Commitment Recommendations

Why this page?

Cloud commitments (Reserved Instances & Savings Plans) are the biggest lever to cut AWS spend on RDS, DynamoDB, Redshift… The Rate Optimization screens surface:

1. How much you've already saved through active commitments.
2. Where additional savings remain (uncovered on-demand hours).
3. A data-driven buy list that you can execute immediately—or snooze for later.

Supported Commitments

Service	Supported
Amazon RDS	✅ Yes
Amazon ElastiCache	✅ Yes
Amazon Redshift	🔄 In Progress
Amazon DynamoDB (reserved capacity)	🔄 In Progress
Amazon OpenSearch Service (formerly ElasticSearch)	🔄 In Progress
Amazon MemoryDB	🔄 In Progress
Amazon DocumentDB	🔄 In Progress

Important terms

Commitment Groups

A commitment group is the smallest "exchange-compatible" pool of compute in which a Reserved Instance or Savings Plan can float. It bundles together all usage and reservations that share the same service (e.g. RDS), instance family or SKU (e.g. R7G), region, database engine and license model. Any reservation purchased inside a commitment group can automatically cover any instance‐hour generated by that same group, regardless of size (thanks to normalisation) or specific DB cluster—so savings and utilisation are calculated across the whole pool, not per individual instance.

The recommendation cards and the details page are shown per commitment group. In practice it groups all usage across all projects that can be covered by the same reservation.

More details on the commitment groups page.

One-year potential savings

Difference between the on-demand equivalent cost and the amortized cost of the recommended reservation, assuming a 100 % usage rate.

Effective Savings Rate (ESR)

Percentage of spend you avoided thanks to commitments:

$ESR = \frac{OnDemand Equivalent − Actual Cost}{OnDemand Equivalent}$

Where $Actual Cost = Amortized Cost + residual Ondemand Cost$.

Effective Savings Rate Performance

$ESR_{Perf} = \frac{\text{Your current ESR}}{\text{ESR if all recommendations applied}}$

A value of 1.00 means you already capture every available saving; 0.80 means you achieve 80 % of the potential.

Usage Rate

We analyse every hour since the commitment became active.

1. Committed quantity – normalised instances you are paying for in that hour.
2. Used quantity – the share of hourly usage that maps to the commitment (after proportional allocation).

$Usage Rate = \frac{\sum{qty_{used}}}{\sum{qty_{commited}}}$

The value is capped at 100 %.

Savings

$Savings = OnDemand Equivalent − Actual Cost$