Thomas Baxendale Thanks for posting your question in Microsoft Q&A. Based on the description, it seems like you are hitting 1000 requests per day limit in Azure App Configuration and faced 429
throttling errors.
#1 The first step is to estimate the total number of requests from all your applications (all func apps as well as others) which includes initial configuration loading/reloading as well as monitoring (all individual keys or use sentinel key) and the doc reference How do I estimate the number of requests my application may send to App Configuration? would be very helpful with the calculation.
#2 Then, you can optimize the requests made to App Configuration by increasing the refresh timeout, or using sentinel key instead of individual keys etc. (see other suggestions below)
If you require more than 1000 requests per day, then you would need to upgrade to Standard tier which offer high availability. Please note, you cannot downgrade from Standard to Free tier later.
#3 It seems you follow the code snippet described in Reload data from App Configuration doc (and it is good) and in isolated mode, there is middleware to refresh the configuration which is much better than in-process mode in my opinion. Also, @Microsoft.AppConfiguration(...)
syntax is not going to help much with your scenario.
I suggest you follow these steps to avoid throttling errors on App Configuration before considering Func app upgrade. I hope this helps and let me know if you have any questions or face issues.
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