AWS Cloud Architecting Practice Exam

The floating IP pattern primarily refers to the use of an Elastic IP address in the context of failover and high availability in cloud architectures. By attaching an Elastic IP to a backend instance, you can provide a static public IP address that can be reassigned to another instance in the event of a failure. This means that if the instance that was initially using the Elastic IP goes down, the Elastic IP can be quickly and automatically switched to another healthy instance, allowing for minimal downtime and uninterrupted service.

This approach is advantageous in scenarios where you want to ensure that a service remains accessible via a consistent IP address despite underlying infrastructure changes or failures. It enhances the resiliency and flexibility of deployment by allowing seamless transitions between instances without the need to reconfigure DNS settings or inform users of an IP address change.

The other choices do not accurately represent the floating IP pattern. Using a static IP for all instances does not provide the dynamic failover capability that an Elastic IP offers. Rebooting an instance that has gone down does not ensure continued availability or seamless transition, and disabling the IP address on the original instance does not facilitate the ability to instantly transfer the IP address to a backup instance in a failure scenario. Thus, the emphasis on the Elastic IP's ability to