AWS Cost Optimizer

Analyze and optimize AWS costs with actionable recommendations.

Quick Start

Review Cost Explorer, identify top costs, right-size instances, use Reserved Instances, delete unused resources.

Instructions

Cost Analysis Process

• Identify cost drivers

• Analyze usage patterns

• Recommend optimizations

• Estimate savings

• Implement changes

Using AWS Cost Explorer

Access Cost Explorer:

• AWS Console → Billing → Cost Explorer

• View costs by service, region, tag

Key metrics to check:

• Monthly costs by service

• Cost trends over time

• Unused or underutilized resources

• Data transfer costs

EC2 Cost Optimization

Right-sizing instances:

Check utilization:

Get CloudWatch metrics

aws cloudwatch get-metric-statistics
--namespace AWS/EC2
--metric-name CPUUtilization
--dimensions Name=InstanceId,Value=i-1234567890abcdef0
--start-time 2024-01-01T00:00:00Z
--end-time 2024-01-31T23:59:59Z
--period 3600
--statistics Average

Recommendations:

• CPU < 20%: Downsize instance type

• CPU > 80%: Upsize or add instances

• Memory < 50%: Consider smaller instance

Reserved Instances:

• 1-year: ~30-40% savings

• 3-year: ~50-70% savings

• Best for predictable workloads

Savings Plans:

• More flexible than Reserved Instances

• Commit to $/hour usage

• Apply across instance families

Spot Instances:

• Up to 90% savings

• For fault-tolerant workloads

• Batch processing, CI/CD, testing

Stop unused instances:

Find stopped instances

aws ec2 describe-instances
--filters "Name=instance-state-name,Values=stopped"
--query 'Reservations[].Instances[].[InstanceId,Tags[?Key==Name].Value|[0]]'

Terminate if not needed

aws ec2 terminate-instances --instance-ids i-1234567890abcdef0

S3 Cost Optimization

Lifecycle policies:

{ "Rules": [{ "Id": "Archive old data", "Status": "Enabled", "Transitions": [ { "Days": 30, "StorageClass": "STANDARD_IA" }, { "Days": 90, "StorageClass": "GLACIER" } ], "Expiration": { "Days": 365 } }] }

Storage classes:

• Standard: Frequent access

• Standard-IA: Infrequent access (30+ days)

• Glacier: Archive (90+ days)

• Glacier Deep Archive: Long-term archive

Delete incomplete multipart uploads:

aws s3api list-multipart-uploads --bucket my-bucket

Set lifecycle rule to abort after 7 days

Analyze storage:

Get bucket size

aws s3 ls s3://my-bucket --recursive --summarize

RDS Cost Optimization

Right-size databases:

• Check CPU, memory, IOPS utilization

• Downsize if consistently low

• Use Aurora Serverless for variable workloads

Reserved Instances:

• 1-year: ~30-40% savings

• 3-year: ~50-60% savings

Stop dev/test databases:

Stop RDS instance

aws rds stop-db-instance --db-instance-identifier mydb

Start when needed

aws rds start-db-instance --db-instance-identifier mydb

Delete old snapshots:

List snapshots

aws rds describe-db-snapshots --query 'DBSnapshots[?SnapshotCreateTime<2023-01-01]'

Delete old snapshots

aws rds delete-db-snapshot --db-snapshot-identifier snapshot-id

Data Transfer Costs

Reduce data transfer:

• Use CloudFront for content delivery

• Keep data in same region

• Use VPC endpoints for AWS services

• Compress data before transfer

VPC endpoints:

Create S3 VPC endpoint (no data transfer charges)

aws ec2 create-vpc-endpoint
--vpc-id vpc-12345678
--service-name com.amazonaws.us-east-1.s3
--route-table-ids rtb-12345678

EBS Cost Optimization

Delete unattached volumes:

Find unattached volumes

aws ec2 describe-volumes
--filters "Name=status,Values=available"
--query 'Volumes[].[VolumeId,Size,VolumeType]'

Delete if not needed

aws ec2 delete-volume --volume-id vol-1234567890abcdef0

Delete old snapshots:

