I need help with the following scenario. I’d like to utilize my Oracle EE BYOL Amazon RDS instances as Reserved Instances.
When I check the recommendations via Cost Explorer > RI > Recommendations (RDS), the amount of RI recommended differs from the amount of instances I have created.
Is this real behavior?
I need help to understand if the scenario I’ve been explained is correct.
Size flexibility with RDS Reserved Instances could also cause a discrepancy between Cost Explorer recommendations and your actual number of BYOL instances.
A few things to consider around size flexibility: If you have size flexible RIs, Cost Explorer will recommend RIs based on your typical usage within the size range. This may be lower than your max instance count.
Double check the size flexibility range of your existing RIs. Cost Explorer will assume those ranges remain optimal.
If you recently resized your BYOL instances outside the existing RI size ranges, the recommendations may lag behind your new sizes.
Make sure you have appropriate Oracle licensing for the largest size you wish to use with size flexible RIs.
So in summary, if using size flexible RIs, the recommendations try to optimize your RI coverage for typical usage, not peak usage.
Check if your instances have grown outside your existing flexibility ranges, and adjust RI purchases accordingly while staying compliant with Oracle licenses. You can check this document as reference