Examkin

Question

Difficulty: EasyCost-Optimized Compute Selection and Purchasing Strategies

A company is deploying a new web application on AWS. The application consists of Amazon EC2 instances running a steady-state web server 24/7, and an Amazon DynamoDB table storing session data with highly spiky and unpredictable access patterns. Which TWO strategies should a solutions architect select to run this workload in the most cost-effective manner?

  1. Purchase a Compute Savings Plan to cover the Amazon EC2 instances.Answer
  2. Configure the Amazon DynamoDB table to use On-Demand capacity mode.Answer
  3. C
    Purchase a Compute Savings Plan to cover both the Amazon EC2 instances and the Amazon DynamoDB table capacity.
  4. D
    Migrate the continuously running EC2 web application server to AWS Lambda to eliminate idle compute costs.
  5. E
    Configure the Amazon DynamoDB table with Provisioned Capacity Mode to optimize for the spiky traffic.

Answer

Select the option to purchase a Compute Savings Plan for the EC2 instances, and the option to configure the DynamoDB table to use On-Demand capacity mode.
Purchasing a Compute Savings Plan is the most cost-effective way to run the steady-state 24/7 EC2 instances because it offers significant discounts in exchange for a usage commitment. Additionally, configuring the DynamoDB table to use On-Demand capacity mode is optimal for spiky, unpredictable workloads, as it charges per request and avoids the waste of over-provisioning capacity that goes unused during low-traffic periods.

Step-by-Step Solution

1
Analyze the compute requirements for the web server.
The web server runs 24/7 in a steady state, meaning it has a constant, baseline compute usage.
Identifying the workload behavior helps choose the appropriate purchasing option (e.g., Savings Plans or Reserved Instances rather than On-Demand or Spot).
2
Analyze the database requirements for the session data.
The DynamoDB table has highly spiky and unpredictable access patterns.
Determining traffic predictability is key to choosing between Provisioned and On-Demand capacity modes for DynamoDB.
3
Select the most cost-effective purchasing strategies for each component.
Apply a Compute Savings Plan to the EC2 instances to reduce steady-state costs, and use On-Demand capacity mode for DynamoDB to pay only for actual requests and avoid over-provisioning.
This combination minimizes costs while meeting performance requirements for both workloads without misapplying discount scopes.

Key Concept

Selecting cost-effective purchasing strategies (Compute Savings Plans vs. On-Demand vs. Provisioned Capacity) based on workload predictability and service compatibility.
Rate this question

Topics

Cost-Optimized Compute Selection and Purchasing Strategies