you shoul either use ssh (id_rsa) or install ambari-agent on all hosts after ambari agent is installed (change the  /etc/ambari-agent/conf/ambari-agent.ini ) and set the hostname of ambari-server machine for all machines  then change the /etc/hosts file ( ip_of_machine1 name_of_machine1                                                   ip_of_machine2 name_of_machine2....) then ==> ambari-agent restart for all machines  trusted and tested  ... View more

@Siddharth Mishra Good to know it's always important to scrutinise the logs ... View more