Scaling policies (target tracking, step, simple) in AWS - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is a simple scaling policy in AWS Auto Scaling?

A simple scaling policy adds or removes a fixed number of instances when a specific CloudWatch alarm triggers. It reacts directly to a threshold being crossed.

intermediate

How does a step scaling policy differ from a simple scaling policy?

Step scaling adjusts the number of instances in steps based on how much a metric deviates from a threshold. Larger deviations cause bigger scaling actions.

beginner

What is target tracking scaling in AWS Auto Scaling?

Target tracking scaling automatically adjusts capacity to keep a metric, like CPU usage, close to a target value you set, similar to a thermostat keeping temperature steady.

intermediate

Why is target tracking scaling often preferred over simple or step scaling?

Because it automatically adjusts capacity to maintain a target metric, it requires less manual tuning and responds smoothly to changes in demand.

beginner

What role do CloudWatch alarms play in simple and step scaling policies?

CloudWatch alarms monitor metrics and trigger scaling actions when thresholds are crossed, acting as the signal for scaling up or down.

Which scaling policy automatically adjusts capacity to keep a metric near a target value?

A Simple scaling

B Step scaling

C Manual scaling

D Target tracking scaling

Target tracking scaling adjusts capacity automatically to maintain a specified metric target.

In step scaling, what determines the size of the scaling adjustment?

A Fixed number of instances every time

B How far the metric is from the threshold

C Time of day

D Random selection

Step scaling changes capacity in steps based on how much the metric deviates from the threshold.

What triggers scaling actions in simple and step scaling policies?

A User manual input

B Fixed schedule

C CloudWatch alarms

D Random events

CloudWatch alarms monitor metrics and trigger scaling when thresholds are crossed.

Which scaling policy is most like a thermostat keeping temperature steady?

A Target tracking scaling

B Step scaling

C Simple scaling

D Manual scaling

Target tracking scaling maintains a metric near a target value, like a thermostat.

Which scaling policy requires the least manual tuning?

A Target tracking scaling

B Step scaling

C Simple scaling

D Manual scaling

Target tracking scaling automatically adjusts capacity to maintain the target metric, reducing manual tuning.

Explain the differences between simple, step, and target tracking scaling policies in AWS Auto Scaling.

Think about how each policy decides when and how much to scale.

Describe how CloudWatch alarms interact with scaling policies in AWS Auto Scaling.

Consider the role of alarms as signals for scaling.