Release 1.6.1

docs/sharding.md

@@ -11,6 +11,7 @@ In latest SDK, we add support for configuring multiple SignalR service instances
     * [How to add multiple endpoints from code](#aspnet-code)
     * [How to customize endpoint router](#aspnet-customize-router)
 * [Configuration in cross-geo scenarios](#cross-geo)
+* [Dynamic Scale ServiceEndpoints](#dynamic-scale)
 * [Failover](#failover)
 
 ## For ASP.NET Core
@@ -112,6 +113,19 @@ private class CustomRouter : EndpointRouterDecorator
 }
 ```
 
+From version 1.6.0, we're exposing metrics synced from service side to help with customized routing for balancing and load use. So you can select the endpoints with minimal clients in below sample.
+
+```cs
+private class CustomRouter : EndpointRouterDecorator
+{
+    public override ServiceEndpoint GetNegotiateEndpoint(HttpContext context, IEnumerable<ServiceEndpoint> endpoints)
+    {
+        return endpoints.OrderBy(x => x.EndpointMetrics.ClientConnectionCount).FirstOrDefault(x => x.Online) // Get the available endpoint with minimal clients load
+               ?? base.GetNegotiateEndpoint(context, endpoints); // Or fallback to the default behavior to randomly select one from primary endpoints, or fallback to secondary when no primary ones are online
+    }
+}
+```
+
 And don't forget to register the router to DI container using:
 
 ```cs
@@ -202,6 +216,20 @@ private class CustomRouter : EndpointRouterDecorator
     }
 }
 ```
+
+Another example about you can select the endpoints with minimal clients, supported from version 1.6.0.
+
+```cs
+private class CustomRouter : EndpointRouterDecorator
+{
+    public override ServiceEndpoint GetNegotiateEndpoint(HttpContext context, IEnumerable<ServiceEndpoint> endpoints)
+    {
+        return endpoints.OrderBy(x => x.EndpointMetrics.ClientConnectionCount).FirstOrDefault(x => x.Online) // Get the available endpoint with minimal clients load
+               ?? base.GetNegotiateEndpoint(context, endpoints); // Or fallback to the default behavior to randomly select one from primary endpoints, or fallback to secondary when no primary ones are online
+    }
+}
+```
+
 And don't forget to register the router to DI container using:
 
 ```cs
@@ -235,6 +263,18 @@ In cross-geo scenario, when a client `/negotiate` with the app server hosted in
 
 ![Normal Negotiate](./images/normal_negotiate.png)
 
+## Dynamic Scale ServiceEndpoints
+<a name="dynamic-scale"></a>
+
+From version 1.5.0, we're enabling dynamic scale ServiceEndpoints for ASP.NET Core version first. So you don't have to restart app server when you need to add/remove a ServiceEndpoint. As ASP.NET Core is supporting default configuration like `appsettings.json` with `reloadOnChange: true`, you don't need to change a code and it's supported by nature. And if you'd like to add some customized configuration and work with hot-reload, please refer to [this](https://docs.microsoft.com/en-us/aspnet/core/fundamentals/configuration/?view=aspnetcore-3.1).
+
+> Note
+> 
+> Considering the time of connection set-up between server/service and client/service may be a few difference, to ensure no message loss during the scale process, we have a staging period waiting for server connection be ready before open the new ServiceEndpoint to clients. Usually it takes seconds to complete and you'll be able to see log like `Succeed in adding endpoint: '{endpoint}'` which indicates the process completes. But for some unexpected reasons like cross-region network issue or configuration inconsistent on different app servers, the staging period will not be able to finish correctly. Since limited things can be done during the dynamic scale process, we choose to promote the scale as it is. It's suggested to restart App Server when you find the scaling process not working correctly.
+> 
+>  The default timeout period for the scale is 5 minutes, and it can be customized by setting the value in [`ServiceOptions.ServiceScaleTimeout`](https://github.com/Azure/azure-signalr/blob/dev/docs/use-signalr-service.md#servicescaletimeout). If you have a lot of app servers, it's suggested to extend the value a little more.
+
+
 ## Failover
 <a name="failover"></a>
 

docs/use-signalr-service.md

@@ -174,8 +174,8 @@ services.AddSignalR()
                 options.AccessTokenLifetime = TimeSpan.FromDays(1);
                 options.ClaimsProvider = context => context.User.Claims;
 
