Minimum, maximum, and desired capacity in AWS - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is the minimum capacity in an Auto Scaling group?

The minimum capacity is the smallest number of instances that the Auto Scaling group will keep running at all times, even if demand is low.

beginner

Define maximum capacity in the context of Auto Scaling.

Maximum capacity is the highest number of instances the Auto Scaling group can scale out to, preventing it from launching more than this number.

beginner

What does desired capacity mean in an Auto Scaling group?

Desired capacity is the target number of instances the Auto Scaling group tries to maintain, balancing between minimum and maximum capacity.

intermediate

Why is it important to set a minimum capacity in Auto Scaling?

Setting a minimum capacity ensures your application always has enough instances running to handle basic traffic and stay available.

intermediate

How do minimum, maximum, and desired capacity work together?

Minimum sets the floor, maximum sets the ceiling, and desired capacity is the current target number of instances between those limits.

What happens if the desired capacity is set below the minimum capacity in an Auto Scaling group?

A The group will scale up to the maximum capacity.

B The group will maintain the minimum capacity instead.

C The group will scale down to the desired capacity anyway.

D The group will stop all instances.

The Auto Scaling group will not go below the minimum capacity, so it keeps at least that many instances running.

If you want to limit costs but still handle traffic spikes, which capacity setting should you adjust?

A None of the above

B Minimum capacity

C Desired capacity

D Maximum capacity

Maximum capacity limits how many instances can run, controlling costs during traffic spikes.

Which capacity value does Auto Scaling try to maintain under normal conditions?

A Minimum capacity

B Maximum capacity

C Desired capacity

D Zero

Desired capacity is the target number of instances Auto Scaling tries to keep running.

What is the risk of setting minimum capacity too high?

A Higher costs due to more running instances

B Slower scaling

C Instances may stop unexpectedly

D No risk at all

A high minimum capacity means more instances always run, increasing costs even when demand is low.

If traffic suddenly drops, what will Auto Scaling do if desired capacity is above minimum capacity?

A Scale down to minimum capacity

B Scale up to maximum capacity

C Keep current instances running

D Terminate all instances

Auto Scaling will reduce instances but not below the minimum capacity.

Explain in your own words how minimum, maximum, and desired capacity settings affect an Auto Scaling group.

Think of minimum as a safety net, maximum as a limit, and desired as the current goal.

Describe a real-life example where adjusting minimum, maximum, and desired capacity would help manage an application’s performance and cost.

Imagine a store that needs more workers during busy times but fewer when quiet.