SessionMetrics.HoldLifetime,
         SessionMetrics.TrainLoss, SessionMetrics.TrainJitter, SessionMetrics.TrainRate, SessionMetrics.SamplesConnect,
     ];
@@ -26,6 +28,7 @@ public static class MetricRegistry
         new("udp", "QUIC Datagram (legacy alias)", ["loss.up", "loss.down", "loss.total", "rtt.p50", "rtt.p95", "rtt.p99", "jitter.up.p95", "jitter.down.p95", "loss.run_max", "reorder", "dup"]),
         new("tcp", "TCP", ["tcp.rtt.p50", "tcp.rtt.p95", "tcp.rtt.p99", "tcp.rtt.p999", "tcp.rtt.max", "tcp.rtt.tail", "tcp.slow", "tcp.stall.per_min", "tcp.stall_max", "tcp.retrans", "tcp.retrans.up", "tcp.retrans.down", "tcp.srtt.p95"]),
         new("connect", "Connect", ["connect.success", "connect.tcp_ms.p95", "connect.tls_ms.p95", "connect.fail.timeout", "connect.fail.rst", "connect.fail.tls"]),
+        new("http", "HTTP", ["http.success", "http.dns_ms.p95", "http.tcp_ms.p95", "http.ttfb_ms.p50", "http.ttfb_ms.p95", "http.ttfb_ms.p99", "http.total_ms.p50", "http.total_ms.p95", "http.total_ms.p99", "http.fail.timeout", "http.fail.dns", "http.fail.rst", "http.fail.tls", "http.fail.status", "http.fail.unsupported", "http.fail.other"]),
         new("session", "Session", ["hold.resets.per_h", "hold.lifetime_max"]),
         new("scores", "Scores", ["score.base", "score.mc", "score.hy2", "score.reality"]),
     ];

backend/src/MoShiro.Backend.Analysis/Metrics/SessionMetrics.cs

@@ -1,11 +1,11 @@
 namespace MoShiro.Backend.Analysis;
 
-/// <summary>TCP 建连、长连接、QUIC Datagram 压测（legacy kind udp_train）的指标。</summary>
+/// <summary>TCP 建连、长连接、QUIC Datagram 压测（legacy kind quic_stream）的指标。</summary>
 public static class SessionMetrics
 {
-    private static readonly string[] s_conn = ["connect.conn"];
-    private static readonly string[] s_hold = ["hold.hold"];
-    private static readonly string[] s_train = ["udp_train.pkt"];
+    private static readonly string[] s_conn = ["tcp_connect.conn"];
+    private static readonly string[] s_hold = ["tls_hold.hold"];
+    private static readonly string[] s_train = ["quic_stream.pkt"];
 
     public static readonly MetricDef ConnectSuccess = new(
         "connect.success", AccKind.Ratio, s_conn, Ops.OutcomeRatio(ConnectOutcome.Ok), "Connect success", "Share of connection attempts that completed.", Better.Higher,

backend/src/MoShiro.Backend.Analysis/Metrics/TcpMetrics.cs

@@ -3,9 +3,9 @@ namespace MoShiro.Backend.Analysis;
 /// <summary>TCP 指标：回显的 RTT 与卡顿、内核采样的重传、批量传输的吞吐。</summary>
 public static class TcpMetrics
 {
-    private static readonly string[] s_tcpMsg = ["tcp_echo.msg"];
-    private static readonly string[] s_tcpInfo = ["tcp_echo.tcp_info", "tcp_bulk.tcp_info"];
-    private static readonly string[] s_bulkBytes = ["tcp_bulk.bytes"];
+    private static readonly string[] s_tcpMsg = ["tcp_ping.msg"];
+    private static readonly string[] s_tcpInfo = ["tcp_ping.tcp_info", "tcp_transfer.tcp_info"];
+    private static readonly string[] s_bulkBytes = ["tcp_transfer.bytes"];
 
     public static readonly MetricDef Rtt = Metric.Histogram(
         "tcp.rtt", s_tcpMsg, Ops.Rtt, "TCP RTT", "Application-level echo round trip over TCP (includes retransmission delay).", Unit.Ms,
@@ -47,5 +47,5 @@ public static class TcpMetrics
         [Stat.Max], Better.Higher);
 
     public static readonly MetricDef SamplesTcp = Metric.Counter(
-        "n.tcp_echo", s_tcpMsg, Ops.RowCount, "tcp_echo samples", "Number of tcp_echo records.", new MetricExport("n.tcp_echo", Stat.Count, Unit.Count), Better.None);
+        "n.tcp_ping", s_tcpMsg, Ops.RowCount, "tcp_ping samples", "Number of tcp_ping records.", new MetricExport("n.tcp_ping", Stat.Count, Unit.Count), Better.None);
 }

backend/src/MoShiro.Backend.Analysis/Models/Models.cs

@@ -32,7 +32,7 @@ public sealed class BaseModel : ServiceModelBase
 
 /// <summary>
 /// Minecraft：TCP 上不会丢包，丢包表现为重传和卡顿（队头阻塞）。
-/// 没有 tcp_echo 数据时，用 udp_echo 的丢包与 RTT 代入简化的 TCP 恢复模型估算，并标记为 estimated。
+/// 没有 tcp_ping 数据时，用 quic_ping 的丢包与 RTT 代入简化的 TCP 恢复模型估算，并标记为 estimated。
 /// </summary>
 public sealed class McModel : ServiceModelBase
 {
@@ -99,7 +99,7 @@ public sealed class McModel : ServiceModelBase
 
 /// <summary>
 /// Hysteria2（Brutal 固定码率）：有 hy2_ladder 测试结果时，用可持续码率、有效吞吐和限速开始的位置评分；
-/// 没有测试时，只能用持续的 udp_echo 趋势粗略估算，并标记为 estimated。
+/// 没有测试时，只能用持续的 quic_ping 趋势粗略估算，并标记为 estimated。
 /// </summary>
 public sealed class Hy2Model : ServiceModelBase
 {

backend/src/MoShiro.Backend.Analysis/Ops/EchoOps.cs

@@ -26,6 +26,7 @@ internal readonly struct EchoColumns
         T2 = stream.Find("t2");
         T3 = stream.Find("t3");
         T4 = stream.Find("t4");
+        W = stream.Find("w");
     }
 
     public int Count { get; }
@@ -40,6 +41,11 @@ internal readonly struct EchoColumns
 
     public RawColumn? T4 { get; }
 
+    /// <summary>每个包的权重（它代表多少个基础网格间隔）；旧数据和固定频率的任务没有这一列，按 1 算。</summary>
+    public RawColumn? W { get; }
+
+    public int Weight(int i) => W is null || !W.IsValid(i) ? 1 : (int)Math.Clamp(W.Values[i], 1, 65535);
+
     public bool HasBasics => T1 is not null && T4 is not null;
 
     /// <summary>行 i 的发送时刻（UTC 毫秒）。</summary>
@@ -75,7 +81,7 @@ internal readonly struct EchoColumns
 
 internal sealed class RttOp : MetricOp
 {
-    public override string Signature => "rtt/1";
+    public override string Signature => "rtt/2";
 
     public override void Evaluate(ChunkView view, RawStream stream, IObservationSink sink)
     {
@@ -100,7 +106,11 @@ internal sealed class RttOp : MetricOp
 
             if (rttUs >= 0)
             {
-                sink.Emit(c.SentUtcMs(view, i), rttUs / 1000.0);
+                // 权重 k：这个样本代表 k 个网格间隔，按 k 次累计，分位数就是按时间平均的
+                for (int k = c.Weight(i); k > 0; k--)
+                {
+                    sink.Emit(c.SentUtcMs(view, i), rttUs / 1000.0);
+                }
             }
         }
     }
@@ -160,7 +170,7 @@ internal sealed class SlowShareOp : MetricOp
         double threshold = Math.Max(baseline * 1.8, baseline + Math.Max(15, baseline * 0.35));
         foreach ((int row, double ms) in rtts)
         {
-            sink.Emit(c.SentUtcMs(view, row), ms >= threshold ? 1 : 0, 1);
+            sink.Emit(c.SentUtcMs(view, row), ms >= threshold ? c.Weight(row) : 0, c.Weight(row));
         }
     }
 }
@@ -174,7 +184,7 @@ internal sealed class LossOp : MetricOp
         _dir = dir;
     }
 
-    public override string Signature => "loss/" + _dir + "/1";
+    public override string Signature => "loss/" + _dir + "/2";
 
     public override void Evaluate(ChunkView view, RawStream stream, IObservationSink sink)
     {
@@ -194,18 +204,18 @@ internal sealed class LossOp : MetricOp
             switch (_dir)
             {
                 case Dir.Up:
-                    sink.Emit(c.SentUtcMs(view, i), c.IsUpLost(i) ? 1 : 0, 1);
+                    sink.Emit(c.SentUtcMs(view, i), c.IsUpLost(i) ? c.Weight(i) : 0, c.Weight(i));
                     break;
                 case Dir.Down:
                     // 只统计上行已经到达 Agent 的包：回复没回来就是下行丢失。
                     if (!c.IsUpLost(i))
                     {
-                        sink.Emit(c.SentUtcMs(view, i), c.IsReplyLost(i) ? 1 : 0, 1);
+                        sink.Emit(c.SentUtcMs(view, i), c.IsReplyLost(i) ? c.Weight(i) : 0, c.Weight(i));
                     }
 
                     break;
                 default:
-                    sink.Emit(c.SentUtcMs(view, i), c.IsReplyLost(i) ? 1 : 0, 1);
+                    sink.Emit(c.SentUtcMs(view, i), c.IsReplyLost(i) ? c.Weight(i) : 0, c.Weight(i));
                     break;
             }
         }
@@ -452,7 +462,7 @@ internal sealed class GapOp : MetricOp
         _thresholdMs = thresholdMs;
     }
 
-    public override string Signature => $"gap/{_output}/{_rateParam}/{_thresholdMs}/1";
+    public override string Signature => $"gap/{_output}/{_rateParam}/{_thresholdMs}/2";
 
     public override void Evaluate(ChunkView view, RawStream stream, IObservationSink sink)
     {
@@ -462,11 +472,13 @@ internal sealed class GapOp : MetricOp
             return;
         }
 
-        double rate = Math.Max(0.1, view.ParamNumber(_rateParam, 1));
-        double expectedMs = 1000.0 / rate;
+        // 自适应频率时，每个包的权重就是它和上一个包的间隔（以 1/rate_max_hz 为单位），期望间隔按它算
+        bool adaptive = view.ParamBool("adaptive", false);
+        double rate = Math.Max(0.1, view.ParamNumber(adaptive ? "rate_max_hz" : _rateParam, 1));
         int[] order = c.ArrivalOrder();
         for (int i = 1; i < order.Length; i++)
         {
+            double expectedMs = 1000.0 * (adaptive ? c.Weight(order[i]) : 1) / rate;
             double gapMs = (c.T4!.Values[order[i]] - c.T4.Values[order[i - 1]]) / 1000.0;
             if (gapMs - expectedMs <= _thresholdMs)
             {

backend/src/MoShiro.Backend.Analysis/Ops/HttpOps.cs

@@ -0,0 +1,119 @@
+using MoShiro.Protocol;
+
+namespace MoShiro.Backend.Analysis;
+
+/// <summary>http 请求的结果，编码与 Agent 的 <c>HttpOutcomes</c> 一致。</summary>
+public enum HttpOutcome
+{
+    Ok = 0,
+    Timeout = 1,
+    Reset = 2,
+    Tls = 3,
+    Other = 4,
+    Dns = 5,
+    BadStatus = 6,
+    Unsupported = 7,
+    NotAllowed = 8,
+}
+
+/// <summary>http 流（req）的公共读法：权重 <c>w</c> 是这一行代表的网格间隔数（自适应降频后每次请求代表更长的时间）。</summary>
+internal readonly struct HttpColumns
+{
+    public HttpColumns(RawStream stream)
+    {
+        Stream = stream;
+        Ts = stream.Find("ts");
+        Outcome = stream.Find("outcome");
+        Weights = stream.Find("w");
+    }
+
+    public RawStream Stream { get; }
+
+    public RawColumn? Ts { get; }
+
+    public RawColumn? Outcome { get; }
+
+    private RawColumn? Weights { get; }
+
+    public bool Has => Ts is not null && Outcome is not null;
+
+    public int Weight(int row) => Weights is not null && Weights.IsValid(row) ? (int)Math.Clamp(Weights.Values[row], 1, 65535) : 1;
+}
+
+/// <summary>成功率（分子是按权重累计的成功次数）或某种结果的次数。</summary>
+internal sealed class HttpOutcomeOp : MetricOp
+{
+    private readonly HttpOutcome _code;
+    private readonly bool _asRatio;
+
+    public HttpOutcomeOp(HttpOutcome code, bool asRatio)
+    {
+        _code = code;
+        _asRatio = asRatio;
+    }
+
+    public override string Signature => $"http_outcome/{_code}/{(_asRatio ? "ratio" : "count")}/1";
+
+    public override void Evaluate(ChunkView view, RawStream stream, IObservationSink sink)
+    {
+        var c = new HttpColumns(stream);
+        if (!c.Has)
+        {
+            return;
+        }
+
+        for (int i = 0; i < stream.Count; i++)
+        {
+            bool hit = c.Outcome!.Values[i] == (long)_code;
+            long at = view.ColumnToUtcMs(c.Ts!, c.Ts!.Values[i]);
+            if (_asRatio)
+            {
+                int w = c.Weight(i);
+                sink.Emit(at, hit ? w : 0, w);
+            }
+            else if (hit)
+            {
+                sink.Emit(at, 1);
+            }
+        }
+    }
+}
+
+/// <summary>一个阶段的耗时（毫秒）：只统计成功的请求，按权重累计，所以分位数是按时间平均的。</summary>
+internal sealed class HttpPhaseMsOp : MetricOp
+{
+    private const int MaxRepeat = 256;
+
+    private readonly string _column;
+
+    public HttpPhaseMsOp(string column)
+    {
+        _column = column;
+    }
+
+    public override string Signature => $"http_phase_ms/{_column}/1";
+
+    public override void Evaluate(ChunkView view, RawStream stream, IObservationSink sink)
+    {
+        var c = new HttpColumns(stream);
+        RawColumn? column = stream.Find(_column);
+        if (!c.Has || column is null)
+        {
+            return;
+        }
+
+        for (int i = 0; i < stream.Count; i++)
+        {
+            if (c.Outcome!.Values[i] != (long)HttpOutcome.Ok || !column.IsValid(i))
+            {
+                continue;
+            }
+
+            long at = view.ColumnToUtcMs(c.Ts!, c.Ts!.Values[i]);
+            for (int k = Math.Min(c.Weight(i), MaxRepeat); k > 0; k--)
+            {
+                sink.Emit(at, column.Values[i] / 1000.0);
+            }
+        }
+    }
+}

backend/src/MoShiro.Backend.Analysis/Ops/Ops.cs

@@ -37,6 +37,12 @@ public static class Ops
 
     public static MetricOp OutcomeCount(ConnectOutcome code) => new OutcomeOp(code, asRatio: false);
 
+    public static MetricOp HttpSuccess { get; } = new HttpOutcomeOp(HttpOutcome.Ok, asRatio: true);
+
+    public static MetricOp HttpOutcomeCount(HttpOutcome code) => new HttpOutcomeOp(code, asRatio: false);
+
+    public static MetricOp HttpPhaseMs(string column) => new HttpPhaseMsOp(column);
+
     public static MetricOp HoldEvents(HoldEvent holdEvent) => new HoldEventOp(holdEvent);
 
     public static MetricOp HoldLifetime { get; } = new HoldLifetimeOp();

backend/src/MoShiro.Backend.Analysis/Ops/SessionOps.cs

@@ -330,7 +330,7 @@ internal sealed class HoldLifetimeOp : MetricOp
     }
 }
 
-/// <summary>单向 UDP 流（udp_train）的丢包：接收端没有记录到 t_recv 即为丢失。</summary>
+/// <summary>单向 UDP 流（quic_stream）的丢包：接收端没有记录到 t_recv 即为丢失。</summary>
 internal sealed class TrainLossOp : MetricOp
 {
     public override string Signature => "train_loss/1";

backend/src/MoShiro.Backend.Api/Admin/AgentEndpoints.cs

@@ -23,7 +23,7 @@ public static class AgentEndpoints
             .Api("agents_get", "One agent", AgentsTag).Returns<AgentDto>().ProducesProblems(401, 403, 404)
             .Requires(Capability.FleetRead);
         group.MapGet("/nodes/{id}/logs", ListNodeLogsAsync)
-            .Api("node_runtime_logs", "Recent runtime logs of a node", "admin-nodes").Returns<NodeRuntimeLogsDto>().ProducesProblems(401, 403)
+            .Api("node_runtime_logs", "Recent runtime logs of a node: pulled from the node when it is online, otherwise what the backend kept", "admin-nodes").Returns<NodeRuntimeLogsDto>().ProducesProblems(401, 403)
             .Requires(Capability.FleetRead);
         group.MapPatch("/agents/{id}", PatchAsync)
             .Accepts<AgentPatchRequest>("application/merge-patch+json", "application/json")
@@ -69,10 +69,13 @@ public static class AgentEndpoints
     private static async Task<IResult> ListAsync(AgentService agents, CancellationToken ct) =>
         TypedResults.Json(new PageDto<AgentDto>([.. (await agents.ListAsync(ct)).Select(Mappers.ToDto)], null), ApiJsonContext.Default.PageDtoAgentDto);
 
