AWS Certified Developer – Associate (DVA-C02) — Question 235

A company has a three-tier application that is deployed in Amazon Elastic Container Service (Amazon ECS). The application is using an Amazon RDS for MySQL DB instance. The application performs more database reads than writes.

During times of peak usage, the application’s performance degrades. When this performance degradation occurs, the DB instance’s ReadLatency metric in Amazon CloudWatch increases suddenly.

How should a developer modify the application to improve performance?

Answer options

• A. Use Amazon ElastiCache to cache query results.
• B. Scale the ECS cluster to contain more ECS instances.
• C. Add read capacity units (RCUs) to the DB instance.
• D. Modify the ECS task definition to increase the task memory.

Correct answer: A

Explanation

The correct answer is A because using Amazon ElastiCache can help cache frequently accessed query results, reducing the load on the database and improving read performance. Option B may help with overall application performance but does not directly address the database read issue. Option C is not valid because Amazon RDS for MySQL does not use RCUs; that term applies to DynamoDB. Option D does not specifically target the database read performance issue either.