2. Update Agents

On each agent host, stop the agent.

ambari-agent stop

Remove old agent certificates.

rm /var/lib/ambari-agent/keys/*

Using a text editor, edit /etc/ambari-agent/conf/ambari-agent.ini to point to the new host.

[server] hostname= <NEW FULLY.QUALIFIED.DOMAIN.NAME>

url_port=8440

secured_url_port=8441