Application Gateway Basic Tier pricing is off

Question

Hey,

I created a test project utilizing an Azure Application Gateway, forwarding traffic to a Hello World Container App.

I am confused by the pricing model and I feel its off compared to the calculator and Azure documentation.

The Azure Application Gateway I created is a "Basic" tier in 1 availability zone.

After 2,5 days I accumulated about 10 Euros of cost with basically nobody using it since its just a test page. I can see some minor random requests coming in from people most likely scanning the internet but nothing serious.

I then checked the metrics via the Azure Portal and it says:

• Capacity units at 0,7 and sometimes at 2,5
• Estimated billed capacity units 20

When I check the Azure calculator the basic tier Application Gateway is billed at about 20 Euros for a "Small" one. Weird thing is I cannot select Small, Medium or Large when creating the App Gateway in the Azure Portal.

So technically I am right now billed a "Standard v2" Tier, even though I selected the "Basic" version.
What is the issue here? Why is the cost equivalent to a "Standard v2" when only selecting the stripped down "Basic" version?

Regards,
Tom Wöllert

Answer 1

Just to conclude my initial question, based on all the input I received here and my own further investigation.

Thanks DarylNZ also for your input, it was extremely helpful.

We decided now to go with a VM (as a replacement for the Application Gateway) created through Terraform and configured via Ansible. For us the pricing on the Application Gateway V2 is just not feasible. The old Application Gateway Basic tier for around 30$ would have been fine but V2 pricing is not working out.

For normal use case scenarios the V2 does not offer any additional features which we need compared to the old V1, so the increase in pricing up to around 130$ (from the old 30$) is not worth it.

I know there are benefits in using the App Gateway compared to a VM but these also do not matter for our use case scenario. With the smallest VM now being at about 9$ per month it can do plenty for us until we need to even think about scaling it up.

I strongly recommend Microsoft to update the Azure Calculator as well as their documentation on the pricing of the App Gateway V2. To me the information about how the compute and capacity units are handled (having a certain minimum always assigned) would have been helpful in making this decision quicker and saving some time implementing module in Terraform.

Tom

Answer 2

Hi Thomas,

I have exactly the same issues as you describe, we were looking to use the new Azure App Gateway v2 Basic SKU. Where the requirements did not necessitate the use of the higher SKU during the initial phase.

Azure Pricing Calculator
I ran into the same issue with the Azure Pricing Calculator when selecting the Tier Basic SKU and given the sizing options for Small, Medium and Large. I believe that the pricing calculator has not yet been updated with the Azure App Gateway v2 Basic SKU pricing.

But is in fact showing the App Gateway V1 pricing. If you go to the https://azure.microsoft.com/en-us/pricing/details/application-gateway/ and select App Gateway v1, you will see the Application Gateway Types as Small, Medium, Large

Azure App Gateway v2 Basic

I also ran into the same issue, where the metric shows that the App Gateway v2 Basic utilisation was around 2 to 3 compute units but the estimated billed capacity units was always 20 not matter what.

This seemed incorrect, according to the table https://learn.microsoft.com/en-us/azure/application-gateway/overview-v2#sku-types.

• The v2 Basic SKU was able to scale up to 200 connections per second and that each compute unit was capable of around 10 connections per second.
• With some maths means, that 20 compute units is the maximum.
  For some unexplained reason, the v2 Basic SKU was running at maximum capacity with minimal load.

I raised an Azure support case to try to understand why this was happening.

In discussion with an engineer of the App Gateway product team, confirmed that this is currently the way it is. That the estimated billed capacity is 20 is correct. It seems odd to me for this to be the case.

As accordingly, this prices the Azure App Gateway v2 Basic at over 80% to an Azure App Gateway v2 Standard with reduced features, limiting its usefulness.

It was relayed to me that the 20 is made up of 2 instances x 10 compute units, hence the 20 units.

I've asked for the documentation to reflect this as this is not clearly documented anywhere that I have been able to locate.

I've also tried using Az PowerShell

Set-AzApplicationGatewayAutoscaleConfiguration -ApplicationGateway $appgw -MinCapacity 1 -MaxCapacity 2

It returns an error in essence that the App Gateway Basic instance does not support Autoscaling for the selected SKU tier Basic. Supported SKU tiers are Standard_v2, WAF_v2

Billing
I've looked at the Cost Analysis export, and it confirms indeed being billed at 20 capacity units for the Azure App Gateway v2 Basic SKU.

In short, I believe that the Azure App Gateway v2 Basic SKU shouldn't be billed at the 20 compute units regardless of the traffic load as it effectively does not make a lot of sense in the introduction of this lower SKU.

But this is what has been provided to me. Hopefully this design can be changed.

Daryl

Answer 3

Hi Tom,

Please verify that you are being billed using correct meterName/ product / effectivePrice / quantity /etc. for Application Gateway Basic v2. If it turns out you are being billed incorrectly I recommend you open a billing support case (it is free) so that they can issue a refund for the overcharge.

For example, in your billing usage details you should see entries similar to below. I've omitted most of the columns for readability purposes and am showing USD price:

meterName	product	effectivePrice
Basic Capacity Units	Application Gateway Basic v2 - Basic - DE West Central	0.008
Basic Fixed Cost	Application Gateway Basic v2 - Basic - DE West Central	0.027

To export .csv file with your actual cost/usage data, please navigate to Cost Management -- Reporting + analytics -- Exports blade:

Select appropriate Scope, click Create, click Cost and usage (actual), enter a prefix, Next, select the details of the storage account/container/directory where you want the .csv file to be exported to, select Compression type: None, Next, click Create.

Once it has finished creating the export, select it and click Run now. Make sure it says it is queued and verify that execution shows as in progress by clicking on the export name and viewing run history at bottom.

After 15-30 minutes if you go back in and check run history it should show as Succeeded. At this point you can navigate to the storage account container via the portal and download the .csv file to your local PC. Use Excel/Sheets/etc. to view the file and check if you are being charged correctly.

If above is unclear and/or you are unsure about something add a comment below.

Please click Accept Answer and upvote if the above was helpful.

Thanks.

-TP