What should a solutions architect do to meet these requirements with the LEAST amount of downtime?
Create an Auto Scaling group and a load balancer in the disaster recovery Region. Configure the DynamoDB table as a global table. Configure DNS failover to point to the new disaster recovery Region’s load balancer.
Create an AWS CloudFormation template to create EC2 instances, load balancers, and DynamoDB tables to be executed when needed. Configure DNS failover to point to the new disaster recovery Region’s load balancer.
Create an AWS CloudFormation template to create EC2 instances and a load balancer to be executed when needed. Configure the DynamoDB table as a global table. Configure DNS failover to point to the new disaster recovery Region’s load balancer.
Create an Auto Scaling group and load balancer in the disaster recovery Region. Configure the DynamoDB table as a global table. Create an Amazon CloudWatch alarm to trigger and AWS Lambda function that updates Amazon Route 53 pointing to the disaster recovery load balancer.
Explanations:
This option establishes an Auto Scaling group and load balancer in a disaster recovery region and uses DynamoDB as a global table, which allows for seamless data replication across regions. DNS failover enables quick switching to the disaster recovery region’s load balancer, minimizing downtime.
While using CloudFormation templates allows for infrastructure creation, it does not provide a continuous, real-time solution. The setup would incur downtime while resources are created in the disaster recovery region, and there is no mention of data replication between regions.
Similar to option B, while a CloudFormation template can create necessary resources, it does not address real-time data availability. Configuring DynamoDB as a global table is beneficial, but the downtime during resource creation is a significant drawback.
Although this option incorporates an Auto Scaling group, load balancer, and a global DynamoDB table, it relies on a CloudWatch alarm and Lambda function for DNS updates. This introduces potential delays and complexities in switching over, which can increase downtime during a failure.
I judge that the answer is:
Create an Auto Scaling group and a load balancer in the disaster recovery Region. Configure the DynamoDB table as a global table. Configure DNS failover to point to the new disaster recovery Region’s load balancer.