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 also utilizes all nodes but typically requires additional shared infrastructure such as storage arrays or dedicated hardware load balancers to coordinate the active nodes.

Active-passive clustering keeps one or more nodes in an idle standby state, meaning those nodes consume hardware resources without serving traffic and do not make full use of all four servers.

All-nodes is not a recognized standard clustering topology and does not correspond to a defined high-availability technology or implementation model.

Round robin load balancing cycles incoming requests evenly across all four nodes using DNS or software logic, making full use of the existing cluster hardware without requiring dedicated load balancer appliances or standby servers. Because it is a software-defined distribution method built into DNS or the application tier, no additional hardware cost is introduced while still achieving high availability across the entire cluster.