AWS Certified Cloud Practitioner / Question #1371 of 719

Question #1371

Which scenario best aligns with the optimal use of Amazon EC2 On-Demand Instances?

A

A consistent and continuous workload requiring dedicated EC2 capacity for over six months

B

A fault-tolerant application that can prioritize cost savings over immediate availability

C

A variable workload with sporadic bursts that cannot tolerate reserved capacity commitments

D

A long-running enterprise application with predictable resource utilization for 18 months

Explanation

Option C is correct because:
- On-Demand Instances are designed for workloads with unpredictable usage patterns and no need for long-term commitments. They allow users to pay for compute capacity by the hour/second without upfront costs.
- Variable/sporadic workloads (e.g., sudden traffic spikes) benefit from On-Demand's flexibility, as scaling can be done dynamically without reserved capacity constraints.
- Why other options are incorrect:
- A: A 6+ month consistent workload aligns better with Reserved Instances (lower costs with commitment).
- B: A fault-tolerant app prioritizing cost savings suits Spot Instances (interruptible, cheaper than On-Demand).
- D: A predictable 18-month workload also favors Reserved Instances for cost efficiency.
Key Takeaway: On-Demand is ideal for short-term, irregular, or experimental workloads where capacity requirements are uncertain.

Answer

The correct answer is: C