# Underutilized RDS commitment due to workload drift Canonical: https://www.pointfive.co/efficiency-hub/inefficiencies/underutilized-rds-commitment-due-to-workload-drift RDS workloads often evolve - changing engine types, rightsizing instances, or shifting to Aurora or serverless models. By: Jason DiDomenico Updated: 2026-09-28 [Cloud Efficiency Hub](https://www.pointfive.co/efficiency-hub) # Underutilized RDS Commitment Due to Workload Drift The short version RDS workloads often evolve - changing engine types, rightsizing instances, or shifting to Aurora or serverless models. [Jason DiDomenico](https://www.linkedin.com/in/jasondidomenico/) Director of FinOps @ Discover Financial Services AWS service [AWS RDS](https://www.pointfive.co/efficiency-hub/cloud-services/aws-rds) Category [Databases](https://www.pointfive.co/efficiency-hub/service-category/databases) Reference CER-0030 Type Underutilized Commitment ## Explanation Why the waste happens and who it affects. When these changes occur after Reserved Instances have been purchased, the existing commitments may no longer match active usage. This results in silent overspend, as underutilized RIs continue billing without offsetting usage. Unlike Convertible EC2 RIs, RDS RIs cannot be exchanged. Selling unused RDS RIs is not supported. In rare cases, AWS Support may approve a goodwill adjustment, but this is not guaranteed. The most effective way to recover value is to steer eligible workloads back toward the reserved configuration. ## Billing model The pricing dimensions that drive this cost. - Standard RDS Reserved Instances are billed hourly regardless of instance usage - RIs are tied to specific configurations and cannot be modified once purchased, but for most engines they are size-flexible: the discount applies automatically across sizes of the same instance class type in the same Region and engine, and across Single-AZ and Multi-AZ, so rightsizing within the family keeps the RI utilized (size flexibility does not apply to RDS for SQL Server or RDS for Oracle License Included) - If RDS usage patterns change or migrate away from covered configurations, the RI continues to accrue cost without providing benefit ## How to detect 4 checks to find it in your estate. - Identify underutilized RDS Reserved Instances using billing and utilization data - Break down the instance classes, engines, and regions with low or zero usage - Trace whether existing workloads have moved off those configurations - and why - Quantify the cost of unused commitment to prioritize remediation ## How to fix 6 ways to remove the waste. - Evaluate whether current or new workloads can run on the reserved instance types - Prioritize launching new RDS instances that align with the unused commitment - Where feasible, upgrade or shift workloads to covered instance classes while monitoring performance and future fit - Document changes made to consume the commitment and reassess once the reservation expires - In rare cases, contact AWS Support to request a reservation adjustment - note that approval depends on RI type, remaining term, and value parity - For future commitments on workloads likely to change engine, instance family or size, or move to Aurora Serverless, consider Database Savings Plans, which apply across supported engines, instance families, sizes, deployment options and Regions ## Documentation Vendor references for pricing and configuration. - [AWS RDS Reserved Instances aws.amazon.com](https://aws.amazon.com/rds/reserved-instances/) - [RDS Pricing aws.amazon.com](https://aws.amazon.com/rds/pricing/) - [Reserved DB instances for Amazon RDS docs.aws.amazon.com](https://docs.aws.amazon.com/AmazonRDS/latest/UserGuide/USER_WorkingWithReservedDBInstances.html) ## Related inefficiencies [Browse the library](https://www.pointfive.co/efficiency-hub) - AWS RDS CER-0323 ### [RDS SQL Server Running Bundled Licensing on Older Instance Families](https://www.pointfive.co/efficiency-hub/inefficiencies/rds-sql-server-running-bundled-licensing-on-older-instance-families) Amazon RDS for SQL Server has traditionally used a License Included model where the SQL Server license cost is bundled into a single hourly instance price alongside Windows OS licensing, compute resources, and RDS management capabilities.... Databases - AWS RDS CER-0322 ### [Non-Production RDS SQL Server Using Standard or Enterprise Edition Instead of Developer Edition](https://www.pointfive.co/efficiency-hub/inefficiencies/non-production-rds-sql-server-using-standard-or-enterprise-edition-instead-of-developer-edition) Amazon RDS for SQL Server uses a License Included pricing model where the hourly instance rate bundles Microsoft SQL Server licensing fees on a per-vCPU basis. When non-production workloads - such as development, testing, staging, QA, or... Databases - AWS RDS CER-0320 ### [Excess vCPU Licensing Costs on RDS for SQL Server Instances](https://www.pointfive.co/efficiency-hub/inefficiencies/excess-vcpu-licensing-costs-on-rds-for-sql-server-instances) Amazon RDS for SQL Server uses a License Included pricing model where SQL Server and Windows OS licensing costs are bundled into the per-instance-hour rate - and those licensing costs scale directly with the number of vCPUs on the... Databases --- Source: the public page above. Product screenshots and illustrative interfaces are examples, not live customer data.