Creating Blob in Azure Blob Storage with the same name simultaneously

Question

I have task to load some images into the blob storage simultaneously. Name of blob is defined as md5 of the blob. It can happen that different threads try to load same files from different locations.

Now I need to know how to block other threads from loading same file, if first already trying to upload such blob.

Answer 1

You can do it without leasing it by using optimistic concurrency. Basicly set an access condition that says this blob will be different from all etags of blobs with this name. If there is indeed a blob with some etag the second upload will fail.

var access = AccessCondition.GenerateIfNoneMatchCondition("*");
await blobRef.UploadFromStreamAsync(stream, access, null, null);