Constant avml::DEFAULT_CONCURRENCY

pub const DEFAULT_CONCURRENCY: usize = 10;

Azure’s default max request rate for a storage account is 20,000 per second. By keeping to 10 or fewer concurrent upload threads, AVML can be used to simultaneously upload images from 1000 different hosts concurrently (a full VM scaleset) to a single default storage account.

https://docs.microsoft.com/en-us/azure/storage/common/scalability-targets-standard-account#scale-targets-for-standard-storage-accounts