#level100 #cur #finops ## Source - [AWS documentation - Reserved Instance pricing](https://aws.amazon.com/ec2/pricing/reserved-instances/pricing/) - [AWS documentation - # Understanding your reservations](https://docs.aws.amazon.com/cur/latest/userguide/understanding-ri.html) ## Relevant notes RIFee lines and DiscountedUsage lines are connected via the [[reservation_ReservationARN]] ### Math and checks [[to complete]] with Athena Queries and the [cur documentation](https://docs.aws.amazon.com/cur/latest/userguide/reservation-columns.html) - [[reservation_TotalReservedUnits]] = [[reservation_NormalizedUnitsPerReservation]] * [[reservation_NumberOfReservations]] - [[reservation_NormalizedUnitsPerReservation]] = [[lineItem_NormalizationFactor]] * [[reservation_NormalizedUnitsPerReservation]] ## Notes There are three [[lineItem_LineItemType]] relevant to Reserved Instances. - Fee when the initial upfront fee is paid. Valid for partial-upfront and full-upfront. There is no Fee line for nothing-upfront. [[to check]] - RIFee which represent the reservation(i.e. commitment) contract. And include - DiscountedUsage which represent the consumption of the contract. ### Different types of fees - Upfront fee. - Recurring - Monthly - fee ### Subscriptions vs Reservations vs offer [[to complete]] - As there is a direct 1-to-1 mapping between [[reservation_SubscriptionId]] and [[reservation_ReservationARN]], they seems to be synonyms. - The only difference I see is that the documentation for [[reservation_SubscriptionId]] also include Usage while the [[reservation_ReservationARN]] does not. - There is a [[reservation_SubscriptionId]] even when there is no reservation, in which case the [[reservation_ReservationARN]] is empty or null. - [[to check]] ### RIFee - Represent the commitment contract. [[to complete]] - Some fields are month specific - [[reservation_AmortizedUpfrontFeeForBillingPeriod]] - Some fields are contract specific - [[reservation_StartTime]] - [[reservation_EndTime]] - Is like a mix of information and a pool for unused resources available for consumption - Some values in the RIFee line change everytime a CUR is updates, as resources (i.e. DiscountedUsage lines) are consumed. - Represent the static aspect of the RI and is updated based on the DiscountedUsage rows - contains the details of the RI and also what is left to consume for the month - one line per month per RI. - RIFee contains month level values - Unused RI amortised dollars are in the RIFee lineitem - At the beginning of the month all the potential value of the RI is all in the RIFee line and gets consumed throughout the month. ### DiscountedUsage - Represent the use of part of the commitment contract - Describe how the resources initially available in the RIFee have been consumed - Usually on an hourly basis - Represent the Dynamic part of RI consumption