c# – WinHttpException：与服务器的连接异常终止

>通过名为ProcessController的控制器接收请求.
>获取传入的请求并将数据格式化为字符串.
>使用以下HttpProcessor类中的PostChargeAsync方法在URL上发布上述格式化消息,并等待响应消息执行进一步处理.

请注意,HttpClient是使用IoC注入的,并且是单例.

public class HttpProcessor
{
    private readonly HttpClient _httpClient;

    public HttpProcessor(HttpClient httpClient)
    {
        _httpClient = httpClient ?? throw new ArgumentNullException(nameof(httpClient));            
    }

    public async Task<string> PostChargeAsync(string payload)
    {
        using (var httpRequest = BuildHttpRequest(payload))
        {
            try
            {
                using (var httpResponse = await _httpClient.SendAsync(httpRequest).ConfigureAwait(false))
                {
                    httpResponse.EnsureSuccessStatusCode();

                    using (var httpContent = httpResponse.Content)
                    {
                        return await httpContent.ReadAsStringAsync();
                    }
                }
            }
            catch (HttpRequestException ex)
            {
                throw;
            }
            catch (TimeoutException ex)
            {
                throw;
            }
            catch (System.Exception ex)
            {
                throw;
            }
        }
    }

    private HttpRequestMessage BuildHttpRequest(string content)
    {
        return new HttpRequestMessage
        {
            Content = new StringContent(content,Encoding.UTF8,"application/xml"),Method = HttpMethod.Post,RequestUri = new Uri("https://test/process"),};
    }
}

问题是当在ProcessController上发送并行请求(~30-50请求/分钟)并调用PostChargeAsync方法时,我得到以下异常：

System.Net.Http.HttpRequestException: An error occurred while sending the request. ---> System.Net.Http.WinHttpException: The connection with the server was terminated abnormally

我尝试在Web.Config中添加以下设置以增加connectionManagement中的maxconnection：

<system.net>
    <connectionManagement>
      <add address="*" maxconnection="100"/>
    </connectionManagement>
  </system.net>

但我仍然得到上述异常.

什么会引起上述问题？