ACloud Guru Certified Cloud Practitioner Practice Exam

What is the best EC2 option for a short term computing task that must run uninterrupted?

1. Spot Instances

2. Reserved Instances

3. On-Demand Instances

4. Dedicated Hosts

The correct answer is: On-Demand Instances

On-Demand Instances are the best option for a short-term computing task that requires uninterrupted operation because they provide flexibility and immediate access to compute resources without the need for upfront payments or long-term commitments. With On-Demand Instances, users can scale their usage according to demand, launching instances as needed and terminating them when they are no longer required. This option allows for predictable pricing since you pay for the compute capacity by the hour or the second, depending on the instance type, without the risks associated with price fluctuations seen in other options like Spot Instances. The uninterrupted nature of this instance type means that the instances will remain available until you choose to stop or terminate them, making it ideal for tasks that cannot experience downtime. The other options are less suitable for this scenario. Spot Instances, while cost-effective, can be interrupted by AWS if their prices exceed your bid or if there’s higher demand for those resources at that moment. Reserved Instances require a commitment for a term of one or three years, which isn’t ideal for short-term tasks. Dedicated Hosts are designed for specific compliance or licensing requirements and are generally used for more stable, long-term applications, making them unnecessary and costly for a short computing task.