-                option.GracefulShutdown.Mode = GracefulShutdownMode.WaitForClientsClose;
-                option.GracefulShutdown.Timeout = TimeSpan.FromSeconds(10);
+                options.GracefulShutdown.Mode = GracefulShutdownMode.WaitForClientsClose;
+                options.GracefulShutdown.Timeout = TimeSpan.FromSeconds(10);
             });
 ```
 

samples/ChatSample/ChatSample/Startup.cs

@@ -1,6 +1,7 @@
 using System;
 using Microsoft.AspNetCore.Builder;
 using Microsoft.AspNetCore.Hosting;
+using Microsoft.AspNetCore.SignalR;
 using Microsoft.Azure.SignalR;
 using Microsoft.Extensions.DependencyInjection;
 using Microsoft.Extensions.Hosting;
@@ -18,7 +19,12 @@ public void ConfigureServices(IServiceCollection services)
                 .AddAzureSignalR(option =>
                 {
                     option.GracefulShutdown.Mode = GracefulShutdownMode.WaitForClientsClose;
-                    option.GracefulShutdown.Timeout = TimeSpan.FromSeconds(10);
+                    option.GracefulShutdown.Timeout = TimeSpan.FromSeconds(30);
+
+                    option.GracefulShutdown.Add<Chat>(async (c) =>
+                    {
+                        await c.Clients.All.SendAsync("exit");
+                    });
                 })
                 .AddMessagePackProtocol();
         }

samples/ChatSample/ChatSample/wwwroot/index.html

@@ -28,7 +28,17 @@ <h2 class="text-center" style="margin-top: 0; padding-top: 30px; padding-bottom:
             <div class="modal-content">
                 <div class="modal-header">
                     <div>Connection Error...</div>
-                    <div><strong style="font-size: 1.5em;">Hit Refresh/F5</strong> to rejoin. ;)</div>
+                    <div><strong style="font-size: 1.5em;">Hit Refresh/F5</strong> to rejoin. :)</div>
+                </div>
+            </div>
+        </div>
+    </div>
+    <div class="modal alert alert-success fade" id="closeModal" tabindex="-1" role="dialog" aria-labelledby="myModalLabel">
+        <div class="modal-dialog" role="document">
+            <div class="modal-content">
+                <div class="modal-header">
+                    <div>Connection Closed</div>
+                    <div><strong style="font-size: 1.5em;">Hit Refresh/F5</strong> to rejoin. :)</div>
                 </div>
             </div>
         </div>
@@ -97,9 +107,15 @@ <h2 class="text-center" style="margin-top: 0; padding-top: 30px; padding-bottom:
                     messageBox.appendChild(messageEntry);
                     messageBox.scrollTop = messageBox.scrollHeight;
                 };
+
+                var close = function (name, message) {
+                    setTimeout(() => connection.stop(), 3000);
+                }
+
                 // Create a function that the hub can call to broadcast messages.
                 connection.on('broadcastMessage', messageCallback);
                 connection.on('echo', messageCallback);
+                connection.on('exit', close);
                 connection.onclose(onConnectionError);
             }
 
@@ -138,8 +154,10 @@ <h2 class="text-center" style="margin-top: 0; padding-top: 30px; padding-bottom:
             function onConnectionError(error) {
                 if (error && error.message) {
                     console.error(error.message);
+                    var modal = document.getElementById('myModal');
+                } else {
+                    var modal = document.getElementById('closeModal');
                 }
-                var modal = document.getElementById('myModal');
                 modal.classList.add('in');
                 modal.style = 'display: block;';
             }

src/Microsoft.Azure.SignalR.AspNet/HubHost/ServiceHubDispatcher.cs

@@ -3,9 +3,7 @@
 
 using System;
 using System.Collections.Generic;
-using System.Linq;
 using System.Threading.Tasks;
-using Microsoft.Azure.SignalR.Protocol;
 using Microsoft.Extensions.Logging;
