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Difficulty: Very hardAWS Pricing Models

A logistics company is planning to migrate three distinct workloads to Amazon EC2:

* Workload A: A microservices platform running continuously that will initially deploy in the us-east-1 Region, but is scheduled to migrate to the us-west-2 Region in six months.
* Workload B: A daily stateful data synchronization task that runs for exactly 2 hours each night and cannot tolerate any interruptions.
* Workload C: A stateless, containerized image-processing batch job that can run at any time, can be paused and resumed, and scales dynamically based on queue depth.

Which combination of EC2 pricing models provides the most cost-effective solution for these workloads?

  1. A
    EC2 Instance Savings Plan for Workload A; Spot Instances for Workload B; On-Demand Instances for Workload C
  2. B
    Compute Savings Plan for Workload A; Compute Savings Plan for Workload B; Spot Instances for Workload C
  3. Compute Savings Plan for Workload A; On-Demand Instances for Workload B; Spot Instances for Workload CAnswer
  4. D
    EC2 Instance Savings Plan for Workload A; On-Demand Instances for Workload B; On-Demand Instances for Workload C

Answer

Compute Savings Plan for Workload A; On-Demand Instances for Workload B; Spot Instances for Workload C
The correct choice combines a Compute Savings Plan for Workload A, On-Demand Instances for Workload B, and Spot Instances for Workload C. A Compute Savings Plan provides the flexibility to apply discounts across different AWS Regions (from us-east-1 to us-west-2), which an EC2 Instance Savings Plan cannot do. On-Demand Instances are the most cost-effective for Workload B because it only runs for 2 hours a day; committing to a Savings Plan would result in paying for 22 unused hours daily, and Spot Instances cannot be used since the workload is stateful and cannot tolerate interruptions. Spot Instances are ideal for Workload C because it is stateless and fault-tolerant, allowing for maximum cost savings.

Step-by-Step Solution

1
Analyze Workload A requirements
Workload A runs continuously (requiring a committed discount) but shifts regions from us-east-1 to us-west-2. Compute Savings Plans provide the necessary regional flexibility, whereas EC2 Instance Savings Plans are locked to a specific region.
To ensure discount applicability post-migration across regions.
2
Analyze Workload B requirements
Workload B runs for only 2 hours daily and is stateful (cannot tolerate interruptions). Spot Instances are ruled out. A Savings Plan or Reserved Instance charges for 24 hours a day, meaning 22 hours of waste. On-Demand is the most cost-effective option here.
To avoid paying for continuous idle capacity for a short-duration daily task.
3
Analyze Workload C requirements
Workload C is stateless, containerized, and fault-tolerant, making it a perfect fit for Spot Instances which offer up to 90% savings.
To maximize cost savings on interruptible batch processing.
4
Select the correct combination
The correct combination is Compute Savings Plan (Workload A), On-Demand Instances (Workload B), and Spot Instances (Workload C).
This matches the requirements of all three workloads perfectly.

Key Concept

AWS EC2 pricing model selection based on workload flexibility, duration, and fault tolerance.
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Topics

AWS Pricing Models

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