DOP-C02 Question 147
Select 3Your organization has deployed a multi-tier application that spans multiple AWS Regions. The compute layer consists of Amazon EC2 instances running in Auto Scaling groups, and the data layer uses Amazon RDS with a primary database in one Region and a read replica in another Region. During a failover scenario where the primary database becomes unavailable, which strategies should you implement to ensure application availability and minimal downtime?
- A
Update the application to read from the RDS read replica in the secondary Region during failover.
- B
Configure Route 53 health checks and DNS failover to redirect application requests to the compute layer in the secondary Region.
- C
Promote the RDS read replica in the secondary Region to a standalone primary database.
- D
Modify the Auto Scaling group in the primary Region to redirect traffic to the secondary Region's compute instances.
- E
Use AWS Global Accelerator to dynamically redirect requests to the compute layer closest to the user.
Show answer and explanation
Correct answers: A, B, C
Explanation
In a multi-Region deployment, failover strategies must include mechanisms to redirect both compute and database traffic to the secondary Region. Updating the application to use the read replica, promoting it to a primary database, and leveraging Route 53 for DNS failover are critical steps to ensure availability and minimal downtime. While AWS Global Accelerator improves routing performance, it does not directly address the failover requirements.
- A. Correct.
Correct. During a failover, the application must switch to the read replica in the secondary Region to maintain availability. This ensures that the application can still access the database.
- B. Correct.
Correct. Route 53 health checks and DNS failover can automatically redirect traffic to the compute layer in the secondary Region, ensuring application availability during a failover.
- C. Correct.
Correct. Promoting the RDS read replica in the secondary Region to a primary database is required to restore full database functionality after the failover.
- D. Incorrect.
Incorrect. Modifying the Auto Scaling group in the primary Region does not redirect traffic to the secondary Region and does not address the failover scenario.
- E. Incorrect.
Incorrect. AWS Global Accelerator can improve performance by routing requests to the closest Region, but it does not handle failover strategies specific to the application or data layer.