Net core api to upload 1GB size csv file - asp.net-core

Question

I have following code segment it works for small file. But if the file is larger then application is loading for long and recieves No 'Access-Control-Allow-Origin' header is present on the requested resource.
[HttpPost]
[ScopeAuthorize(Constants.ClaimScopeSGCanManageAll, Constants.ClaimScopeUserCanManage)]
[DisableRequestSizeLimit, RequestFormLimits(MultipartBodyLengthLimit = int.MaxValue, ValueLengthLimit = int.MaxValue)]
public async Task<IActionResult> UploadFile()
{
if (!Request.Form.Files.Any())
{
throw new Common.Exceptions.ValidationException("Empty file");
}
IFormFile formFile = Request.Form.Files[0];
var csvDatas = new List<PatientsCSVItem>();
using (var reader = new StreamReader(formFile.OpenReadStream()))
{
while (!reader.EndOfStream)
{
var line = reader.ReadLine();
var values = line.Split(';');
//process csv rows
}
}
PatientCsvLog executionLog = _patientCsvManager.AddOrUpdatePatientsByCsvData(csvDatas, _userManager.GetLoggedUserId(User));
if (executionLog == null)
{
throw new ArgumentNullException(nameof(executionLog));
}
var response = new
{
NumberRecordImported = executionLog.NumberRecordImported,
NumberRecordUpdated = executionLog.NumberRecordUpdated,
NumberRecordDiscarded = executionLog.NumberRecordDiscarded,
DiscardedRecordList = executionLog.DiscardedRecordList
};
return Ok(response);
}