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JamesNKJamesNK
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Propagate trace parent to SignalR hub invocations (#57049)
1 parent ae86074 commit 1d88c6c

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14 files changed

+742
-125
lines changed

14 files changed

+742
-125
lines changed

‎src/Hosting/Hosting/src/Internal/HostingApplicationDiagnostics.cs

Lines changed: 11 additions & 66 deletions
Original file line numberDiff line numberDiff line change
@@ -9,6 +9,7 @@
99
using Microsoft.AspNetCore.Http;
1010
using Microsoft.AspNetCore.Http.Features;
1111
using Microsoft.AspNetCore.Http.Metadata;
12+
using Microsoft.AspNetCore.Shared;
1213
using Microsoft.Extensions.Logging;
1314

1415
namespace Microsoft.AspNetCore.Hosting;
@@ -389,80 +390,24 @@ private void RecordRequestStartMetrics(HttpContext httpContext)
389390
hasDiagnosticListener = false;
390391

391392
var headers = httpContext.Request.Headers;
392-
_propagator.ExtractTraceIdAndState(headers,
393+
var activity = ActivityCreator.CreateFromRemote(
394+
_activitySource,
395+
_propagator,
396+
headers,
393397
static (object? carrier, string fieldName, out string? fieldValue, out IEnumerable<string>? fieldValues) =>
394398
{
395399
fieldValues = default;
396400
var headers = (IHeaderDictionary)carrier!;
397401
fieldValue = headers[fieldName];
398402
},
399-
out var requestId,
400-
out var traceState);
401-
402-
Activity? activity = null;
403-
if (_activitySource.HasListeners())
404-
{
405-
if (ActivityContext.TryParse(requestId, traceState, isRemote: true, out ActivityContext context))
406-
{
407-
// The requestId used the W3C ID format. Unfortunately, the ActivitySource.CreateActivity overload that
408-
// takes a string parentId never sets HasRemoteParent to true. We work around that by calling the
409-
// ActivityContext overload instead which sets HasRemoteParent to parentContext.IsRemote.
410-
// https://github.com/dotnet/aspnetcore/pull/41568#discussion_r868733305
411-
activity = _activitySource.CreateActivity(ActivityName, ActivityKind.Server, context);
412-
}
413-
else
414-
{
415-
// Pass in the ID we got from the headers if there was one.
416-
activity = _activitySource.CreateActivity(ActivityName, ActivityKind.Server, string.IsNullOrEmpty(requestId) ? null! : requestId);
417-
}
418-
}
419-
403+
ActivityName,
404+
ActivityKind.Server,
405+
tags: null,
406+
links: null,
407+
loggingEnabled || diagnosticListenerActivityCreationEnabled);
420408
if (activity is null)
421409
{
422-
// CreateActivity didn't create an Activity (this is an optimization for the
423-
// case when there are no listeners). Let's create it here if needed.
424-
if (loggingEnabled || diagnosticListenerActivityCreationEnabled)
425-
{
426-
activity = new Activity(ActivityName);
427-
if (!string.IsNullOrEmpty(requestId))
428-
{
429-
activity.SetParentId(requestId);
430-
}
431-
}
432-
else
433-
{
434-
return null;
435-
}
436-
}
437-
438-
// The trace id was successfully extracted, so we can set the trace state
439-
// https://www.w3.org/TR/trace-context/#tracestate-header
440-
if (!string.IsNullOrEmpty(requestId))
441-
{
442-
if (!string.IsNullOrEmpty(traceState))
443-
{
444-
activity.TraceStateString = traceState;
445-
}
446-
}
447-
448-
// Baggage can be used regardless of whether a distributed trace id was present on the inbound request.
449-
// https://www.w3.org/TR/baggage/#abstract
450-
var baggage = _propagator.ExtractBaggage(headers, static (object? carrier, string fieldName, out string? fieldValue, out IEnumerable<string>? fieldValues) =>
451-
{
452-
fieldValues = default;
453-
var headers = (IHeaderDictionary)carrier!;
454-
fieldValue = headers[fieldName];
455-
});
456-
457-
// AddBaggage adds items at the beginning of the list, so we need to add them in reverse to keep the same order as the client
458-
// By contract, the propagator has already reversed the order of items so we need not reverse it again
459-
// Order could be important if baggage has two items with the same key (that is allowed by the contract)
460-
if (baggage is not null)
461-
{
462-
foreach (var baggageItem in baggage)
463-
{
464-
activity.AddBaggage(baggageItem.Key, baggageItem.Value);
465-
}
410+
return null;
466411
}
467412

