使用C＃检查负载平衡服务器

Question

I have four application server for my application.Application is working on all server using load balancing.If one of my server goes down I have to check it manually using my system hosts file.To avoid this manual process I have created one program using C#.I write server IP address one by one in host file and remove previous one.

 private void RunWithUAC()
    {
        List<string> lstIPAddress = new List<string>();
        lstIPAddress.Add("1.1.1.1 example.com");
        lstIPAddress.Add("1.1.1.1 example.com");
        lstIPAddress.Add("1.1.1.1 example.com");
        lstIPAddress.Add("1.1.1.1 example.com");
        var systemPath = Environment.GetFolderPath(Environment.SpecialFolder.System);
        Console.WriteLine(systemPath);
        var path = @"C:\Windows\System32\drivers\etc\hosts";

        foreach (var item in lstIPAddress)
        {
            System.IO.File.WriteAllText(path, string.Empty);
            try
            {
                File.WriteAllText(path, item);

                WebRequest request = WebRequest.Create("https://example.com");
                request.Timeout = 10000;
                HttpWebResponse response = (HttpWebResponse)request.GetResponse();
            }
            catch (Exception)
            {
                MessageBox.Show(item);
            }
            Thread.Sleep(1000);
        }
    }

But When second server goes down.It will give me timeout error for third server. Please check the code and let me know what is wrong with this code.

Answer 1

Probably some kind of connection pooling, HTTP pipelining or keep-alive. This is the wrong approach in the first place.

Connect directly to the right IP ( WebRequest.Create("https://1.1.1.1") ). If you need to send a Host header add that manually to the request .