I got exactly same error on a cluster of EC2 instances. Then I realized that the ip addresses shown in the hosts tab is not correct: If you have a similar problem, than the fix is deleting the line starting with 127.0.1.1: 127.0.1.1 $fqdn $hostname from your /etc/hosts file and/or master template file (i.e. /etc/cloud/templates/hosts.debian.tmpl) Then I reinstalled the ambari and the issue gone. I am not sure what to do without reinstalling ambari... ... View more