SignalR MaximumReceiveMessageSize

My previous code was:

app.UseSignalR((options) =>{
  options.MapHub<Pages.Hubs.ClientsHub>("/hubs/clientshub", configureOptions => {
      configureOptions.TransportMaxBufferSize = 999999;
      configureOptions.ApplicationMaxBufferSize = 999999;
  });
});

Which worked fine with long buffers.

I now upgraded to preview 8 and changed my code to:

app.UseEndpoints((options) => {
  options.MapHub<ClientsHub>("/hubs/clientshub", configureOptions => {
    configureOptions.TransportMaxBufferSize = 999999;
    configureOptions.ApplicationMaxBufferSize = 999999;
  });
});

but SignalR no longer handles big buffers, I get:

System.IO.InvalidDataException: The maximum message size of 32768B was exceeded. The message size can be configured in AddHubOptions.
   at Microsoft.AspNetCore.SignalR.HubConnectionHandler`1.DispatchMessagesAsync(HubConnectionContext connection)
   at Microsoft.AspNetCore.SignalR.HubConnectionHandler`1.RunHubAsync(HubConnectionContext connection)

I looked at many threads and found recommendations to use MaximumReceiveMessageSize

However if I try:

app.UseEndpoints((options) =>{
  options.MapHub<ClientsHub>("/hubs/clientshub", configureOptions => {
    configureOptions.MaximumReceiveMessageSize = 102400000;
  });
});

I get :

Error CS1061 ‘HttpConnectionDispatcherOptions’ does not contain a definition for ‘MaximumReceiveMessageSize’ and no accessible extension method ‘MaximumReceiveMessageSize’ accepting a first argument of type ‘HttpConnectionDispatcherOptions’ could be found

There seems to be very little documentation for this - What is the current (preview8) correct way to increase the buffer size for SignalR ?

[kofifus]

Thanks! please add this to the documentation (SignalR is wonderful, thanks for the work…)

[davidfowl]

@BrennanConroy lets add this to the migration guide.