Ошибка подключения к signalr

SignalR sometime throws exception (approximately 4 exceptions/week) «Failed connection handshake».
I think reason could be unstable internet connection on client but I’m not sure (other reason could be wrong configuration or implementation). Has anyone the same problem? And should I solve it when most of the time it is ok?
It is MVC .Net Core app.

Here is log:

{"EventId":{"Id":5,"Name":"HandshakeFailed"},"SourceContext":"Microsoft.AspNetCore.SignalR.HubConnectionContext","TransportConnectionId":"rC64r0HCfzSQCqE7OB5h-A","RequestId":"0HLNJ4TCNIKN8:00000002","RequestPath":"/hub/status","CorrelationId":null,"ConnectionId":"0HLNJ4TCNIKN8"}

I am trying to use SignalR in my .NET CORE 3.1 webapi(server) and angular 10(client) project. API (https://localhost:44305/api) and client angular (https://localhost:44305/user/signup) project shares same domain. This is how I have setup signalR in the server side:

1. I have created Hub class

   using Microsoft.AspNetCore.SignalR;
   namespace Web.Hubs
   {
       public class ResponseHub : Hub
       {
       }
   }
   

2. In Startup.cs class, added services.AddSignalR() in the ConfigureService method. And Enabled CORS like :

               services.AddCors(options =>{
                   options.AddPolicy(MyAllowSpecificOrigins,
                   builder =>
                   {
                       builder
                       .WithOrigins(Configuration.GetValue<string>("https://localhost:44305"))
                       .AllowAnyHeader()
                       .AllowAnyMethod()
                       .AllowCredentials();
                   });
               });
   
   

And added following lines in configure method :

 app.UseEndpoints(endpoints =>
            {
               
                endpoints.MapControllerRoute(
                    name: "default",
                    pattern: "{controller}/{action=Index}/{id?}");
                endpoints.MapHub<ResponseHub>("/userdetails/response");
            });

In the client side,

1. I have installed «@microsoft/signalr»: «^3.1.9» package in the angular project.

2. created service for the signalR like :

   import { Signalrresponse } from "./signalrresponse";
   import { Router } from "@angular/router";
   import * as signalR from '@microsoft/signalr'; 
   
   @Injectable({
       providedIn: 'root'
   })
   export class SignalRService{
       constructor(private router: Router){}
    public data : Signalrresponse;
    private hubConnection: signalR.HubConnection
       public startConnection = () =>{
           this.hubConnection = new signalR.HubConnectionBuilder()
                                   .withUrl("https://localhost:44305/api/userdetails/response")
                                   .build();
           this.hubConnection
               .start()
               .then(() => console.log("Connection Started"))
               .catch(err => console.log('Error while starting connection: ' + err))
       }
   
       public addTransferChartDataListener = () =>{
           this.hubConnection.on('changestatus',(data)=>{
               console.log("Received data");
               this.data = data;
           })
       }
   }
   
   

I am getting error while trying to establish connection from the client side. Error message : Error: Failed to start the connection: Error: None of the transports supported by the client are supported by the server.
Please help me in fixing this.
Thanks.

I am trying to use SignalR in my .NET CORE 3.1 webapi(server) and angular 10(client) project. API (https://localhost:44305/api) and client angular (https://localhost:44305/user/signup) project shares same domain. This is how I have setup signalR in the server side:

1. I have created Hub class

   using Microsoft.AspNetCore.SignalR;
   namespace Web.Hubs
   {
       public class ResponseHub : Hub
       {
       }
   }
   

2. In Startup.cs class, added services.AddSignalR() in the ConfigureService method. And Enabled CORS like :

               services.AddCors(options =>{
                   options.AddPolicy(MyAllowSpecificOrigins,
                   builder =>
                   {
                       builder
                       .WithOrigins(Configuration.GetValue<string>("https://localhost:44305"))
                       .AllowAnyHeader()
                       .AllowAnyMethod()
                       .AllowCredentials();
                   });
               });
   
   

And added following lines in configure method :

 app.UseEndpoints(endpoints =>
            {
               
                endpoints.MapControllerRoute(
                    name: "default",
                    pattern: "{controller}/{action=Index}/{id?}");
                endpoints.MapHub<ResponseHub>("/userdetails/response");
            });

In the client side,

1. I have installed «@microsoft/signalr»: «^3.1.9» package in the angular project.

2. created service for the signalR like :

   import { Signalrresponse } from "./signalrresponse";
   import { Router } from "@angular/router";
   import * as signalR from '@microsoft/signalr'; 
   
