AWS Certified Database – Specialty — Question 333

An online gaming company is using an Amazon DynamoDB table in on-demand mode to store game scores. After an intensive advertisement campaign in South
America, the average number of concurrent users rapidly increases from 100,000 to 500,000 in less than 10 minutes every day around 5 PM.
The on-call software reliability engineer has observed that the application logs contain a high number of DynamoDB throttling exceptions caused by game score insertions around 5 PM. Customer service has also reported that several users are complaining about their scores not being registered.
How should the database administrator remediate this issue at the lowest cost?

Answer options

• A. Enable auto scaling and set the target usage rate to 90%.
• B. Switch the table to provisioned mode and enable auto scaling.
• C. Switch the table to provisioned mode and set the throughput to the peak value.
• D. Create a DynamoDB Accelerator cluster and use it to access the DynamoDB table.

Correct answer: B

Explanation

Amazon DynamoDB on-demand mode can only scale up instantly to twice the previous peak traffic, so a sudden 5x spike causes throttling exceptions. Switching the table to provisioned capacity mode with auto scaling configured allows the system to scale efficiently and handle the predictable daily load at the lowest cost, unlike keeping it permanently provisioned at peak capacity. DynamoDB Accelerator (DAX) is a read cache and would not resolve throttling issues related to game score insertions, which are write operations.