Rightsizing

Rightsizing is one of the highest-impact cost optimisation strategies in cloud computing. Guardian Pro analyses the utilisation of your compute and database resources, then provides specific recommendations to downsize, terminate, or modernise underutilised infrastructure.

What is Rightsizing?

Rightsizing means matching your resource capacity to actual workload requirements. In many AWS environments, resources are initially provisioned for peak capacity and never adjusted downward, resulting in persistent over-provisioning.

Guardian Pro's AI-powered analysis identifies resources where actual utilisation is significantly below provisioned capacity, and recommends the appropriate action:

Action	When Recommended
Downsize	Resource is partially utilised -- a smaller instance type would handle the workload
Terminate	Resource shows minimal or no utilisation -- it can likely be removed entirely
Modernise	Resource uses an older generation type -- a newer type offers better performance at lower cost

Supported Resource Types

Amazon EC2

Guardian Pro analyses EC2 instance utilisation across multiple dimensions:

Metric	Analysis
CPU utilisation	Average and peak CPU usage over the analysis period
Memory utilisation	Available when CloudWatch agent is installed
Network throughput	Actual vs. capacity of the instance type
Storage IOPS	Actual vs. provisioned I/O performance

Recommendations include:

• Terminate -- Instances with consistently very low CPU utilisation that appear to be idle or forgotten.
• Downsize -- Instances with low-to-moderate CPU utilisation that would perform adequately on a smaller instance type. The recommendation specifies the target instance type.
• Change family -- Instances on older generations (e.g., m4 to m6i) where the newer generation provides equivalent or better performance at a lower price.
• Switch to Graviton -- x86 instances where an ARM-based Graviton alternative exists at a lower cost, when the workload is compatible.

tip

Before acting on a terminate recommendation, verify that the instance is not serving a critical function with intermittent usage patterns (e.g., a batch processing server that runs jobs weekly). Check CloudWatch metrics over at least a 14-day period.

Amazon RDS

Guardian Pro analyses RDS database instance utilisation:

Metric	Analysis
CPU utilisation	Average and peak database CPU
Database connections	Active connections vs. maximum allowed
Storage utilisation	Allocated vs. used storage
IOPS	Provisioned vs. actual I/O operations

Recommendations include:

• Downsize -- Instances with low CPU utilisation and low connection counts relative to the instance class capacity.
• Storage optimisation -- Over-provisioned storage or unnecessarily expensive storage types (e.g., Provisioned IOPS when General Purpose would suffice).
• Multi-AZ review -- Non-production databases running with Multi-AZ enabled, where the availability benefit does not justify the doubled cost.

warning

Database rightsizing carries higher risk than compute rightsizing. Always test performance on the target instance class before applying changes in production. Consider using read replica promotion for zero-downtime migrations.

Amazon EBS

Guardian Pro analyses EBS volume utilisation and configuration:

Check	Description
Unattached volumes	Volumes not connected to any EC2 instance
Idle volumes	Attached volumes with minimal I/O activity
Volume type migration	gp2 volumes that can be migrated to gp3 for cost savings
Over-provisioned IOPS	Provisioned IOPS volumes (io1/io2) with low actual IOPS usage

Key savings opportunity -- gp2 to gp3 migration:

gp3 volumes provide a baseline of 3,000 IOPS and 125 MiB/s throughput at a lower price than gp2. For most workloads, migrating from gp2 to gp3 delivers:

• Up to 20% cost reduction
• Equal or better performance
• No downtime required (online migration)

Understanding Recommendations

Each rightsizing recommendation includes:

Field	Description
Resource	The specific resource (instance ID, volume ID, etc.)
Current Configuration	Current instance type, storage type, or size
Recommended Change	The specific action and target configuration
Estimated Monthly Savings	Projected cost reduction from implementing the recommendation
Confidence	How confident the analysis is in the recommendation (based on data quality and observation period)
Risk Level	The potential impact of implementing the change (Low, Medium, High)
Utilisation Data	The metrics that support the recommendation

Implementing Recommendations

From Cost Intelligence

1. Review the recommendation details and supporting utilisation data.
2. Verify the resource is safe to modify (check with the team that owns it).
3. For downsizing, consider implementing during a maintenance window.
4. Track the realised savings in the Savings Tracker.

From the Action Centre

Rightsizing recommendations also appear in the Action Centre as cost optimisation findings. From the Action Centre, you can:

• View the recommendation alongside related security and compliance findings for the same resource.
• For supported checks, use Guardian Pro's automated remediation to apply the change directly.
• Track the status of the remediation through the activity monitor.

info

Automated remediation for rightsizing is available for select changes such as EBS volume type migration (gp2 to gp3). Changes that require instance restarts or carry higher risk are presented as guided recommendations with manual steps.

Prioritising Recommendations

Guardian Pro ranks rightsizing recommendations by estimated savings impact, making it easy to focus on the highest-value opportunities first. A general prioritisation approach:

1. Terminate idle resources -- Zero risk of performance impact, immediate savings.
2. gp2 to gp3 migration -- Low risk, no downtime, consistent savings.
3. Oversized instances with clear evidence -- Moderate risk, validate with a test period.
4. Generation upgrades -- Low risk, often improves performance while reducing cost.
5. Database rightsizing -- Higher risk, requires careful testing.

Ongoing Rightsizing

Rightsizing is not a one-time activity. As workloads evolve, resource utilisation patterns change. Guardian Pro continuously monitors utilisation and surfaces new recommendations as they arise.

Best practices for ongoing rightsizing:

• Review rightsizing recommendations during your monthly cost review.
• After implementing a recommendation, verify that the workload performs correctly on the new configuration.
• Use the Savings Tracker to measure cumulative savings from rightsizing actions.
• Combine rightsizing with Savings Plans -- rightsize first to establish your true baseline, then commit for additional discounts.

tip

Always rightsize before purchasing commitments (Savings Plans or Reserved Instances). Committing to an oversized resource locks in a higher cost for the commitment term.

Next Steps

• Waste Detection -- Find idle and unused resources beyond compute and database
• Savings Plans -- Commit to usage after rightsizing for additional savings
• Savings Tracker -- Track the impact of your rightsizing efforts