Amazon OpenSearch Service · Finder + automated fixer
OpenSearch Resize Instances
ResizeInstances
Rightsize over-provisioned OpenSearch domains. CloudFix identifies domains whose instances are larger than their workload needs and moves them to a smaller instance type.
What happens, in order.
Finder · read-only
Finds the opportunity
Scans your connected accounts with a read-only role. It can see resource metadata and usage; it can’t change anything.
You
Approve in Recommendations
It appears in your Recommendations view with what it would save. Approve the resources you choose. Nothing has changed yet.
Fixer
Runs in your account
The fixer runs as an AWS Systems Manager Automation runbook in your AWS account, and acts only on the resources you approved.
Record
Logs the execution
The Systems Manager execution is logged, so every change can be audited.
Finder role
Read-only. It can see resource metadata and usage. It can’t change anything.
Fixer role
A separate, minimal role that acts only on the resources you approved, through AWS Systems Manager.
Saves by
OpenSearch Service bills per node-hour for every node in a domain. This Finder/Fixer identifies domains whose instances are consistently larger than their workload requires and moves them to a smaller instance type that still leaves headroom, lowering the hourly cost of the domain.
Amazon OpenSearch Service domains are often sized for a peak that never arrives, so their data nodes run on instance types far larger than the workload needs. This CloudFix Finder/Fixer identifies over-provisioned OpenSearch domains and moves them to a smaller instance type that still fits how they are actually used.
Overview
An OpenSearch domain is billed per node-hour for every node it runs, whatever the load. Domains are commonly provisioned generously at launch, or scaled up for a one-off event and never scaled back, so many run well below the capacity they pay for. Rightsizing the data nodes to an instance type that matches real usage lowers the hourly cost of the domain without changing how it is used.
AWS Services Affected
How It Works
The Finder works read-only, using your cost and usage data and the utilization metrics OpenSearch already reports to CloudWatch to find domains whose instances are consistently larger than their workload requires. Each domain appears in your CloudFix Recommendations with a suggested instance type and the projected savings, and nothing changes until you approve it.
Once approved, the Fixer runs as an AWS Systems Manager Automation runbook in your own account and updates the domain configuration to the recommended instance type. OpenSearch Service applies an instance type change as a blue/green deployment, so the domain stays available while the new nodes are brought up and the data is moved across. Every execution is logged.
FAQ
How does CloudFix decide a domain is over-provisioned?
CloudFix looks at how each domain’s nodes are actually used over time and only recommends a smaller instance type when the smaller type still leaves headroom for the observed workload. You can exclude any domain you do not want changed.
What are the potential savings?
Savings depend on the gap between the current and recommended instance types and on the number of nodes in the domain. CloudFix shows the projected savings for each domain before you approve anything.
Is the fix automatic after accepting the recommendation?
Yes. Once you approve the recommendation, CloudFix applies the new instance type through an AWS Systems Manager Automation runbook in your account.
Does this fix require downtime?
No. OpenSearch Service applies the change through a blue/green deployment, and the domain keeps serving requests while it runs. Performance can be affected temporarily while data is copied to the new nodes, so large domains are best changed at a quiet time.
Can changes be rolled back?
Yes. If the smaller instance type does not suit the workload, you can change the domain back to its previous instance type in the same way.
Related Resources
- Sizing Amazon OpenSearch Service domains
- Making configuration changes in Amazon OpenSearch Service
- Amazon OpenSearch Service Pricing
Related Articles
See whether this one applies to your account.
A free savings assessment reports which fixers can be applied to your environment. Results typically within 24 hours.