代理调用api需要15+秒

Question

在C#应用程序中，调用API接口时，往往需要15+秒才能访问。 API部署在内网的另一个网段，需要代理访问。有人说是DNS问题，尝试设置主机，没有效果。 环境：Windows Server 2012 R2，IIS v8.5 代码脚本：

  private string PostHttp(string url, string authHeader, string requestBody)
        {
            var webRequest = System.Net.WebRequest.Create(url);

            ServicePointManager.ServerCertificateValidationCallback = new System.Net.Security.RemoteCertificateValidationCallback(CheckValidationResult);

            byte[] data = System.Text.Encoding.UTF8.GetBytes(requestBody);
            webRequest.Method = "POST";
            webRequest.Headers.Add("Accept-Language", "zh-cn,zh;q=0.8,en-us;q=0.5,en;q=0.3");
            webRequest.Headers.Add("Accept-Encoding", "gzip, deflate");
            webRequest.Headers.Add("Authorization", authHeader);
            webRequest.ContentLength = data.Length;
            webRequest.ContentType = "application/x-www-form-urlencoded";


            System.Net.WebProxy proxy = new System.Net.WebProxy("http://myHttpProxyAddress", false);
            proxy.Credentials = new System.Net.NetworkCredential("HttpProxyUser", "HttpProxyPassword");
        
            webRequest.Proxy = proxy;

            var writer = webRequest.GetRequestStream();
            writer.Write(data, 0, data.Length);
            writer.Close();

            using (WebResponse webResponse = webRequest.GetResponse())
            {
                System.IO.StreamReader reader = null;

                if (webResponse.Headers["Content-Encoding"] == "gzip")
                    reader = new System.IO.StreamReader(new GZipStream(webResponse.GetResponseStream(), CompressionMode.Decompress), System.Text.Encoding.UTF8);
                else
                    reader = new System.IO.StreamReader(webResponse.GetResponseStream(), System.Text.Encoding.UTF8);

                var result = reader.ReadToEnd();
                reader.Close();

                return result;
            }
        }

Answer 1

仅听到有人说其中一种可能性（例如 DNS 错误）很难指出，尝试使用一些 http 实用程序（例如 Curl）来检查和衡量。

您可以在本指南下方包装上面的请求并测量时间细节。

How do I measure request and response times at once using cURL?