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Directeam RDS Recommendations

The RDS(Amazon Relational Database Service) Recommendations page aggregates RDS instances from all your AWS accounts. By using this feature, you will gain access to valuable RDS RI(Reserved Instance) savings insights to ease your decision-making and create a commitment plan

Getting started​

Simply follow the next steps:

  1. Choose the required time range (1m - 1 month, 2w - 2 weeks) and select the RDS instances you would like to commit for a specific time range, 1 or 3 years. We recommend filtering the stable(24*7 running) RDS instances using the “Uptime” column.

The selected databases are aggregated based on Region, Engine and Family Type,

  1. In the RDS Commitment Plan table modify the input of the “Target Normalized Units” column to change the target commitment coverage.
  2. Once commitment coverage is decided, calculate how many RDS RIs you need to buy based on the “Target Normalized Units” you chose. You can calculate it using the AWS RDS Normalize Units table or by reviewing the example below.

RDS RIs Recommendation​

Cover 75%-85% of the stable RDS instances (considering future architecture changes): Covering 100% of the stable RDS instances risks costs for unused RIs commitment in case of database optimizations or any unplanned changes.

Limitations​

  1. When the instance type of RDS database is changed, it will appear twice with different uptime, be sure to select only the new one and consider that this database recently changed. Example:
  1. The following features are currently on our roadmap and aren’t supported yet:
    • RDS Recommendations doesn’t consider the current RIs commitment. When buying RDS RIs based on the recommendation calculator, check the existing commitments using the following link in our AWS account in the relevant region.
    • RDS Recommendations doesn’t support Aurora IO/optimized. Aurora IO/optimized NUs are currently considered as Aurora Standard ( Aurora IO/optimized NUs are 1.3x bigger than Aurora Standard.

What are Normalized Units (NU)​

AWS uses Normalize Units to calculate how many RDS instances are covered, the Normalize Units are decided by the instance size (for example, "2xlarge" instance equals 16 Normalize Units). This method allows customers to buy RIs using different sizes of RDS Instances for better RI coverage management.

Example

You need to cover 75% of 2 r6g.2xlarge instances with RDS RIs. Two 2xlarge Instances are equivalent to 32 Normalize Units, to get 75% coverage you would need to buy 24 NUs of r6g family (0.75 * 32 = 24 NUs).

There are multiple ways to cover 24 NUs;

  1. Three r6g.xlarge RIs instances.
  2. One instance of r6g.xlarge and one of r6g.2xlarge.
  3. Six instances of r6g.large.

RDS Reserved Instances - https://aws.amazon.com/rds/reserved-instances/

RDS Normalize Units - https://docs.aws.amazon.com/AmazonRDS/latest/UserGuide/USER_WorkingWithReservedDBInstances.html

RDS Aurora Normalize Units - https://docs.aws.amazon.com/AmazonRDS/latest/UserGuide/USER_WorkingWithReservedDBInstances.html