AWS DevOps Engineer Professional DOP-C01 – Question408

You need your API backed by DynamoDB to stay online during a total regional AWS failure. You can tolerate a couple minutes of lag or slowness during a large failure event, but the system should recover with normal operation after those few minutes.
What is a good approach?

A.
Set up DynamoDB cross-region replication in a master-standby configuration, with a single standby in another region. Create an Auto Scaling Group behind an ELB in each of the two regions DynamoDB is running in. Add a Route53 Latency DNS Record with DNS Failover, using the ELBs in the two regions as the resource records.
B. Set up a DynamoDB Multi-Region table. Create an Auto Scaling Group behind an ELB in each of the two regions DynamoDB is running in. Add a Route53 Latency DNS Record with DNS Failover, using the ELBs in the two regions as the resource records.
C. Set up a DynamoDB Multi-Region table. Create a cross-region ELB pointing to a cross-region Auto Scaling Group, and direct a Route53 Latency DNS Record with DNS Failover to the crossregion ELB.
D. Set up DynamoDB cross-region replication in a master-standby configuration, with a single standby in another region. Create a cross-region ELB pointing to a cross-region Auto Scaling Group, and direct a Route53 Latency DNS Record with DNS Failover to the cross-region ELB.

Correct Answer: A

Explanation:

Explanation:
There is no such thing as a cross-region ELB, nor such thing as a cross-region Auto Scaling Group, nor such thing as a DynamoDB Multi-Region Table. The only option that makes sense is the cross-regional replication version with two ELBs and ASGs with Route53 Failover and Latency DNS.
Reference: http://docs.aws.amazon.com/amazondynamodb/latest/developerguide/Str…