-    private static Microsoft.AspNetCore.Http.HttpResults.JsonHttpResult<NodeRuntimeLogsDto> ListNodeLogsAsync(NodeRuntimeLogService logs, string id, int? limit) =>
-        TypedResults.Json(
-            ToDto(logs.List(new NodeId(id), Math.Clamp(limit ?? 100, 1, 200))),
-            ApiJsonContext.Default.NodeRuntimeLogsDto);
+    /// <summary>先向节点拉一次最新的日志（离线或超时就算了），再返回 Backend 里保留的；页面开着时前端每几秒请求一次，就是实时拉取。</summary>
+    private static async Task<IResult> ListNodeLogsAsync(NodeRuntimeLogService logs, string id, int? limit, CancellationToken ct)
+    {
+        var node = new NodeId(id);
+        await logs.PullAsync(node, 100, null, ct);
+        return TypedResults.Json(ToDto(logs.List(node, Math.Clamp(limit ?? 100, 1, 200))), ApiJsonContext.Default.NodeRuntimeLogsDto);
+    }
 
     private static NodeRuntimeLogsDto ToDto(NodeRuntimeLogSnapshot snapshot) =>
         new([.. snapshot.Items.Select(item => new NodeRuntimeLogDto(item.Id, Mappers.Time(item.AtUtcMs), item.Level, item.Message, item.Fields))], snapshot.Dropped);

backend/src/MoShiro.Backend.Api/ApiModule.cs

@@ -98,6 +98,8 @@ public static class ApiModule
     {
         RouteGroupBuilder publicGroup = app.MapGroup("/api/public").AddEndpointFilter(PublicGuard.InvokeAsync);
         QueryEndpoints.Map(publicGroup);
+        TargetEndpoints.Map(publicGroup);
+        AdaptiveEndpoints.Map(publicGroup);
         LiveEndpoints.Map(publicGroup);
         HostEndpoints.Map(publicGroup);
         NodeEndpoints.Map(publicGroup);

backend/src/MoShiro.Backend.Api/Common/Mappers.cs

@@ -53,7 +53,7 @@ public static class Mappers
                 QuicState.Retrying => "retry_wait",
                 QuicState.Idle => "idle",
                 _ => "connecting",
-            }, quic.RetryAttempt, quic.RetryInMs, ControlStateName(link.Control.State));
+            }, quic.RetryAttempt, quic.RetryInMs, ControlStateName(link.Control.State), Time(snapshot.DownSinceMs));
     }
 
     private static string ControlStateName(ControlState state) => state switch

backend/src/MoShiro.Backend.Api/Contracts/ApiJsonContext.cs

@@ -18,6 +18,7 @@ namespace MoShiro.Backend.Api;
 [JsonSerializable(typeof(IdDto))]
 [JsonSerializable(typeof(OverviewDto))]
 [JsonSerializable(typeof(SeriesDto))]
+[JsonSerializable(typeof(AdaptiveDto))]
 [JsonSerializable(typeof(CompareDto))]
 [JsonSerializable(typeof(DistributionDto))]
 [JsonSerializable(typeof(HeatmapDto))]
@@ -25,6 +26,7 @@ namespace MoShiro.Backend.Api;
 [JsonSerializable(typeof(QuicLineHealthDto))]
 [JsonSerializable(typeof(TestDto))]
 [JsonSerializable(typeof(PageDto<TestDto>))]
+[JsonSerializable(typeof(PageDto<TargetDto>))]
 [JsonSerializable(typeof(PageDto<KindDto>))]
 [JsonSerializable(typeof(PageDto<PlanDto>))]
 [JsonSerializable(typeof(PageDto<MetricDto>))]

backend/src/MoShiro.Backend.Api/Contracts/PublicDtos.cs

@@ -52,7 +52,8 @@ public sealed record QuicLineHealthDto(
     string State = "connecting",
     int RetryAttempt = 0,
     long? RetryInMs = null,
-    string ControlState = "dialing");
+    string ControlState = "dialing",
+    DateTimeOffset? ControlDownSince = null);
 
 public sealed record OverviewDto(string Range, DateTimeOffset From, DateTimeOffset To, string Step, string Source, bool Degraded, IReadOnlyList<OverviewLineDto> Lines);
 
@@ -218,3 +219,34 @@ public sealed record LiveHostDto(string Id, bool Online, HostDto Host);
 
 /// <summary>主机资源占用的历史（列式，按步长取平均）。</summary>
 public sealed record HostSeriesDto(string Id, DateTimeOffset From, DateTimeOffset To, string Step, IReadOnlyList<long> T, IReadOnlyDictionary<string, double?[]> Values);
+
+/// <summary>
+/// 一个 Agent 上的一个单个 Agent 任务：它测的目标、现在的状态和最近一段时间的时序。
+/// <c>status</c>：<c>running</c> 有最近的数据；<c>waiting</c> 任务已下发、还没有数据；<c>stale</c> 有过数据但最近没有；
+/// <c>rejected</c> Agent 本机拒绝执行（<c>reason</c> 是原因）；<c>offline</c> Agent 不在线。
+/// </summary>
+public sealed record TargetDto(
+    string TaskId,
+    string AgentId,
+    string AgentName,
+    string Kind,
+    string Target,
+    string Status,
+    string? Reason,
+    DateTimeOffset? LastSample,
+    DateTimeOffset From,
+    DateTimeOffset To,
+    string Step,
+    IReadOnlyList<long> T,
+    IReadOnlyDictionary<string, double?[]> Values,
+    SummaryDto Summary);
+
+/// <summary>一个时间桶里一种采集方法的自适应探测频率：各状态的秒数、时间加权的平均频率（Hz，不知道时为 null）、状态变化次数、变化时的最大丢包率（%）。</summary>
+public sealed record AdaptiveBucketDto(DateTimeOffset Start, double QuietSeconds, double WatchSeconds, double ActiveSeconds, double DeadSeconds, double? AverageHz, int Changes, double MaxLossPct);
+
+public sealed record AdaptiveKindDto(string Kind, IReadOnlyList<AdaptiveBucketDto> Buckets);
+
+/// <summary>自适应探测频率的一次状态变化：从哪个状态到哪个状态、之后的频率、原因，以及当时的丢包率和包数。</summary>
+public sealed record AdaptiveChangeDto(DateTimeOffset At, string Kind, string From, string To, double Hz, string Reason, double LossPct, int Sent, int Lost);
+
+public sealed record AdaptiveDto(string LineId, DateTimeOffset From, DateTimeOffset To, string Step, IReadOnlyList<AdaptiveKindDto> Kinds, IReadOnlyList<AdaptiveChangeDto> Changes);

backend/src/MoShiro.Backend.Api/Public/AdaptiveEndpoints.cs

@@ -0,0 +1,68 @@
+using Fleet.Core;
+using Microsoft.AspNetCore.Builder;
+using Microsoft.AspNetCore.Http;
+using Microsoft.AspNetCore.Routing;
+using MoShiro.Backend.Application;
+using MoShiro.Protocol;
+
+namespace MoShiro.Backend.Api;
+
+/// <summary>自适应探测频率的审计：一条线路在一段时间里每种采集方法各状态占多久、平均频率多少，以及每一次状态变化和原因。</summary>
+public static class AdaptiveEndpoints
+{
+    private const string Tag = "public";
+    private const long MaxRangeMs = 30 * Steps.Day;
+    private const int MaxBuckets = 1000;
+
+    public static void Map(RouteGroupBuilder group) =>
+        group.MapGet("/lines/{line_id}/adaptive", AdaptiveAsync)
+            .Api("lines_adaptive", "Adaptive probe-rate states of one line over time (audit)", Tag)
+            .Returns<AdaptiveDto>().ProducesProblems(403, 404, 422, 503);
+
+    private static Task<IResult> AdaptiveAsync(
+        HttpContext http, LineService lines, AdaptiveAuditService audit, TimeProvider time, string line_id, string? range, DateTimeOffset? from, DateTimeOffset? to, string? step) =>
+        QueryHelpers.GuardedAsync(http, async ct =>
+        {
+            Result<LineView> found = await QueryHelpers.FindVisibleLineAsync(http, lines, line_id, ct);
+            if (!found.TryGet(out LineView? view, out FleetError? error))
+            {
+                return Problems.From(http, error);
+            }
+
+            long now = time.GetUtcNow().ToUnixTimeMilliseconds();
+            long toMs = to?.ToUnixTimeMilliseconds() ?? now;
+            long spanMs;
+            if (from is { } start)
+            {
+                spanMs = toMs - start.ToUnixTimeMilliseconds();
+            }
+            else if (!RangeResolver.TryParseSpan(range ?? "48h", out spanMs))
+            {
+                return Problems.From(http, ValidationError.Single("range", "must look like 48h or 7d"));
+            }
+
+            if (spanMs <= 0 || spanMs > MaxRangeMs)
+            {
+                return Problems.From(http, ValidationError.Single("range", "must be between 1 minute and 30 days"));
+            }
+
+            long stepMs = Steps.Hour;
+            if (step is not null && (!RangeResolver.TryParseSpan(step, out stepMs) || stepMs < Steps.Minute))
+            {
+                return Problems.From(http, ValidationError.Single("step", "must look like 15m or 1h"));
+            }
+
+            if (spanMs / stepMs > MaxBuckets)
+            {
+                return Problems.From(http, ValidationError.Single("step", $"too fine for this range (at most {MaxBuckets} buckets)"));
+            }
+
+            long fromMs = toMs - spanMs;
+            AdaptiveResult result = await audit.GetAsync(view.Key, fromMs, toMs, stepMs, ct);
+            var dto = new AdaptiveDto(
+                view.Key.Id, Mappers.Time(result.FromMs), Mappers.Time(result.ToMs), Steps.Format(result.StepMs),
+                [.. result.Kinds.Select(k => new AdaptiveKindDto(k.Kind, [.. k.Buckets.Select(b => new AdaptiveBucketDto(Mappers.Time(b.StartMs), b.QuietSeconds, b.WatchSeconds, b.ActiveSeconds, b.DeadSeconds, b.AverageHz, b.Changes, b.MaxLossPct))]))],
+                [.. result.Changes.Select(c => new AdaptiveChangeDto(Mappers.Time(c.AtMs), c.Kind, c.From, c.To, c.Hz, c.Reason, c.LossPct, c.Sent, c.Lost))]);
+            return TypedResults.Json(dto, ApiJsonContext.Default.AdaptiveDto);
+        });
+}

backend/src/MoShiro.Backend.Api/Public/TargetEndpoints.cs

@@ -0,0 +1,112 @@
+using System.Text.Json;
+using Fleet.Core;
+using Microsoft.AspNetCore.Builder;
+using Microsoft.AspNetCore.Http;
+using Microsoft.AspNetCore.Routing;
+using MoShiro.Backend.Application;
+using MoShiro.Protocol;
+
+namespace MoShiro.Backend.Api;
+
+/// <summary>单个 Agent 任务（Agent 自己去测一个外部地址）：每个 Agent 实际在执行的目标、状态和最近的时序。</summary>
+public static class TargetEndpoints
+{
+    private const string Tag = "public";
+
+    /// <summary>最近多久内有样本算「在运行」：自适应退避到最慢是几分钟一次，所以要留够余量。</summary>
+    private static readonly TimeSpan s_running = TimeSpan.FromMinutes(15);
+
+    /// <summary>每种方法默认看的指标。</summary>
+    private static readonly Dictionary<string, string> s_metrics = new(StringComparer.Ordinal)
+    {
+        ["http_request"] = "http.success,http.ttfb_ms.p50,http.ttfb_ms.p95,http.total_ms.p95,http.dns_ms.p95,http.tcp_ms.p95,http.fail.timeout,http.fail.dns,http.fail.rst,http.fail.tls,http.fail.status,http.fail.unsupported,http.fail.other",
+        ["tcp_connect"] = "connect.success,connect.tcp_ms.p95,connect.tls_ms.p95",
+        ["icmp_ping"] = "rtt.p50,rtt.p95,loss.total",
+    };
+
+    /// <summary>详情页要的指标：卡片上的那些再加上分位数和各种失败计数。</summary>
+    private static readonly Dictionary<string, string> s_fullMetrics = new(StringComparer.Ordinal)
+    {
+        ["http_request"] = "http.success,http.ttfb_ms.p50,http.ttfb_ms.p95,http.ttfb_ms.p99,http.total_ms.p50,http.total_ms.p95,http.total_ms.p99,http.dns_ms.p95,http.tcp_ms.p95,http.fail.timeout,http.fail.dns,http.fail.rst,http.fail.tls,http.fail.status,http.fail.unsupported,http.fail.other,n.http",
+        ["tcp_connect"] = "connect.success,connect.tcp_ms.p95,connect.tls_ms.p95,connect.fail.timeout,connect.fail.rst,connect.fail.tls,n.connect",
+        ["icmp_ping"] = "rtt.p50,rtt.p95,rtt.p99,loss.total",
+    };
+
+    public static void Map(RouteGroupBuilder group) =>
+        group.MapGet("/targets", ListAsync)
+            .Api("targets_list", "Single-Agent tasks with their status and recent series", Tag)
+            .Returns<PageDto<TargetDto>>().ProducesProblems(403, 422, 429, 503);
+
+    /// <remarks><c>agent_id</c> 和 <c>task_id</c> 只看一个目标；<c>full=true</c> 返回详情页要的全部指标。</remarks>
+    private static Task<IResult> ListAsync(
+        HttpContext http, TargetService targets, QueryService query, BackendOptions options, TimeProvider time,
+        string? range, DateTimeOffset? from, DateTimeOffset? to, string? step, string? agent_id, string? task_id, bool? full) =>
+        QueryHelpers.GuardedAsync(http, async ct =>
+        {
+            IReadOnlyList<TargetView> views = await targets.ListAsync(a => a.Agent.PublicVisible || PublicGuard.CanSeeHidden(http), ct);
+            var items = new List<TargetDto>(views.Count);
+            long now = time.GetUtcNow().ToUnixTimeMilliseconds();
+            foreach (TargetView view in views.Where(v => (agent_id is null || v.Agent.Agent.Id.Value == agent_id) && (task_id is null || v.Task.Id.Value == task_id)))
+            {
+                string wanted = (full == true ? s_fullMetrics : s_metrics).GetValueOrDefault(view.Task.Kind, "rtt.p50");
+                Result<MetricSelection> selection = MetricSelection.Resolve(wanted, null, options.MaxMetricsPerQuery);
+                if (!selection.TryGet(out MetricSelection? sel, out FleetError? error))
+                {
+                    return Problems.From(http, error);
+                }
+
+                Result<TargetSeriesResult> series = await query.TargetSeriesAsync(view.Agent.Agent.Id, view.Task.Id, new RangeRequest(range ?? "3h", from, to, step, null, null), sel, ct);
+                if (!series.TryGet(out TargetSeriesResult? result, out error))
+                {
+                    return Problems.From(http, error);
+                }
+
+                long? latest = await query.TargetLatestAsync(view.Agent.Agent.Id, view.Task.Id, ct);
+                (string status, string? reason) = StatusOf(view, latest, now);
+                items.Add(new TargetDto(
+                    view.Task.Id.Value, view.Agent.Agent.Id.Value, view.Agent.Agent.Name, view.Task.Kind, view.Task.Target ?? "", status, reason,
+                    latest is { } at ? Mappers.Time(at) : null, Mappers.Time(result.Range.FromMs), Mappers.Time(result.Range.ToMs), Steps.Format(result.Range.StepMs),
+                    result.T, result.Values, Mappers.ToDto(result.Summary)));
+            }
+
+            return TypedResults.Json(new PageDto<TargetDto>(items, null), ApiJsonContext.Default.PageDtoTargetDto);
+        });
+
+    private static (string Status, string? Reason) StatusOf(TargetView view, long? latest, long now)
+    {
+        if (RejectedReason(view) is { } reason)
+        {
+            return ("rejected", reason);
+        }
+
+        if (!view.Agent.Online)
+        {
+            return ("offline", null);
+        }
+
+        if (latest is null)
+        {
+            return ("waiting", null);
+        }
+
+        return (now - latest.Value <= s_running.TotalMilliseconds ? "running" : "stale", null);
+    }
+
+    /// <summary>Agent 本机拒绝执行这个任务的原因（心跳里的 rejected[]，条目 id 是任务 id）。</summary>
+    private static string? RejectedReason(TargetView view)
+    {
+        if (view.Agent.Agent.RejectedJson is not { } json)
+        {
+            return null;
+        }
+
+        try
+        {
+            return JsonSerializer.Deserialize(json, ApiJsonContext.Default.ListRejectedItem)?.FirstOrDefault(r => r.Id == view.Task.Id.Value)?.Reason;
+        }
+        catch (JsonException)
+        {
+            return null;
+        }
+    }
+}

backend/src/MoShiro.Backend.Application/Agents/LinkRuntime.cs

@@ -3,7 +3,8 @@ using MoShiro.Protocol;
 
 namespace MoShiro.Backend.Application;
 
