AWS: Transition from DBR to CUR

These Frequently Asked Questions (FAQs) answer the most probable questions about the transition from the Detailed Billing Report (DBR) to the Cost and Usage Report (CUR).

Overview

For several years, AWS has focused its attention on its next-generation billing tool, the CUR, which goes beyond the features offered in its current default billing method, the DBR. In addition, AWS plans to completely deprecate the DBR in the near future.

As a valued AWS partner, CloudCheckr has made it a priority to understand how the CUR will enhance our customers' experience. Over the past year, our billing team has worked tirelessly to integrate the CUR functionality into our application. At this time, CloudCheckr supports the CUR and the DBR, but the CUR will eventually replace the DBR as CloudCheckr's default billing method.

For our customers who use the DBR, learning a new tool like the CUR may feel a bit intimidating. We hope that this article will help you transition to the CUR with confidence.

Question: Why is AWS retiring the DBR?

Answer:

AWS customers have used the DBR for their billing needs since the early days of the cloud. But as customers grew more cloud-savvy and cloud deployments became more sophisticated, AWS noticed an uptick in customer requests for billing improvements. In particular, customers were overwhelmed by the sheer amount of data that the DBR provided and they were not always sure how to interpret that data. Customers also wanted more insight into key data points—such as which accounts were consuming Reserved Instances (RIs). In response, AWS decided to create a new billing tool that could better meet their customers' growing needs.

Question: Why are my numbers in the CUR and DBR not matching?

Answer:

The short answer is that the DBR and CUR calculate unblended costs differently once RIs are shared between accounts. As a result, the costs for individual line items may not match, but the grand totals for the DBR and CUR will always match. Let's unpack the reasons for this answer a bit more...

The AWS Cost Explorer, the tool that enables you to review and analyze your costs and usage, uses the CUR as its source for cost calculations while CloudCheckr uses the DBR for its cost calculations. If all RIs are used in the account that purchased the RI, you will not see any variations in cost between the CUR and DBR.

But, once an RI is shared between accounts, you may start to see disparities between the CUR and DBR values:

  • In the CUR, all RI costs stay in the account that purchased the RI and the accounts that used the RI are not charged for using that RI.
  • In the DBR, the RI costs are applied to the account(s) that used the RI—not the account that purchased the RI.

Most of the time, these disparities will be neglible and can be dismissed as rounding errors. However, there are two cases where these variances may be harder to evaluate:

As an enterprise customer (payer account), you buy an RI that costs $.10/hour for a 744 hour month but a linked account (payee account) uses the full 744 hours or $7.44. The table shows the differences in the CUR and DBR cost calculations:

Method

Explanation

Payer Cost

Payee Cost

CUR

Payer buys RI and the costs stay in the payer account even if a payee account used the RI

Zero (0) hours = $7.44

744 hours = $0.00

DBR

Payer buys RI and the costs move to the payee account(s) that used the RI

Zero (0) hours = $0.00

744 hours = $7.44

As a MSP, you buy RIs for the purpose of arbitrage—buying and then selling them to customers (payee accounts) at a higher price to maximize your profit. In the ideal arbitrage scenario, no services are running in your payer account and the payee accounts have used all of the RIs, which generates additional profit for you. In the table, the unblended costs for the CUR equal the total cost of all RIs, regardless if they are used or not, bought by each account. The unblended costs for the DBR equal the total cost of the unused RIs bought by each account. As you can see, the way that AWS assigns unblended costs can dramatically impact your profitability as an MSP and the success of your arbitrage strategy.

Account

CUR Unblended Cost

DBR Unblended Cost

CUR Profit

DBR Profit

Payer

$593,271.03

$128,694.01

($593,271.03)

($128,694.01)

Account 1

$143,418.90

$186,399.78

$72,052.53

$29,071.65

Account 2

$114,260.66

$152,089.80

$61,223.09

$23,393.95

Account 3

$79,500.99

$120,815.16

$65,583.27

$24,269.10

Account 4

$72,602.87

$85,550.31

$21,829.37

$8,881.93

Account 5

$71,963.72

$82,816.98

$20,096.28

$9,243.02

Account 6

$70,774.69

$72,919.42

$4,765.41

$2,620.68

Account 7

$43,811.38

$65,259.38

$28,887.58

$7,439.58

Account 8

$42,845.52

$59,346.85

$23,428.28

$6,926.95

Account 9

$38,929.84

$48,205.87

$25,061.34

$15,785.31

Account 10

$38,557.62

$47,139.41

$24,176.53

$24,176.53

Question: What improvements does the CUR offer and how will they help me?

Answer:

Here's a quick summary of the top improvements that the CUR will provide and how these improvements will impact you.

