Analyzing Your Reserved Instance Purchases

Performing an analysis of your RI purchases is key to understanding where your monetary investment went and where it is going in the future. CloudCheckr provides functionality to retrieve all of Amazon’s various RI upfront cost metrics and data – direct from your Detailed Billing Report – and also provides ways to understand how your costs will affect your deployment moving forward.

In this example, we will break down how to get visibility into your RI purchases via the following CloudCheckr reports:

  1. Advanced Grouping – You’ll be able to find the RI Purchase as a line item in your billing data, along with other details (such as Description and Resource ID), which will give you more insight into how the RI is being applied.
  2. List of Reserved Instances – A comprehensive and exportable/filterable list of all your RIs.
  3. RI Upfront Cost Amortization – Track how your RI upfront costs are amortized over time.


Using Advanced Grouping to Analyze your RI Purchases

Advanced Grouping is a powerful tool which allow you to search, filter, and pivot the entire breadth of your raw Detailed Billing Report – the gigabytes of monthly data that AWS uses to record your spend.

Begin by navigating to the report, located at Cost/AWS Billing/Custom Reporting/Advanced Grouping.


Finding your RI Purchases

Try searching for your RI purchases as illustrated in the following example – this will help you to understand the grouping and filtering functionality of Advanced Grouping.


RI purchases are marked with an Operation and Usage Type field to make them easily searchable. In the Filters section, click on the Operation filter binoculars icon to open up all the options. You’ll see that all the available operations are selected by default. Unclick Select all, then in the text box type in “ripurchase”. As you type in, the options will automatically filter. When you see RIPurchase, select only that option, then click OK to save your selection.




Next, we will configure what data is actually displayed in our results. Go to the Group By section. By default it has one grouping already selected. Add three more groupings by clicking on the green + symbol three times. Then, change the groupings to be as follows:

  1. Account: This is already selected; groups your results by AWS account number.
  2. Description: This presents the description that AWS gives to your item (in this case our ‘item’ is the RI Purchase we have already filtered to above). This field is very helpful for gaining extra insight into what you’re viewing.
  3. Service: Displays the AWS service for the RI purchase.
  4. Resource ID: Displays the resource ID for the item in question, in this case, the unique identifier for the reserved instance.


Your Search Results


Advanced Grouping arranges your data in hierarchical manner. In the results, above you can see that in account 2150XXX there is $2,806.00 of cost classified as RI Purchases. Of that $2,806.00, $2,500 is for an Amazon Partner Network fee. The other three charges of $204, $51, and $51 make up the remainder of the RI purchases, and you can see they are for the EC2 service.

Advanced Grouping’s search functionality is fully customizable according to how you want your information displayed. You can switch around your groupings however you’d like – for example, a slight change where you instead group the identical search by Account-Service-Description-Resource ID will give you identical cost numbers but pivoted slightly to highlight the AWS services:




Using the List of Reserved Instances to Understand Upfront Costs

All of the AWS services that have RIs have a List of Reserved Instances report within CloudCheckr, which provides a daily-updated ledger of all owned RIs and all their relevant data. For our example, we will look at the List of EC2 Reserved Instances located at Cost/Reserved Usage/EC2/List of Reserved Instances.


Below is an example search that was made. You’ll see that to show only the RIs that had actual upfront costs, a filter was selected to choose Offering Type is not equal to: No Upfront. We eliminated No Upfront RIs and are left with everything else, i.e. All Upfront or Partial Upfront.


The arrows marked by the red box indicate that all the filtered RIs are actually under-utilized – a key piece of information because the owner has paid upfront costs but is not using them correctly and therefore is wasting money.

The items marked by the pink box show some quick data you that provide detail around the upfront costs for these under-utilized RIs:

  • Start Time: When the RI was started.
  • End Time: When the RI will end.
  • Time Left: The remaining time, in days, on the reservation.
  • Upfront Fee: The upfront fee for the RI in question.
  • Total Upfront Fee: The total upfront fees for all the RIs in your search results.

You can perform further filters within this report to refine your search, such as filtering by AWS Account ID, Instance Type, Region, whether the RI is fully utilized or not, or searching for RIs that will end within XX days (such as within the next 30 days).


Additionally, the entire list of RIs is fully exportable to CSV, allowing you perform further processing via Excel or other viewer. By clicking on Show retired Reserved Instances in the filter section, you can even choose to see all RIs – current and retired – that have ever been part of your deployment.



Amortization of Your RI Upfront Costs

CloudCheckr’s RI Upfront Cost Amortization report allows you to understand the lifecycle of your upfront costs. You can access the report at Cost/AWS Billing/Other Features/Amortization.

The report allows you to track upfront cost amortization for EC2, Elasticache, RDS, and Redshift.


From within the main bar chart of the report you can select the date range and service type for amortization tracking. The result will show you the upfront cost, the amount of the amortization that was incurred during the month, and the amount of amortized cost remaining in the life cycle of the RI.

For even more detail, you can view a monthly amortization breakdown for any of the months in question:


The monthly breakdown shows you all relevant details about your amortized upfront costs:

  • All RI upfront purchases in the month, their type, and cost.
  • How the RI was actually amortized – how much went into the amortized cost in the month in question and how much remains.

With the info in this report, you can get quick summaries of your upfront costs, as well as (by exporting all the data) you can get details for any time period – organized by any particular Reserved Instance ID – thereby getting specific amortization numbers for one or all RIs.