-public sealed record ReportedLink(LinkHealth Health, long AtMs);
+/// <summary><paramref name="DownSinceMs"/>：控制层从什么时候起一直不是在线（Unix 毫秒）；在线时为空。重试会让控制层状态反复进出退避，所以由 Backend 连着记，不用状态自己的时间。</summary>
+public sealed record ReportedLink(LinkHealth Health, long AtMs, long? DownSinceMs = null);
 
 /// <summary>Latest per-line control and task health reported by dialing nodes. Volatile runtime state, not historical metrics.</summary>
 public sealed class LinkRuntime
@@ -20,7 +21,8 @@ public sealed class LinkRuntime
         {
             var key = (dialerId, link.ListenerId, link.IpVersion);
             current.Add(key);
-            _links[key] = new ReportedLink(link, atMs);
+            long? downSince = link.Control.State == ControlState.Up ? null : _links.TryGetValue(key, out ReportedLink? previous) && previous.DownSinceMs is { } since ? since : atMs;
+            _links[key] = new ReportedLink(link, atMs, downSince);
         }
 
         foreach ((string Dialer, string Listener, string IpVersion) key in _links.Keys.Where(k => k.Dialer == dialerId && !current.Contains(k)))
@@ -41,7 +43,7 @@ public sealed class LinkRuntime
             old.Control.RetryInMs = null;
             old.Task.Quic.State = QuicState.Idle;
             old.Task.Quic.RetryInMs = null;
-            _links[pair.Key] = new ReportedLink(old, atMs);
+            _links[pair.Key] = new ReportedLink(old, atMs, pair.Value.DownSinceMs ?? atMs);
         }
     }
 }

backend/src/MoShiro.Backend.Application/Agents/MoShiroFleetHooks.cs

@@ -108,6 +108,22 @@ public sealed class MoShiroNodeEventSink : INodeEventSink
         }
     }
 
+    /// <summary>
+    /// 自适应探测频率的状态变化存成事件（<see cref="AdaptiveAudit.EventKind"/>）：线路任务记在监听方名下（和线路的数据同一个归属），
+    /// 单个 Agent 任务记在上报的节点名下。时间以节点上报的为准，明显不对（未来、或太久以前）的用心跳的时间。
+    /// </summary>
+    private async ValueTask RecordRateChangesAsync(NodeId reporter, long heartbeatMs, List<RateChange> changes, CancellationToken ct)
+    {
+        foreach (RateChange change in changes.Take(256))
+        {
+            change.Dialer = reporter.Value;
+            long at = change.AtMs > heartbeatMs - 3_600_000 && change.AtMs <= heartbeatMs + 60_000 ? change.AtMs : heartbeatMs;
+            change.AtMs = at;
+            NodeId owner = change.Listener is { Length: > 0 } listener ? new NodeId(listener) : reporter;
+            await _events.AddAsync(owner, AdaptiveAudit.EventKind, at, System.Text.Json.JsonSerializer.Serialize(change, MoShiroJsonContext.Default.RateChange), ct);
+        }
+    }
+
     private async ValueTask ApplyHeartbeatAsync(NodeId id, NodeEvent nodeEvent, System.Text.Json.JsonElement extra, CancellationToken ct)
     {
         await _nodes.SetVersionAsync(id.Value, nodeEvent.Node.NodeVersion, ct);
@@ -128,7 +144,12 @@ public sealed class MoShiroNodeEventSink : INodeEventSink
                 return;
             }
 
-            _nodeLogs.Append(id, beat.RuntimeLogs, beat.DroppedRuntimeLogs ?? 0);
+            _nodeLogs.Observe(id, beat.LogSummary);
+            if (beat.RateChanges is { Count: > 0 } rateChanges)
+            {
+                await RecordRateChangesAsync(id, nodeEvent.AtMs, rateChanges, ct);
+            }
+
             state.ReplaceDialers(beat.Dialers.Select(d => new ConnectedDialerInfo(d.Id.Value, d.Version, d.Remote, d.SinceUtcMs, d.IpVersion)));
             foreach (ConnectedDialer dialer in beat.Dialers)
             {

backend/src/MoShiro.Backend.Application/Agents/NodeRuntimeLogService.cs

@@ -8,47 +8,89 @@ public sealed record NodeRuntimeLog(long Id, long AtUtcMs, string Level, string
 
 public sealed record NodeRuntimeLogSnapshot(IReadOnlyList<NodeRuntimeLog> Items, long Dropped);
 
-/// <summary>Bounded in-memory recent logs uploaded by authenticated Agent and 拨号方 heartbeats.</summary>
-public sealed class NodeRuntimeLogService(TimeProvider time)
+/// <summary>
+/// 节点日志：心跳只带各级别的计数（不带文本），文本由这里按需向节点拉取。管理端打开日志页时拉最新的；
+/// 节点报告了错误，也会自动拉一次警告以上的日志留着，供事后查看（Backend 内存里每个节点保留最近 <see cref="CapacityPerNode"/> 条）。
+/// </summary>
+public sealed class NodeRuntimeLogService(TimeProvider time, IAgentGateway gateway)
 {
-    private const int CapacityPerNode = 256;
-    private const int MaxBatch = 32;
+    private const int CapacityPerNode = 512;
+    private const int PullLimit = 200;
+    private static readonly TimeSpan s_autoPullEvery = TimeSpan.FromMinutes(1);
+
     private readonly ConcurrentDictionary<NodeId, LogBuffer> _nodes = new();
 
-    public void Append(NodeId node, IReadOnlyList<NodeLogRecord>? records, long droppedByNode)
+    /// <summary>心跳里的日志计数：有新的错误就在后台自动拉一次警告以上的日志。</summary>
+    public void Observe(NodeId node, LogSummaryDto? summary)
     {
-        if ((records is null || records.Count == 0) && droppedByNode <= 0)
+        if (summary is null || summary.Error <= 0)
         {
             return;
         }
 
         LogBuffer buffer = _nodes.GetOrAdd(node, static _ => new LogBuffer());
+        long now = time.GetUtcNow().ToUnixTimeMilliseconds();
         lock (buffer.Gate)
         {
-            buffer.DroppedByNode += Math.Max(0, droppedByNode);
-            if (records is null)
+            if (buffer.Pulling || now - buffer.LastAutoPullMs < s_autoPullEvery.TotalMilliseconds)
             {
                 return;
             }
 
-            foreach (NodeLogRecord record in records.Take(MaxBatch))
+            buffer.LastAutoPullMs = now;
+        }
+
+        _ = Task.Run(async () =>
+        {
+            try
             {
-                long now = time.GetUtcNow().ToUnixTimeMilliseconds();
-                long at = record.AtUtcMs < now - 86_400_000 || record.AtUtcMs > now + 86_400_000 ? now : record.AtUtcMs;
-                var entry = new NodeRuntimeLog(
-                    ++buffer.LastId,
-                    at,
-                    record.Level is "info" or "warn" or "error" ? record.Level : "info",
-                    Truncate(record.Message ?? "", 384),
-                    SafeFields(record.Fields));
+                await PullAsync(node, PullLimit, "warn", CancellationToken.None);
+            }
+            catch (Exception ex) when (ex is not OutOfMemoryException)
+            {
+                // 拉取是尽力而为：节点刚好断开或超时，下次有新错误再拉
+            }
+        });
+    }
 
-                if (buffer.Items.Count == CapacityPerNode)
-                {
-                    buffer.Items.Dequeue();
-                    buffer.DroppedByBackend++;
-                }
+    /// <summary>向节点拉取上次之后的新日志；节点离线或超时返回 false，已有的日志照常可看。</summary>
+    public async ValueTask<bool> PullAsync(NodeId node, int limit, string? minLevel, CancellationToken ct)
+    {
+        LogBuffer buffer = _nodes.GetOrAdd(node, static _ => new LogBuffer());
+        long after;
+        lock (buffer.Gate)
+        {
+            if (buffer.Pulling)
+            {
+                return true; // 已经有一次拉取在进行，它的结果同样会进缓冲区
+            }
 
-                buffer.Items.Enqueue(entry);
+            buffer.Pulling = true;
+            after = buffer.LastFetchedId;
+        }
+
+        try
+        {
+            using var timeout = CancellationTokenSource.CreateLinkedTokenSource(ct);
+            timeout.CancelAfter(TimeSpan.FromSeconds(5));
+            Result<LogsFetchResult> result = await gateway.FetchLogsAsync(node, new LogsFetchParams { AfterId = after, Limit = Math.Clamp(limit, 1, PullLimit), MinLevel = minLevel }, timeout.Token);
+            if (!result.TryGet(out LogsFetchResult? page, out _))
+            {
+                return false;
+            }
+
+            Append(buffer, after, page);
+            return true;
+        }
+        catch (OperationCanceledException) when (!ct.IsCancellationRequested)
+        {
+            return false;
+        }
+        finally
+        {
+            lock (buffer.Gate)
+            {
+                buffer.Pulling = false;
             }
         }
     }
@@ -62,9 +104,56 @@ public sealed class NodeRuntimeLogService(TimeProvider time)
 
         lock (buffer.Gate)
         {
-            return new NodeRuntimeLogSnapshot(
-                [.. buffer.Items.Reverse().Take(Math.Clamp(limit, 1, 200))],
-                buffer.DroppedByNode + buffer.DroppedByBackend);
+            return new NodeRuntimeLogSnapshot([.. buffer.Items.Reverse().Take(Math.Clamp(limit, 1, 200))], buffer.Dropped);
+        }
+    }
+
+    private void Append(LogBuffer buffer, long after, LogsFetchResult page)
+    {
+        long now = time.GetUtcNow().ToUnixTimeMilliseconds();
+        lock (buffer.Gate)
+        {
+            if (page.LastId < after)
+            {
+                // 节点重启过，编号从头开始：旧的编号不再有意义
+                buffer.LastFetchedId = 0;
+                after = 0;
+            }
+
+            long expected = after + 1;
+            foreach (LogEntryDto entry in page.Items)
+            {
+                if (entry.Id <= buffer.LastFetchedId)
+                {
+                    continue;
+                }
+
+                if (entry.Id > expected && buffer.LastFetchedId > 0)
+                {
+                    buffer.Dropped += entry.Id - expected; // 中间的几条在节点上已经被环挤掉了
+                }
+
+                expected = entry.Id + 1;
+                long at = entry.AtUtcMs < now - 86_400_000 || entry.AtUtcMs > now + 86_400_000 ? now : entry.AtUtcMs;
+                if (buffer.Items.Count == CapacityPerNode)
+                {
+                    buffer.Items.Dequeue();
+                    buffer.Dropped++;
+                }
+
+                buffer.Items.Enqueue(new NodeRuntimeLog(
+                    entry.Id,
+                    at,
+                    entry.Level is "info" or "warn" or "error" ? entry.Level : "info",
+                    Truncate(entry.Message, 384),
+                    SafeFields(entry.Fields)));
+                buffer.LastFetchedId = entry.Id;
+            }
+
+            if (page.Items.Count == 0 && page.LastId > buffer.LastFetchedId)
+            {
+                buffer.LastFetchedId = page.LastId; // 没有符合级别的新日志：下次从这里接着拉，不用重复扫
+            }
         }
     }
 
@@ -80,17 +169,11 @@ public sealed class NodeRuntimeLogService(TimeProvider time)
 
         foreach ((string key, string value) in fields.Take(20))
         {
-            string safeKey = Truncate(key, 48);
             string lower = key.ToLowerInvariant();
-            bool sensitive = lower.Contains("token", StringComparison.Ordinal)
-                || lower.Contains("secret", StringComparison.Ordinal)
-                || lower.Contains("password", StringComparison.Ordinal)
-                || lower.Contains("private", StringComparison.Ordinal)
-                || lower.Contains("signature", StringComparison.Ordinal)
-                || lower.Contains("authorization", StringComparison.Ordinal)
-                || lower.Contains("cookie", StringComparison.Ordinal)
-                || lower == "mac";
-            safe[safeKey] = sensitive ? "[redacted]" : Truncate(value ?? "", 128);
+            bool sensitive = lower.Contains("token", StringComparison.Ordinal) || lower.Contains("secret", StringComparison.Ordinal) || lower.Contains("password", StringComparison.Ordinal)
+                || lower.Contains("private", StringComparison.Ordinal) || lower.Contains("signature", StringComparison.Ordinal) || lower.Contains("authorization", StringComparison.Ordinal)
+                || lower.Contains("cookie", StringComparison.Ordinal) || lower == "mac";
+            safe[Truncate(key, 64)] = sensitive ? "[redacted]" : Truncate(value, 128);
         }
 
         return safe;
@@ -99,9 +182,15 @@ public sealed class NodeRuntimeLogService(TimeProvider time)
     private sealed class LogBuffer
     {
         public object Gate { get; } = new();
-        public Queue<NodeRuntimeLog> Items { get; } = [];
-        public long LastId;
-        public long DroppedByNode;
-        public long DroppedByBackend;
+
+        public Queue<NodeRuntimeLog> Items { get; } = new();
+
+        public long LastFetchedId { get; set; }
+
+        public long Dropped { get; set; }
+
+        public long LastAutoPullMs { get; set; }
+
+        public bool Pulling { get; set; }
     }
 }

backend/src/MoShiro.Backend.Application/ApplicationServiceCollectionExtensions.cs

@@ -32,6 +32,8 @@ public static class ApplicationServiceCollectionExtensions
         services.AddSingleton<NodeInfoService>();
         services.AddSingleton<LinkService>();
         services.AddSingleton<LineService>();
+        services.AddSingleton<TargetService>();
+        services.AddSingleton<AdaptiveAuditService>();
         services.AddSingleton<TestService>();
         services.AddSingleton<IngestService>();
         services.AddSingleton<WindowComputer>();
@@ -50,6 +52,8 @@ public static class ApplicationServiceCollectionExtensions
         services.AddSingleton<ReleaseService>();
         services.AddSingleton<ScheduleService>();
         services.AddSingleton<BackendUpdates>();
+        services.AddSingleton<BackendAutoUpdater>();
+        services.AddHostedService(provider => provider.GetRequiredService<BackendAutoUpdater>());
         services.AddSingleton<JoinTokenService>();
         services.AddSingleton<RawBrowserService>();
         services.AddSingleton<EventService>();

backend/src/MoShiro.Backend.Application/BackendOptions.cs

@@ -21,6 +21,15 @@ public sealed class BackendOptions
     /// </summary>
     public string? UpdateMode { get; set; } = Environment.GetEnvironmentVariable("MOSHIRO_UPDATE");
 
+    /// <summary>
+    /// 自动更新（环境变量 <c>MoShiro__AutoUpdate=true</c>）：新版本登记之后过了 <see cref="AutoUpdateDelayMinutes"/> 分钟自动确认，和管理员点「更新并重启」是同一条路径
+    /// （先备份数据库，备份失败就不更新）。默认关：Backend 重启会让所有节点断一两分钟。同样需要 <see cref="UpdateMode"/> 是 <c>restart</c>。
+    /// </summary>
+    public bool AutoUpdate { get; set; }
+
+    /// <summary>新版本登记之后等多久再自动更新（分钟）：连着推几次的时候只更新到最后一版，也给 CI 里同时发布的 Agent 版本留出时间。</summary>
+    public int AutoUpdateDelayMinutes { get; set; } = 10;
+
     /// <summary>
     /// 每个 Agent 都必须有属主（passkey）：创建加入码时必须已经建立信任根，并且至少选一把操作员集合里的 passkey 作为属主。
     /// 属主是节点敏感内容（extension 会话、加密数据）绑定的人，装上时固定在节点本地，面板改不了。默认开；没有信任根的老部署才需要关掉。
@@ -60,6 +69,9 @@ public sealed class BackendOptions
 
     public int LoginAttemptsPerMinute { get; set; } = 10;
 
