SignalR Logging: Add ActivitySource for server and client

aspnetcore/signalr/diagnostics.md

@@ -5,7 +5,7 @@ description: Learn how to gather diagnostics from your ASP.NET Core SignalR app.
 monikerRange: '>= aspnetcore-2.1'
 ms.author: wpickett
 ms.custom: devx-track-csharp, signalr, linux-related-content
-ms.date: 06/12/2020
+ms.date: 11/20/2024
 uid: signalr/diagnostics
 ---
 # Logging and diagnostics in ASP.NET Core SignalR
@@ -43,6 +43,46 @@ Check the documentation for your configuration system to determine how to specif
 
 We recommend using the `Debug` level when gathering more detailed diagnostics for your app. The `Trace` level produces very low-level diagnostics and is rarely needed to diagnose issues in your app.
 
+## SignalR ActivitySource
+
+SignalR has an ActivitySource for both the hub server and client, avaialble starting wtih .NET 9.
+
+An ActivitySource is a component used in distributed tracing to create and manage activities (or spans) that represent operations in your application. These activities can be used to track the flow of requests and operations across different components and services, providing valuable insights into the performance and behavior of your application.
+
+### .NET SignalR server ActivitySource
+
+The SignalR ActivitySource named `Microsoft.AspNetCore.SignalR.Server` emits events for hub method calls:
+
+* Every method is its own activity, so anything that emits an activity during the hub method call is under the hub method activity.
+* Hub method activities don't have a parent. This means they are not bundled under the long-running SignalR connection.
+
+The following example uses the [.NET Aspire dashboard](/dotnet/aspire/fundamentals/dashboard/overview?tabs=bash#using-the-dashboard-with-net-aspire-projects) and the [OpenTelemetry](https://www.nuget.org/packages/OpenTelemetry.Extensions.Hosting) packages:
+
+```xml
+<PackageReference Include="OpenTelemetry.Exporter.OpenTelemetryProtocol" Version="1.9.0" />
+<PackageReference Include="OpenTelemetry.Extensions.Hosting" Version="1.9.0" />
+<PackageReference Include="OpenTelemetry.Instrumentation.AspNetCore" Version="1.9.0" />
+```
+
+Add the following startup code to the `Program.cs` file:
+
+[!code-csharp[](~/signalr/diagnostics/samples/9.x/SignalRChatTraceExample/Program.cs?name=snippet_trace_signalr_server&highlight=1,10-23)]
+
+The following is example output from the Aspire Dashboard:
+
+:::image type="content" source="~/signalr/diagnostics/_static/9.x/signalr-activities-events.png" alt-text="Activity list for SignalR Hub method call events":::
+
+### .NET SignalR client ActivitySource
+
+The SignalR ActivitySource named `Microsoft.AspNetCore.SignalR.Client` emits events for a SignalR client:
+
+* The .NET SignalR client has an `ActivitySource` named `Microsoft.AspNetCore.SignalR.Client`. Hub invocations now create a client span. Note that other SignalR clients, such as the JavaScript client, don't support tracing. This feature will be added to more clients in future releases.
+* Hub invocations on the client and server support [context propagation](https://opentelemetry.io/docs/concepts/context-propagation/). Propagating the trace context enables true distributed tracing. It's now possible to see invocations flow from the client to the server and back.
+
+Here's how these new activities look in the [.NET Aspire dashboard](/dotnet/aspire/fundamentals/dashboard/overview?tabs=bash#standalone-mode):
+
+![SignalR distributed tracing in Aspire dashboard](~/signalr/diagnostics/_static/9.x/signalr-distributed-tracing-aspire-dashboard.png) 
+
 ## Access server-side logs
 
 How you access server-side logs depends on the environment in which you're running.

aspnetcore/signalr/diagnostics/samples/9.x/SignalRChatTraceExample/ChatHub/ChatHub.cs

@@ -0,0 +1,12 @@
+using Microsoft.AspNetCore.SignalR;
+
+namespace SignalRChat.Hubs
+{
+    public class ChatHub : Hub
+    {
+        public async Task SendMessage(string user, string message)
+        {
+            await Clients.All.SendAsync("ReceiveMessage", user, message);
+        }
+    }
+}

aspnetcore/signalr/diagnostics/samples/9.x/SignalRChatTraceExample/Pages/Error.cshtml

