AWS Cost Optimizer

Analyze AWS spending patterns, identify waste, and provide actionable cost reduction strategies.

When to Use This Skill

Use this skill when you need to analyze AWS spending, identify cost optimization opportunities, or reduce cloud waste.

Core Capabilities

Cost Analysis

• Parse AWS Cost Explorer data for trends and anomalies
• Break down costs by service, region, and resource tags
• Identify month-over-month spending increases

Resource Optimization

• Detect idle EC2 instances (low CPU utilization)
• Find unattached EBS volumes and old snapshots
• Identify unused Elastic IPs
• Locate underutilized RDS instances
• Find old S3 objects eligible for lifecycle policies

Savings Recommendations

• Suggest Reserved Instance/Savings Plans opportunities
• Recommend instance rightsizing based on CloudWatch metrics
• Identify resources in expensive regions
• Calculate potential savings with specific actions

AWS CLI Commands

Get Cost and Usage

# Last 30 days cost by service
aws ce get-cost-and-usage \
  --time-period Start=$(date -d '30 days ago' +%Y-%m-%d),End=$(date +%Y-%m-%d) \
  --granularity MONTHLY \
  --metrics BlendedCost \
  --group-by Type=DIMENSION,Key=SERVICE

# Daily costs for current month
aws ce get-cost-and-usage \
  --time-period Start=$(date +%Y-%m-01),End=$(date +%Y-%m-%d) \
  --granularity DAILY \
  --metrics UnblendedCost

Find Unused Resources

# Unattached EBS volumes
aws ec2 describe-volumes \
  --filters Name=status,Values=available \
  --query 'Volumes[*].[VolumeId,Size,VolumeType,CreateTime]' \
  --output table

# Unused Elastic IPs
aws ec2 describe-addresses \
  --query 'Addresses[?AssociationId==null].[PublicIp,AllocationId]' \
  --output table

# Idle EC2 instances (requires CloudWatch)
aws cloudwatch get-metric-statistics \
  --namespace AWS/EC2 \
  --metric-name CPUUtilization \
  --dimensions Name=InstanceId,Value=i-xxxxx \
  --start-time $(date -u -d '7 days ago' +%Y-%m-%dT%H:%M:%S) \
  --end-time $(date -u +%Y-%m-%dT%H:%M:%S) \
  --period 86400 \
  --statistics Average

# Old EBS snapshots (>90 days)
aws ec2 describe-snapshots \
  --owner-ids self \
  --query 'Snapshots[?StartTime<=`'$(date -d '90 days ago' --iso-8601)'`].[SnapshotId,StartTime,VolumeSize]' \
  --output table

Rightsizing Analysis

# List EC2 instances with their types
aws ec2 describe-instances \
  --query 'Reservations[*].Instances[*].[InstanceId,InstanceType,State.Name,Tags[?Key==`Name`].Value|[0]]' \
  --output table

# Get RDS instance utilization
aws cloudwatch get-metric-statistics \
  --namespace AWS/RDS \
  --metric-name CPUUtilization \
  --dimensions Name=DBInstanceIdentifier,Value=mydb \
  --start-time $(date -u -d '30 days ago' +%Y-%m-%dT%H:%M:%S) \
  --end-time $(date -u +%Y-%m-%dT%H:%M:%S) \
  --period 86400 \
  --statistics Average,Maximum

Optimization Workflow

1. Baseline Assessment

   • Pull 3-6 months of cost data
   • Identify top 5 spending services
   • Calculate growth rate

2. Quick Wins

   • Delete unattached EBS volumes
   • Release unused Elastic IPs
   • Stop/terminate idle EC2 instances
   • Delete old snapshots

3. Strategic Optimization

   • Analyze Reserved Instance coverage
   • Review instance types vs. workload
   • Implement S3 lifecycle policies
   • Consider Spot instances for non-critical workloads

4. Ongoing Monitoring

   • Set up AWS Budgets with alerts
   • Enable Cost Anomaly Detection
   • Tag resources for cost allocation
   • Monthly cost review meetings

Cost Optimization Checklist

• Enable AWS Cost Explorer
• Set up cost allocation tags
• Create AWS Budget with alerts
• Review and delete unused resources
• Analyze Reserved Instance opportunities
• Implement S3 Intelligent-Tiering
• Review data transfer costs
• Optimize Lambda memory allocation
• Use CloudWatch Logs retention policies
• Consider multi-region cost differences

Example Prompts

Analysis

• "Show me AWS costs for the last 3 months broken down by service"
• "What are my top 10 most expensive resources?"
• "Compare this month's spending to last month"

Optimization

• "Find all unattached EBS volumes and calculate savings"
• "Identify EC2 instances with <5% CPU utilization"
• "Suggest Reserved Instance purchases based on usage"
• "Calculate savings from deleting snapshots older than 90 days"

Implementation

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