How to identify unused Azure functions

Question

I'm trying to find a way to find any unused Azure Functions in my environment. So far I've tried looking at Cost Analyzer, which shows costs per resources, though I'm seeing costs of $0 for functions I know are active (If I go into app insights and click a given function, the server connections graph has considerable data).

Due to this discrepancy I'm not entirely sure how to truly validate if a function is not used. I'd also like some place to give me an overall summary vs drilling into each each, one by one, looking at their respective app insights dashboards.

Is there any way to do this?

Answer 1

@McDonald, Matthew Thanks for reaching out. The only way to find whether there are any request coming to your function app is to review the application insights logs or the monitoring data of your resource. Unfortunately, there is no out of box solution which can display the request/monitoring data of the resource. The only solution would be navigating to the individual resource and verifying the metrics /application insights data. As Azure dashboard (select different resource and metrics based on user input) or azure graph query (cannot get the monitor data for the resource) couldn't be used as the possible solution. You need to either manually verify it or automate it by writing your own code (PowerShell scripts etc.) to verify it.

Azure Cost Analyzer is the alternative way to verify the current forecast cost for all your resources. As you have mentioned that you see $0 for your function app resource then it could be your subscription has only consumption function apps and it may be under the free grant that is provided Pay as you go with Azure. As per this document there are one million free requests every month.