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Use Case for ASG Underutilization Detection

  1. Configure ASG Underutilization Detection
  2. Use Case for ASG Underutilization Detection
  3. Triage Guides by Violation Type
    1. Triage ASG Underutilization Detection UNDERUTILIZED_ASG

AWS Auto Scaling Group Underutilization Use Case

This policy helps to optimize resource usage within your AWS environment by identifying underutilized Auto Scaling Groups (ASGs). By setting a minimum threshold for CPU utilization, you can pinpoint ASGs that may be scaled down or configured more cost-effectively.

Pros and Cons​

Pros:

  • Reduces unnecessary costs due to overprovisioned resources.
  • Improves efficiency by reallocating or terminating resources.

Cons:

  • May require additional context to determine if low CPU utilization is acceptable based on the workload.

How It Works​

By monitoring CloudWatch metrics, this policy checks if the average CPU utilization across all instances in an ASG falls below the specified threshold (cpuUtilizationThreshold). Additionally, it verifies that the ASG is older than a certain number of days (ageThresholdDays) to avoid penalizing ASGs that are still in their initial scaling phase.

Variables and Defaults​

  • cpuUtilizationThreshold: The minimum average CPU utilization percentage for an ASG to be considered adequately utilized. Default is 20% if not specified.
  • ageThresholdDays: The ASG must be older than this threshold to be evaluated. Default is 30 days if not specified.

Violation Types​

  • UNDERUTILIZED_ASG: Emitted when the average CPU utilization is below the configured threshold, and the ASG is older than the ageThresholdDays.