@@ -0,0 +1,26 @@
+@page
+@model ErrorModel
+@{
+    ViewData["Title"] = "Error";
+}
+
+<h1 class="text-danger">Error.</h1>
+<h2 class="text-danger">An error occurred while processing your request.</h2>
+
+@if (Model.ShowRequestId)
+{
+    <p>
+        <strong>Request ID:</strong> <code>@Model.RequestId</code>
+    </p>
+}
+
+<h3>Development Mode</h3>
+<p>
+    Swapping to the <strong>Development</strong> environment displays detailed information about the error that occurred.
+</p>
+<p>
+    <strong>The Development environment shouldn't be enabled for deployed applications.</strong>
+    It can result in displaying sensitive information from exceptions to end users.
+    For local debugging, enable the <strong>Development</strong> environment by setting the <strong>ASPNETCORE_ENVIRONMENT</strong> environment variable to <strong>Development</strong>
+    and restarting the app.
+</p>

aspnetcore/signalr/diagnostics/samples/9.x/SignalRChatTraceExample/Pages/Error.cshtml.cs

@@ -0,0 +1,28 @@
+using System.Diagnostics;
+using Microsoft.AspNetCore.Mvc;
+using Microsoft.AspNetCore.Mvc.RazorPages;
+
+namespace SignalRChat.Pages
+{
+    [ResponseCache(Duration = 0, Location = ResponseCacheLocation.None, NoStore = true)]
+    [IgnoreAntiforgeryToken]
+    public class ErrorModel : PageModel
+    {
+        public string? RequestId { get; set; }
+
+        public bool ShowRequestId => !string.IsNullOrEmpty(RequestId);
+
+        private readonly ILogger<ErrorModel> _logger;
+
+        public ErrorModel(ILogger<ErrorModel> logger)
+        {
+            _logger = logger;
+        }
+
+        public void OnGet()
+        {
+            RequestId = Activity.Current?.Id ?? HttpContext.TraceIdentifier;
+        }
+    }
+
+}

aspnetcore/signalr/diagnostics/samples/9.x/SignalRChatTraceExample/Pages/Index.cshtml

@@ -0,0 +1,28 @@
+@page
+<div class="container">
+    <div class="row p-1">
+        <div class="col-1">User</div>
+        <div class="col-5"><input type="text" id="userInput" /></div>
+    </div>
+    <div class="row p-1">
+        <div class="col-1">Message</div>
+        <div class="col-5"><input type="text" class="w-100" id="messageInput" /></div>
+    </div>
+    <div class="row p-1">
+        <div class="col-6 text-end">
+            <input type="button" id="sendButton" value="Send Message" />
+        </div>
+    </div>
+    <div class="row p-1">
+        <div class="col-6">
+            <hr />
+        </div>
+    </div>
+    <div class="row p-1">
+        <div class="col-6">
+            <ul id="messagesList"></ul>
+        </div>
+    </div>
+</div>
+<script src="~/js/signalr/dist/browser/signalr.js"></script>
+<script src="~/js/chat.js"></script>

aspnetcore/signalr/diagnostics/samples/9.x/SignalRChatTraceExample/Pages/Index.cshtml.cs

@@ -0,0 +1,20 @@
+using Microsoft.AspNetCore.Mvc;
+using Microsoft.AspNetCore.Mvc.RazorPages;
+
+namespace SignalRChat.Pages
+{
+    public class IndexModel : PageModel
+    {
+        private readonly ILogger<IndexModel> _logger;
+
+        public IndexModel(ILogger<IndexModel> logger)
+        {
+            _logger = logger;
+        }
+
+        public void OnGet()
+        {
+
+        }
+    }
+}

aspnetcore/signalr/diagnostics/samples/9.x/SignalRChatTraceExample/Pages/Privacy.cshtml

@@ -0,0 +1,8 @@
+@page
+@model PrivacyModel
+@{
+    ViewData["Title"] = "Privacy Policy";
+}
+<h1>@ViewData["Title"]</h1>
+
+<p>Use this page to detail your site's privacy policy.</p>

aspnetcore/signalr/diagnostics/samples/9.x/SignalRChatTraceExample/Pages/Privacy.cshtml.cs

