Improving IIS 6.0 Scalability and Availability with Network Load Balancing

Applies To: Windows Server 2003, Windows Server 2003 with SP1

The best way to guarantee the scalability and availability of your Internet services is to host your site with more than one computer. Microsoft Windows Server 2003 includes the Network Load Balancing service. Network Load Balancing enhances the availability and scalability of Internet server applications such as those used on Web, File Transfer Protocol (FTP), firewall, proxy, and virtual private network (VPN) servers, in addition to other mission-critical servers. A single computer running Windows can provide a limited level of server reliability and scalable performance. However, by combining the resources of two or more computers running Windows Server 2003 into a single cluster, Network Load Balancing can deliver the reliability and performance that Web servers and other mission-critical servers need. