DNS Cluster

Hello, I have confusion about DNS Cluster and server roles. I have 1 webserver eg. "cpanel.domain.com" and 2 DNSONLY servers "dns1.domain.com" and "dns2.domain.com" both on different VPS. What I want to achieve is to use these DNS servers for my webserver and DNS2 to be replication and failover if DNS1 fails. I also plan to have more webservers in future and to use the same DNS servers for other webservers as well. So how should I configure server roles here? Which role should I set on webserver for DNS servers and which role should I set on other way around?