@@ -0,0 +1,20 @@
+using Microsoft.AspNetCore.Mvc;
+using Microsoft.AspNetCore.Mvc.RazorPages;
+
+namespace SignalRChat.Pages
+{
+    public class PrivacyModel : PageModel
+    {
+        private readonly ILogger<PrivacyModel> _logger;
+
+        public PrivacyModel(ILogger<PrivacyModel> logger)
+        {
+            _logger = logger;
+        }
+
+        public void OnGet()
+        {
+        }
+    }
+
+}

aspnetcore/signalr/diagnostics/samples/9.x/SignalRChatTraceExample/Pages/Shared/_Layout.cshtml

@@ -0,0 +1,52 @@
+<!DOCTYPE html>
+<html lang="en">
+<head>
+    <meta charset="utf-8" />
+    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
+    <title>@ViewData["Title"] - SignalRChat</title>
+    <script type="importmap"></script>
+    <link rel="stylesheet" href="~/lib/bootstrap/dist/css/bootstrap.css" />
+    <link rel="stylesheet" href="~/css/site.css" asp-append-version="true" />
+    <link rel="stylesheet" href="~/SignalRChat.styles.css" asp-append-version="true" />
+</head>
+<body>
+    <header>
+        <nav class="navbar navbar-expand-sm navbar-toggleable-sm navbar-light bg-white border-bottom box-shadow mb-3">
+            <div class="container">
+                <a class="navbar-brand" asp-area="" asp-page="/Index">SignalRChat</a>
+                <button class="navbar-toggler" type="button" data-bs-toggle="collapse" data-bs-target=".navbar-collapse" aria-controls="navbarSupportedContent"
+                        aria-expanded="false" aria-label="Toggle navigation">
+                    <span class="navbar-toggler-icon"></span>
+                </button>
+                <div class="navbar-collapse collapse d-sm-inline-flex justify-content-between">
+                    <ul class="navbar-nav flex-grow-1">
+                        <li class="nav-item">
+                            <a class="nav-link text-dark" asp-area="" asp-page="/Index">Home</a>
+                        </li>
+                        <li class="nav-item">
+                            <a class="nav-link text-dark" asp-area="" asp-page="/Privacy">Privacy</a>
+                        </li>
+                    </ul>
+                </div>
+            </div>
+        </nav>
+    </header>
+    <div class="container">
+        <main role="main" class="pb-3">
+            @RenderBody()
+        </main>
+    </div>
+
+    <footer class="border-top footer text-muted">
+        <div class="container">
+            &copy; 2024 - SignalRChat - <a asp-area="" asp-page="/Privacy">Privacy</a>
+        </div>
+    </footer>
+
+    <script src="~/lib/jquery/dist/jquery.js"></script>
+    <script src="~/lib/bootstrap/dist/js/bootstrap.bundle.js"></script>
+    <script src="~/js/site.js" asp-append-version="true"></script>
+
+    @await RenderSectionAsync("Scripts", required: false)
+</body>
+</html>

aspnetcore/signalr/diagnostics/samples/9.x/SignalRChatTraceExample/Pages/Shared/_Layout.cshtml.css

@@ -0,0 +1,48 @@
+/* Please see documentation at https://learn.microsoft.com/aspnet/core/client-side/bundling-and-minification
+for details on configuring this project to bundle and minify static web assets. */
+
+a.navbar-brand {
+  white-space: normal;
+  text-align: center;
+  word-break: break-all;
+}
+
+a {
+  color: #0077cc;
+}
+
+.btn-primary {
+  color: #fff;
+  background-color: #1b6ec2;
+  border-color: #1861ac;
+}
+
+.nav-pills .nav-link.active, .nav-pills .show > .nav-link {
+  color: #fff;
+  background-color: #1b6ec2;
+  border-color: #1861ac;
+}
+
+.border-top {
+  border-top: 1px solid #e5e5e5;
+}
+.border-bottom {
+  border-bottom: 1px solid #e5e5e5;
+}
+
+.box-shadow {
+  box-shadow: 0 .25rem .75rem rgba(0, 0, 0, .05);
+}
+
+button.accept-policy {
+  font-size: 1rem;
+  line-height: inherit;
+}
+
+.footer {
+  position: absolute;
+  bottom: 0;
+  width: 100%;
+  white-space: nowrap;
+  line-height: 60px;
+}

aspnetcore/signalr/diagnostics/samples/9.x/SignalRChatTraceExample/Pages/Shared/_ValidationScriptsPartial.cshtml

