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 designing a new web application that will run on Amazon EC2 Instances. The application will use Amazon DynamoDB for backend data storage. The application traffic will be unpredictable. The company expects that the application read and write throughput to the database will be moderate to high. The company needs to scale in response to application traffic.
Which DynamoDB table configuration will meet these requirements MOST cost-effectively?
Other
Community
UAnonymous
A
Configure DynamoDB with provisioned read and write by using the DynamoDB Standard table class. Set DynamoDB auto scaling to a maximum defined capacity.
B
Configure DynamoDB in on-demand mode by using the DynamoDB Standard table class.
C
Configure DynamoDB with provisioned read and write by using the DynamoDB Standard Infrequent Access (DynamoDB Standard-IA) table class. Set DynamoDB auto scaling to a maximum defined capacity.
D
Configure DynamoDB in on-demand mode by using the DynamoDB Standard Infrequent Access (DynamoDB Standard-IA) table class.
Explanation:
Explanation
Correct Answer: B
Why Option B is correct:
- Unpredictable traffic pattern: The question states that "application traffic will be unpredictable." DynamoDB On-Demand mode is specifically designed for unpredictable workloads where you cannot accurately forecast capacity requirements.
- Moderate to high throughput: On-Demand mode can handle moderate to high throughput automatically without capacity planning.
- Cost-effectiveness: For unpredictable workloads, On-Demand mode is typically more cost-effective than provisioned capacity because:
- You pay only for what you use (per request pricing)
- No need to provision capacity in advance
- No need to pay for unused provisioned capacity during low-traffic periods
- Automatic scaling without any configuration
- Standard table class: This is appropriate for general-purpose workloads with frequent access patterns.
Why other options are incorrect:
Option A (Provisioned with auto scaling):
- While auto scaling can help with some unpredictability, it still requires setting minimum and maximum capacity limits
- You pay for provisioned capacity even during low-traffic periods
- Less cost-effective for truly unpredictable workloads compared to On-Demand
Option C (Provisioned with Standard-IA table class):
- DynamoDB Standard-IA is designed for infrequently accessed data with lower storage costs but higher read/write costs
- This is inappropriate for a web application with "moderate to high" throughput
- The higher per-request costs would make this option expensive for the described workload
Option D (On-Demand with Standard-IA table class):
- Standard-IA table class has higher read/write costs than Standard table class
- This would be more expensive than Option B for moderate to high throughput workloads
- Standard-IA is optimized for infrequently accessed data, not active web application workloads
Key AWS Concepts:
- DynamoDB On-Demand: Pay-per-request pricing model, ideal for unpredictable workloads
- DynamoDB Provisioned: Pay for provisioned read/write capacity, better for predictable workloads
- DynamoDB Standard Table Class: Default table class for general-purpose workloads
- DynamoDB Standard-IA Table Class: Lower storage costs but higher read/write costs, designed for infrequently accessed data
For the given scenario with unpredictable traffic and moderate to high throughput, DynamoDB On-Demand with Standard table class provides the most cost-effective solution.
Comments
Loading comments...