CLF-C02 Cloud Technology and Services Practice Question
Which Amazon EC2 pricing option allows customers to bid for unused EC2 capacity with potential savings of up to 90%, while accepting that instances may be interrupted?
⚠ Common exam trap
Many exam-takers confuse Spot Instances with Reserved Instances, thinking both offer similar discounts, but Reserved Instances require a commitment and are not interruptible, while Spot Instances are interruptible and involve bidding on unused capacity.
Answer choices
Why each option matters
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
Spot Instances
Spot Instances allow customers to bid for unused EC2 capacity, offering potential savings of up to 90% compared to On-Demand pricing. However, these instances can be interrupted (terminated or hibernated) by AWS when the Spot price exceeds the customer's bid or when capacity is needed for On-Demand or Reserved Instance customers, making them ideal for fault-tolerant and flexible workloads.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
On-Demand Instances
Why it's wrong here
On-Demand Instances are a poor fit for this question because they offer full compute capacity at standard, non-discounted prices with no risk of interruption. Unlike Spot Instances, they are not sourced from AWS's unused spare capacity and are never reclaimed based on fluctuating capacity needs, making them the opposite of the cost-efficient, interruptible option the scenario requires.
- ✗
Reserved Instances
Why it's wrong here
Reserved Instances are incorrect here because they deliver a discount through a steady 1- or 3-year commitment, not by tapping into spare capacity. While they can provide a capacity reservation and lower costs compared to On-Demand, they are not subject to the two-minute reclaim notice that characterizes Spot Instances, and the pricing is fixed by upfront commitment rather than dynamic spot market pricing.
- ✓
Spot Instances
Why this is correct
Spot Instances are the correct answer because they let you use AWS's spare EC2 capacity at discounts reaching up to 90%, with the critical trade-off that AWS can reclaim the instance with only a two-minute notice when that capacity is needed elsewhere. This makes them ideal for stateless, fault-tolerant, or flexible workloads, but you must design applications to handle sudden interruptions—exactly the behavior the question is testing.
- ✗
Dedicated Instances
Why it's wrong here
Dedicated Instances are wrong because they focus on physical isolation by running your instances on hardware dedicated to a single customer, not on using spare capacity for discount pricing. They actually cost more than standard On-Demand instances due to the dedicated hardware premium, and they are never reclaimed by AWS, so they do not match the 'spare capacity with interruption risk' concept that defines Spot Instances.
Go deeper
Related to this question
About these practice questions
This CLF-C02 question is part of Courseiva's 988-question bank — original exam-style content with full explanations and wrong-answer analysis, never real exam questions or exam dumps. Learn why practice questions differ from exam dumps →
JA
Written by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
This CLF-C02 practice question is part of Courseiva's free Amazon Web Services certification practice question bank. Courseiva provides original exam-style practice questions with explanations, topic-based practice, mock exams, readiness tracking, and study analytics to help learners prepare for the CLF-C02 exam.