Under The Stairs: Testing Server 2008 NLB clusters

Thursday, October 30, 2008

Testing Server 2008 NLB clusters

I am working on an article for Server Management magazine, due out on December focusing on Clustering. One aspect of this article is around NLB clusters in Server 2008. To test this, I wrote a very simple ASP.Net Application.

Here’s the default.aspx web page:

 1 <%@ Page Language="C#" AutoEventWireup="true" CodeBehind="Default.aspx.cs" Inherits="myip._Default" %>
 2 <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
 3 <html xmlns="http://www.w3.org/1999/xhtml" >
 4 <head runat="server"> <title>NLB Test on NLB 1Tool</title></head>
 5 <body>
 6     <form id="form1" runat="server"><div></div>
 7     <p>        NLB Test Tool</p><p></p>
 8     <p>        The IP address of this server is:</p>
 9     <asp:Label ID="Label1" runat="server"></asp:Label>
10     </form>
11 </body>
12 </html>

As you can see, this ASP.NET has some code:

using System;
using System.Collections;
using System.Configuration;
using System.Data;
using System.Linq;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.HtmlControls;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Xml.Linq;
using System.Net;

namespace myip
{
    public partial class _Default : System.Web.UI.Page
    {
        protected void Page_Load(object sender, EventArgs e)
        {
        string strHostName = " ";
        strHostName = System.Net.Dns.GetHostName();
        IPHostEntry ipEntry = System.Net.Dns.GetHostByName(strHostName);
        IPAddress[] addr = ipEntry.AddressList;
        Label1.Text = addr[0].ToString();
        }
    }
}

I loaded this onto two NLB cluster hosts changing the HTML title on each host to reflect the host name (the HTML avove is used on Node 1)! When I then navigated to the page, I saw this:

As you can seem, in this case, the cluster served up Node 2. Depending on which underlying host serviced the request, I saw a different title and a different IP address.

Thanks for http://www.codeproject.com/KB/cs/network.aspx and Naveen K Kohli for the important parts of the C#code.

Technorati Tags: C#,ASP.NET,NLB

Thursday, October 30, 2008

Testing Server 2008 NLB clusters

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