Blob trigger stream too long - Typescript

Question

When attempting to trigger a Blob Trigger Function App with a ~2 GB file, I receive a Stream too long error.
As I understand it, the Function App loads the entire file into memory, which likely causes this issue.
Is there any known workaround for this problem?

Thanks!

Answer 1

Hello Ivan !

Thank you for posting on Microsoft Learn Q&A.

This is expected behavior for very large blobs because blob trigger provides the blob content as input to the function and the TypeScript example uses a Buffer so a 2 GB file can hit memory limits before your function logic really starts. Loading full blob content into memory is only suitable for small blobs.

https://learn.microsoft.com/en-us/azure/azure-functions/functions-bindings-storage-blob-trigger

The usual workaround is not to process the large file directly through the Blob Trigger binding. Instead, you can use Event Grid to notify the function that a blob was created then use the Azure Storage SDK to read the blob yourself as a stream.