RC1 Failed connection handshake after update from Preview 7 -> RC1

[cbdg-mitch]

Hi all,

I just updated my blazor applications to RC1 as well as all other nugets that were preview 7 -> RC1, and am now getting this on all of my blazor apps. My MVC apps are working fine after the update, but all 4 of my updated blazor apps are doing this. Should I revert back to Preview 7? Pretty blocked here.

Microsoft.AspNetCore.Http.Connections.Internal.HttpConnectionManager: Debug: New connection JKAjyXbT2EB55U85XkOndA created.
Microsoft.AspNetCore.Http.Connections.Internal.HttpConnectionDispatcher: Debug: Sending negotiation response.
Microsoft.AspNetCore.Http.Connections.Internal.HttpConnectionDispatcher: Debug: Establishing new connection.
Microsoft.AspNetCore.SignalR.HubConnectionHandler: Debug: OnConnectedAsync started.
Microsoft.AspNetCore.Http.Connections.Internal.Transports.WebSocketsTransport: Debug: Socket opened using Sub-Protocol: '(null)'.
Microsoft.AspNetCore.Http.Connections.Internal.Transports.WebSocketsTransport: Debug: Waiting for the application to finish sending data.
Microsoft.AspNetCore.SignalR.HubConnectionContext: Debug: Failed connection handshake.
Microsoft.AspNetCore.Http.Connections.Internal.Transports.WebSocketsTransport: Debug: Socket closed.
Microsoft.AspNetCore.Http.Connections.Internal.HttpConnectionManager: Debug: Removing connection RyCTYkvlKdR_KNL529goQg from the list of connections.

[cbdg-mitch]

Update: here's what's in the chrome dev tools console at the time of the failure:
blazor.server.js:1 [2021-09-17T19:20:46.863Z] Error: WebSocket is not in the OPEN state
log @ blazor.server.js:1
blazor.server.js:1 [2021-09-17T19:20:46.863Z] Error: Failed to start the circuit.

Again, all I did was update from Preview 7 to RC1 with no other code changes.

[BrennanConroy]

Could you capture a network trace https://docs.microsoft.com/aspnet/core/signalr/diagnostics?view=aspnetcore-5.0#network-traces

Just confirming, this looks like this is server-side blazor?
What did preview7 look like in your logs?

[cbdg-mitch]

I've attached both the RC1 session and the Preview 7 session to this message @BrennanConroy

Sessions.zip

[cbdg-mitch]

And yes, this is Blazor Server.

[BrennanConroy]

Huh, the preview7 trace doesn't seem to contain any info. If you know how to use Wireshark I actually prefer that over Fiddler for websocket connections.

What I'm trying to figure out is if your preview7 app was falling back to longpolling, but as of RC1 blazor no longer allows that fallback by default #34644 so if you were having issues connecting to websockets before it might have been silently falling back.

How are you hosting your app? Can you confirm that websockets was working in preview7?

[cbdg-mitch]

@BrennanConroy Let me try and get better logs. If it helps, here is the front end for the Preview 7 app (hosted on IIS) http://app.frdb.bscapps.ca - it does redirect to identity server quickly, but perhaps you can get the logs you need from it when it loads.

[cbdg-mitch]

FWIW, I did add the code suggested in the breaking change update for long polling and that didn't fix the issue on RC1.

[BrennanConroy]

http://app.frdb.bscapps.ca - it does redirect to identity server quickly, but perhaps you can get the logs you need from it when it loads.

Ok, that one is using websockets successfully.

I'm not able to repro the issue locally when running RC1.

Let me try and get better logs

Yes please.

[cbdg-mitch]

@BrennanConroy I went ahead and updated our Preview 7 staging site to the local code RC1 code that was failing -> https://app.frdb.bscapps.ca/

Same error now on the URL you were able to review above.

[cbdg-mitch]

However, if you actually click "login" you'll see you're redirected to the identity server (MVC Core RC1) just fine, and the login form works fine (calls the .net core APIs, etc). If I log in, the Blazor Rc1 app loads, but indeed I keep getting the same socket not open error within the app itself.

[BrennanConroy]

Dug into this a little, and the issue seems to be related to someone replacing the browser websocket implementation so that the WebSocket.OPEN constant is now a function instead of the value 1.

Searching the js files from your site I can see that vendors.min.js from BscTheme is overriding the websocket implementation incorrectly which is likely causing the issues. Is this a file of yours?