+    /// <summary>Agent 至少要是哪个版本才能连上（如 <c>0.4.2-dev.80</c>）；空 = 不要求。低于它的 Agent 握手时被拒绝，5 秒后重试（它可能正在更新）。环境变量 <c>MoShiro__MinAgentVersion</c>。</summary>
+    public string? MinAgentVersion { get; set; }
+
     public int RawRetentionDays { get; set; } = 30;
 
     public int TestRawRetentionDays { get; set; } = 90;

backend/src/MoShiro.Backend.Application/Ports/IAgentGateway.cs

@@ -25,6 +25,9 @@ public interface IAgentGateway
 
     ValueTask CancelTestAsync(NodeId agent, TestId test, CancellationToken ct);
 
+    /// <summary>向节点拉取日志（编号大于 <c>AfterId</c> 的、不低于 <c>MinLevel</c> 的，最旧的在前）。节点离线时失败。</summary>
+    ValueTask<Result<LogsFetchResult>> FetchLogsAsync(NodeId node, LogsFetchParams request, CancellationToken ct);
+
     /// <summary>让监听方断开某个拨号方的会话。返回监听方是否真的有这个会话。</summary>
     ValueTask<Result<bool>> DisconnectDialerAsync(NodeId listener, NodeId dialer, CancellationToken ct);
 

backend/src/MoShiro.Backend.Application/Query/AdaptiveAudit.cs

@@ -0,0 +1,156 @@
+using System.Text.Json;
+using Fleet.Core;
+using MoShiro.Protocol;
+
+namespace MoShiro.Backend.Application;
+
+/// <summary>一个时间桶里一种采集方法的自适应探测频率：各状态各占多少秒、时间加权的平均频率、状态变化次数、变化时的最大丢包率。</summary>
+public sealed record AdaptiveBucket(long StartMs, double QuietSeconds, double WatchSeconds, double ActiveSeconds, double DeadSeconds, double? AverageHz, int Changes, double MaxLossPct);
+
+public sealed record AdaptiveKind(string Kind, IReadOnlyList<AdaptiveBucket> Buckets);
+
+public sealed record AdaptiveResult(long FromMs, long ToMs, long StepMs, IReadOnlyList<AdaptiveKind> Kinds, IReadOnlyList<RateChange> Changes);
+
+/// <summary>
+/// 自适应探测频率的审计：节点把每一次状态变化（Quiet / Watch / Active / Dead、频率、原因、丢包）随心跳上报，Backend 存成事件（保留期和别的事件一样），
+/// 这里把它们还原成「某个时段里各状态占多久、平均频率多少」，所以几天之后也能回答「晚高峰的时候自适应是什么状态」。
+/// </summary>
+public sealed class AdaptiveAuditService
+{
+    private readonly IEventStore _events;
+
+    public AdaptiveAuditService(IEventStore events)
+    {
+        _events = events;
+    }
+
+    public async ValueTask<AdaptiveResult> GetAsync(LineKey line, long fromMs, long toMs, long stepMs, CancellationToken ct)
+    {
+        // 往前多取一段：区间开头的状态要由这之前最近的一次变化决定
+        IReadOnlyList<EventRecord> records = await _events.ListAsync(line.Listener, AdaptiveAudit.EventKind, fromMs - AdaptiveAudit.LookBackMs, toMs, null, 20_000, ct);
+        List<RateChange> changes = [];
+        foreach (EventRecord record in records.OrderBy(r => r.AtMs).ThenBy(r => r.Id))
+        {
+            RateChange? change = AdaptiveAudit.Parse(record);
+            if (change is not null && change.Dialer == line.Dialer.Value && (change.IpVersion ?? "ipv4") == line.IpVersion && change.Listener == line.Listener.Value)
+            {
+                changes.Add(change);
+            }
+        }
+
+        return AdaptiveAudit.Summarize(changes, fromMs, toMs, stepMs);
+    }
+}
+
+public static class AdaptiveAudit
+{
+    public const string EventKind = "rate_change";
+
+    /// <summary>区间开头之前最多往回看多久，找那时的状态。</summary>
+    public const long LookBackMs = 24 * 3_600_000L;
+
+    public static RateChange? Parse(EventRecord record)
+    {
+        if (record.Detail is null)
+        {
+            return null;
+        }
+
+        try
+        {
+            RateChange? change = JsonSerializer.Deserialize(record.Detail, MoShiroJsonContext.Default.RateChange);
+            if (change is not null)
+            {
+                change.AtMs = record.AtMs;
+            }
+
+            return change;
+        }
+        catch (JsonException)
+        {
+            return null;
+        }
+    }
+
+    /// <summary>
+    /// 把按时间排好的状态变化还原成每个时间桶里各状态的秒数。一次变化之后到下一次变化之前，是变化后的状态和频率；
+    /// 第一次记录之前什么都不知道，不计入任何状态（节点启动时会记一条「start → watch」，所以每个自适应的任务从启动起就有记录；
+    /// 没有这条记录的时段是节点还没升级到会上报的版本）。一种采集方法一条时间线（同一条线路上每种方法各自变化）。
+    /// </summary>
+    public static AdaptiveResult Summarize(IReadOnlyList<RateChange> changes, long fromMs, long toMs, long stepMs)
+    {
+        int count = (int)Math.Max(1, Math.Ceiling((toMs - fromMs) / (double)stepMs));
+        var kinds = new List<AdaptiveKind>();
+        foreach (IGrouping<string, RateChange> group in changes.GroupBy(c => c.Kind).OrderBy(g => g.Key, StringComparer.Ordinal))
+        {
+            var quiet = new double[count];
+            var watch = new double[count];
+            var active = new double[count];
+            var dead = new double[count];
+            var hzWeighted = new double[count];
+            var hzSeconds = new double[count];
+            var changeCounts = new int[count];
+            var maxLoss = new double[count];
+            RateChange[] ordered = [.. group.OrderBy(c => c.AtMs)];
+
+            // 每一段：[这次变化, 下一次变化) 内是变化后的状态和频率；第一次记录之前不知道，不计
+            string state = ordered[0].To;
+            double? hz = ordered[0].Hz;
+            long cursor = ordered[0].AtMs;
+            foreach (RateChange change in ordered)
+            {
+                AddSegment(cursor, change.AtMs, state, hz);
+                int slot = (int)((change.AtMs - fromMs) / stepMs);
+                if (change.AtMs >= fromMs && change.AtMs < toMs && slot >= 0 && slot < count)
+                {
+                    changeCounts[slot]++;
+                    maxLoss[slot] = Math.Max(maxLoss[slot], change.LossPct);
+                }
+
+                cursor = change.AtMs;
+                state = change.To;
+                hz = change.Hz;
+            }
+
+            AddSegment(cursor, toMs, state, hz);
+            var buckets = new List<AdaptiveBucket>(count);
+            for (int i = 0; i < count; i++)
+            {
+                buckets.Add(new AdaptiveBucket(fromMs + (i * stepMs), Math.Round(quiet[i], 1), Math.Round(watch[i], 1), Math.Round(active[i], 1), Math.Round(dead[i], 1),
+                    hzSeconds[i] > 0 ? Math.Round(hzWeighted[i] / hzSeconds[i], 3) : null, changeCounts[i], maxLoss[i]));
+            }
+
+            kinds.Add(new AdaptiveKind(group.Key, buckets));
+
+            void AddSegment(long start, long end, string segmentState, double? segmentHz)
+            {
+                start = Math.Max(start, fromMs);
+                end = Math.Min(end, toMs);
+                for (long t = start; t < end;)
+                {
+                    int slot = (int)((t - fromMs) / stepMs);
+                    long slotEnd = Math.Min(end, fromMs + ((slot + 1) * stepMs));
+                    double seconds = (slotEnd - t) / 1000.0;
+                    switch (segmentState)
+                    {
+                        case "quiet": quiet[slot] += seconds; break;
+                        case "watch": watch[slot] += seconds; break;
+                        case "active": active[slot] += seconds; break;
+                        case "dead": dead[slot] += seconds; break;
+                    }
+
+                    if (segmentHz is { } known)
+                    {
+                        hzWeighted[slot] += known * seconds;
+                        hzSeconds[slot] += seconds;
+                    }
+
+                    t = slotEnd;
+                }
+            }
+        }
+
+        RateChange[] inRange = [.. changes.Where(c => c.AtMs >= fromMs && c.AtMs < toMs).OrderByDescending(c => c.AtMs).Take(200)];
+        return new AdaptiveResult(fromMs, toMs, stepMs, kinds, inRange);
+    }
+}

backend/src/MoShiro.Backend.Application/Query/QueryResults.cs

@@ -45,3 +45,12 @@ public sealed record CompareResult(
     string Metric,
     QueryRange Range,
     SourcePlan Plan);
+
+/// <summary>单个 Agent 任务（目标任务）的时序：和线路时序同一套分层与汇总，只是没有线路、事件和评分。</summary>
+public sealed record TargetSeriesResult(
+    QueryRange Range,
+    SourcePlan Plan,
+    IReadOnlyList<long> T,
+    IReadOnlyDictionary<string, double?[]> Values,
+    SummaryResult Summary,
+    IReadOnlyDictionary<string, string> Versions);

backend/src/MoShiro.Backend.Application/Query/QueryService.cs

@@ -138,6 +138,61 @@ public sealed class QueryService
         return Result<SeriesResult>.Ok(new SeriesResult(line, p.Range, p.Plan, bucketed.T, values, summary, gaps, events, versions));
     }
 
+    /// <summary>某个 Agent 上一个单个 Agent 任务的时序（序列 <c>target:&lt;任务 id&gt;</c>）。</summary>
+    public async ValueTask<Result<TargetSeriesResult>> TargetSeriesAsync(NodeId agent, TaskId task, RangeRequest request, MetricSelection selection, CancellationToken ct)
+    {
+        Result<(QueryRange Range, SourcePlan Plan)> planned = Plan(request, "3h");
+        if (!planned.TryGet(out (QueryRange Range, SourcePlan Plan) p, out FleetError? error))
+        {
+            return Result<TargetSeriesResult>.Fail(error);
+        }
+
+        Result<IReadOnlyList<SourceRow>> loaded = await _loader.LoadAsync(p.Plan, p.Range, agent, TargetSeries(task), ct);
+        if (!loaded.TryGet(out IReadOnlyList<SourceRow>? rows, out error))
+        {
+            return Result<TargetSeriesResult>.Fail(error);
+        }
+
+        BucketedRows bucketed = BucketedRows.Create(rows, p.Range);
+        int n = p.Range.Points;
+        var values = selection.ExportIds.ToDictionary(id => id, _ => new double?[n], StringComparer.Ordinal);
+        double widthSeconds = p.Plan.LevelWidthMs / 1000.0;
+        for (int i = 0; i < n; i++)
+        {
+            if (bucketed.Sets[i] is not { } set)
+            {
+                continue;
+            }
+
+            Dictionary<string, double> exported = ExportEvaluator.Evaluate(set, selection.ExportIds, bucketed.RowCounts[i] * widthSeconds);
+            foreach (string id in selection.ExportIds)
+            {
+                if (exported.TryGetValue(id, out double v))
+                {
+                    values[id][i] = v;
+                }
+            }
+        }
+
+        var versions = new Dictionary<string, string>(StringComparer.Ordinal);
+        foreach (string id in selection.ExportIds)
+        {
+            if (MetricRegistry.TryFindExport(id, out MetricDef def, out _))
+            {
+                versions[id] = def.Fingerprint;
+            }
+        }
+
+        SummaryResult summary = Summarize(bucketed.Merge(), bucketed.TotalRows, p.Plan, p.Range, selection, new Dictionary<string, double>());
+        return Result<TargetSeriesResult>.Ok(new TargetSeriesResult(p.Range, p.Plan, bucketed.T, values, summary, versions));
+    }
+
+    /// <summary>这个单个 Agent 任务最后一个样本的时刻（Unix 毫秒）；还没有数据返回 null。</summary>
+    public ValueTask<long?> TargetLatestAsync(NodeId agent, TaskId task, CancellationToken ct) =>
+        _loader.LatestSampleMsAsync(agent, TargetSeries(task), _time.GetUtcNow().ToUnixTimeMilliseconds(), ct);
+
+    private static string TargetSeries(TaskId task) => "target:" + task.Value;
+
     /// <summary>这条线路最早的数据（Unix 毫秒）；没有数据返回 null。</summary>
     public ValueTask<long?> EarliestAsync(LineKey line, CancellationToken ct) =>
         _loader.EarliestSampleMsAsync(line.Listener, line.Series, _time.GetUtcNow().ToUnixTimeMilliseconds(), ct);

backend/src/MoShiro.Backend.Application/Query/Targets.cs

@@ -0,0 +1,39 @@
+using Fleet.Server;
+
+namespace MoShiro.Backend.Application;
+
+/// <summary>一个 Agent 上正在（或应该）运行的单个 Agent 任务：这个 Agent 的有效任务集里 <c>scope=target</c> 的那些。</summary>
+public sealed record TargetView(AgentView Agent, EffectiveTask Task);
+
+/// <summary>单个 Agent 任务目录：按 Agent 展开模板、覆盖和专属任务，列出每个 Agent 实际执行的目标。</summary>
+public sealed class TargetService
+{
+    private readonly AgentService _agents;
+    private readonly ITaskStore _tasks;
+
+    public TargetService(AgentService agents, ITaskStore tasks)
+    {
+        _agents = agents;
+        _tasks = tasks;
+    }
+
+    public async ValueTask<IReadOnlyList<TargetView>> ListAsync(Func<AgentView, bool> include, CancellationToken ct)
+    {
+        IReadOnlyList<TaskRecord> all = await _tasks.ListAsync(ct);
+        var result = new List<TargetView>();
+        foreach (AgentView view in await _agents.ListAsync(ct))
+        {
+            if (view.Agent.Status != NodeStatus.Active || !include(view))
+            {
+                continue;
+            }
+
+            foreach (EffectiveTask task in EffectiveTasks.Compute(all, view.Agent, filterByAgentKinds: false).Where(t => t.Scope == EffectiveTasks.TargetScope))
+            {
+                result.Add(new TargetView(view, task));
+            }
+        }
+
+        return result;
+    }
+}

backend/src/MoShiro.Backend.Application/Tasks/EffectiveTasks.cs

@@ -13,7 +13,7 @@ public sealed record EffectiveTask(
     ParamValues Resolved);
 
 /// <summary>
-/// 有效任务集：线路任务模板 + 针对单个 Agent 的覆盖 + 该 Agent 的目标任务。
+/// 有效任务集：任务模板（线路任务、单个 Agent 的任务）+ 针对单个 Agent 的覆盖 + 只属于该 Agent 的目标任务。
 /// 参数经 ParamSpec 校验并补全默认值，Backend 和节点使用同一套规则。
 /// </summary>
 public static class EffectiveTasks
@@ -35,23 +35,23 @@ public static class EffectiveTasks
 
         foreach (TaskRecord task in all.OrderBy(t => t.Id.Value, StringComparer.Ordinal))
         {
-            if (task.Scope == LineScope && task.AgentId is null)
+            if (task.AgentId is null)
             {
-                // 模板：有覆盖时以覆盖为准（覆盖可以停用或改参数）
+                // 模板（线路任务或单个 Agent 的任务）：有覆盖时以覆盖为准（覆盖可以停用、改参数，单个 Agent 的任务还可以换目标）
                 TaskRecord? over = overrides.GetValueOrDefault(task.Id);
                 if (over is not null)
                 {
                     if (over.Enabled)
                     {
-                        Add(result, over.Id, task.Scope, over.Kind, null, Merge(task.Params, over.Params), over.Schedule, agent, filterByAgentKinds);
+                        Add(result, over.Id, task.Scope, over.Kind, over.Target ?? task.Target, Merge(task.Params, over.Params), over.Schedule, agent, filterByAgentKinds);
                     }
                 }
                 else if (task.Enabled)
                 {
-                    Add(result, task.Id, task.Scope, task.Kind, null, task.Params, task.Schedule, agent, filterByAgentKinds);
+                    Add(result, task.Id, task.Scope, task.Kind, task.Target, task.Params, task.Schedule, agent, filterByAgentKinds);
                 }
             }
-            else if (task.Scope == TargetScope && task.AgentId == agent.Id && task.Enabled)
+            else if (task.Scope == TargetScope && task.AgentId == agent.Id && task.BaseTaskId is null && task.Enabled)
             {
                 Add(result, task.Id, task.Scope, task.Kind, task.Target, task.Params, task.Schedule, agent, filterByAgentKinds);
             }

backend/src/MoShiro.Backend.Application/Tasks/TaskService.cs

@@ -41,7 +41,7 @@ public sealed class TaskService
     public ValueTask<TaskRecord?> GetAsync(TaskId id, CancellationToken ct) => _tasks.GetAsync(id, ct);
 
