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SQL Database elastic pools pricing model : x3 RRS feed

  • Question

  • TL;DR :  Standard DB (S0 to S2) price per DTU per month is 1.12 € ; Elastic pool price per DTU per month is 3.42 € (x3) ; why such difference ?

    Hi,

    We are a company providing a SaaS, with one database per customer. Exactly the kind of target for the new SQL Database elastic pools solution announced at //build yesterday.

    But we do not understand the pricing model at all.

    Please note that for the following example I will use the final prices (without the current preview discount) as we are speaking about long term business model, from the official pricing page (in euros).

    I know that it is a preview subject to changes, but I can't understand how this pricing model could be so far from our usage (that I do not consider so different from other).

    Supposing :

    • We have 150 databases on the S0 pricing model. For a total of 1500 DTU. The same level name as the only model available : "standard".
    • The databases are supposed working correctly. For some specific non recurring operations the resources are capped, but for most cases consider a 50% usage. So, 750 DTU

    Actually, we pay 1700 € (~12 € * 150)

    Now, we want to switch to the Elastic Database model.

    Using Elastic Database :

    • We have to use 2 pools because of the maximum of 100 DB per pool.
    • We set each pool to 400 DTU, for a total of 800 DTU (compared to the 745 DTU used)
    • We split the databases in 2 : 75 db on each pool.

    The new solution :

    • delivers us with approximatively the same average usage resources capacity : 800 vs 745 DTU
    • add some peak usage available : 55 DTU / 2 pools = 27 DTU per pool vs 5 DTU per database (half the S0)

    The cost of this new solution ?

    3016 € !! (+77%)

    • 800 eDTU * ~3.42 € = 2738 €
    • 150 DB * ~1.93 € = 279 €

    Seriously, can you provide at least ONE example where the pricing model for this solution is interesting or at least mostly similar ?

    Or can you justify the difference with the current pricing model ? I could accept a higher price because of the benefits (best peak performances availability), but not so high.

    I hope you won't say that this differences are based on the features added. The job are an interesting feature, but certainly not at this price (and you can suppose that we have already developed a custom multi-db querying mechanism on our own).

    I am sorry for the tone of this message, but it reflects my astonishment after I received such a good news then calculate the cost of this new offer.

    Regards,


    • Edited by Thomas B_ Thursday, April 30, 2015 3:16 PM
    Thursday, April 30, 2015 1:26 PM

Answers

  • Thomas, thanks for the feedback. 

    What's missing for me from your analysis is a discussion about how active each DB is.  By design elastic databases are targeted at a collection of DBs that have stochastic usage.  By that I mean that some are active at any one interval of time, and other are inactive.

    So I wouldn't expect that you would need 1500 DTUs as you have provisioned today with your 150 x S0.

    Explicitly the preview portal http://portal.azure.com has recommendations as you configure the elastic database pool after selecting a group of databases on pool creation.

    Thanks Guy

    Thursday, April 30, 2015 4:51 PM

All replies

  • To sum up, here are the price per DTU compared between the different offers, in Price / DTU / month :

    • Basic : 0.74 €
    • Standard : 1.12 €
    • Premium : 2.77 €
    • eDTU (discounted) : 1.71 €
    • eDTU (standard price) : 3.42 €

    Also you should note that the eDTU pricing does not include the additional Database Fee (0.93 € / 1.93 €).

    So, one eDTU costs three times a Standard DTU.

    • Edited by Thomas B_ Thursday, April 30, 2015 3:15 PM
    Thursday, April 30, 2015 1:52 PM
  • Hi Thomas,

    I had similar thoughts to this, especially when you look at the database sizes.

    For S0 you have a max DB size of 250GB, but the maximum size on the elastic pool is 1200GB, less than 5 of the S0 option.

    Regards,

    Darren

    Thursday, April 30, 2015 3:14 PM
  • Thomas, thanks for the feedback. 

    What's missing for me from your analysis is a discussion about how active each DB is.  By design elastic databases are targeted at a collection of DBs that have stochastic usage.  By that I mean that some are active at any one interval of time, and other are inactive.

    So I wouldn't expect that you would need 1500 DTUs as you have provisioned today with your 150 x S0.

    Explicitly the preview portal http://portal.azure.com has recommendations as you configure the elastic database pool after selecting a group of databases on pool creation.

    Thanks Guy

    Thursday, April 30, 2015 4:51 PM
  • Hi Guy,

    Thank you for your answer. I am still surprised by the price per DTU ratio.

    I will do further studies in our environment by starting a new pool then migrate some databases in this environment to see the effective DTU consumption.

    In our case, the DTU per database is often between 0 and 1, so because of the 100 databases limit, the pooling solution (1 x 200 eDTU) still costs more than 100 x Basic Edition databases.

    Regards,

    Tuesday, May 5, 2015 8:05 AM