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AWS Certified Solutions Architect - Associate Exam Question Walkthrough
Master cost optimization for AWS with this question walkthrough, focusing on the best ways to reduce costs for EC2 fleets.
A common area of confusion for candidates is cost optimization strategies for EC2 fleets. Many options exist, but understanding when and how to implement these strategies is crucial for effective decision-making.
The question
A development EC2 fleet is only needed during business hours on weekdays. What is the simplest way to reduce its cost?
- A) Purchase 3-year Reserved Instances
- B) Automatically stop instances outside business hours (for example with Instance Scheduler)
- C) Move the instances to Spot
- D) Increase the instance size
Think before you scroll
Consider the nature of the workload and the billing implications of each option. Look for a solution that minimizes costs without sacrificing necessary uptime.
The answer
The correct option is B) Automatically stop instances outside business hours (for example with Instance Scheduler). This option effectively eliminates charges during idle time, resulting in significant cost savings.
Why the other options lose
- A) Purchase 3-year Reserved Instances: This option assumes a steady, always-on usage which is not the case here. Reserved Instances do not offer cost savings for workloads that are not running continuously.
- C) Move the instances to Spot: Spot Instances are ideal for flexible workloads that can tolerate interruptions, but they do not address the primary issue of needing instances only during business hours. This option does not guarantee cost-effectiveness for this specific scenario.
- D) Increase the instance size: This option will only increase costs further without improving the situation. Scaling up does not solve the problem of unnecessary charges during non-business hours.
The concept behind it
The principle here is simple: only pay for what you use. By stopping instances during non-business hours, you avoid charges for idle resources. This applies not just to EC2, but to other AWS resources as well. Always assess your workload requirements and align your usage with your actual needs.
Exam trap to remember
The two-question rule: If a question involves cost reduction for non-continuous workloads, look for options that eliminate charges during idle times.