How to get detailed log information from SignalR.SelfHost?

Question

Hi everybody, Our SignalR.Selfhost crashes in a certain situation with a very unspecific System.Net.WebSockets.WebSocketException (System.Net.WebSockets.WebSocketException (0x80004005): Ein interner WebSocket-Fehler ist aufgetreten. Weitere Informationen können Sie, sofern vorhanden, der InnerException entnehmen. ---> System.Net.Sockets.SocketException (0x80004005): Eine vorhandene Verbindung wurde vom Remotehost geschlossen) but I don´t understand why. Some detailed log information from the hub would be useful. How do I retrieve this information? Thanks in advance Jo

Answer 1

Hello Jo, to retrieve detailed log information from SignalR.SelfHost, you can enable server-side logging by using ConfigureLogging. Here is a sample usage:

using Microsoft.AspNetCore.SignalR;
using Microsoft.Extensions.Logging;

public class MyHub : Hub
{
    private readonly ILogger<MyHub> _logger;

    public MyHub(ILogger<MyHub> logger)
    {
        _logger = logger;
    }

    public async Task SendMessage(string user, string message)
    {
        _logger.LogInformation($"Received message from {user}: {message}");
        await Clients.All.SendAsync("ReceiveMessage", user, message);
    }
}

You can then configure logging in your Startup.cs file:

public class Startup
{
    public void ConfigureServices(IServiceCollection services)
    {
        services.AddSignalR();
        services.AddLogging();
    }

    public void Configure(IApplicationBuilder app, IWebHostEnvironment env, ILoggerFactory loggerFactory)
    {
        loggerFactory.AddFile("Logs/myapp-{Date}.txt");

        app.UseRouting();
        app.UseEndpoints(endpoints =>
        {
            endpoints.MapHub<MyHub>("/myhub");
        });
    }
}

This will log information to a file named myapp-{Date}.txt in the Logs folder. You can customize the logging behavior by modifying the loggerFactory object. I hope this helps! Let me know if you have any further questions.