468413
_diagnosticListener.OnActivityImport(activity, httpContext);

‎src/Hosting/Hosting/src/Microsoft.AspNetCore.Hosting.csproj

Lines changed: 1 addition & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -18,6 +18,7 @@
1818
<Compile Include="$(SharedSourceRoot)StaticWebAssets\**\*.cs" LinkBase="StaticWebAssets" />
1919
<Compile Include="$(SharedSourceRoot)Metrics\MetricsExtensions.cs" />
2020
<Compile Include="$(SharedSourceRoot)Metrics\MetricsConstants.cs" />
21+
<Compile Include="$(SharedSourceRoot)Diagnostics\ActivityCreator.cs" />
2122
</ItemGroup>
2223

2324
<ItemGroup>

‎src/Shared/Diagnostics/ActivityCreator.cs

Lines changed: 123 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,123 @@
1+
// Licensed to the .NET Foundation under one or more agreements.
2+
// The .NET Foundation licenses this file to you under the MIT license.
3+
4+
using System.Diagnostics;
5+
6+
namespace Microsoft.AspNetCore.Shared;
7+
8+
internal static class ActivityCreator
9+
{
10+
/// <summary>
11+
/// Create an activity with details received from a remote source.
12+
/// </summary>
13+
public static Activity? CreateFromRemote(
14+
ActivitySource activitySource,
15+
DistributedContextPropagator propagator,
16+
object distributedContextCarrier,
17+
DistributedContextPropagator.PropagatorGetterCallback propagatorGetter,
18+
string activityName,
19+
ActivityKind kind,
20+
IEnumerable<KeyValuePair<string, object?>>? tags,
21+
IEnumerable<ActivityLink>? links,
22+
bool diagnosticsOrLoggingEnabled)
23+
{
24+
Activity? activity = null;
25+
string? requestId = null;
26+
string? traceState = null;
27+
28+
if (activitySource.HasListeners())
29+
{
30+
propagator.ExtractTraceIdAndState(
31+
distributedContextCarrier,
32+
propagatorGetter,
33+
out requestId,
34+
out traceState);
35+
36+
if (ActivityContext.TryParse(requestId, traceState, isRemote: true, out ActivityContext context))
37+
{
38+
// The requestId used the W3C ID format. Unfortunately, the ActivitySource.CreateActivity overload that
39+
// takes a string parentId never sets HasRemoteParent to true. We work around that by calling the
40+
// ActivityContext overload instead which sets HasRemoteParent to parentContext.IsRemote.
41+
// https://github.com/dotnet/aspnetcore/pull/41568#discussion_r868733305
42+
activity = activitySource.CreateActivity(activityName, kind, context, tags: tags, links: links);
43+
}
44+
else
45+
{
46+
// Pass in the ID we got from the headers if there was one.
47+
activity = activitySource.CreateActivity(activityName, kind, string.IsNullOrEmpty(requestId) ? null : requestId, tags: tags, links: links);
48+
}
49+
}
50+
51+
if (activity is null)
52+
{
53+
// CreateActivity didn't create an Activity (this is an optimization for the
54+
// case when there are no listeners). Let's create it here if needed.
55+
if (diagnosticsOrLoggingEnabled)
56+
{
57+
// Note that there is a very small chance that propagator has already been called.
58+
// Requires that the activity source had listened, but it didn't create an activity.
59+
// Can only happen if there is a race between HasListeners and CreateActivity calls,
60+
// and someone removing the listener.
61+
//
62+
// The only negative of calling the propagator twice is a small performance hit.
63+
// It's small and unlikely so it's not worth trying to optimize.
64+
propagator.ExtractTraceIdAndState(
65+
distributedContextCarrier,
66+
propagatorGetter,
67+
out requestId,
68+
out traceState);
69+
70+
activity = new Activity(activityName);
71+
if (!string.IsNullOrEmpty(requestId))
72+
{
73+
activity.SetParentId(requestId);
74+
}
75+
if (tags != null)
76+
{
77+
foreach (var tag in tags)
78+
{
79+
activity.AddTag(tag.Key, tag.Value);
80+
}
81+
}
82+
if (links != null)
83+
{
84+
foreach (var link in links)
85+
{
86+
activity.AddLink(link);
87+
}
88+
}
89+
}
90+
else
91+
{
92+
return null;
93+
}
94+
}
95+
96+
// The trace id was successfully extracted, so we can set the trace state
97+
// https://www.w3.org/TR/trace-context/#tracestate-header
98+
if (!string.IsNullOrEmpty(requestId))
99+
{
100+
if (!string.IsNullOrEmpty(traceState))
101+
{
102+
activity.TraceStateString = traceState;
103+
}
104+
}
105+
106+
// Baggage can be used regardless of whether a distributed trace id was present on the inbound request.
107+
// https://www.w3.org/TR/baggage/#abstract
108+
var baggage = propagator.ExtractBaggage(distributedContextCarrier, propagatorGetter);
109+
110+
// AddBaggage adds items at the beginning of the list, so we need to add them in reverse to keep the same order as the client
111+
// By contract, the propagator has already reversed the order of items so we need not reverse it again
112+
// Order could be important if baggage has two items with the same key (that is allowed by the contract)
113+
if (baggage is not null)
114+
{
115+
foreach (var baggageItem in baggage)
116+
{
117+
activity.AddBaggage(baggageItem.Key, baggageItem.Value);
118+
}
119+
}
120+
121+
return activity;
122+
}
123+
}

