While deploying a new four-node web server cluster, a systems administrator has been instructed to use a technology that will make the website highly available without incurring any additional…

Active-active clustering often requires dedicated load balancing hardware or sophisticated software solutions that typically incur additional costs beyond the servers themselves.

Active-passive clustering, while providing high availability, often involves specialized software or hardware for failover management and does not utilize all nodes concurrently for load balancing, potentially incurring additional costs.

'All-nodes' is not a standard or recognized clustering configuration that specifically addresses the constraints of high availability without additional hardware costs.

Round robin DNS is a method of load distribution where a DNS server cycles through a list of IP addresses associated with a single domain name, directing client requests to different servers in a rotating fashion. This method provides a form of high availability and load balancing without requiring additional dedicated hardware, aligning with the 'no additional hardware costs' constraint.