List old snapshots

aws ec2 describe-snapshots --owner-ids self
--query 'Snapshots[?StartTime<2023-01-01]'

Delete

aws ec2 delete-snapshot --snapshot-id snap-1234567890abcdef0

Use gp3 instead of gp2:

• gp3 is 20% cheaper

• Better performance

• Migrate existing volumes

Lambda Cost Optimization

Optimize memory allocation:

• More memory = faster execution = lower cost

• Test different memory settings

• Use AWS Lambda Power Tuning tool

Reduce cold starts:

• Use provisioned concurrency (if needed)

• Keep functions warm with scheduled events

• Minimize dependencies

Monitor invocations:

Get Lambda metrics

aws cloudwatch get-metric-statistics
--namespace AWS/Lambda
--metric-name Invocations
--dimensions Name=FunctionName,Value=my-function
--start-time 2024-01-01T00:00:00Z
--end-time 2024-01-31T23:59:59Z
--period 86400
--statistics Sum

CloudWatch Costs

Reduce log retention:

Set log retention to 7 days

aws logs put-retention-policy
--log-group-name /aws/lambda/my-function
--retention-in-days 7

Delete unused log groups:

List log groups

aws logs describe-log-groups

Delete

aws logs delete-log-group --log-group-name /aws/lambda/old-function

Unused Resources

Find unused resources:

Elastic IPs not attached:

aws ec2 describe-addresses
--query 'Addresses[?AssociationId==null]'

Load balancers with no targets:

aws elbv2 describe-load-balancers aws elbv2 describe-target-health --target-group-arn arn

NAT Gateways with low traffic:

Check CloudWatch metrics for BytesOutToDestination

Cost Optimization Checklist

Compute:

• Right-size EC2 instances

• Use Reserved Instances for predictable workloads

• Use Spot Instances for fault-tolerant workloads

• Stop/terminate unused instances

• Implement auto-scaling

Storage:

• Implement S3 lifecycle policies

• Delete old EBS snapshots

• Delete unattached EBS volumes

• Use appropriate S3 storage classes

• Delete incomplete multipart uploads

Database:

• Right-size RDS instances

• Use Reserved Instances

• Stop dev/test databases when not in use

• Delete old RDS snapshots

• Consider Aurora Serverless

Networking:

• Use CloudFront to reduce data transfer

• Delete unused Elastic IPs

• Use VPC endpoints

• Review NAT Gateway usage

Monitoring:

• Reduce CloudWatch log retention

• Delete unused log groups

• Review custom metrics

General:

• Enable AWS Cost Anomaly Detection

• Set up billing alerts

• Use AWS Budgets

• Tag resources for cost allocation

• Review Cost Explorer regularly

Savings Estimation

Reserved Instances:

• 1-year, no upfront: ~30% savings

• 1-year, all upfront: ~40% savings

• 3-year, all upfront: ~60% savings

Spot Instances:

• 70-90% savings vs On-Demand

S3 Lifecycle:

• Standard-IA: ~50% cheaper than Standard

• Glacier: ~80% cheaper than Standard

Right-sizing:

• Typical savings: 20-40% on oversized instances

Tools and Commands

AWS Cost Explorer:

• View costs by service, region, tag

• Forecast future costs

• Identify cost anomalies

AWS Budgets:

Create budget

aws budgets create-budget
--account-id 123456789012
--budget file://budget.json

AWS Trusted Advisor:

• Cost optimization recommendations

• Underutilized resources

• Idle resources

Third-party tools:

• CloudHealth

• CloudCheckr

• Spot.io

Best Practices

Tagging strategy:

• Tag all resources

• Use tags for cost allocation

• Common tags: Environment, Project, Owner, CostCenter

Regular reviews:

• Weekly: Check for anomalies

• Monthly: Review Cost Explorer

• Quarterly: Optimize Reserved Instances

Automation:

• Auto-stop dev instances at night

• Auto-delete old snapshots

• Auto-scale based on demand

Monitoring:

• Set up billing alerts

• Use AWS Budgets

• Enable Cost Anomaly Detection