SystemLink Server Refuses Client Connection Request

Issue Details

My SystemLink client goes into "Disconnected" state after configuring it and it does not appear in the Systems Management>>Systems>>Pending Systems tab in the SystemLink server web UI.

Solution

This usually happens when the server has cached an old public key for that specific client system. Follow the below steps, in order, to clear out the cached public key on the server.

Removing a salt minion cached public key

1. Open the Windows Services dialog on the client and stop “NI Salt-Minion“.
2. Run the command below on the SystemLink server in a DOS shell with admin privileges.
   • “C:\Program Files\National Instruments\Shared\salt-master\salt-key” -d <minionID>
3. Type “y” when prompted and hit <Enter>
4. Open the Windows Services dialog on the client and start “NI Salt-Minion“.
5. The system should appear in the “Pending” tab. Approve it and it should connect.

If the SystemLink client was connected at some point but now is disconnected.

You can tell the client was once connected if the server displays the client name, part number, etc. in the Systems Management tab in the web UI. If this is the case try these suggestions:

1. Follow the method described in the previous section of this article.
2. Make sure the client’s minionID is accepted, by running this command in DOS on the SystemLink server:
   • "C:\Program Files\National Instruments\Shared\salt-master\salt-key"
3. Check the salt connectivity to that client, by running this command (as administrator):
   • “C:\Program Files\National Instruments\Shared\salt-master\salt” minionID test.ping
     • The output should contain the “True” value and usually takes about 10 seconds to return. Any other result indicates a communication problem between the salt-master and salt-minion. If this fails, then you must check the server configuration on the client side and ensure that the server is still reachable from the client side.
       •  The client could have a missing or not-allowed time zone string in the following registry key: HKEY_LOCAL_MACHINE\System\CurrentControlSet\Control\TimeZoneInformation. The list of allowed time zones are listed in the win_timezone.py file of the Salt Stack documentation: https://github.com/saltstack/salt/blob/v3000.2/salt/modules/win_timezone.py#L52
   • If the test.ping job succeeds, then this state could indicate an issue in the Systems Management service around reporting the connection status of this client. Check the Skyline logs for any reported issues.
4. You might need to force a reconnection attempt, to do this you can:

• Restart SystemLink Server services (with the NI SystemLink Server Config dialog)
• Restart (reboot) the SystemLink client computer
• Restart the “NI Salt-Minion” (Windows) service on the SystemLink client
• Remove / Re-approve SystemLink client from list of systems in SystemLink Server
  • This loses SystemLink client info in SystemLink Server (alias, jobs, properties)

Additional Information

This is an expected behavior after removing the SystemLink Client application and then re-installing it onto the client computer. SystemLink Server will then create a new public key for that client, even though it still has the old public key cached. At that point, any attempt by that client to connect to the SystemLink Server will be denied and reported in the log files of both server and client.