Load data in parallel

program.cs

private static async Task StreamDataInParallel(StreamReader fileSource, HttpClient httpClient, string path, int maxParallel)
{
  var block = new ActionBlock<string>(
    async json =>
    {
      await httpClient.PostAsync(path, new StringContent(json, Encoding.UTF8, "application/json"));
    }, new ExecutionDataflowBlockOptions
    {
      // Tells the action block how many we want to run at once.
      MaxDegreeOfParallelism = maxParallel,
      // 'Buffer' the same number of lines as there are parallel requests.
      BoundedCapacity = maxParallel
    });

  string line;

  while ((line = await fileSource.ReadLineAsync()) != null)
  {
    // This will not continue until there is space in the buffer.
    await block.SendAsync(GetDataJson(line));
  }
}