Auto Scaling Groups (ASGs) are a powerful AWS feature that helps maintain application availability by automatically adjusting the number of EC2 instances. However, if not properly optimized, ASGs can lead to unnecessary costs. CloudFix’s EC2 Resize ASG Instances Finder/Fixer helps identify and implement cost-saving opportunities for your Auto Scaling Groups while maintaining performance.

Contents

Overview

The EC2 Resize ASG Instances Finder/Fixer analyzes your Auto Scaling Groups to identify instances that could be optimized for better cost efficiency. It leverages AWS Compute Optimizer recommendations to ensure all suggested changes maintain performance while reducing costs.

How It Works

Finding Optimization Opportunities

The Finder evaluates your ASG configurations by:

  • Analyzing EC2 instances associated with Auto Scaling Groups
  • Reviewing usage patterns over the last 31 days
  • Identifying instances with significant cost impact
  • Excluding resources managed by services like EMR or EKS
  • Respecting exclusions for CloudFormation-managed resources and resources tagged with cloudfix_dont_fix_it

Validation Process

Before implementing any changes, the Fixer performs multiple validation checks:

  • Verifies ASG existence and configuration
  • Checks for launch template usage (skips legacy launch configurations)
  • Evaluates existing Reserved Instance coverage
  • Assesses instance age and configuration complexity
  • Reviews Compute Optimizer recommendations

Implementation

The implementation process involves:

  1. Reviewing automatically generated savings recommendations
  2. Creating a change ticket through JIRA integration
  3. Manual implementation of the recommended changes
  4. Verification of performance post-change

Benefits

  • Typical cost savings of 10-15% on applicable ASGs
  • Zero performance impact due to AWS validation
  • Automated identification of optimization opportunities
  • Safe implementation through manual verification
  • Continuous optimization as new instance types become available

AWS Services Affected

Amazon EC2
AWS Auto Scaling
Amazon EC2 AWS Auto Scaling

Requirements

  • AWS Compute Optimizer must be enabled
  • ASGs must use launch templates (not launch configurations)
  • Instances should not have active Reserved Instance coverage
  • ASGs should not use warm pools or complex overrides

Ready to start saving on AWS? See how much you could cut from your cloud bill with a free cost optimization assessment, or explore CloudFix automated Finder/Fixers that eliminate waste across 30+ AWS services.

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