Exam AWS Certified Advanced Networking - Specialty ANS-C01 topic 1 question 268 discussion

Amazon CloudFront supports origin failover natively for primary and secondary origins. It can automatically fail over to the secondary origin if the primary is unhealthy. To control how quickly failover happens, you use: Origin connection timeout: Time CloudFront waits to establish a connection. Origin connection attempts: Number of retry attempts before declaring failure. If you set timeout to 5 seconds and attempts to 2, the total failover time is 10 seconds. CloudFront will try the primary origin twice, each with a 5-second timeout. If both fail, it moves to the secondary origin — all within 15 seconds, satisfying your requirement.

CloudFront determines origin health based on timeout and retry settings: ✅ Origin connection timeout: The time CloudFront waits before considering the origin unresponsive. Setting this to 5 seconds minimizes failover delay. ✅ Origin connection attempts: The number of retry attempts before marking the origin as unhealthy. Setting this to 2 attempts ensures failover within (5 sec * 2) = 10 seconds, well within the 15-second requirement. B.❌ Incorrect – An NLB does not provide failover between different origins in the way CloudFront does. CloudFront’s origin failover feature is simpler and requires less management.

CloudFront Failover Mechanism: • CloudFront allows you to configure multiple origins with automatic failover when the primary origin is unavailable. Connection timeout and retry attempts control how quickly CloudFront will attempt to use a secondary origin if the primary origin fails to respond.