AWS Resource Type:
Amazon OpenSearch Reserved Instances (RIs)
Opportunity Description:
This Finder identifies OpenSearch Reserved Instances (RIs) that are approaching expiration and are still needed to cover your usage, and recommends extending them to avoid falling back to on-demand pricing. For each instance-type family, CloudFix compares your total reserved capacity to what you actually use: it lets enough of the earliest-expiring reservations lapse to shed any unused capacity, and recommends extending only the reservations still required to cover current usage — even when that means a partial extension of a reservation well below 100% utilization. Extending RIs still needed before they expire ensures sustained cost savings and prevents unexpected billing increases.
The Finder is especially useful for organizations managing multiple OpenSearch clusters across different regions and instance types — where manual tracking of reservations, utilization, and expiration windows is error-prone and time-consuming.
Criteria for identifying the opportunity:
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An OpenSearch RI is expiring within a configurable look-ahead window (default: 30 days).
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Utilization is calculated per instance-type family using AWS Cost Explorer data over the previous 30-day usage history (configurable, 1-365 days).
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CloudFix compares total reserved capacity to actually used capacity for each instance-type family. Where reserved capacity exceeds usage, enough of the earliest-expiring reservations are allowed to lapse to absorb that surplus.
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The remaining reservations — those still needed once the earliest-expiring ones lapse — are recommended for extension. This can include a partial extension of a reservation that is below 100% utilized, if some of its capacity is still in use.
Potential Savings (Annual Estimate):
Savings are estimated by comparing:
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The cost of running expiring instances at on-demand rates
vs. -
The cost of renewing the reservation with your preferred term (1-year or 3-year) and payment option (No Upfront, Partial, or All Upfront)
These savings are calculated per reservation and aggregated across all accounts and regions. The recommendation report includes a detailed breakdown.
What happens when the Fixer is executed?
This Finder does not perform any actions automatically. Instead, it generates:
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A per-reservation recommendation to extend (or not) based on usage patterns and expiration dates.
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Estimated annual cost savings for each recommended extension.
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A cost comparison for your configured reservation term and payment option (default: 1-year, No Upfront — both configurable in the Finder settings).
You can use this data to manually extend reservations using the AWS Console or CLI.
Is it possible to roll back once CloudFix implements the Fixer?
Not applicable. CloudFix does not execute any changes. However, if you manually extend a reservation through AWS, that commitment is non-refundable.
Can CloudFix implement the fix automatically once I accept the recommendation?
No. This Finder is recommendation-only. It helps identify RIs worth extending but does not execute the reservation purchase.
Does the fix require downtime?
No. OpenSearch RIs affect billing, not performance or availability. Extending or not extending an RI does not cause service interruption.
Bill Gleeson
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