在我使用SignalR客户端应用程序连接SignalRHub时遇到了问题，下面是错误日志：
info: Microsoft.AspNetCore.Sockets.Client.WebSocketsTransport[0]
02/01/2018 15:20:13: Connection Id f763a939-3fb9-4812-ae6e-dfe3198ab37b: Starting transport. Transfer mode: Text.
fail: Microsoft.AspNetCore.Sockets.Client.HttpConnection[9]02/01/2018 15:20:13: Connection Id f763a939-3fb9-4812-ae6e-dfe3198ab37b: Failed to start connection. Error starting transport 'WebSocketsTransport'.
System.Net.WebSockets.WebSocketException (0x80004005): Unable to connect to the remote server ---> System.Net.WebException: The remote server returned an error: (404) Not Found.
at System.Net.HttpWebRequest.EndGetResponse(IAsyncResult asyncResult)
at System.Threading.Tasks.TaskFactory`1.FromAsyncCoreLogic(IAsyncResult iar, Func`2 endFunction, Action`1 endAction, Task`1 promise, Boolean requiresSynchronization)
--- End of stack trace from previous location where exception was thrown ---
at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
at System.Net.WebSockets.ClientWebSocket.<ConnectAsyncCore>d__21.MoveNext()
at System.Net.WebSockets.ClientWebSocket.<ConnectAsyncCore>d__21.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
at Microsoft.AspNetCore.Sockets.Client.WebSocketsTransport.<Connect>d__19.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
at Microsoft.AspNetCore.Sockets.Client.WebSocketsTransport.<StartAsync>d__16.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
at Microsoft.AspNetCore.Sockets.Client.HttpConnection.<StartTransport>d__46.MoveNext()
SignalR中心正在无状态服务织物服务上运行，并部署在Azure服务织物集群上。
在服务器端，我使用nuget库
Microsoft.AspNetCore.SignalR，以下是AspNetCore 2.0无状态服务端的参考代码：
Startup.cs：
using Microsoft.AspNetCore.Builder;
using Microsoft.AspNetCore.Hosting;
using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.DependencyInjection;
namespace SampleChat
{
public class Startup
{
public Startup(IConfiguration configuration)
{
Configuration = configuration;
}
public IConfiguration Configuration { get; }
// This method gets called by the runtime. Use this method to add services to the container.
public void ConfigureServices(IServiceCollection services)
{
services.AddMvc();
services.AddSignalR();
services.AddCors(options =>
{
options.AddPolicy("CorsPolicy",
builder => builder.AllowAnyOrigin()
.AllowAnyMethod()
.AllowAnyHeader()
.AllowCredentials());
});
}
// This method gets called by the runtime. Use this method to configure the HTTP request pipeline.
public void Configure(IApplicationBuilder app, IHostingEnvironment env)
{
if (env.IsDevelopment())
app.UseDeveloperExceptionPage();
app.UseMvc();
app.UseFileServer();
app.UseCors("CorsPolicy");
app.UseWebSockets();
app.UseSignalR(routes => { routes.MapHub<ChatHub>("SignalRHub"); });
}
}
}
ChatHub.cs:-
using Microsoft.AspNetCore.SignalR;
namespace SampleChat
{
public class ChatHub : Hub
{
public void Send(string message)
{
// Call the broadcastMessage method to update clients.
Clients.All.InvokeAsync("Send", message);
}
}
}
SampleChat.cs
using System.Collections.Generic;
using System.Fabric;
using System.IO;
using Microsoft.AspNetCore.Hosting;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.ServiceFabric.Services.Communication.AspNetCore;
using Microsoft.ServiceFabric.Services.Communication.Runtime;
using Microsoft.ServiceFabric.Services.Runtime;
namespace SampleChat
{
/// <summary>
/// The FabricRuntime creates an instance of this class for each service type instance.
/// </summary>
internal sealed class SampleChat : StatelessService
{
public SampleChat(StatelessServiceContext context)
: base(context)
{
}
/// <summary>
/// Optional override to create listeners (like tcp, http) for this service instance.
/// </summary>
/// <returns>The collection of listeners.</returns>
protected override IEnumerable<ServiceInstanceListener> CreateServiceInstanceListeners()
{
return new[]
{
new ServiceInstanceListener(serviceContext =>
new KestrelCommunicationListener(serviceContext, "ServiceEndpoint", (url, listener) =>
{
ServiceEventSource.Current.ServiceMessage(serviceContext, $"Starting Kestrel on {url}");
return new WebHostBuilder()
.UseKestrel()
.ConfigureServices(
services => services
.AddSingleton(serviceContext))
.UseContentRoot(Directory.GetCurrentDirectory())
.UseStartup<Startup>()
.UseServiceFabricIntegration(listener, ServiceFabricIntegrationOptions.None)
.UseUrls(url)
.Build();
}))
};
}
}
}
在客户端，我正在使用Nuget库 Microsoft.AspNetCore.SignalR.Client。
下面是SignalR客户端代码：
Program.cs：
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
namespace SampleChatCoreApplication
{
class Program
{
static void Main(string[] args)
{
try
{
SignalRConnector.ConnectoToSignalR().GetAwaiter().GetResult();
}
catch (Exception ex)
{
Console.WriteLine(ex);
};
Console.ReadKey();
}
}
}
SignalRConnector.cs:-
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using Microsoft.AspNetCore.SignalR.Client;
namespace SampleChatCoreApplication
{
static class SignalRConnector
{
public static async Task<bool> ConnectoToSignalR()
{
var connection = new HubConnectionBuilder()
.WithUrl("http://localhost:8634/SignalRHub")
.WithConsoleLogger()
.WithTransport(Microsoft.AspNetCore.Sockets.TransportType.WebSockets)
.Build();
connection.On<string>("Send", data =>
{
Console.WriteLine($"Received data: {data}");
});
await connection.StartAsync();
await connection.InvokeAsync("Send", "Send data to Hub");
Console.ReadKey();
return true;
}
}
}
当我在本地系统上运行无状态服务时，我能够成功连接SignalR Hub。
但是当该服务在Azure Service Fabric集群上运行时，我不确定为什么连接SignalR客户端与SignalR Hub会遇到问题。
额外提供的信息是，我已经检查了网络和负载均衡器规则，并且从网络方面没有连通性问题（我通过在此服务中添加控制器进行验证，我能够从控制器中获取结果）。