When security and ACL is enabled, but not spnego, the OMDBCheckpointServlet throws an error:
10:02:29.094 PM ERROR OMDBCheckpointServlet
Permission denied: User principal 'dr.who' does not have access to /dbCheckpoint.
This can happen when Ozone Manager is started with a different user.
Please append 'dr.who' to OM 'ozone.administrators' config and restart OM to grant current user access to this endpoint.
When Spnego is disabled, permissions cannot be checked since HTTP request will not have an identity (kerberos principal) which is causing this error.