     /// <summary>
-    /// 创建默认的线路任务模板，这样新 Agent 注册后自动获得任务：udp_echo、tcp_echo 持续运行，connect（TCP 建连和 TLS 握手耗时，
+    /// 创建默认的线路任务模板，这样新 Agent 注册后自动获得任务：quic_ping、tcp_ping 持续运行，connect（TCP 建连和 TLS 握手耗时，
     /// 每分钟 6 次）也持续运行。每一批默认任务只种一次，用设置里的标记记住；你删掉的默认模板不会被重新建出来，
     /// 后来新增的默认任务（connect）在已有部署升级后会补建一次。
     /// </summary>
@@ -49,13 +49,13 @@ public sealed class TaskService
     {
         if (await _settings.GetAsync("tasks.seeded", ct) is null)
         {
-            await SeedAsync([Kinds.UdpEcho, Kinds.TcpEcho], ct);
+            await SeedAsync([Kinds.QuicPing, Kinds.TcpPing], ct);
             await _settings.SetAsync("tasks.seeded", "1", ct);
         }
 
         if (await _settings.GetAsync("tasks.seeded.connect", ct) is null)
         {
-            await SeedAsync([Kinds.Connect], ct);
+            await SeedAsync([Kinds.TcpConnect], ct);
             await _settings.SetAsync("tasks.seeded.connect", "1", ct);
         }
     }
@@ -223,9 +223,31 @@ public sealed class TaskService
 
         if (scope == EffectiveTasks.TargetScope)
         {
-            if (agentId is null || !TryNormalizeTarget(target, out string? normalized))
+            // 单个 Agent 的任务：没有 agent_id 是模板（所有 Agent 各自对这个目标执行），有 agent_id 是只属于这个 Agent 的任务，
+            // 或者（带 base_task_id）覆盖模板的参数、停用它、换一个目标
+            if (baseTaskId is { } templateId)
             {
-                return ValidationError.Fail<ValidatedTask>("target", agentId is null ? "agent_id is required for target tasks" : "must be an IP address with an optional port");
+                TaskRecord? template = await _tasks.GetAsync(templateId, ct);
+                if (agentId is null || template is null || template.AgentId is not null || template.Scope != EffectiveTasks.TargetScope)
+                {
+                    return ValidationError.Fail<ValidatedTask>("base_task_id", "must reference a single-agent template and requires agent_id");
+                }
+
+                if (template.Kind != kind)
+                {
+                    return ValidationError.Fail<ValidatedTask>("kind", "an override must use the same kind as its template");
+                }
+
+                if (target is null)
+                {
+                    return Result<ValidatedTask>.Ok(new ValidatedTask(null));
+                }
+            }
+
+            string? normalized = TargetHost.Normalize(kind, target);
+            if (normalized is null)
+            {
+                return ValidationError.Fail<ValidatedTask>("target", kind == TargetHost.HttpKind ? "must be an http:// or https:// URL" : "must be a host name or IP address with an optional port");
             }
 
             return Result<ValidatedTask>.Ok(new ValidatedTask(normalized));
@@ -288,28 +310,4 @@ public sealed class TaskService
 
         return Result<bool>.Ok(true);
     }
-
-    /// <summary>只接受 IP 地址（可带端口），不做 DNS 解析，避免把 Agent 用作解析器。</summary>
-    public static bool TryNormalizeTarget(string? target, out string? normalized)
-    {
-        normalized = null;
-        if (string.IsNullOrWhiteSpace(target))
-        {
-            return false;
-        }
-
-        if (IPAddress.TryParse(target, out IPAddress? ip))
-        {
-            normalized = ip.ToString();
-            return true;
-        }
-
-        if (IPEndPoint.TryParse(target, out IPEndPoint? endpoint) && endpoint.Port is > 0 and <= 65535)
-        {
-            normalized = endpoint.ToString();
-            return true;
-        }
-
-        return false;
-    }
 }

backend/src/MoShiro.Backend.Application/Tests/Plans.cs

@@ -18,7 +18,7 @@ public static class Plans
     private static JsonElement S(string value) => JsonSerializer.SerializeToElement(value, PlanJson.Default.String);
 
     private static PhaseSpec Train(double mbps) =>
-        new("udp_train", new Dictionary<string, JsonElement> { ["mbps"] = N(mbps), ["duration_s"] = N(10) }, 10);
+        new("quic_stream", new Dictionary<string, JsonElement> { ["mbps"] = N(mbps), ["duration_s"] = N(10) }, 10);
 
     public static readonly PlanSpec Hy2Ladder = new(
         "hy2_ladder",
@@ -31,9 +31,9 @@ public static class Plans
         "REALITY session",
         "Connection establishment, a short (4 s) bulk transfer for the peak throughput and a held connection.",
         [
-            new PhaseSpec("connect", new Dictionary<string, JsonElement> { ["per_minute"] = N(20) }, 30),
-            new PhaseSpec("tcp_bulk", new Dictionary<string, JsonElement> { ["duration_s"] = N(4), ["direction"] = S("rev") }, 4),
-            new PhaseSpec("hold", new Dictionary<string, JsonElement> { ["heartbeat_s"] = N(5) }, 30),
+            new PhaseSpec("tcp_connect", new Dictionary<string, JsonElement> { ["per_minute"] = N(20) }, 30),
+            new PhaseSpec("tcp_transfer", new Dictionary<string, JsonElement> { ["duration_s"] = N(4), ["direction"] = S("rev") }, 4),
+            new PhaseSpec("tls_hold", new Dictionary<string, JsonElement> { ["heartbeat_s"] = N(5) }, 30),
         ]);
 
     public static readonly IReadOnlyList<PlanSpec> All = [Hy2Ladder, RealitySession];

backend/src/MoShiro.Backend.Application/Updates/BackendAutoUpdater.cs

@@ -0,0 +1,100 @@
+using Microsoft.Extensions.Hosting;
+using Microsoft.Extensions.Logging;
+using MoShiro.Protocol;
+
+namespace MoShiro.Backend.Application;
+
+/// <summary>
+/// 自动更新（<see cref="BackendOptions.AutoUpdate"/>，默认关）：每分钟看一眼面板上登记的 Backend 新版本，登记满 <see cref="BackendOptions.AutoUpdateDelayMinutes"/> 分钟之后
+/// 替管理员确认。确认走 <see cref="BackendUpdates.ConfirmAsync"/>，所以数据库备份、清单签名、「只更新到登记时的那一版」都和手动更新一样；
+/// 更新是有序退出，由 Quadlet 单元（<c>Pull=always</c>、<c>Restart=always</c>）拉起新镜像。
+/// </summary>
+public sealed partial class BackendAutoUpdater : BackgroundService
+{
+    private static readonly TimeSpan s_startupDelay = TimeSpan.FromMinutes(2);
+    private static readonly TimeSpan s_interval = TimeSpan.FromMinutes(1);
+
+    private readonly BackendUpdates _updates;
+    private readonly BackendOptions _options;
+    private readonly TimeProvider _time;
+    private readonly ILogger<BackendAutoUpdater> _log;
+
+    public BackendAutoUpdater(BackendUpdates updates, BackendOptions options, TimeProvider time, ILogger<BackendAutoUpdater> log)
+    {
+        _updates = updates;
+        _options = options;
+        _time = time;
+        _log = log;
+    }
+
+    protected override async Task ExecuteAsync(CancellationToken stoppingToken)
+    {
+        if (!_options.AutoUpdate)
+        {
+            return;
+        }
+
+        try
+        {
+            await Task.Delay(s_startupDelay, _time, stoppingToken);
+            using var timer = new PeriodicTimer(s_interval, _time);
+            do
+            {
+                try
+                {
+                    await RunOnceAsync(stoppingToken);
+                }
+                catch (Exception ex) when (ex is not OperationCanceledException)
+                {
+                    Failed(ex);
+                }
+            }
+            while (await timer.WaitForNextTickAsync(stoppingToken));
+        }
+        catch (OperationCanceledException)
+        {
+            // 后端正在停止
+        }
+    }
+
+    /// <summary>检查一次；确认了更新（Backend 即将有序退出）返回 true。</summary>
+    public async ValueTask<bool> RunOnceAsync(CancellationToken ct)
+    {
+        if (!_options.AutoUpdate || !_updates.Enabled)
+        {
+            return false;
+        }
+
+        BackendUpdateView view = await _updates.GetAsync(ct);
+        if (view.State != "available" || view.Available is not { } offer)
+        {
+            return false;
+        }
+
+        // 清单的 seq 是发布时间（秒）
+        TimeSpan age = _time.GetUtcNow() - DateTimeOffset.FromUnixTimeSeconds(offer.Seq);
+        if (age < TimeSpan.FromMinutes(Math.Max(0, _options.AutoUpdateDelayMinutes)))
+        {
+            return false;
+        }
+
+        Fleet.Core.Result<bool> result = await _updates.ConfirmAsync(offer.Seq, ct);
+        if (!result.IsSuccess)
+        {
+            Refused(offer.Tag, result.Error.Message);
+            return false;
+        }
+
+        AutoConfirmed(offer.Tag, (int)age.TotalMinutes);
+        return true;
+    }
+
+    [LoggerMessage(Level = LogLevel.Information, Message = "auto update: {Tag} was offered {Minutes} minutes ago, confirming it")]
+    private partial void AutoConfirmed(string tag, int minutes);
+
+    [LoggerMessage(Level = LogLevel.Warning, Message = "auto update to {Tag} was not started: {Reason}")]
+    private partial void Refused(string tag, string reason);
+
+    [LoggerMessage(Level = LogLevel.Warning, Message = "the auto update check failed")]
+    private partial void Failed(Exception exception);
+}

backend/src/MoShiro.Backend.Gateway/FleetGateway.cs

@@ -50,6 +50,15 @@ public sealed class FleetGateway : IAgentGateway
         await Connections.RequestAsync(
             agent, MoShiroMethods.TestCancel, new TestCancelParams { TestId = test }, MoShiroJsonContext.Default.TestCancelParams, MoShiroJsonContext.Default.TestRunResult, ct);
 
+    public async ValueTask<Result<LogsFetchResult>> FetchLogsAsync(NodeId node, LogsFetchParams request, CancellationToken ct)
+    {
+        Result<LogsFetchResult> result = await Connections.RequestAsync(
+            node, MoShiroMethods.LogsFetch, request, MoShiroJsonContext.Default.LogsFetchParams, MoShiroJsonContext.Default.LogsFetchResult, ct);
+        return result.TryGet(out LogsFetchResult? page, out FleetError? error)
+            ? Result<LogsFetchResult>.Ok(page)
+            : Result<LogsFetchResult>.Fail(error.Code == FleetErrors.NodeOffline ? MoShiroErrors.AgentOffline : error.Code, error.Message);
+    }
+
     public async ValueTask<Result<bool>> DisconnectDialerAsync(NodeId listener, NodeId dialer, CancellationToken ct)
     {
         Result<TestRunResult> result = await Connections.RequestAsync(

backend/src/MoShiro.Backend.Gateway/GatewayServiceCollectionExtensions.cs

@@ -16,6 +16,7 @@ public static class GatewayServiceCollectionExtensions
     public static IServiceCollection AddMoShiroGateway(this IServiceCollection services)
     {
         services.AddSingleton<IAgentGateway, FleetGateway>();
+        services.AddSingleton<IFleetVersionPolicy, BackendVersionPolicy>();
         services.AddHostedService<ConnectionShutdown>();
         services.AddFleetEnrollment();
         services.AddFleetServer(options => options.NodeIdPrefix = AgentIds.Prefix)
@@ -44,3 +45,11 @@ public static class GatewayServiceCollectionExtensions
                 (context, parameters, ct) => services.GetRequiredService<TestService>().OnStatusAsync(context.Node.Id, parameters, ct));
     }
 }
+
+/// <summary>握手时的版本要求：告诉 Agent 面板的版本，并要求 Agent 不低于配置的最低版本。</summary>
+internal sealed class BackendVersionPolicy(BackendOptions options) : IFleetVersionPolicy
+{
+    public string? ServerVersion => BuildInfo.Version;
+
+    public string? MinNodeVersion => string.IsNullOrWhiteSpace(options.MinAgentVersion) ? null : options.MinAgentVersion;
+}

backend/src/MoShiro.Backend.Storage.Sqlite/Schema.cs

@@ -3,12 +3,12 @@ using Microsoft.Data.Sqlite;
 namespace MoShiro.Backend.Storage.Sqlite;
 
 /// <summary>
-/// 表结构。版本记录在 <c>PRAGMA user_version</c>。当前只有一个版本：不是这个版本的数据库（包括更早的构建留下的）不会被迁移，
-/// 启动时报错，删除 <c>moshiro.db</c> 和 <c>raw/</c> 之后重新开始。以后的结构变更按版本号追加内置 SQL。
+/// 表结构。版本记录在 <c>PRAGMA user_version</c>。版本 1 到 2 只改了 Kind 的名字（见 <see cref="RenameKinds"/>）；
+/// 其他版本的数据库（包括更早的构建留下的）不会被迁移，启动时报错，删除 <c>moshiro.db</c> 和 <c>raw/</c> 之后重新开始。以后的结构变更按版本号追加内置 SQL。
 /// </summary>
 internal static class Schema
 {
-    public const int CurrentVersion = 1;
+    public const int CurrentVersion = 2;
 
     public static void Migrate(SqliteConnection connection)
     {
@@ -18,6 +18,21 @@ internal static class Schema
             return;
         }
 
+        if (version == 1)
+        {
+            using SqliteTransaction upgrade = connection.BeginTransaction();
+            foreach ((string from, string to) in RenameKinds)
+            {
+                connection.Exec($"UPDATE tasks SET kind = '{to}' WHERE kind = '{from}'");
+                connection.Exec($"UPDATE raw_chunks SET kind = '{to}' WHERE kind = '{from}'");
+                connection.Exec($"UPDATE tests SET plan = REPLACE(plan, '\"{from}\"', '\"{to}\"')");
+            }
+
+            connection.Exec("PRAGMA user_version = 2");
+            upgrade.Commit();
+            return;
+        }
+
         if (version != 0)
         {
             throw new InvalidOperationException($"database schema version {version} is not supported by this build (expected {CurrentVersion}); delete moshiro.db and the raw/ directory to start over");
@@ -25,10 +40,17 @@ internal static class Schema
 
         using SqliteTransaction transaction = connection.BeginTransaction();
         connection.Exec(V1);
-        connection.Exec("PRAGMA user_version = 1");
+        connection.Exec("PRAGMA user_version = 2");
         transaction.Commit();
     }
 
