Signalr WebSockets not working on Windows server 2012 R2 + IIS 8.5 with enabled websocket protocol, But works on local development machine (Win 10)

Question

Signalr WebSockets not working on Windows server 2012 R2 + IIS 8.5 with enabled websocket protocol, But works on local development machine (Win 10).

Both set-up as per: https://www.iis.net/configreference/system.webserver/websocket

Server (Websockets not working) -Windows 2012 R2 Standard -IIS 8.5 -Websockets enabled -Client Chrome version 58 64bit (Running locally on server just like dev machine - to eliminate load balancer, or network issue) Signal returns TryWebSockets:false (SSE, longpolling and Forever Frame do work)

Local Development Machine (WebSockets are working) -Windows 10 -IIS 10.0.10586.0 -Client Chrome version 58 64bit Signal returns TryWebSockets:true

Web.config has:

<system.web>
        <httpRuntime targetFramework="4.5"...

and

<compilation defaultLanguage="c#" debug="true" targetFramework="4.6.2">

Grasping at straws:

1. Adding <appSettings><add key="aspnet:UseTaskFriendlySynchronizationContext" value="true"/> ~No change Local works / server did not

2. re-install the signalr packages ~No change Local works / server did not (referenced Form: SignalR won't use Websocket protocol even though I have the protocol installed in windows 8 )

3. Tried uppgrading to Signalr 2.2.2 form 2.2.1 ~No change Local works / server did not

4. Server restarts ~No change Local works / server did not

5. Testing change to <httpRuntime targetFramework="4.6.2"... ~No change Local works / server did not

6. Client side explicitly set to use websockets

   $.connection.hub.start({ transport: 'webSockets' }, function () { console.log('connection started WebSockets!'); }).done(function ()

~No change Local works / server did not

Checked Assemblies https://forums.asp.net/p/1872743/5263876.aspx

Answer 1

原来是在applicationhost.config中缺少一行，需要更新以包括：

<add name="WebSocketModule" lockItem="true" />