Avoid Azure BlobTrigger like the Plague

Avoid using BlobTrigger attributes on your functions like the plague. They are not ready for production use.

If you have been using them for a while, there’s a good chance you missed this giant warning text in the recently updated documentation.

Warning

In addition, storage logs are created on a “best effort” basis. There’s no guarantee that all events are captured. Under some conditions, logs may be missed.

If you require faster or more reliable blob processing, consider creating a queue message when you create the blob. Then use a queue trigger instead of a blob trigger to process the blob. Another option is to use Event Grid; see the tutorial Automate resizing uploaded images using Event Grid.

Impact

If you are currently using blob triggers and you have more than 10,000 blobs in your storage account, not all blob triggers are being delivered.

Alternatives

As the document says, you’ll either have to build your own rudimentary eventing system through storage queues, or look at using event grid bindings.

Saving Money

Avoiding BlobTriggers is one of the ways I’ve identified of reducing your Azure Storage Account burden. If you’d like to read some other approaches please checkout: https://medium.com/@loopjockey/ways-to-reduce-azure-storage-account-costs-dd06fdc1775d