+    /// <summary>版本 2：Kind 改成「协议 + 做什么」的名字。任务和原始数据索引跟着改；已经落盘的原始块头里还是旧名字，按旧名字解不出指标，重算不到它们，已经算好的指标不受影响。</summary>
+    private static readonly (string From, string To)[] RenameKinds =
+    [
+        ("udp_echo", "quic_ping"), ("tcp_echo", "tcp_ping"), ("udp_train", "quic_stream"), ("tcp_bulk", "tcp_transfer"),
+        ("connect", "tcp_connect"), ("hold", "tls_hold"), ("icmp_echo", "icmp_ping"),
+    ];
+
     /// <summary>
     /// 新增 Kind 或指标都不需要改表结构：指标是 <c>metric_*.metrics</c> 里的一个键，Kind 只是 <c>raw_chunks.kind</c> 的一个取值。
     /// 节点只有一张表（<c>agents</c>）：监听的节点有地址和端口，不监听的节点只拨出。线路 <c>(agent_id, series)</c> 里的 agent_id 是监听方，series 里是拨号方。

backend/tests/MoShiro.Backend.Analysis.Tests/ModelAndTestEvaluatorTests.cs

@@ -32,8 +32,8 @@ public sealed class ModelAndTestEvaluatorTests
     [Fact]
     public void Fingerprint_ChangesWhenTheOpChanges()
     {
-        var a = Metric.Counter("x", ["udp_echo.msg"], Ops.Gap(GapOutput.Count, "rate_hz", 100), "x", "x", new MetricExport("x", Stat.Count, Unit.Count));
-        var b = Metric.Counter("x", ["udp_echo.msg"], Ops.Gap(GapOutput.Count, "rate_hz", 200), "x", "x", new MetricExport("x", Stat.Count, Unit.Count));
+        var a = Metric.Counter("x", ["quic_ping.msg"], Ops.Gap(GapOutput.Count, "rate_hz", 100), "x", "x", new MetricExport("x", Stat.Count, Unit.Count));
+        var b = Metric.Counter("x", ["quic_ping.msg"], Ops.Gap(GapOutput.Count, "rate_hz", 200), "x", "x", new MetricExport("x", Stat.Count, Unit.Count));
         Assert.NotEqual(a.Fingerprint, b.Fingerprint);
     }
 

backend/tests/MoShiro.Backend.Analysis.Tests/OpTests.cs

@@ -25,17 +25,36 @@ public sealed class OpTests
     [Fact]
     public void Rtt_RemovesAgentProcessingTime()
     {
-        RawChunk chunk = ChunkFactory.Echo(s_agent, "udp_echo", T0, 100, 100, _ => new EchoPacket(false, false, 20_000, 30_000, ProcessUs: 5_000));
+        RawChunk chunk = ChunkFactory.Echo(s_agent, "quic_ping", T0, 100, 100, _ => new EchoPacket(false, false, 20_000, 30_000, ProcessUs: 5_000));
         var rtt = (HistogramAcc)EvaluateOneBucket(chunk, "rtt").Items["rtt"];
         Assert.Equal(100UL, rtt.Count);
         Assert.InRange(rtt.Quantile(0.5)!.Value, 50 * 0.955, 50 * 1.045);
     }
 
+    [Fact]
+    public void SampleWeights_KeepRttQuantilesAndLossTimeAveraged_WhenTheProbeRateChanges()
+    {
+        static EchoPacket At(int i) => new(LostUp: i % 20 < 2, LostDown: false, i % 10 < 2 ? 100_000 : 20_000, 20_000);
+
+        // 每 100 ms 一个包，每个权重 1；对照：只取偶数行，每 200 ms 一个包，每个权重 2——代表同样长的时间
+        RawChunk dense = ChunkFactory.Echo(s_agent, "quic_ping", T0, 100, 100, At);
+        RawChunk sparse = ChunkFactory.Echo(s_agent, "quic_ping", T0, 50, 200, i => At(i * 2), weight: _ => 2);
+
+        MetricSet d = EvaluateOneBucket(dense, "rtt", "loss.up", "loss.total");
+        MetricSet s = EvaluateOneBucket(sparse, "rtt", "loss.up", "loss.total");
+        var dr = (HistogramAcc)d.Items["rtt"];
+        var sr = (HistogramAcc)s.Items["rtt"];
+        Assert.Equal(dr.Count, sr.Count); // 稀疏的 45 个回复各按权重 2 累计，和密集的 90 个一样
+        Assert.Equal(dr.Quantile(0.5), sr.Quantile(0.5));
+        Assert.Equal(dr.Quantile(0.95), sr.Quantile(0.95));
+        Assert.Equal(((RatioAcc)d.Items["loss.up"]).Percent, ((RatioAcc)s.Items["loss.up"]).Percent);
+    }
+
     [Fact]
     public void Loss_SeparatesUpAndDown()
     {
         RawChunk chunk = ChunkFactory.Echo(
-            s_agent, "udp_echo", T0, 100, 100,
+            s_agent, "quic_ping", T0, 100, 100,
             i => new EchoPacket(LostUp: i < 10, LostDown: i is >= 10 and < 15, 20_000, 20_000));
         MetricSet set = EvaluateOneBucket(chunk, "loss.up", "loss.down", "loss.total");
 
@@ -58,7 +77,7 @@ public sealed class OpTests
     public void Jitter_OnlyOneDirectionVaries_IsAttributedToThatDirection()
     {
         // 下行时延每隔一个包多 20 ms
-        RawChunk chunk = ChunkFactory.Echo(s_agent, "udp_echo", T0, 100, 100, i => new EchoPacket(false, false, 20_000, 20_000 + (i % 2 == 0 ? 20_000 : 0)));
+        RawChunk chunk = ChunkFactory.Echo(s_agent, "quic_ping", T0, 100, 100, i => new EchoPacket(false, false, 20_000, 20_000 + (i % 2 == 0 ? 20_000 : 0)));
         MetricSet set = EvaluateOneBucket(chunk, "jitter.up", "jitter.down");
         Assert.True(((HistogramAcc)set.Items["jitter.up"]).Quantile(0.95) < 0.5);
         Assert.InRange(((HistogramAcc)set.Items["jitter.down"]).Quantile(0.95)!.Value, 15, 25);
@@ -76,7 +95,7 @@ public sealed class OpTests
     public void LossRuns_ReportsConsecutiveLosses()
     {
         bool[] lost = [false, true, true, true, false, true, false, false, true, true];
-        RawChunk chunk = ChunkFactory.Echo(s_agent, "udp_echo", T0, lost.Length, 100, i => new EchoPacket(false, lost[i], 20_000, 20_000));
+        RawChunk chunk = ChunkFactory.Echo(s_agent, "quic_ping", T0, lost.Length, 100, i => new EchoPacket(false, lost[i], 20_000, 20_000));
         var runs = (RunLengthAcc)EvaluateOneBucket(chunk, "loss.run").Items["loss.run"];
         Assert.Equal(3UL, runs.Runs);
         Assert.Equal(3, runs.Max);
@@ -86,7 +105,7 @@ public sealed class OpTests
     [Fact]
     public void LossRuns_TrailingRunIsReported()
     {
-        RawChunk chunk = ChunkFactory.Echo(s_agent, "udp_echo", T0, 4, 100, i => new EchoPacket(false, i >= 2, 20_000, 20_000));
+        RawChunk chunk = ChunkFactory.Echo(s_agent, "quic_ping", T0, 4, 100, i => new EchoPacket(false, i >= 2, 20_000, 20_000));
         Assert.Equal(2, ((RunLengthAcc)EvaluateOneBucket(chunk, "loss.run").Items["loss.run"]).Max);
     }
 
@@ -95,7 +114,7 @@ public sealed class OpTests
     {
         bool[] upLost = [false, true, true, false, false, false, true, true];
         bool[] downLost = [false, false, true, true, false, true, false, true];
-        RawChunk chunk = ChunkFactory.Echo(s_agent, "udp_echo", T0, upLost.Length, 100,
+        RawChunk chunk = ChunkFactory.Echo(s_agent, "quic_ping", T0, upLost.Length, 100,
             i => new EchoPacket(upLost[i], downLost[i], 20_000, 20_000));
 
         MetricSet set = EvaluateOneBucket(chunk, "loss.run.up", "loss.run.down");
@@ -116,7 +135,7 @@ public sealed class OpTests
     public void Reorder_CountsLateArrivals_AndIgnoresDuplicates()
     {
         // 包 3 的回复比包 4 晚到
-        RawChunk chunk = ChunkFactory.Echo(s_agent, "udp_echo", T0, 6, 100, i => new EchoPacket(false, false, 20_000, i == 3 ? 150_000 : 20_000));
+        RawChunk chunk = ChunkFactory.Echo(s_agent, "quic_ping", T0, 6, 100, i => new EchoPacket(false, false, 20_000, i == 3 ? 150_000 : 20_000));
         MetricSet set = EvaluateOneBucket(chunk, "reorder", "dup");
         Assert.Equal(1UL, ((CounterAcc)set.Items["reorder"]).Value);
         Assert.False(set.Items.ContainsKey("dup"));
@@ -127,7 +146,7 @@ public sealed class OpTests
     {
         // 第 40 个包之后的 10 个包被队头阻塞，全部在 2540 ms 之后几乎同时到达
         RawChunk chunk = ChunkFactory.Echo(
-            s_agent, "tcp_echo", T0, 100, 50,
+            s_agent, "tcp_ping", T0, 100, 50,
             i => new EchoPacket(false, false, 20_000, i is >= 40 and < 50 ? ((2540 + (i - 40) - (50 * i) - 20) * 1000) - 50 : 20_000));
         MetricSet set = EvaluateOneBucket(chunk, "tcp.stall", "tcp.stall_max");
         Assert.Equal(1UL, ((CounterAcc)set.Items["tcp.stall"]).Value);
@@ -137,7 +156,7 @@ public sealed class OpTests
     [Fact]
     public void Stall_SteadyArrivals_AreNotStalls()
     {
-        RawChunk chunk = ChunkFactory.Echo(s_agent, "tcp_echo", T0, 100, 50, _ => new EchoPacket(false, false, 20_000, 20_000));
+        RawChunk chunk = ChunkFactory.Echo(s_agent, "tcp_ping", T0, 100, 50, _ => new EchoPacket(false, false, 20_000, 20_000));
         MetricSet set = EvaluateOneBucket(chunk, "tcp.stall");
         Assert.False(set.Items.ContainsKey("tcp.stall"));
     }
@@ -147,7 +166,7 @@ public sealed class OpTests
     {
         // 基线 50 ms（单程 25 ms），阈值 = max(90, 50 + max(15, 17.5)) = 90 ms；第 10、20、30 个回显的 RTT 是 200 ms
         RawChunk chunk = ChunkFactory.Echo(
-            s_agent, "tcp_echo", T0, 100, 50,
+            s_agent, "tcp_ping", T0, 100, 50,
             i => new EchoPacket(false, false, 25_000, i % 10 == 0 && i > 0 && i < 40 ? 175_000 : 25_000, ProcessUs: 0));
         var slow = (RatioAcc)EvaluateOneBucket(chunk, "tcp.slow").Items["tcp.slow"];
         Assert.Equal(100UL, slow.Denominator);
@@ -157,10 +176,10 @@ public sealed class OpTests
     [Fact]
     public void Slow_ASteadyConnection_HasNoLongTail_AndTooFewSamplesGiveNoObservation()
     {
-        RawChunk steady = ChunkFactory.Echo(s_agent, "tcp_echo", T0, 100, 50, _ => new EchoPacket(false, false, 25_000, 25_000));
+        RawChunk steady = ChunkFactory.Echo(s_agent, "tcp_ping", T0, 100, 50, _ => new EchoPacket(false, false, 25_000, 25_000));
         Assert.Equal(0UL, ((RatioAcc)EvaluateOneBucket(steady, "tcp.slow").Items["tcp.slow"]).Numerator);
 
-        RawChunk few = ChunkFactory.Echo(s_agent, "tcp_echo", T0, 10, 50, i => new EchoPacket(false, false, 25_000, i == 5 ? 500_000 : 25_000));
+        RawChunk few = ChunkFactory.Echo(s_agent, "tcp_ping", T0, 10, 50, i => new EchoPacket(false, false, 25_000, i == 5 ? 500_000 : 25_000));
         Assert.False(EvaluateOneBucket(few, "tcp.slow").Items.ContainsKey("tcp.slow"));
     }
 
@@ -169,7 +188,7 @@ public sealed class OpTests
     {
         // 1000 个回显，其中 5 个 1 s 的长尾：p50 约 50 ms，p99 仍在 50 ms 附近，p99.9 落在长尾上
         RawChunk chunk = ChunkFactory.Echo(
-            s_agent, "tcp_echo", T0, 1000, 10,
+            s_agent, "tcp_ping", T0, 1000, 10,
             i => new EchoPacket(false, false, 25_000, i % 200 == 0 && i > 0 ? 975_000 : 25_000, ProcessUs: 0), durationMs: 20_000);
         var rtt = (HistogramAcc)EvaluateOneBucket(chunk, "tcp.rtt").Items["tcp.rtt"];
         MetricDef def = TcpMetrics.Rtt;
@@ -194,7 +213,7 @@ public sealed class OpTests
             (baseUs + 1_000_000, 0, 40_000u, 2u, 300u),
             (baseUs + 2_000_000, 0, 40_000u, 2u, 500u),
         ]);
-        RawChunk chunk = ChunkFactory.Echo(s_agent, "tcp_echo", T0, 10, 100, _ => new EchoPacket(false, false, 20_000, 20_000), extraStreams: [info]);
+        RawChunk chunk = ChunkFactory.Echo(s_agent, "tcp_ping", T0, 10, 100, _ => new EchoPacket(false, false, 20_000, 20_000), extraStreams: [info]);
         var retrans = (RatioAcc)EvaluateOneBucket(chunk, "tcp.retrans").Items["tcp.retrans"];
         Assert.Equal(2UL, retrans.Numerator);
         Assert.Equal(400UL, retrans.Denominator);
@@ -205,7 +224,7 @@ public sealed class OpTests
     {
         long baseUs = ChunkFactory.DialerUs(0);
         RawStream info = ChunkFactory.TcpInfo([(baseUs, 0, 1u, 10u, 100u), (baseUs + 1_000_000, 0, 1u, 0u, 50u), (baseUs + 2_000_000, 0, 1u, 1u, 150u)]);
-        RawChunk chunk = ChunkFactory.Echo(s_agent, "tcp_echo", T0, 10, 100, _ => new EchoPacket(false, false, 20_000, 20_000), extraStreams: [info]);
+        RawChunk chunk = ChunkFactory.Echo(s_agent, "tcp_ping", T0, 10, 100, _ => new EchoPacket(false, false, 20_000, 20_000), extraStreams: [info]);
         var retrans = (RatioAcc)EvaluateOneBucket(chunk, "tcp.retrans").Items["tcp.retrans"];
         Assert.Equal(1UL, retrans.Numerator);
         Assert.Equal(100UL, retrans.Denominator);
@@ -215,12 +234,12 @@ public sealed class OpTests
     public void Retrans_InterleavedConnections_DoNotCreateFalseRetransmissions()
     {
         long ts = ChunkFactory.DialerUs(0);
-        var builder = new StreamBuilder(Kinds.TcpEcho.FindStream("tcp_info")!);
+        var builder = new StreamBuilder(Kinds.TcpPing.FindStream("tcp_info")!);
         builder.Add(ts, 0, 40_000, 0, 10, 10, 1000, 0, 1);
         builder.Add(ts + 1_000_000, 0, 40_000, 0, 10, 20, 1100, 0, 2);
         builder.Add(ts + 2_000_000, 0, 40_000, 0, 10, 11, 1100, 0, 1);
         builder.Add(ts + 3_000_000, 0, 40_000, 0, 10, 21, 1200, 0, 2);
-        RawChunk chunk = ChunkFactory.Echo(s_agent, "tcp_echo", T0, 10, 100,
+        RawChunk chunk = ChunkFactory.Echo(s_agent, "tcp_ping", T0, 10, 100,
             _ => new EchoPacket(false, false, 20_000, 20_000), extraStreams: [builder.Build()]);
         var retrans = (RatioAcc)EvaluateOneBucket(chunk, "tcp.retrans").Items["tcp.retrans"];
         Assert.Equal(2UL, retrans.Numerator);
@@ -237,7 +256,7 @@ public sealed class OpTests
             (ts + 1_000_000, 0, 40_000u, 1u, 200u),
             (ts + 3_000_000, 0, 40_000u, 3u, 400u),
         ]);
-        RawChunk chunk = ChunkFactory.Echo(s_agent, "tcp_echo", T0, 10, 100,
+        RawChunk chunk = ChunkFactory.Echo(s_agent, "tcp_ping", T0, 10, 100,
             _ => new EchoPacket(false, false, 20_000, 20_000), extraStreams: [info]);
         var retrans = (RatioAcc)EvaluateOneBucket(chunk, "tcp.retrans").Items["tcp.retrans"];
         Assert.Equal(3UL, retrans.Numerator);
@@ -248,12 +267,12 @@ public sealed class OpTests
     public void Retrans_EqualConnectionIdsOnDifferentSides_AreIndependent()
     {
         long ts = ChunkFactory.DialerUs(0);
-        var builder = new StreamBuilder(Kinds.TcpEcho.FindStream("tcp_info")!);
+        var builder = new StreamBuilder(Kinds.TcpPing.FindStream("tcp_info")!);
         builder.Add(ts, 0, 40_000, 0, 10, 10, 1000, 0, 1);
         builder.Add(ts, 1, 40_000, 0, 10, 100, 2000, 0, 1);
         builder.Add(ts + 1_000_000, 0, 40_000, 0, 10, 11, 1100, 0, 1);
         builder.Add(ts + 1_000_000, 1, 40_000, 0, 10, 102, 2200, 0, 1);
-        RawChunk chunk = ChunkFactory.Echo(s_agent, "tcp_echo", T0, 10, 100,
+        RawChunk chunk = ChunkFactory.Echo(s_agent, "tcp_ping", T0, 10, 100,
             _ => new EchoPacket(false, false, 20_000, 20_000), extraStreams: [builder.Build()]);
         var retrans = (RatioAcc)EvaluateOneBucket(chunk, "tcp.retrans").Items["tcp.retrans"];
         Assert.Equal(3UL, retrans.Numerator);
@@ -264,12 +283,12 @@ public sealed class OpTests
     public void Retrans_ForwardAndReturnAreSplitBySide()
     {
         long ts = ChunkFactory.DialerUs(0);
-        var builder = new StreamBuilder(Kinds.TcpEcho.FindStream("tcp_info")!);
+        var builder = new StreamBuilder(Kinds.TcpPing.FindStream("tcp_info")!);
         builder.Add(ts, 0, 40_000, 0, 10, 10, 1000, 0, 1);
         builder.Add(ts, 1, 40_000, 0, 10, 100, 2000, 0, 1);
         builder.Add(ts + 1_000_000, 0, 40_000, 0, 10, 11, 1100, 0, 1);
         builder.Add(ts + 1_000_000, 1, 40_000, 0, 10, 102, 2200, 0, 1);
-        RawChunk chunk = ChunkFactory.Echo(s_agent, "tcp_echo", T0, 10, 100,
+        RawChunk chunk = ChunkFactory.Echo(s_agent, "tcp_ping", T0, 10, 100,
             _ => new EchoPacket(false, false, 20_000, 20_000), extraStreams: [builder.Build()]);
         var forward = (RatioAcc)EvaluateOneBucket(chunk, "tcp.retrans.up").Items["tcp.retrans.up"];
         var back = (RatioAcc)EvaluateOneBucket(chunk, "tcp.retrans.down").Items["tcp.retrans.down"];
@@ -303,9 +322,9 @@ public sealed class OpTests
         // 10 秒的块，按 1 秒分桶：每个桶 10 个包
         RawChunk chunk = ChunkFactory.UdpEchoClean(s_agent, T0);
         var buckets = new SortedDictionary<long, MetricSet>();
-        WindowEvaluator.Default.Evaluate(chunk, 1000, buckets, new HashSet<string> { "n.udp_echo" });
+        WindowEvaluator.Default.Evaluate(chunk, 1000, buckets, new HashSet<string> { "n.quic_ping" });
         Assert.Equal(10, buckets.Count);
-        Assert.All(buckets.Values, set => Assert.Equal(10UL, ((CounterAcc)set.Items["n.udp_echo"]).Value));
+        Assert.All(buckets.Values, set => Assert.Equal(10UL, ((CounterAcc)set.Items["n.quic_ping"]).Value));
         Assert.Equal(T0, buckets.Keys.First());
     }
 

