SemaphoreSlim vs Parallel Processing for API post calls in .NET-CodePudding

I have a chron job which calls a database table and gets about half a million records returned. I need to loop through all of that data, and send API post's to a third party API. In general, this works fine, but the processing time is forever (10 hours). I need a way to speed it up. I've been trying to use a list of Task with SemaphoreSlim, but running into issues (it doesn't like that my api call returns a Task). I'm wondering if anyone has a solution to this that won't destroy the VM's memory?

Current code looks something like:

foreach(var data in dataList)
{
  try 
  {
    var response = await _apiService.PostData(data);
    _logger.Trace(response.Message);
  } catch//
}

But I'm trying to do this and getting the syntax wrong:

var tasks = new List<Task<DataObj>>();
var throttler = new SemaphoreSlim(10);
foreach(var data in dataList)
{
  await throttler.WaitAsync();
  tasks.Add(Task.Run(async () => {
    try
    {
      var response = await _apiService.PostData(data);
        _logger.Trace(response.Message);
    }
    finally
    {
      throttler.Release();
    }
  }));
}

CodePudding user response：