The customer noticed this type of message in the agent logs:
[1D79B860870, WS: 13C0, RECV: 5E6E1401][1D79B860870, WS: DA0] UPGRADE request failed, error: HTTP status 200: The request has succeeded (0x8FA100C8)
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Date: 8/27/2021 3:04:34 PM, Tick Count: 25074062 (06:57:54.0620000), Size: 395 B
Process: AeXNSAgent.exe (8676), Thread ID: 4704, Module: AeXNetComms.dll
Priority: 1, Source: SMAIO.WSTransport.Socket
The Agent UI shows a warning of Task Status:
Failed to establish persistent connection to Task Server Error: HTTP status 200: The request has succeeded (0x8FA100C8)
ITMS 8.5, 8.6
The error means that for some reason the connection cannot be upgraded from HTTP to Websocket. The "UPGRADE request failed, error: HTTP status 200" message usually refers that IIS is not responding to websocket connection UPGRADE request.
Client Task Agent (CTA) always tries to use HTTP and HTTPs during the registration on a task server.
It could be the case when Task Server (TS) is located behind some intermediate device and this is that device that is answering the HTTP requests.
Make sure the Task Server supports Websockets.
To enable support for the WebSocket Protocol, use the following steps:
Note:
Sometimes you may need to add these IIS Roles:
If you need to enable Persistent Connection in order to take advantage of Websockets, refer to KB 174422 "Enabling and monitoring persistent connection in IT Management Suite 8.5.x"