Which architecture has one active node and one standby node for failover?

The architecture characterized by having one active node and one standby node for failover is defined as Active-Passive Architecture. In this setup, the active node is responsible for handling all operations and processes, while the standby node remains in a monitoring state, ready to take over in the event of a failure of the active node. This ensures high availability and reliability since there is always a backup ready to assume operations without requiring additional intervention.

The key benefit of the Active-Passive model is that it provides a straightforward mechanism for failover, which is critical in environments where uptime is essential. The standby node can be configured with the same data and settings as the active node, allowing for a seamless transition when failover occurs.

This architecture differs from Active-Active, where multiple nodes are operational simultaneously, balancing the load across them, and both can serve requests. Scale-Up refers to increasing resource capabilities of a single node, while Scale-Out involves adding additional nodes to distribute load, neither of which inherently includes a standby configuration for failover. Hence, the focus on failover readiness in the context of a single active and a single standby node clearly identifies Active-Passive Architecture as the correct answer.