AWS Certified SysOps Administrator – Associate — Question 469

A company wants to reduce costs for jobs that can be completed at any time. The jobs currently run by using multiple Amazon EC2 On-Demand Instances and the jobs take slightly less than 2 hours to complete. If a job falls for any reason it must be restarted from the beginning.
Which solution will meet these requirements MOST cost-effectively?

Answer options

• A. Purchase Reserved Instances for the jobs.
• B. Submit a request for a one-time Spot Instance for the jobs.
• C. Submit a request for Spot Instances with a defined duration for the jobs.
• D. Use a mixture of On-Demand Instances and Spot Instances for the jobs.

Correct answer: C

Explanation

Spot Instances with a defined duration (Spot blocks) are designed to run continuously for a specified timeframe without being interrupted, making them ideal for 2-hour jobs that cannot tolerate interruption and must restart from the beginning if failed. Standard Spot Instances run the risk of being reclaimed by AWS, which would trigger a full restart of the progress-less jobs. Reserved Instances require a 1-year or 3-year commitment, which is not cost-effective for flexible jobs that can run at any time.