Exam AWS Certified Solutions Architect - Associate SAA-C03 topic 1 question 874 discussion

A - By creating an Auto Scaling group and ELB in the DR Region upfront, you ensure that the infrastructure is ready to handle traffic immediately in case of a failure in the primary Region. This minimizes downtime during a disaster. B & C - Waiting for the CloudFormation stack to create instances, ELBs, and DynamoDB tables delays recovery. D - CloudWatch alarms and Lambda functions will introduce additional complexity and potential delays due to the evaluation period (>= 10 minutes). For A, simply create an Auto Scaling group and ELB in the DR Region. Use the same configurations as the primary Region. Just make sure that the AMI used for EC2 instances includes all necessary application code and dependencies.

B and C seems to take a while to launch, so it is not minimal down time

Downtime I would choose Auto scaling + DNS failover rather than use cloud formation create infrastructure in DR region or Auto scaling + Lambda

Downtime I would choose Auto scaling + DNS failover rather than use cloud formation create infrastructure in DR region or Auto scaling + Lambda

AnswerA Hence there is no information that solution need to be cost effective and the main requirement is minimal downtime i would go with AUTOSCALING in DR region with 1 ELB and 1 server there but in case of need amount of servers can be increased automatically. Hence at least 1 server and ELB will be waiting and DynamoDB thanks to global table will be active in the same DR region as well, hence we need to inform users, using DNS about new destination, hence DNS failover to the ELB in DR region is the best solution here.

With dynamo global tables, we just need to create an ELB and a ASG in the DR region resources. This resources will be used only if the main region fail over.

Create an Auto Scaling group and an ELB in the DR Region, configuring the DynamoDB table as a global table, and setting up DNS failover to the new ELB. This approach allows for quick failover since the infrastructure is already in place and only DNS needs to be updated to redirect traffic.

Least downtime. C does not offer minimal downtime

Option C