backend/tests/MoShiro.Backend.Tests/AdaptiveAuditTests.cs

@@ -0,0 +1,108 @@
+using System.Text.Json.Nodes;
+using Fleet.Core;
+using MoShiro.Backend.Application;
+using MoShiro.Protocol;
+using MoShiro.TestSupport;
+
+namespace MoShiro.Backend.Tests;
+
+public sealed class AdaptiveAuditTests : IClassFixture<BackendFixture>
+{
+    private static readonly long s_t0 = new DateTimeOffset(2026, 10, 22, 10, 0, 0, TimeSpan.Zero).ToUnixTimeMilliseconds();
+    private const long Minute = 60_000;
+    private const long Hour = 3_600_000;
+
+    private readonly BackendFixture _backend;
+
+    public AdaptiveAuditTests(BackendFixture backend)
+    {
+        _backend = backend;
+    }
+
+    private static RateChange Change(long atMs, string kind, string from, string to, double hz, string reason = "quiet", double lossPct = 0) =>
+        new() { AtMs = atMs, Kind = kind, From = from, To = to, Hz = hz, Reason = reason, LossPct = lossPct, Sent = 1000, Lost = (int)(lossPct * 10) };
+
+    /// <summary>状态变化还原成每个时间桶里各状态的秒数：跨桶的一段要切开，区间开头的状态取第一次变化的「从」，不同方法各算各的。</summary>
+    [Fact]
+    public void Summarize_SplitsStateTimeAcrossBuckets_AndWeightsTheAverageRateByTime()
+    {
+        RateChange[] changes =
+        [
+            Change(s_t0, "quic_ping", "start", "watch", 10, "start"),                              // 10:00 起步：watch 10 Hz
+            Change(s_t0 + (30 * Minute), "quic_ping", "watch", "quiet", 2),                        // 10:30 起 quiet 2 Hz
+            Change(s_t0 + (90 * Minute), "quic_ping", "quiet", "active", 10, "sustained loss", 0.4), // 11:30 起 active 10 Hz
+            Change(s_t0 + (30 * Minute), "tcp_ping", "quiet", "watch", 20, "rtt above baseline"),  // 这条方法 10:30 才有第一条记录
+        ];
+
+        AdaptiveResult result = AdaptiveAudit.Summarize(changes, s_t0, s_t0 + (2 * Hour), Hour);
+
+        AdaptiveKind quic = Assert.Single(result.Kinds, k => k.Kind == "quic_ping");
+        Assert.Equal(2, quic.Buckets.Count);
+        AdaptiveBucket first = quic.Buckets[0];
+        Assert.Equal((1800, 1800, 0), ((int)first.WatchSeconds, (int)first.QuietSeconds, (int)first.ActiveSeconds)); // 10:00–10:30 watch，10:30–11:00 quiet
+        Assert.Equal(6, first.AverageHz);                                                                           // (10 Hz × 30 min + 2 Hz × 30 min) / 60 min
+        Assert.Equal(2, first.Changes);
+        AdaptiveBucket second = quic.Buckets[1];
+        Assert.Equal((1800, 1800), ((int)second.QuietSeconds, (int)second.ActiveSeconds));                          // 11:00–11:30 quiet，11:30–12:00 active
+        Assert.Equal(6, second.AverageHz);                                                                          // (2 Hz × 30 min + 10 Hz × 30 min) / 60 min
+        Assert.Equal((1, 0.4), (second.Changes, second.MaxLossPct));
+
+        AdaptiveKind tcp = Assert.Single(result.Kinds, k => k.Kind == "tcp_ping");
+        Assert.Equal((0, 1800), ((int)tcp.Buckets[0].QuietSeconds, (int)tcp.Buckets[0].WatchSeconds)); // 10:00–10:30 没有记录，不算任何状态
+        Assert.Equal(3600, (int)tcp.Buckets[1].WatchSeconds);
+
+        Assert.Equal(4, result.Changes.Count);
+        Assert.Equal("quic_ping", result.Changes[0].Kind); // 最新的在前
+    }
+
+    /// <summary>变化在区间开头之前发生：那之后的状态延续到区间里。</summary>
+    [Fact]
+    public void Summarize_CarriesTheStateInFromBeforeTheRange()
+    {
+        RateChange[] changes = [Change(s_t0 - (2 * Hour), "quic_ping", "quiet", "active", 10, "sustained loss", 1)];
+
+        AdaptiveResult result = Summarize(changes);
+
+        AdaptiveBucket bucket = Assert.Single(Assert.Single(result.Kinds).Buckets);
+        Assert.Equal(3600, (int)bucket.ActiveSeconds);
+        Assert.Equal((10, 0), (bucket.AverageHz, bucket.Changes));
+        Assert.Empty(result.Changes); // 区间里没有变化
+
+        AdaptiveResult Summarize(RateChange[] c) => AdaptiveAudit.Summarize(c, s_t0, s_t0 + Hour, Hour);
+    }
+
+    /// <summary>端到端：拨号节点随心跳上报的状态变化存成事件，几天后还能通过接口按时段查到。</summary>
+    [Fact]
+    public async Task RateChangesReportedInHeartbeats_AreStored_AndServedByTheAdaptiveEndpoint()
+    {
+        await using AgentSimulator first = await _backend.ConnectAgentAsync();
+        await using AgentSimulator second = await _backend.ConnectAgentAsync();
+        (AgentSimulator dialer, AgentSimulator listener) = string.CompareOrdinal(first.NodeId.Value, second.NodeId.Value) < 0 ? (first, second) : (second, first); // 小 id 拨大 id
+        long now = TimeProvider.System.GetUtcNow().ToUnixTimeMilliseconds();
+
+        RateChange Of(long atMs, string from, string to, double hz, string reason, double loss)
+        {
+            RateChange change = Change(atMs, "quic_ping", from, to, hz, reason, loss);
+            change.Listener = listener.NodeId.Value;
+            change.IpVersion = "ipv4";
+            return change;
+        }
+
+        await dialer.SendRateChangesAsync(Of(now - (20 * Minute), "watch", "quiet", 2, "quiet", 0), Of(now - (10 * Minute), "quiet", "active", 10, "sustained loss", 0.5));
+
+        string lineId = listener.NodeId.Value + "~" + dialer.NodeId.Value;
+        JsonNode? audit = null;
+        await BackendFixture.EventuallyAsync(async () =>
+        {
+            audit = await _backend.GetJsonAsync(_backend.Admin, $"/api/public/lines/{lineId}/adaptive?range=1h&step=10m");
+            return audit["changes"]!.AsArray().Count == 2;
+        });
+
+        JsonNode quic = Assert.Single(audit!["kinds"]!.AsArray())!;
+        Assert.Equal("quic_ping", quic["kind"]!.GetValue<string>());
+        double active = quic["buckets"]!.AsArray().Sum(b => b!["active_seconds"]!.GetValue<double>());
+        Assert.InRange(active, 500, 700); // 最近 10 分钟 active
+        JsonNode newest = audit!["changes"]![0]!;
+        Assert.Equal(("quiet", "active", "sustained loss"), (newest["from"]!.GetValue<string>(), newest["to"]!.GetValue<string>(), newest["reason"]!.GetValue<string>()));
+    }
+}

backend/tests/MoShiro.Backend.Tests/AgentDataPlaneTests.cs

@@ -22,8 +22,8 @@ public sealed class AgentDataPlaneTests : IClassFixture<BackendFixture>
         AgentHarness agent = await AgentHarness.StartAsync(_backend);
         await agent.OverrideLineTasksAsync(rateHz: 30);
         DialerSimulator dialer = await agent.ConnectDialerAsync();
-        LineTaskSet set = await dialer.WaitForTasksAsync(s => s.Tasks.Any(t => t.Kind == "udp_echo" && t.Port == agent.App.QuicPorts[0]));
-        return (agent, dialer, set.Tasks.Single(t => t.Kind == "udp_echo"));
+        LineTaskSet set = await dialer.WaitForTasksAsync(s => s.Tasks.Any(t => t.Kind == "quic_ping" && t.Port == agent.App.QuicPorts[0]));
+        return (agent, dialer, set.Tasks.Single(t => t.Kind == "quic_ping"));
     }
 
     [Fact]

backend/tests/MoShiro.Backend.Tests/AgentEndToEndTests.cs

@@ -23,8 +23,8 @@ public sealed class AgentEndToEndTests : IClassFixture<BackendFixture>
         AgentHarness agent = await AgentHarness.StartAsync(_backend);
         await agent.OverrideLineTasksAsync(rateHz: 30);
         DialerSimulator dialer = await agent.ConnectDialerAsync();
-        LineTaskSet set = await dialer.WaitForTasksAsync(s => s.Tasks.Any(t => t.Kind == "udp_echo" && t.Port == agent.App.QuicPorts[0]));
-        return (agent, dialer, set.Tasks.Single(t => t.Kind == "udp_echo"));
+        LineTaskSet set = await dialer.WaitForTasksAsync(s => s.Tasks.Any(t => t.Kind == "quic_ping" && t.Port == agent.App.QuicPorts[0]));
+        return (agent, dialer, set.Tasks.Single(t => t.Kind == "quic_ping"));
     }
 
     private async Task<JsonNode> AgentViewAsync(AgentHarness agent) => await _backend.GetJsonAsync(_backend.Admin, "/api/admin/agents/" + agent.Id);
@@ -61,7 +61,7 @@ public sealed class AgentEndToEndTests : IClassFixture<BackendFixture>
             }, because: (await _backend.GetJsonAsync(_backend.Admin, $"/api/admin/events?agent_id={agent.Id}")).ToJsonString() + $" fragments={agent.App.Counters.Fragments} discarded={agent.App.Counters.FragmentsDiscarded} outbox={agent.App.Link.Outbox.PendingCount}");
             JsonNode chunk = stored["items"]![0]!;
             Assert.True(chunk["kind"] is not null, stored.ToJsonString());
-            Assert.Equal("udp_echo", chunk["kind"]!.GetValue<string>());
+            Assert.Equal("quic_ping", chunk["kind"]!.GetValue<string>());
             Assert.True(agent.App.Counters.Fragments >= 1);
             Assert.True(agent.App.Counters.PacketsIn >= 40);
         }
@@ -76,11 +76,11 @@ public sealed class AgentEndToEndTests : IClassFixture<BackendFixture>
         await using (agent)
         await using (dialer)
         {
-            LineTask tcp = (await dialer.WaitForTasksAsync(s => s.Tasks.Any(t => t.Kind == "tcp_echo" && t.Port == agent.App.TcpPorts[0]))).Tasks.Single(t => t.Kind == "tcp_echo");
+            LineTask tcp = (await dialer.WaitForTasksAsync(s => s.Tasks.Any(t => t.Kind == "tcp_ping" && t.Port == agent.App.TcpPorts[0]))).Tasks.Single(t => t.Kind == "tcp_ping");
             (int sent, int received) = await dialer.RunTcpEchoAsync(tcp, agent.App.TcpPorts[0], 15, TimeSpan.FromMilliseconds(60), tls);
             Assert.Equal(15, sent);
             Assert.Equal(15, received);
-            await BackendFixture.EventuallyAsync(async () => (await _backend.GetJsonAsync(_backend.Admin, $"/api/admin/raw/chunks?agent_id={agent.Id}"))["items"]!.AsArray().Any(c => c!["kind"]!.GetValue<string>() == "tcp_echo"));
+            await BackendFixture.EventuallyAsync(async () => (await _backend.GetJsonAsync(_backend.Admin, $"/api/admin/raw/chunks?agent_id={agent.Id}"))["items"]!.AsArray().Any(c => c!["kind"]!.GetValue<string>() == "tcp_ping"));
         }
     }
 
@@ -98,8 +98,8 @@ public sealed class AgentEndToEndTests : IClassFixture<BackendFixture>
             // The dialer process restarts: a new session with its own streams; sequence numbers start from 0 again
             await using DialerSimulator second = first.Restarted();
             await second.ConnectAsync("127.0.0.1", agent.App.ControlPort, agent.TlsPublicKey, agent.App.QuicPorts[0], agent.NodeId);
-            LineTaskSet set = await second.WaitForTasksAsync(s => s.Tasks.Any(t => t.Kind == "udp_echo" && t.Port == agent.App.QuicPorts[0]));
-            LineTask udp2 = set.Tasks.Single(t => t.Kind == "udp_echo");
+            LineTaskSet set = await second.WaitForTasksAsync(s => s.Tasks.Any(t => t.Kind == "quic_ping" && t.Port == agent.App.QuicPorts[0]));
+            LineTask udp2 = set.Tasks.Single(t => t.Kind == "quic_ping");
             Assert.NotEqual(udp.StreamId, udp2.StreamId);
 
             // The previous session's streams are released with it ...
@@ -135,9 +135,9 @@ public sealed class AgentEndToEndTests : IClassFixture<BackendFixture>
         Assert.Equal(agent.Id, dialerView["outgoing"]![0]!["listener_id"]!.GetValue<string>());
 
         // Both get their own task set (own streams)
-        LineTaskSet setA = await a.WaitForTasksAsync(s => s.Tasks.Any(t => t.Kind == "udp_echo"));
-        LineTaskSet setB = await b.WaitForTasksAsync(s => s.Tasks.Any(t => t.Kind == "udp_echo"));
-        Assert.NotEqual(setA.Tasks.Single(t => t.Kind == "udp_echo").StreamId, setB.Tasks.Single(t => t.Kind == "udp_echo").StreamId);
+        LineTaskSet setA = await a.WaitForTasksAsync(s => s.Tasks.Any(t => t.Kind == "quic_ping"));
+        LineTaskSet setB = await b.WaitForTasksAsync(s => s.Tasks.Any(t => t.Kind == "quic_ping"));
+        Assert.NotEqual(setA.Tasks.Single(t => t.Kind == "quic_ping").StreamId, setB.Tasks.Single(t => t.Kind == "quic_ping").StreamId);
 
