AWS Certified Solutions Architect – Professional — Question 323

A company's main intranet page has experienced degraded response times as its user base has increased although there are no reports of users seeing error pages. The application uses Amazon DynamoDB in read-only mode.
Amazon DynamoDB latency metrics for successful requests have been in a steady state even during times when users have reported degradation. The
Development team has correlated the issue to ProvisionedThrough put Exceeded exceptions in the application logs when doing Scan and read operations The team also identified an access pattern of steady spikes of read activity on a distributed set of individual data items.
The Chief Technology Officer wants to improve the user experience.
Which solutions will meet these requirements with the LEAST amount of changes to the application? (Choose two.)

Answer options

• A. Change the data model of the DynamoDB tables to ensure that all Scan and read operations meet DynamoDB best practices of uniform data access, reaching the full request throughput provisioned for the DynamoDB tables.
• B. Enable DynamoDB Auto Scaling to manage the throughput capacity as table traffic increases. Set the upper and lower limits to control costs and set a target utilization given the peak usage and how quickly the traffic changes.
• C. Provision Amazon ElastiCache for Redis with cluster mode enabled. The cluster should be provisioned with enough shards to spread the application load and provision at least one read replica node for each shard.
• D. Implement the DynamoDB Accelerator (DAX) client and provision a DAX cluster with the appropriate node types to sustain the application load. Tune the item and query cache configuration for an optimal user experience.
• E. Remove error retries and exponential backoffs in the application code to handle throttling errors.

Correct answer: A, E

Explanation

Refactoring the data model to ensure uniform data access (Option A) directly addresses the root cause of uneven read activity, allowing the application to utilize its provisioned throughput efficiently without hitting partition limits. Removing or adjusting error retries and exponential backoffs (Option E) prevents the application from compounding the throttling issue during spikes, thereby stabilizing response times and improving overall user experience with minimal code changes.