@@ -0,0 +1,2 @@
+<script src="~/lib/jquery-validation/dist/jquery.validate.js"></script>
+<script src="~/lib/jquery-validation-unobtrusive/dist/jquery.validate.unobtrusive.js"></script>

aspnetcore/signalr/diagnostics/samples/9.x/SignalRChatTraceExample/Pages/_ViewImports.cshtml

@@ -0,0 +1,3 @@
+@using SignalRChat
+@namespace SignalRChat.Pages
+@addTagHelper *, Microsoft.AspNetCore.Mvc.TagHelpers

aspnetcore/signalr/diagnostics/samples/9.x/SignalRChatTraceExample/Pages/_ViewStart.cshtml

@@ -0,0 +1,3 @@
+@{
+    Layout = "_Layout";
+}

aspnetcore/signalr/diagnostics/samples/9.x/SignalRChatTraceExample/Program.cs

@@ -0,0 +1,49 @@
+// <snippet_trace_signalr_server>
+using OpenTelemetry.Trace;
+using SignalRChat.Hubs;
+
+// Set OTEL_EXPORTER_OTLP_ENDPOINT environment variable depending on where your OTEL endpoint is.
+var builder = WebApplication.CreateBuilder(args);
+
+builder.Services.AddRazorPages();
+builder.Services.AddSignalR();
+
+builder.Services.AddOpenTelemetry()
+    .WithTracing(tracing =>
+    {
+        if (builder.Environment.IsDevelopment())
+        {
+            // View all traces only in development environment.
+            tracing.SetSampler(new AlwaysOnSampler());
+        }
+
+        tracing.AddAspNetCoreInstrumentation();
+        tracing.AddSource("Microsoft.AspNetCore.SignalR.Server");
+    });
+
+builder.Services.ConfigureOpenTelemetryTracerProvider(tracing => tracing.AddOtlpExporter());
+
+var app = builder.Build();
+
+// </snippet_trace_signalr_server>
+
+// Configure the HTTP request pipeline.
+if (!app.Environment.IsDevelopment())
+{
+    app.UseExceptionHandler("/Error");
+    // The default HSTS value is 30 days. You may want to change this for production scenarios, see https://aka.ms/aspnetcore-hsts.
+    app.UseHsts();
+}
+
+app.UseHttpsRedirection();
+
+app.UseRouting();
+
+app.UseAuthorization();
+
+app.MapStaticAssets();
+app.MapRazorPages()
+   .WithStaticAssets();
+app.MapHub<ChatHub>("/chatHub");
+
+app.Run();

aspnetcore/signalr/diagnostics/samples/9.x/SignalRChatTraceExample/SignalRChat.csproj

@@ -0,0 +1,15 @@
+<Project Sdk="Microsoft.NET.Sdk.Web">
+
+  <PropertyGroup>
+    <TargetFramework>net9.0</TargetFramework>
+    <Nullable>enable</Nullable>
+    <ImplicitUsings>enable</ImplicitUsings>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <PackageReference Include="OpenTelemetry.Exporter.OpenTelemetryProtocol" Version="1.9.0" />
+    <PackageReference Include="OpenTelemetry.Extensions.Hosting" Version="1.9.0" />
+    <PackageReference Include="OpenTelemetry.Instrumentation.AspNetCore" Version="1.9.0" />
+  </ItemGroup>
+
+</Project>

aspnetcore/signalr/diagnostics/samples/9.x/SignalRChatTraceExample/appsettings.Development.json

@@ -0,0 +1,9 @@
+{
+  "DetailedErrors": true,
+  "Logging": {
+    "LogLevel": {
+      "Default": "Information",
+      "Microsoft.AspNetCore": "Warning"
+    }
+  }
+}