C# HttpClient - 我可以强制关闭连接吗？

Question

我们发现客户点击我们的 API 并在请求完成前取消请求。我们相信他们也在关闭连接，因此请求不会写入 IIS 日志。我正在尝试创建一个运行者来复制这种行为。我想不通的是我如何强制关闭连接以使服务器无法发回数据？

这是我当前的代码:

 private static async Task RunMe()
    {

        var cts = new CancellationTokenSource();
        cts.CancelAfter(5000);

        using (var client = new HttpClient())
        {
            try
            {
                client.DefaultRequestHeaders.ConnectionClose = true;
                client.DefaultRequestHeaders.Add("x-apikey", "some key");
                Console.WriteLine("making request");
                using (var response = await client.GetAsync("https://foo.com/api/apitest/testcancel", cts.Token))
                {
                    var result = await response.Content.ReadAsStringAsync();
                    Console.WriteLine($"Request completed: {result}");
                }
            }
            finally
            {                    
                client.CancelPendingRequests();
                Console.WriteLine("about to dispose the client");
                client.Dispose();
            }
        }
    }
}

代码在 5 秒后正确取消了请求，但 IIS 似乎仍会在 API 调用完成后发回数据(设置为 10 秒)。

如何关闭连接，使 IIS 在 5 秒超时后无法发回任何数据？

Answer 1

我终于能够通过使用原始套接字重现该问题，这需要大量工作。让 IIS 记录取消的请求的方法是在下面的代码中执行以下操作:

1. 不要发送连接:关闭
2. 不要调用 Socket.Dispose()

这是最终的工作代码，希望其他人会发现它有用:

private static void SocketTime(int readTimeout, Random random)
        {
            var ip = IPAddress.Parse("127.0.0.1");
            const int hostPort = 80;

            var hostep = new IPEndPoint(ip, hostPort);
            var sock = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);

            sock.Connect(hostep);
            var uniqueID = random.Next().ToString();
            var get = $"GET http://localhost/api/apitest/testcancel/{uniqueID} HTTP/1.1\r\n" +
                      "x-apikey: somekey\r\n" +
                      "Host: foo.com\r\n" +
                      "Connection: Close\r\n" +
                      "\r\n";


            var getBytes = Encoding.UTF8.GetBytes(get);
            sock.ReceiveTimeout = readTimeout;
            sock.Send(getBytes);

            var responseData = new byte[1024];
            try
            {
                var bytesRead = sock.Receive(responseData);
                var responseString = new StringBuilder();
                while (bytesRead != 0)
                {
                    responseString.Append(Encoding.ASCII.GetChars(responseData), 0, bytesRead);
                    bytesRead = sock.Receive(responseData);
                }
                Console.WriteLine($"SUCCESS => Unique ID = {uniqueID}, Timeout = {readTimeout}");
            }
            catch (SocketException e)
            {
                if (e.SocketErrorCode == SocketError.TimedOut)
                {
                    Console.WriteLine($"FAIL => Unique ID = {uniqueID}, Timeout = {readTimeout}");
                }
                else
                {
                    Console.WriteLine("UNHNALDED ERROR: " + e.Message);
                }

            }
            finally
            {
                sock.Dispose();
            }
        }