You can tap into more meaningful cost and usage details about RIs. Before the CUR was part of the AWS landscape, payers could not access any RI information in the payee accounts unless the payee provided them with credentials via a cross-account role policy. With the CUR, payers no longer need these credentials to drill into a payee's account and see:

  • specific EC2 instances and the RIs used by those instances
  • which account purchased an RI that got applied to another account
  • more detail on usage types such as the breakout of EC2 compute from EC2 Other
  • data transfer costs that are now separated into line items within a distinct service category instead of within existing service categories

With more RI details at your fingertips, you can make more informed, educated decisions on how to optimize your cloud deployment.

You can now amortize your RIs. The DBR does not allow you to amortize your RIs, which means that your finance department must spend extra time each month wading through your RI cost data in order to accurately write off the cost according to the installment schedule. Now that you can amortize your RI costs in the CUR, you can ensure that your team can close the books on time.

You can see your AWS Marketplace costs in your monthly bill. A successful cloud deployment often involves a mix of SaaS and cloud tools. Any time that you purchase a SaaS product from the AWS Marketplace, that cost will be reflected in your final AWS bill. By having all of your product cost information in the CUR, you can better manage your vendor products and more effectively compare your SaaS and cloud costs in one bill.

You have many ways to customize your CUR report. By using the CUR, you can focus on the data that is most relevant to your cloud deployment and determine if you want the CUR generated hourly or daily. Another change is that the CUR truncates the data into separate, smaller files so reports are generated quicker and are easier to share. The CUR also easily integrates with other analytical tools so you can query your data for more meaningful cost comparisons. All of these customizations ensure you have complete ownership and oversight into your billing environment.

Question: What actions must I take during this transition?

Answer:

If you are an existing customer:

If you are a new customer:

  • You should email Support or Sales to help you set up the CUR during your onboarding.
  • You must configure the report in AWS and in CloudCheckr.

Question: How do I enable the CUR?

Answer:

Before you can use the CUR, you must complete some setup steps in AWS and in CloudCheckr. If you need help enabling the CUR, reach out to your onboarding specialist or email Support.

Question: How does it benefit me to have access to both reports during this transition?

Answer:

At this time, many of our competitors have already deprecated the DBR and are only providing the CUR to their customers. We felt it would be more valuable to purposefully delay the final cutover for the following reasons:

  • Customers who are loyal to the DBR can continue to use it as their primary billing method in CloudCheckr, but can experiment with the CUR functionality without impact to their monthly bill.
  • Because of our commitment to AWS and our customers, we want to continue to support the DBR since AWS has not deprecated it yet.
  • Based on feedback from our customers, our team continues to test and perfect the CUR integration to ensure that it provides the maximum benefit to them.

Question: How does the CUR compare to the DBR?

Answer:

Click the Comparison Table button to learn more.

Item

CUR

DBR

Where to Configure in CloudCheckr

Account Settings > Billing and Usage Configuration

Account Settings > Billing and Usage Configuration

Where to Configure in AWS

AWS Management Console > My Billing Dashboard > Cost & Usage Reports

AWS Management Console > My Billing Dashboard > Billing Preferences > Detailed Billing Reports [Legacy]

EC2 RI Unblended Cost Differences
  • Unblended costs stay in account that purchased RI
  • If you used an RI but did not purchase it, you get that RI for free
  • May be variances from the DBR in the unblended cost if RIs are used by someone other than purchaser
  • Grand totals between the reports will be the same
  • Unblended costs are charged to account that used the RI—even if that account didn't purchase RI
  • If you used an RI, you pay for what you used and RI purchaser keeps what is not used
  • May be variances from the CUR in the unblended cost if RIs are used by someone other than purchaser
  • Grand totals between the reports will be the same

Who Can Access Report Data in AWS and What Type of Data Can They Access?
  • Users with Cost Explorer access see the data as written to the CUR
  • Only those with access to the S3 bucket to which the CUR is written get full access to the Microsoft Excel ® file(s)
  • Only available to those with access to the S3 bucket to which the DBR is written get full access to the Microsoft Excel ® file(s)

Cost Allocation Tag

Required

Recommended

RI Information

More detail on all RIs

Less detail on all RIs

Cross-Account Role

Recommended for RI unsharing

Required
Report Output

Multiple files; smaller in size

One large file

How Often Are Files Written?
  • Every six hours
  • AWS generates new file daily
  • 6 to 24 hours depending on the size of the file
  • AWS generates one file for each month, over-writing prior versions until the month closes

Billing Data Fields

See the AWS CUR Migration topic for more information.

See the AWS CUR Migration topic for more information.

Question: What are AWS's recent DBR changes and how do they impact me?

Answer:

AWS changed the DBR so that it uses the same RI sharing strategy as the CUR, which ensures that the DBR and the CUR report the same costs for each account.

Review the Changes to the Detailed Billing Report topic in AWS for more information.

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