Azure-docs: Clarification of hourly billing

[bigdatamoore]

Can you please clarify that the billing is based on wall clock hours and not duration hours? In other words, if I scale a collection up to 1000 RUs at 9:59 AM, and then scale it back down to 400 RUs at 10:01 AM, my collection is scaled up for a duration of 2 minutes. According to the documentation:

Billing rate when container or a set of containers are active for less than an hour
You're billed the flat rate for each hour the container or database exists, no matter the usage or if the container or database is active for less than an hour. For example, if you create a container or database and delete it 5 minutes later, your bill will include one hour. 

So, in my scenario, do I pay for two hours at the rate of 1000 RUs (two wall clock hours) or do I pay 1 hour (duration hours)?

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Document Details

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• ID: 09911b22-f73f-d619-6b9d-f34ff8351161
• Version Independent ID: 844afdcd-eabb-1b6b-1130-2ff377b2c71f
• Content: Understanding your Azure Cosmos DB bill
• Content Source: articles/cosmos-db/understand-your-bill.md
• Service: cosmos-db
• GitHub Login: @rimman
• Microsoft Alias: rimman

[Mike-Ubezzi-MSFT]

@bigdatamoore Thank you for bringing this to our attention. I am investigating this and will have an update for you shortly.

[bigdatamoore]

Hi @Mike-Ubezzi-MSFT, below is the response I got when I emailed the [email protected] mailbox. So the answer is that billing is for any portion of a wall-clock hour, not a 60 minute duration.

You will be billed for the peak provisioned throughput within an hour. So in your example, you will be billed for 1,000RUs for 2 hours. 

With Cosmos DB, you can scale up or down as you need and pay only for what you need. With on-premises or IaaS-hosted systems, you can't match this model, because there isn't a way to decommission the hardware every hour.  

Please let me know if there is anything else you need.

Thanks,
Rimma

[Mike-Ubezzi-MSFT]

@bigdatamoore Thank you for this additional detail. Can you include the example you were seeking clarification for and for which a response was provided. I will include this in the doc as the examples provided in the doc do not see to answer a very simple billing rate question.

[Mike-Ubezzi-MSFT]

I will just use the example provided in your question stated above. Thank you!

[Mike-Ubezzi-MSFT]

I have assigned the issue to the content author to evaluate/edit/merge pull request as desired. @SnehaGunda for awareness.

[rimman]

Ack. Please proceed. It's a little bit redundant since all cloud services with hourly billing operate in this manner, (not just on Azure but also in other clouds), but if we think this will help deflect some questions and doubts, it's fine. Please merge. thank you.

[Mike-Ubezzi-MSFT]

@bigdatamoore We added a minor note to the document that will be published shortly. We will now proceed to close this thread. If there are further questions regarding this matter, please comment and we will gladly continue the discussion.