AWS Certified Database – Specialty — Question 90

An online retail company is planning a multi-day flash sale that must support processing of up to 5,000 orders per second. The number of orders and exact schedule for the sale will vary each day. During the sale, approximately 10,000 concurrent users will look at the deals before buying items. Outside of the sale, the traffic volume is very low. The acceptable performance for read/write queries should be under 25 ms. Order items are about 2 KB in size and have a unique identifier. The company requires the most cost-effective solution that will automatically scale and is highly available.
Which solution meets these requirements?

Answer options

• A. Amazon DynamoDB with on-demand capacity mode
• B. Amazon Aurora with one writer node and an Aurora Replica with the parallel query feature enabled
• C. Amazon DynamoDB with provisioned capacity mode with 5,000 write capacity units (WCUs) and 10,000 read capacity units (RCUs)
• D. Amazon Aurora with one writer node and two cross-Region Aurora Replicas

Correct answer: A

Explanation

Option A is correct because Amazon DynamoDB with on-demand capacity mode can automatically adjust to handle the unpredictable load during the flash sale while ensuring high availability and low latency, making it cost-effective as you only pay for what you use. The other options involve fixed provisioning or additional complexity that may not efficiently manage costs or scaling needs during variable traffic periods.