AWS Certified Solutions Architect - Associate
Get started today
Ultimate access to all questions.
Deep dive into the quiz with AI chat providers.
We prepare a focused prompt with your quiz and certificate details so each AI can offer a more tailored, in-depth explanation.
A company is planning to use an Amazon DynamoDB table for data storage. The company is concerned about cost optimization. The table will not be used on most mornings. In the evenings, the read and write traffic will often be unpredictable. When traffic spikes occur, they will happen very quickly. What should a solutions architect recommend?
Other
Community
UAnonymous
A
Create a DynamoDB table in on-demand capacity mode.
B
Create a DynamoDB table with a global secondary index.
C
Create a DynamoDB table with provisioned capacity and auto scaling.
D
Create a DynamoDB table in provisioned capacity mode, and configure it as a global table.
Explanation:
Explanation
Correct Answer: A - Create a DynamoDB table in on-demand capacity mode.
Why Option A is Correct:
-
Cost Optimization: On-demand capacity mode is ideal for unpredictable workloads where traffic patterns are unknown or highly variable. The company pays only for the actual read and write requests made to the table, without needing to provision capacity in advance.
-
Unpredictable Traffic: The scenario states that "read and write traffic will often be unpredictable" and "when traffic spikes occur, they will happen very quickly." On-demand mode automatically scales to accommodate sudden traffic spikes without any manual intervention.
-
Low Morning Usage: The table "will not be used on most mornings," meaning there will be periods of low or no activity. With on-demand mode, the company doesn't pay for provisioned capacity during these idle periods.
-
No Capacity Planning Required: On-demand mode eliminates the need for capacity planning and auto-scaling configurations, which can be complex to manage for unpredictable workloads.
Why Other Options are Incorrect:
Option B (Global Secondary Index): While GSI can improve query performance, it doesn't address the cost optimization concern for unpredictable traffic patterns. GSIs incur additional costs and are primarily for data access patterns, not cost management.
Option C (Provisioned Capacity with Auto Scaling): This approach requires capacity planning and may not respond quickly enough to "very quick" traffic spikes. Auto-scaling has warm-up periods and may not be as responsive as on-demand mode for sudden, unpredictable spikes.
Option D (Provisioned Capacity with Global Table): Global tables are for multi-region replication and high availability, not cost optimization. Provisioned capacity would require paying for capacity even during idle morning periods.
Key AWS Concepts:
- DynamoDB On-Demand Mode: Pay-per-request pricing model, automatically scales to accommodate workloads, no capacity planning needed.
- Provisioned Mode: Requires specifying read/write capacity units in advance, better for predictable workloads with steady traffic.
- Auto Scaling: Can adjust provisioned capacity based on traffic patterns but has limitations in responding to sudden spikes.
For this scenario with unpredictable evening traffic and idle mornings, on-demand mode provides the best balance of cost optimization and performance scalability.
Comments
Loading comments...