Azure Blob Storage - upload file with progress

Question

I have following code - quite normal for uploading files into Azure-Blob-Storage but, when i upload files instead of getting onProgress executed many times, i only have it executed (and always) once with the file.size value (so it is sending - slowly) file to the azure but progress executes only once when finished.

    const requestOptions = this.mergeWithDefaultOptions(perRequestOptions);
    const client = this.getRequestClient(requestOptions);
    const containerClient = await client.getContainerClient(this.options.containerName);
    const blobClient = await containerClient.getBlockBlobClient(file.name);
    const uploadStatus = await blobClient.upload(file.buffer, file.size, {onProgress: progressCallBack});

What i would love to know is if that outcome is normal for this library (for downloading files from azure, the same approach works correctly).

Answer 1

According to my test, the method is a non-parallel uploading method and it just sends a single Put Blob request to Azure Storage server. For more details, please refer to here.

So if you want to get onProgress executed many times, I suggest you use the method uploadStream. It uses Put Block operation and Put Block List operation to upload. For more details, please refer to here

For example

try {
    var creds = new StorageSharedKeyCredential(accountName, accountKey);
    var blobServiceClient = new BlobServiceClient(
      `https://${accountName}.blob.core.windows.net`,
      creds
    );
    var containerClient = blobServiceClient.getContainerClient("upload");
    var blob = containerClient.getBlockBlobClient(
      "spark-3.0.1-bin-hadoop3.2.tgz"
    );

    var maxConcurrency = 20; // max uploading concurrency
    var blockSize = 4 * 1024 * 1024; // the block size in the uploaded block blob
    var res = await blob.uploadStream(
      fs.createReadStream("d:/spark-3.0.1-bin-hadoop3.2.tgz", {
        highWaterMark: blockSize,
      }),
      blockSize,
      maxConcurrency,
      { onProgress: (ev) => console.log(ev) }
    );
    console.log(res._response.status);
  } catch (error) {
    console.log(error);
  }