   @Injectable({
       providedIn: 'root'
   })
   export class SignalRService{
       constructor(private router: Router){}
    public data : Signalrresponse;
    private hubConnection: signalR.HubConnection
       public startConnection = () =>{
           this.hubConnection = new signalR.HubConnectionBuilder()
                                   .withUrl("https://localhost:44305/api/userdetails/response")
                                   .build();
           this.hubConnection
               .start()
               .then(() => console.log("Connection Started"))
               .catch(err => console.log('Error while starting connection: ' + err))
       }
   
       public addTransferChartDataListener = () =>{
           this.hubConnection.on('changestatus',(data)=>{
               console.log("Received data");
               this.data = data;
           })
       }
   }
   
   

I am getting error while trying to establish connection from the client side. Error message : Error: Failed to start the connection: Error: None of the transports supported by the client are supported by the server.
Please help me in fixing this.
Thanks.

У меня есть простой проект клиента чата, работающий с использованием SignalR и MVC, который почти идентичен ASP.Net один (Я просто экспериментирую — код клиента идентичен). Я подключил следующее, чтобы наблюдать за происходящим:

$.connection.hub.stateChanged(function(state){console.log(state)});

Соединения работают нормально, но я заметил, что если я закрываю IIS Express и смотрю консоль в Chrome, я вижу это:

//As you would expect the state goes from connected to connecting
Object {oldState: 1, newState: 2}

//Then it times out after about 30 secs and throws this awesomeness at the console
WebSocket connection to 'ws://localhost:61623/signalr?transport=webSockets&connectionToken=VDF640emz7PFMToC6vxle_5-7QS5dZMszV4SPbQO7EFEmSSsITnwKsZreqfl4MGq8TXitG2xB5F-2ZdHp-2t3shPzN2hemTY1ZmEWlB8NOn5orUVexaSoARk9XjEO5B00&connectionData=%5B%7B%22name%22%3A%22chathub%22%7D%5D&messageId=B%2C7%7CL%2C0%7CM%2C0%7CN%2C0&tid=0' failed: WebSocket is closed before the connection is established. jquery.signalR-1.0.1.js:1117

//Reconnecting to Disconnecting - so why the error above?
Object {oldState: 2, newState: 4} 

//Then radio silence if I start IIS again...

2 вопросы:

Как избежать ошибки при неудачной попытке повторного подключения?

Почему SignalR не пытается подключиться к IIS? У меня сложилось впечатление, что в этом суть технологии…

РЕДАКТИРОВАТЬ: то же самое происходит и в FireFox

Error: Connection disconnected with error 'Error: Error occurred'. net::ERR_CONNECTION_RESET
Error: Failed to complete negotiation with the server
Error: Failed to start the connection
Failed to load resource: net::ERR_NAME_NOT_RESOLVED
Uncaught (in promise) Error
    at new e (vendors~main.js:7)
    at XMLHttpRequest.i.onerror

Failed to load resource: net::ERR_NAME_NOT_RESOLVED
Failed to load resource: net::ERR_ADDRESS_UNREACHABLE
Failed to load resource: net::ERR_NETWORK_IO_SUSPENDED

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hubConnection.disconnected(function() {
   setTimeout(function() {
       hubConnection.start();
   }, 5000);
});

__________________
Помощь в написании контрольных, курсовых и дипломных работ, диссертаций здесь

Всем привет. Может быть я и задаю много вопросов. Пытаюсь подключиться к SignalR Hub с SPA-приложения.

this.hubConnection = new HubConnectionBuilder()
    .withUrl('http://localhost:*****/testhub')
    .configureLogging(LogLevel.Information)
    .build()

Появляется ошибка: Error: Failed to complete negotiation with the server: SyntaxError: Unexpected token < in JSON at position 0

Пробовал так:

this.hubConnection = new HubConnectionBuilder()
    .withUrl('http://localhost:*****/testhub', {
      skipNegotiation: true,
      transport: HttpTransportType.WebSockets
    })
    .configureLogging(LogLevel.Information)
    .build()

Ошибка:

WebSocket connection to ‘ws://localhost:50523/testhub’ failed: Error during WebSocket handshake: Unexpected response code: 200

Использование веб-сокетов в Startup.cs я включил. Пробовал менять версию SignalR в клиентской части, ошибка не исчезает. В многостраничных приложениях все нормально.

В чем может быть проблема?