AWS Certified Database – Specialty — Question 324

A company has branch offices in the United States and Singapore. The company has a three-tier web application that uses a shared database. The database runs on an Amazon RDS for MySQL DB instance that is hosted in the us-west-2 Region. The application has a distributed front end that is deployed in us-west-2 and in the ap-southeast-1 Region. The company uses this front end as a dashboard that provides statistics to sales managers in each branch office.
The dashboard loads more slowly in the Singapore branch office than in the United States branch office. The company needs a solution so that the dashboard loads consistently for users in each location.
Which solution will meet these requirements in the MOST operationally efficient way?

Answer options

• A. Take a snapshot of the DB instance in us-west-2. Create a new DB instance in ap-southeast-2 from the snapshot. Reconfigure the ap-southeast-1 front-end dashboard to access the new DB instance.
• B. Create an RDS read replica in ap-southeast-1 from the primary DB instance in us-west-2. Reconfigure the ap-southeast-1 front-end dashboard to access the read replica.
• C. Create a new DB instance in ap-southeast-1. Use AWS Database Migration Service (AWS DMS) and change data capture (CDC) to update the new DB instance in ap-southeast-1. Reconfigure the ap-southeast-1 front-end dashboard to access the new DB instance.
• D. Create an RDS read replica in us-west-2, where the primary DB instance resides. Create a read replica in ap-southeast-1 from the read replica in us-west-2. Reconfigure the ap-southeast-1 front-end dashboard to access the read replica in ap-southeast-1.

Correct answer: B

Explanation

Creating a cross-Region RDS read replica in ap-southeast-1 directly from the primary instance in us-west-2 is the most operationally efficient way to reduce read latency for users in Singapore. Implementing AWS DMS with CDC adds unnecessary operational overhead compared to native RDS replication. Chaining replicas or utilizing manual snapshots does not provide a straightforward, real-time sync in the correct target region.