Currently, user can set hawq_standby_server_host as 'none' in hawq-site.xml to tell HAWQ that there is no standby server, one tricky situation is that if user sets one standby server hostname exactly as 'none', this will cause config not working as expected.
One potential behavior change is to change this value to '' (empty string). This also may cause some confusions. This jira is created to track the discussion about improving this behavior.