ClearPass extenstion restart behaviour

To address occasional issues with a misbehaving extension entering a restart loop some changes were made in ClearPass 6.11. This can result in an extension stopping when it isn’t expected and, crucially, not restarting again.

A restartPolicy option has been added which aims to ensure extensions will always restart when the server or extensions service restarts. A good practice is to add “restartPolicy” : “unless-stopped” to your extension configuration – note that I have only used this with the inTune extension. Below are the options available.

  • “restartPolicy”: “no” – The Extension will not be automatically restarted after the server is restarted.
  • “restartPolicy”: “always” – The Extension will always be restarted after the server is restarted.
  • “restartPolicy”: “unless-stopped” – The Extension will be restarted unless it was stopped prior to the server restart, in which case it will maintain that state.
  • “restartPolicy”: “on-failure:N” – If the Extension fails to restart, the value for “N” specifies the number of times the Extension should try to restart. If you do not provide a value for “N”, the default value will be “0”.

Whilst the default behaviour ought to effectively match the “unless-stopped” policy, in my experience there can be issues with extensions stopping unexpectedly. Prior to release 6.11.5 a bug an unrelated service would restart the extensions service, and this results in stopped extensions. Whilst this should be resolved, I have still run into the problem. Adding “restartPolicy” : “unless-stopped” resolved this issue.