EC2 and Load Balancing
25 questions about Amazon EC2, Auto Scaling, Load Balancers, and instance management for exam preparation.
A web application must run on EC2 instances that can be interrupted without affecting operation, but needs to keep costs low. The team has determined they can tolerate interruptions with 2-minute notice. Which EC2 instance type should the architect use?
Category: Design Cost-Optimized Architectures
Explanation
Detailed breakdown of the correct answer
EC2 Spot Instances
Spot Instances allow you to take advantage of unused EC2 capacity with discounts of up to 90% compared to On-Demand instances.
They can be interrupted by AWS with a 2-minute warning when AWS needs the capacity. They're ideal for fault-tolerant workloads, batch processing, data analysis, and applications with flexible schedules.
Therefore, the correct answer is: Spot Instances.
The option that says: On-Demand Instances is incorrect because although they offer guaranteed availability, they are the most expensive and don't take advantage of Spot's significant savings for interruption-tolerant workloads.
The option that says: Reserved Instances is incorrect because they require 1-3 year commitment and although they save costs (up to 72%), they are not as economical as Spot for this use case.
The option that says: Dedicated Hosts is incorrect because they are the most expensive, designed for specific compliance or licensing requirements, not for cost optimization.