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Difficulty: EasyCost-Optimized Database Design and Capacity Planning

A company is developing a mobile game and needs a cost-optimized database solution. The game has highly unpredictable traffic, experiencing short bursts of intense activity followed by hours of zero usage. The game stores temporary player session data that is only valid for 2424 hours.

Which two configurations should a Solutions Architect recommend? (Select TWO).

  1. Create an Amazon DynamoDB table using On-Demand Capacity mode to scale automatically with the unpredictable traffic.Answer
  2. B
    Create an Amazon DynamoDB table using Provisioned Capacity mode to support peak burst traffic.
  3. Enable DynamoDB Time to Live (TTL) to automatically delete expired player session data and minimize storage costs.Answer
  4. D
    Purchase DynamoDB Reserved Capacity based on the maximum anticipated hourly write throughput.
  5. E
    Deploy Amazon RDS for PostgreSQL and configure Read Replicas to act as the primary failover targets during high-traffic spikes.

Answer

Create an Amazon DynamoDB table using On-Demand Capacity mode, and enable DynamoDB Time to Live (TTL) on the session data table.
For unpredictable, spiky workloads with long periods of zero activity, Amazon DynamoDB On-Demand capacity mode provides the most cost-optimized scaling by charging only for actual read and write requests. Combining this with DynamoDB Time to Live (TTL) allows automatic deletion of expired temporary player sessions after 24 hours, preventing unnecessary storage costs without additional compute overhead.

Step-by-Step Solution

1
Analyze the workload traffic pattern.
The traffic is highly unpredictable and spiky with long periods of zero activity.
This helps determine the optimal database capacity mode. A serverless, auto-scaling option like DynamoDB On-Demand capacity is ideal because it charges only for the requests made and avoids idle capacity costs.
2
Analyze the data lifecycle requirement.
The player session data is temporary and only valid for 24 hours.
This identifies opportunities to reduce storage costs. DynamoDB Time to Live (TTL) automatically deletes expired items, which minimizes stored data size and reduces ongoing storage costs without execution charges.

Key Concept

Selecting the cost-optimal capacity mode and data retention policy for unpredictable, transient database workloads.
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Topics

Cost-Optimized Database Design and Capacity Planning