‎src/Shared/SignalR/InProcessTestServer.cs

Lines changed: 4 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -27,6 +27,8 @@ public abstract class InProcessTestServer : IAsyncDisposable
2727

2828
public abstract string Url { get; }
2929

30+
public abstract IServiceProvider Services { get; }
31+
3032
public abstract ValueTask DisposeAsync();
3133
}
3234

@@ -54,6 +56,8 @@ internal override event Action<LogRecord> ServerLogged
5456

5557
public override string Url => _url;
5658

59+
public override IServiceProvider Services => _host.Services;
60+
5761
public static async Task<InProcessTestServer<TStartup>> StartServer(ILoggerFactory loggerFactory, Action<KestrelServerOptions> configureKestrelServerOptions = null, IDisposable disposable = null)
5862
{
5963
var server = new InProcessTestServer<TStartup>(loggerFactory, configureKestrelServerOptions, disposable);

‎src/SignalR/clients/csharp/Client.Core/src/HubConnection.cs

Lines changed: 21 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -1037,6 +1037,7 @@ private async Task InvokeCore(ConnectionState connectionState, string methodName
10371037

10381038
// Client invocations are always blocking
10391039
var invocationMessage = new InvocationMessage(irq.InvocationId, methodName, args, streams);
1040+
InjectHeaders(invocationMessage);
10401041

10411042
Log.RegisteringInvocation(_logger, irq.InvocationId);
10421043
connectionState.AddInvocation(irq);
@@ -1063,6 +1064,7 @@ private async Task InvokeStreamCore(ConnectionState connectionState, string meth
10631064
Log.PreparingStreamingInvocation(_logger, irq.InvocationId, methodName, irq.ResultType.FullName!, args.Length);
10641065

10651066
var invocationMessage = new StreamInvocationMessage(irq.InvocationId, methodName, args, streams);
1067+
InjectHeaders(invocationMessage);
10661068

10671069
Log.RegisteringInvocation(_logger, irq.InvocationId);
10681070

@@ -1083,6 +1085,25 @@ private async Task InvokeStreamCore(ConnectionState connectionState, string meth
10831085
}
10841086
}
10851087

1088+
private static void InjectHeaders(HubInvocationMessage invocationMessage)
1089+
{
1090+
// TODO: Change when SignalR client has an activity.
1091+
// This sends info about the current activity, regardless of the activity source, to the SignalR server.
1092+
// When SignalR client supports client activities this logic should be updated to only send headers
1093+
// if the SignalR client activity is created. The goal is to match the behavior of distributed tracing in HttpClient.
1094+
if (Activity.Current is { } currentActivity)
1095+
{
1096+
DistributedContextPropagator.Current.Inject(currentActivity, invocationMessage, static (carrier, key, value) =>
1097+
{
1098+
if (carrier is HubInvocationMessage invocationMessage)
1099+
{
1100+
invocationMessage.Headers ??= new Dictionary<string, string>();
1101+
invocationMessage.Headers[key] = value;
1102+
}
1103+
});
1104+
}
1105+
}
1106+
10861107
private async Task SendHubMessage(ConnectionState connectionState, HubMessage hubMessage, CancellationToken cancellationToken = default)
10871108
{
10881109
_state.AssertConnectionValid();

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