How is the cost for Azure Function proxy calculated?

3
votes

We have lots of images in Azure Blob Storage (LRS Hot). We calculate around 15 million downloads per month for a total of 5000 GB egress (files are on average 350kB). I can calculate the price for the Blob Storage but the Function proxy is unknown. The Azure Functions pricing document doesn't say anything about proxy functions and specifically about bandwidth.

Question 1: Are these calculations correct?

Execution count price is €0,169 per million executions, which equals to 15 * 0,169€=2,54€/month.

GB-s price is €0,000014/GB-s and memory usage is rounded to nearest 128MB. If file download time is 0,2s and memory is 128MB we have 0,2 * (128/1024) * 15000000 * 0,000014 = 5,25€/month

Question 2: What about bandwidth? Is there any cost for that?

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azureazure-functionspriceazure-function-app-proxy

1 Answers

1
votes

Q1: Mostly yes.

Azure Functions Proxies (Preview) works just like regular functions, meaning that any routing done by your proxy counts as one execution. Also, just like standard functions, it uses your GB-s while it's running. Your calculation approach is correct, with the caveat that reading from blog storage is actually a streaming activity, which will consume a fixed amount of memory multipled by the time it will take to each file to download.

Q2: This works the same way as Azure App Service. From the pricing page:

165 MB outbound network traffic included, additional outbound network bandwidth charged separately.