Batch requests for multiple App Configuration references in App Services

[avanigupta]

App Config references in Azure App Service are currently resolved individually, with each reference triggering a separate GET request to AppConfig service. However, since AppConfig supports retrieving multiple key-values in a single request, AppService platform could optimize performance by batching these references into fewer GET requests. This would allow users to reference more AppConfig key-values without hitting throttling limits.

Based on customer feedback:

I'm hitting our App Configuration Service (ACS) from an Azure Function using app configuration references. I notice that a request appears to be made to ACS for each app setting individually, ie the config retrieval is not batched into a single call.

I can retrieve all of our app config keyvalues using azure cli eg

az appconfig kv list --key "/ian/api/dev/*" --connectionstring "Endpoint ..."

where "/ian/api/dev/" is the common prefix of all of my app config key names.

Obviously the key names could be completely different with no common prefixing.

But I wonder whether some logic could be built into the "fetch" code that checks for common prefixing and retrieves a whole batch (up to 100 entries?) in a single call. Retrieved keyvalues could then be matched to app settings based on their full keyname.

Would eliminate some of the 429s we're seeing (even in Standard tier).

Thanks!

Originally posted by @ianrandell-sh in #62