AWS Certified Solutions Architect – Associate (SAA-C03)Design Cost-Optimized ArchitecturesEasy

A financial analytics company processes large datasets daily using AWS Batch jobs. These jobs are fault-tolerant and can tolerate interruptions. The company wants to minimize compute costs for these batch processing workloads. Which EC2 purchasing option should they primarily use?

  1. ASpot Instances
  2. BDedicated Hosts
  3. COn-Demand Instances
  4. DReserved Instances
Show answer & explanation

Correct answer: A. Spot Instances

Spot Instances allow users to bid on unused EC2 capacity, offering significant cost savings (up to 90% off On-Demand prices). They are ideal for fault-tolerant, flexible workloads that can be interrupted, such as batch processing.

Why the other options are wrong

  • B. Dedicated Hosts provide physical isolation and are primarily used for licensing requirements, not cost optimization for flexible workloads.
  • C. On-Demand Instances are the most expensive option and do not offer cost savings for interruptible workloads.
  • D. Reserved Instances provide discounts for consistent, long-term workloads, but not for interruptible, flexible ones.

EC2 Spot Instances

Unused EC2 capacity available at a significant discount (up to 90% off On-Demand price) compared to On-Demand instances. Spot Instances can be interrupted by AWS with a two-minute warning.

  • Up to 90% savings compared to On-Demand.
  • Ideal for fault-tolerant or flexible workloads.
  • Can be interrupted by AWS with a two-minute notification.

Memory trick: Spot saves a lot, but mind the interruption plot.

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