Q28 — AWS SAP-C02 Ch.1

Question 28 of 75 | ← Chapter 1

Q103. A company has a multi-tier web application that runs on a fleet of Amazon EC2 instances behind an Application Load Balancer (ALB). The instances are in an Auto Scaling group. The ALB and the Auto Scaling group are replicated in a backup AWS Region. The minimum value and the maximum value for the Auto Scaling group are set to zero.An Amazon RDS Multi-AZ DB instance stores the application's data. The DB instance has a read replica in the backup Region The application presents an endpoint to end users by using an Amazon Route 53 record.The company needs to reduce its RTO to less than 15 minutes by giving the application the ability to automatically fail over to the backup Region. The company does not have a large enough budget for an active-active strategyWhat should a solutions architect recommend to meet these requirements?

Correct Answer: B. Create an AWS Lambda function in the backup Region to promote the read replica and modify the Auto Scaling group values. Configure Route 53 with a health check that monitors the web application and sends an Amazon Simple Notification Service (Amazon SNS) notification to the Lambda function when the health check status is unhealthy. Update the application's Route 53 record with a failover policy that routes traffic to the ALB in the backup Region when a health check failure occurs

Explanation

To meet the requirement of reducing the Recovery Time Objective (RTO) to less than 15 minutes by enabling automatic failover to the backup region without an active-active strategy, a solutions architect should recommend the following: B. Create an AWS Lambda function in the backup Region to promote the read replica and modify the Auto Scaling group values. Configure Route 53 with a health check that monitors the web application and sends an Amazon Simple Notification Service (Amazon SNS) notification to the Lambda function when the health check status is unhealthy. Update the application's Route 53 record with a failover policy that routes traffic to the ALB in the backup Region when a health check failure occurs. Explanation: B. Create an AWS Lambda function in the backup Region to promote the read replica and modify the Auto Scaling group values: By creating a Lambda function in the backup region, you can automate the process of promoting the read replica to become the primary DB instance and modify the Auto Scaling group to launch instances in the backup region. Configure Route 53 with a health check that monitors the web application and sends an Amazon SNS notification to the Lambda function when the health check status is unhealthy: Set up a health check in Route 53 to monitor the web application's health. When the health check status becomes unhealthy, Route 53 can trigger an Amazon SNS notification. Update the application's Route 53 record with a failover policy that routes traffic to the ALB in the backup Region when a health check failure occurs: Configure the Route 53 record to use a failover policy, which will direct traffic to the ALB in the backup region when the health check indicates a failure in the primary region. This ensures that traffic is automatically routed to the backup region in case of a failure. Option A is incorrect because it suggests using a latency-based routing policy to load balance traffic between the two ALBs. While this can provide improved performance, it does not meet the requirement of reducing the RTO to less than 15 minutes. Option C is incorrect because it suggests configuring the Auto Scaling group in the backup region, removing the read replica, and replacing it with a standalone RDS DB instance. This approach does not provide automatic failover capability and does not fulfill the requirement of reducing the RTO. Option D is incorrect because it suggests using AWS Global Accelerator to route traffic to the ALBs and using CloudWatch alarms to invoke the Lambda function. While Global Accelerator can improve performance, it does not provide automatic failover capability. Therefore, the correct recommendation is B: Create a Lambda function in the backup region, configure Route 53 with a health check, and update the application's Route 53 record with a failover policy. NOT A because, It's not Active-Active, Latency based routing is for active-active mainly.We need failover policy. C is incorrect because "The company does not have a large enough budget for an active-active strategy."