Exam AWS Certified Solutions Architect - Professional topic 1 question 947 discussion

https://docs.aws.amazon.com/Route53/latest/DeveloperGuide/dns-failover-complex-configs.html

if latency routing is used, thats the one to decide which region to serve while weighted may be used additionally *within* the region. As the failover to the other region is the problem and not within a region. Even if no health check on the weighted records is set up, the failover to the other region should happen as the weighted matter only for within the region. Therefore I think its B and D.

https://docs.aws.amazon.com/Route53/latest/DeveloperGuide/dns-failover-complex-configs.html Either the "evaluate target health" was not set to yes, or no health check was associated to the target in the original region.

The possible root causes of the issue are: B. One of the web servers in the secondary Region did not pass its HTTP health check. D. The setting to evaluate target health is not turned on for the latency alias resource record set that is associated with the domain in the Region where the web servers were stopped. Explanation: Option A is incorrect because weighted record sets are used to distribute traffic between regions, not within regions. Option C is incorrect because the question explicitly states that latency-based routing is being used in conjunction with weighted record sets. Option E is incorrect because an HTTP health check is not necessary for weighted record sets, which are associated with the stopped web servers. Option B is a possible cause of the issue because if one of the web servers in the secondary Region fails its health check, then Route 53 will not redirect traffic to that Region. Option D is another possible cause of the issue because if the setting to evaluate target health is not turned on, then Route 53 will not know that the web servers in one Region are down and will not redirect traffic to the other Region.