WebSockets 在部署到 Prod 时不能与 SignalR Core 一起使用

Question

ASP.NET Core 2.1 运行落后于 IIS 8.5

SignalR 在连接时似乎没有协商子协议，因此无法完成连接。永远不会收到从客户端发送到服务器的消息。

我无法将站点配置为直接从 Kestrel 提供服务，因为这是共享服务器。将传输更改为长轮询工作。我试过禁用 HTTPS/HSTS 重定向。

附上来自客户端和服务器的日志：

客户端日志:

Information: Normalizing 'hubs/screen' to 'https://<url>/hubs/screen'.
Utils.ts:173 Information: WebSocket connected to ws://<url>/hubs/screen?id=
...
Error: Connection disconnected with error 'Error: Server timeout elapsed without receiving a message from the server.'.<id>

服务器日志：

dbug: Microsoft.AspNetCore.Http.Connections.Internal.HttpConnectionManager[1]
      New connection <id> created.
dbug: Microsoft.AspNetCore.Http.Connections.Internal.HttpConnectionDispatcher[10]
      Sending negotiation response.
dbug: Microsoft.AspNetCore.Http.Connections.Internal.HttpConnectionDispatcher[4]
      Establishing new connection.
dbug: Microsoft.AspNetCore.SignalR.HubConnectionHandler[5]
      OnConnectedAsync started.
dbug: Microsoft.AspNetCore.Http.Connections.Internal.Transports.WebSocketsTransport[1]
      Socket opened using Sub-Protocol: '(null)'.
dbug: Microsoft.AspNetCore.Http.Connections.Internal.Transports.WebSocketsTransport[14]
      Socket connection closed prematurely.
System.Net.WebSockets.WebSocketException (0x80004005): The remote party closed the WebSocket connection without completing the close handshake. ---> System.Net.WebSockets.WebSocketException (0x80004005): The remote party closed the WebSocket connection without completing the close handshake.
   at System.Net.WebSockets.ManagedWebSocket.ThrowIfEOFUnexpected(Boolean throwOnPrematureClosure)
   at System.Net.WebSockets.ManagedWebSocket.EnsureBufferContainsAsync(Int32 minimumRequiredBytes, Boolean throwOnPrematureClosure)
   at System.Net.WebSockets.ManagedWebSocket.ReceiveAsyncPrivate[TWebSocketReceiveResultGetter,TWebSocketReceiveResult](Memory`1 payloadBuffer, CancellationToken cancellationToken, TWebSocketReceiveResultGetter resultGetter)
   at System.Net.WebSockets.ManagedWebSocket.ReceiveAsyncPrivate[TWebSocketReceiveResultGetter,TWebSocketReceiveResult](Memory`1 payloadBuffer, CancellationToken cancellationToken, TWebSocketReceiveResultGetter resultGetter)
   at System.Net.WebSockets.WebSocket.ReceiveAsync(Memory`1 buffer, CancellationToken cancellationToken)
   at Microsoft.AspNetCore.Http.Connections.Internal.Transports.WebSocketsTransport.StartReceiving(WebSocket socket)
fail: Microsoft.AspNetCore.SignalR.HubConnectionContext[5]
      Failed connection handshake.
dbug: Microsoft.AspNetCore.Http.Connections.Internal.Transports.WebSocketsTransport[4]
      Waiting for the application to finish sending data.
dbug: Microsoft.AspNetCore.Http.Connections.Internal.Transports.WebSocketsTransport[2]
      Socket closed.

Answer 1

我找到问题了！

我们有一个自定义 IIS 模块，它以 HTTP header 的形式注入服务器名称 + 请求时间，这导致 SignalR 失败。（该模块可能只是盲目地注入它的 header，而不考虑 Websockets）

WebSockets 在部署到 Prod 时不能与 SignalR Core 一起使用

WebSockets don't work with SignalR Core when deployed to Prod

iis-8

asp.net-core

asp.net-core-signalr