         // Drop one: the other stays
         using HttpResponseMessage dropped = await _backend.Admin.PostAsync($"/api/admin/agents/{agent.Id}/dialers/{a.DialerId}/disconnect", null);
@@ -172,7 +172,7 @@ public sealed class AgentEndToEndTests : IClassFixture<BackendFixture>
         await using AgentHarness agent = await AgentHarness.StartAsync(_backend, config => config.Limits.MaxTotalMbps = 20);
         await agent.OverrideLineTasksAsync();
 
-        var phase = new TestPhase { Kind = "udp_train", DurationSeconds = 1, Params = { ["port"] = System.Text.Json.JsonSerializer.SerializeToElement(agent.App.QuicPorts[0]) } };
+        var phase = new TestPhase { Kind = "quic_stream", DurationSeconds = 1, Params = { ["port"] = System.Text.Json.JsonSerializer.SerializeToElement(agent.App.QuicPorts[0]) } };
         var run = new TestRunParams { TestId = new TestId("tst_x"), DialerId = new NodeId("agt_nobody"), Plan = "x", Phases = [phase] };
         Assert.Equal("dialer_offline", agent.App.Tests.Start(run).Error.Code.Value);
 

backend/tests/MoShiro.Backend.Tests/AgentHarness.cs

@@ -42,7 +42,7 @@ public sealed class AgentHarness : IAsyncDisposable
     public byte[] TlsPublicKey => _identity.Certificate.PublicKey.ExportSubjectPublicKeyInfo();
 
     /// <param name="pin">带信任根固定的加入码（码、创世指纹、属主）：节点按固定了创世和属主的方式注册。</param>
-    public static async Task<AgentHarness> StartAsync(BackendFixture backend, Action<AgentConfig>? configure = null, string? name = null, (string Code, string Genesis, string[] Controllers)? pin = null)
+    public static async Task<AgentHarness> StartAsync(BackendFixture backend, Action<AgentConfig>? configure = null, string? name = null, (string Code, string Genesis, string[] Controllers)? pin = null, bool waitForConnection = true)
     {
         string directory = Path.Combine(Path.GetTempPath(), "moshiro-agent-" + Guid.NewGuid().ToString("N"));
         string token = pin?.Code ?? await backend.CreateJoinTokenAsync();
@@ -71,7 +71,11 @@ public sealed class AgentHarness : IAsyncDisposable
         }
 
         await app.Ready;
-        await BackendFixture.EventuallyAsync(() => Task.FromResult(app.Link.IsConnected), because: "the agent should connect to the backend");
+        if (waitForConnection)
+        {
+            await BackendFixture.EventuallyAsync(() => Task.FromResult(app.Link.IsConnected), because: "the agent should connect to the backend");
+        }
+
         return harness;
     }
 
@@ -101,20 +105,21 @@ public sealed class AgentHarness : IAsyncDisposable
     public async Task OverrideLineTasksAsync(int? rateHz = null)
     {
         JsonNode tasks = await Backend.GetJsonAsync(Backend.Admin, "/api/admin/tasks");
-        // 先处理 connect（关掉），再改 udp_echo / tcp_echo 的速率：否则中途的带宽预算会多出 connect 那一份
-        foreach (JsonNode? task in tasks["items"]!.AsArray().OrderBy(t => t!["kind"]!.GetValue<string>() == "connect" ? 0 : 1))
+        // 先处理 connect（关掉），再改 quic_ping / tcp_ping 的速率：否则中途的带宽预算会多出 connect 那一份
+        foreach (JsonNode? task in tasks["items"]!.AsArray().OrderBy(t => t!["kind"]!.GetValue<string>() == "tcp_connect" ? 0 : 1))
         {
-            if (task!["scope"]!.GetValue<string>() != "line" || task["agent_id"] is not null || task["kind"]!.GetValue<string>() is not ("udp_echo" or "tcp_echo" or "connect"))
+            if (task!["scope"]!.GetValue<string>() != "line" || task["agent_id"] is not null || task["kind"]!.GetValue<string>() is not ("quic_ping" or "tcp_ping" or "tcp_connect"))
             {
                 continue;
             }
 
             string kind = task["kind"]!.GetValue<string>();
-            var parameters = new JsonObject { ["port"] = kind == "udp_echo" ? App.QuicPorts[0] : App.TcpPorts[0] };
+            var parameters = new JsonObject { ["port"] = kind == "quic_ping" ? App.QuicPorts[0] : App.TcpPorts[0] };
             // 默认的 connect 模板在这些用例里不需要（也占预算）：对这个 Agent 关掉它
-            bool enabled = kind != "connect";
-            if (rateHz is { } hz && kind != "connect")
+            bool enabled = kind != "tcp_connect";
+            if (rateHz is { } hz && kind != "tcp_connect")
             {
+                parameters["adaptive"] = false; // 固定频率：用例按这个速率发包，限速也按它算
                 parameters["rate_hz"] = hz;
             }
 

backend/tests/MoShiro.Backend.Tests/AgentMeshTests.cs

@@ -10,18 +10,21 @@ public sealed class AgentMeshTests : IClassFixture<BackendFixture>
 
     public AgentMeshTests(BackendFixture backend) => _backend = backend;
 
+    /// <summary>两个都监听的 Agent 只有一条线路：id 较小的拨出，上下行都在这一条连接上测。</summary>
     [Fact]
-    public async Task ListeningAgents_MeasureBothDirections_AndReportThroughTheirBackendLinks()
+    public async Task ListeningAgents_ShareOneLine_DialedBySmallerId_AndReportThroughTheirBackendLinks()
     {
-        await using AgentHarness a = await AgentHarness.StartAsync(_backend);
-        await using AgentHarness b = await AgentHarness.StartAsync(_backend);
-        await a.OverrideLineTasksAsync(rateHz: 30);
-        await b.OverrideLineTasksAsync(rateHz: 30);
+        await using AgentHarness first = await AgentHarness.StartAsync(_backend);
+        await using AgentHarness second = await AgentHarness.StartAsync(_backend);
+        (AgentHarness dialer, AgentHarness listener) = string.CompareOrdinal(first.Id, second.Id) < 0 ? (first, second) : (second, first);
+        await dialer.OverrideLineTasksAsync(rateHz: 30);
+        await listener.OverrideLineTasksAsync(rateHz: 30);
         await BackendFixture.EventuallyAsync(
-            () => Task.FromResult(a.App.Dialer.IsConnected(b.Id) && b.App.Dialer.IsConnected(a.Id)),
-            TimeSpan.FromSeconds(30), "both listening agents should establish outgoing measurement sessions");
+            () => Task.FromResult(dialer.App.Dialer.IsConnected(listener.Id)),
+            TimeSpan.FromSeconds(30), "the agent with the smaller id should establish the outgoing measurement session");
+        Assert.False(listener.App.Dialer.IsConnected(dialer.Id)); // 反方向不再拨
 
-        using HttpResponseMessage retry = await _backend.Admin.PostAsync($"/api/admin/links/{a.Id}/{b.Id}/retry", null);
+        using HttpResponseMessage retry = await _backend.Admin.PostAsync($"/api/admin/links/{dialer.Id}/{listener.Id}/retry", null);
         Assert.Equal(HttpStatusCode.Accepted, retry.StatusCode);
         JsonNode result = JsonNode.Parse(await retry.Content.ReadAsStringAsync())!;
         Assert.True(result["queued"]!.GetValue<bool>());
@@ -29,18 +32,16 @@ public sealed class AgentMeshTests : IClassFixture<BackendFixture>
         await BackendFixture.EventuallyAsync(async () =>
         {
             JsonNode matrix = await _backend.GetJsonAsync(_backend.Admin, "/api/admin/links");
-            return matrix["items"]!.AsArray().Count(i =>
-                ((i!["dialer_id"]!.GetValue<string>() == a.Id && i["listener_id"]!.GetValue<string>() == b.Id)
-                || (i["dialer_id"]!.GetValue<string>() == b.Id && i["listener_id"]!.GetValue<string>() == a.Id))
-                && i["connected"]!.GetValue<bool>()) == 2;
-        }, TimeSpan.FromSeconds(30), "each agent heartbeat should report its outgoing connection");
+            JsonNode[] pair = [.. matrix["items"]!.AsArray().Select(i => i!).Where(i =>
+                (i["dialer_id"]!.GetValue<string>() == dialer.Id && i["listener_id"]!.GetValue<string>() == listener.Id)
+                || (i["dialer_id"]!.GetValue<string>() == listener.Id && i["listener_id"]!.GetValue<string>() == dialer.Id))];
+            return pair.Length == 1 && pair[0]["connected"]!.GetValue<bool>();
+        }, TimeSpan.FromSeconds(30), "the dialer's heartbeat should report its outgoing connection, and the pair should have a single line");
 
         await BackendFixture.EventuallyAsync(async () =>
         {
-            JsonNode left = await _backend.GetJsonAsync(_backend.Admin, $"/api/admin/raw/chunks?agent_id={a.Id}");
-            JsonNode right = await _backend.GetJsonAsync(_backend.Admin, $"/api/admin/raw/chunks?agent_id={b.Id}");
-            return left["items"]!.AsArray().Any(c => c!["kind"]!.GetValue<string>() == "udp_echo" && c["series"]!.GetValue<string>() == "line:" + b.Id)
-                && right["items"]!.AsArray().Any(c => c!["kind"]!.GetValue<string>() == "udp_echo" && c["series"]!.GetValue<string>() == "line:" + a.Id);
-        }, TimeSpan.FromSeconds(40), "both directed lines should persist measured packet data");
+            JsonNode chunks = await _backend.GetJsonAsync(_backend.Admin, $"/api/admin/raw/chunks?agent_id={listener.Id}");
+            return chunks["items"]!.AsArray().Any(c => c!["kind"]!.GetValue<string>() == "quic_ping" && c["series"]!.GetValue<string>() == "line:" + dialer.Id);
+        }, TimeSpan.FromSeconds(40), "the line should persist measured packet data");
     }
 }

backend/tests/MoShiro.Backend.Tests/AgentTaskSetEndToEndTests.cs

@@ -22,15 +22,15 @@ public sealed class AgentTaskSetEndToEndTests : IClassFixture<BackendFixture>
         await using AgentHarness agent = await AgentHarness.StartAsync(_backend);
         await agent.OverrideLineTasksAsync(rateHz: 30);
         await using DialerSimulator dialer = await agent.ConnectDialerAsync();
-        LineTask udp = (await dialer.WaitForTasksAsync(s => s.Tasks.Any(t => t.Kind == "udp_echo" && t.Port == agent.App.QuicPorts[0])))
-            .Tasks.Single(t => t.Kind == "udp_echo");
+        LineTask udp = (await dialer.WaitForTasksAsync(s => s.Tasks.Any(t => t.Kind == "quic_ping" && t.Port == agent.App.QuicPorts[0])))
+            .Tasks.Single(t => t.Kind == "quic_ping");
 
         JsonNode tasks = await _backend.GetJsonAsync(_backend.Admin, "/api/admin/tasks");
-        JsonNode mine = tasks["items"]!.AsArray().Single(t => t!["agent_id"]?.GetValue<string>() == agent.Id && t["kind"]!.GetValue<string>() == "udp_echo")!;
+        JsonNode mine = tasks["items"]!.AsArray().Single(t => t!["agent_id"]?.GetValue<string>() == agent.Id && t["kind"]!.GetValue<string>() == "quic_ping")!;
         using HttpResponseMessage disabled = await _backend.Admin.PatchAsync("/api/admin/tasks/" + mine["id"]!.GetValue<string>(), BackendFixture.Json(new JsonObject { ["enabled"] = false }, "application/merge-patch+json"));
         disabled.EnsureSuccessStatusCode();
 
-        LineTaskSet next = await dialer.WaitForTasksAsync(s => s.Tasks.All(t => t.Kind != "udp_echo") && s.Version > 0);
+        LineTaskSet next = await dialer.WaitForTasksAsync(s => s.Tasks.All(t => t.Kind != "quic_ping") && s.Version > 0);
         Assert.DoesNotContain(next.Tasks, t => t.Id == udp.Id);
     }
 }

backend/tests/MoShiro.Backend.Tests/AotSmokeTests.cs

@@ -58,28 +58,28 @@ public sealed class AotSmokeTests
         string lineId = $"{agent.NodeId.Value}~{dialerId}";
         await agent.ConnectAsync(baseAddress);
         TaskSet tasks = await agent.WaitForTaskSetAsync(s => s.Tasks.Count >= 2);
-        Assert.Contains(tasks.Tasks, t => t.Kind == "udp_echo");
+        Assert.Contains(tasks.Tasks, t => t.Kind == "quic_ping");
 
         // 原始块：二进制通道 → 段文件与索引 → ACK
         long minute = 60_000;
         long baseMs = ((TimeProvider.System.GetUtcNow().ToUnixTimeMilliseconds() / minute) - 3) * minute;
         for (int k = 0; k < 6; k++)
         {
-            Assert.True(await agent.SendChunkAsync(ChunkFactory.Echo(agent.NodeId, "udp_echo", baseMs + (k * 10_000L), 100, 100, i => new EchoPacket(false, i % 10 == 0, 20_000, 20_000))));
+            Assert.True(await agent.SendChunkAsync(ChunkFactory.Echo(agent.NodeId, "quic_ping", baseMs + (k * 10_000L), 100, 100, i => new EchoPacket(false, i % 10 == 0, 20_000, 20_000))));
         }
 
         // 查询：热层的精确汇总，随后是持久层的分钟窗口
         string range = $"from={Iso(baseMs)}&to={Iso(baseMs + minute)}&metrics=loss.total,rtt.p95";
         JsonNode hot = await GetAsync(http, $"/api/public/lines/{lineId}/series?{range}&step=1s");
         Assert.Equal("hot", hot["source"]!.GetValue<string>());
-        Assert.Equal(600, hot["summary"]!["samples"]!["udp_echo"]!.GetValue<long>());
+        Assert.Equal(600, hot["summary"]!["samples"]!["quic_ping"]!.GetValue<long>());
         Assert.Equal(10.0, hot["summary"]!["metrics"]!["loss.total"]!.GetValue<double>(), 6);
         long deadline = TimeProvider.System.GetTimestamp();
         JsonNode persisted;
         do
         {
             persisted = await GetAsync(http, $"/api/public/lines/{lineId}/series?{range}&step=1m");
-            if (persisted["summary"]!["samples"]!["udp_echo"]?.GetValue<long>() == 600)
+            if (persisted["summary"]!["samples"]!["quic_ping"]?.GetValue<long>() == 600)
             {
                 break;
             }
@@ -88,7 +88,7 @@ public sealed class AotSmokeTests
         }
         while (TimeProvider.System.GetElapsedTime(deadline) < TimeSpan.FromSeconds(15));
         Assert.Equal("1m", persisted["source"]!.GetValue<string>());
-        Assert.Equal(600, persisted["summary"]!["samples"]!["udp_echo"]!.GetValue<long>());
+        Assert.Equal(600, persisted["summary"]!["samples"]!["quic_ping"]!.GetValue<long>());
 
         // 原始块可以按 ID 下载并解码
         JsonNode chunks = await GetAsync(http, $"/api/admin/raw/chunks?agent_id={agent.NodeId.Value}&limit=1");

backend/tests/MoShiro.Backend.Tests/ApiBasicsTests.cs

@@ -194,7 +194,7 @@ public sealed class ApiBasicsTests : IClassFixture<BackendFixture>
         Assert.Equal(HttpStatusCode.NotModified, notModified.StatusCode);
 
         JsonNode kinds = await _backend.GetJsonAsync(_backend.Anonymous, "/api/public/catalog/kinds");
-        JsonNode udp = kinds["items"]!.AsArray().Single(k => k!["id"]!.GetValue<string>() == "udp_echo")!;
+        JsonNode udp = kinds["items"]!.AsArray().Single(k => k!["id"]!.GetValue<string>() == "quic_ping")!;
         JsonNode rate = udp["params"]!.AsArray().Single(p => p!["name"]!.GetValue<string>() == "rate_hz")!;
         Assert.Equal(1, rate["min"]!.GetValue<int>());
         Assert.Equal(200, rate["max"]!.GetValue<int>());