 using Microsoft.Extensions.Options;
 

src/Microsoft.Azure.SignalR.Common/Auth/AadApplicationOptions.cs

@@ -48,9 +48,10 @@ public Uri BuildAuthority()
             return GetUri(AzureActiveDirectoryInstance, TenantId);
         }
 
-        public async Task<string> AcquireAccessToken()
+        public override async Task<string> AcquireAccessToken()
         {
-            var result = await AzureActiveDirectoryHelper.BuildApplication(this).AcquireTokenForClient(DefaultScopes).WithSendX5C(true).ExecuteAsync();
+            var app = AzureActiveDirectoryHelper.BuildApplication(this);
+            var result = await app.AcquireTokenForClient(DefaultScopes).WithSendX5C(true).ExecuteAsync();
             return result.AccessToken;
         }
     }

src/Microsoft.Azure.SignalR.Common/Auth/AadManagedIdentityOptions.cs

@@ -7,7 +7,7 @@ public class AadManagedIdentityOptions : AuthOptions, IAadTokenGenerator
     {
         internal override string AuthType => "ManagedIdentity";
 
-        public async Task<string> AcquireAccessToken()
+        public override async Task<string> AcquireAccessToken()
         {
             var azureServiceTokenProvider = new AzureServiceTokenProvider(azureAdInstance: AzureActiveDirectoryInstance);
             return await azureServiceTokenProvider.GetAccessTokenAsync(Audience);

src/Microsoft.Azure.SignalR.Common/Auth/AuthOptions.cs

@@ -2,6 +2,7 @@
 // Licensed under the MIT license. See LICENSE file in the project root for full license information.
 
 using System;
+using System.Threading.Tasks;
 
 namespace Microsoft.Azure.SignalR
 {
@@ -19,8 +20,12 @@ public abstract class AuthOptions
 
         internal const string USGovernmentInstance = "https://login.microsoftonline.us/";
 
+        internal abstract string AuthType { get; }
+
         protected string AzureActiveDirectoryInstance { get; set; } = GlobalInstance;
 
+        public abstract Task<string> AcquireAccessToken();
+
         public AuthOptions WithChina()
         {
             AzureActiveDirectoryInstance = ChinaInstance;
@@ -57,7 +62,5 @@ internal Uri BuildMetadataAddress()
         }
 
         protected Uri GetUri(string baseUri, string path) => new Uri(new Uri(baseUri), path);
-
-        internal abstract string AuthType { get; }
     }
 }

src/Microsoft.Azure.SignalR.Common/Constants.cs

@@ -9,6 +9,7 @@ internal static class Constants
     {
         public static class Keys
         {
+            public const string AzureSignalRSectionKey = "Azure:SignalR";
             public const string ServerStickyModeDefaultKey = "Azure:SignalR:ServerStickyMode";
             public const string ConnectionStringDefaultKey = "Azure:SignalR:ConnectionString";
             public const string ApplicationNameDefaultKey = "Azure:SignalR:ApplicationName";
@@ -40,6 +41,10 @@ public static class Periods
             public static readonly TimeSpan DefaultServersPingInterval = TimeSpan.FromSeconds(5);
             // Depends on DefaultStatusPingInterval, make 1/2 to fast check.
             public static readonly TimeSpan DefaultCloseDelayInterval = TimeSpan.FromSeconds(5);
+
+            // Custom handshake timeout of SignalR Service
+            public const int DefaultHandshakeTimeout = 15;
+            public const int MaxCustomHandshakeTimeout = 30;
         }
 
         public static class ClaimType
@@ -58,6 +63,7 @@ public static class ClaimType
             public const string ServiceEndpointsCount = AzureSignalRSysPrefix + "secn";
             public const string MaxPollInterval = AzureSignalRSysPrefix + "ttl";
             public const string DiagnosticClient = AzureSignalRSysPrefix + "dc";
+            public const string CustomHandshakeTimeout = AzureSignalRSysPrefix + "cht";
 
             public const string AzureSignalRUserPrefix = "asrs.u.";
         }
@@ -85,4 +91,4 @@ public static class Protocol
             public const string BlazorPack = "blazorpack";
         }
     }
-}
+}