是否可以将字节附加到 Azure Blob 存储中的 Blob？

Question

I had a bit of trouble uploading large files (>2GB) with ASP.NET MVC5 but I managed to fix it by splitting that file in packets with jQuery and uploading each packet separately. In my backend I want to upload those packets to Azure Blob Storage. Is there a way to append those bytes to an already existing blob? Most solutions I find on the internet advice to download the blob, add the bytes and re-upload them. But I think that's kinda a waste of bandwith since you download and reupload a file all the time

Answer 1

Try using append blobs. There is a code sample at https://azure.microsoft.com/en-us/documentation/articles/storage-dotnet-how-to-use-blobs/#writing-to-an-append-blob . From that page:

An append blob is a new type of blob, introduced with version 5.x of the Azure storage client library for .NET. An append blob is optimized for append operations, such as logging. Like a block blob, an append blob is comprised of blocks, but when you add a new block to an append blob, it is always appended to the end of the blob. You cannot update or delete an existing block in an append blob. The block IDs for an append blob are not exposed as they are for a block blob.

Each block in an append blob can be a different size, up to a maximum of 4 MB, and an append blob can include a maximum of 50,000 blocks. The maximum size of an append blob is therefore slightly more than 195 GB (4 MB X 50,000 blocks).

Answer 2

Azure Blob Storage supports re-composing new blobs from existing blocks in already uploaded (and committed) blobs and combining those existing blocks with new blocks you upload. The order of the blocks can be chosen freely, so you can append new blocks or insert new blocks.

Append blobs are mostly used for applications that continuously add data to an object.

For an overview, check here .