Overview
Rightsizing recommendations is a document type in Azure Documenter that provides recommendations for optimizing performance and cost by choosing the right SKUs for the resources in Azure subscriptions.
Business value
Rightsizing recommendations helps teams eliminate over-provisioned or under-provisioned resources, improving performance where needed and cutting cost where capacity is unused.
Prerequisites
Required permissions
| Role | Permission level | Access |
|---|---|---|
| Account owner, Owner, Contributor | - | Full access to the Documentation section |
| Custom role | Read | View documents generated under Documentation |
| Custom role | Manage | View, generate, and manage documents under Documentation |
How it works
Recommendation types
The document contains recommendations on which SKUs to use for Azure resources, organized into four categories:
1. Upgrade
A resource that often consumes the maximum capacity of its SKU receives this recommendation. Upgrading to a higher SKU improves performance.
2. Downgrade
A resource that does not utilize its maximum capacity receives this recommendation. Moving it to a lower SKU reduces cost.
3. Idle
This recommendation indicates that the resource has not been used for an extended period and can be deleted if no longer required.
4. No change
A resource that consistently utilizes the average capacity of its SKU receives this recommendation. No SKU change is required.
Document structure
The document opens with a Summary table showing all selected subscriptions with their Current Cost (USD), Optimized Cost (USD), and total Recommendations count, giving an immediate cross-subscription view of potential savings.
For each subscription, the document provides:
- A Subscription summary with current cost, optimized cost, and total recommendation count
- A Recommendations breakdown by recommendation type (Idle, Upgrade, Downgrade, No change)
- For each recommendation type: a breakdown by resource type (e.g., Virtual Machine, SQL Database, App Service Plan)
- For each resource type: a detailed table
Per-resource table columns:
| Column | Description |
|---|---|
| Resource | The Azure resource name |
| Current Sku | The resource's current SKU |
| Current Cost (USD) | The resource's current monthly cost |
| Recommended Sku | The Azure Documenter-recommended SKU |
| Optimized Cost (USD) | The projected cost at the recommended SKU |
For SQL databases, the table also includes the Server name alongside the resource name. Supported resource types include Virtual Machine, Virtual Machine Scaleset, SQL Database, and App Service Plan.
Steps
Use the following steps to generate a Rightsizing recommendations document. Navigate to Azure Documenter to get started.
- Click New configuration. The Configure your document wizard opens.
- In Step 1 (Basics), enter a configuration name. Under Choose document type, select Rightsizing recommendations. Configure the following options:
- Currency: the currency in which cost data is displayed
- Evaluation duration: the number of days of usage data to analyze (default: 30 days)
- Recommendations: filters the output to a specific recommendation type: All, Idle, Upgrade, Downgrade, or No change
- In Step 2 (Service principal), select the service principal and configure the subscription scope. Click Next.
- Complete Steps 3–6 (Branding, Publish settings, Schedule, Notifications) as required. Click Next after each step.
- In Step 7 (Review), confirm your configuration and click Finish.
By default, the last 30 days of evaluation duration is used to analyze and generate the Rightsizing recommendations document.
Once generation is complete, a URL is created for the document, and you can download it using the Download link.
Example scenario
Contoso's platform team notices rising compute spend on their Development subscription. They generate a Rightsizing recommendations document, identify several idle and over-provisioned VMs flagged under Downgrade and Idle, and resize or remove them to cut costs.
Troubleshooting
-
Rightsizing recommendations document returns no recommendations
Cause: insufficient usage history exists for the selected evaluation duration, or all resources are already optimally sized.
Fix: increase the evaluation duration in the configuration and regenerate, or verify that resources have been active during the evaluation period. -
Document generation fails or returns incomplete data
Cause: the service principal lacks the required permissions to access usage metrics for the selected subscriptions.
Fix: verify the service principal has at least Reader access on all selected subscriptions, then regenerate. -
Evaluation duration change does not reflect in the generated document
Cause: the configuration was edited but the document was not regenerated after saving the change.
Fix: after updating the evaluation duration, regenerate the document using the Context menu ( ⋮ ) next to the configuration.
FAQs
-
Who can access the Documentation section by default?
Account owner, Owner, and Contributor roles have full access by default. No additional configuration is required. -
What's the difference between Read and Manage for Documentation?
Read lets a user view documents generated under Document Types. Manage lets a user view, generate, and manage them. -
What evaluation window is used to calculate the recommendations?
The last 30 days by default. You can change the evaluation duration from an existing configuration's Advanced settings section.