Please open a case with Tableau Technical Support to investigate - they will need to take a deeper look at your logs to determine what the cause of ClusterController restarting is, and whether the error message you've posted above is related. Thank you!
It's probably a good idea to open a support case as Carisa suggested. I have seen at a few customer locations where the security team is doing a scan of Tableau Server typically by trying to add in an unauthorized node. So in addition to opening a case it may not be a bad idea to reach out to your IT/Security team to see if your Tableau cluster is part of a scan.
Any update on this ? we are having the same issue.
I raised a case about this a few months ago.
As Mark mentioned, the issue can occur during specific vulnerability scans/tests that your security team is running periodically.
Long story short, there was an enhancement request raised to fix this but you'll need to chase your account manager to get it prioritised. I ended up just asking our security team to put exceptions on our Tableau Server machines (which is not ideal from a security standpoint).