Reservations…
Is a pricing model that provides savings of up to 75% compared to On-Demand prices.
Is available in 3 options – All upfront, partial upfront or no upfront payments.
Offers significant savings in exchange for a 1- or 3-year commitment to use a specific product.
Subtitles are available in English, French and Spanish. Click here to get the full masterclass.
Which RIs give greater discount?
RDS Reserved Instances
- Can save you up to 69% over On-Demand rates when used in steady state (available 24x7).
- Require no change to how you use Amazon RDS.
- Are available for all supported DB Engines.
- Offer instance size flexibility for the MySQL, MariaDB, PostgreSQL, and Amazon Aurora database engines as well as the “Bring your own license” (BYOL) edition of the Oracle database engine.
Example for MySQL pricing in Paris Region.
Instance Size Flexibility
When you purchase a reserved DB instance, one thing that you specify is the instance class, e.g., db.r5.large, but also a size, e.g., large.
Most RDS platforms offer size-flexibility. Size-flexible reserved DB instances are available for DB instances with the same AWS Region and database engine; and can only scale in their instance class type.
For example, a reserved DB instance for a db.t2.medium can apply to a db.t2.large, but not to a db.r6g.large.
How Billing Works
During billing, running DB instance usage is first compared to your active Reserved Instances to minimize costs.
Each hour, if the amount of running instances is less than or equal to the total Reserved Instances you have purchased, all running DB instances will be charged at the Reserved Instance rate.
Any usage of running DB instances that exceeds the amount of applicable Reserved Instances you have purchased will be charged the On-Demand rate.
Utilization and Coverage Report
Go in Billing Service > Savings and Commitments > Reservations.
The utilization report shows the percentage of your Reservations commitments that you are using across your applicable AWS usage.
Ideally, you want this to be at 100% to ensure you are not wasting any of your committed spend.
The coverage report indicates what percentage of your eligible AWS usage costs are being covered by your RIs during your selected time period.
Ideally, you want this to be around 80 to 100% for each service to ensure you are covering most of the potential savings.
How to purchase a Reserved Instance?
- In each dedicated service (e.g. RDS, ElastiCache, MemoryDB, OpenSearch, …), click on Reserved Instances or Reservation section, then Purchase.
- Choose an engine type, term, instance class, payment option and hourly commitment in your current region.
- Click Purchase Reserved Instance.
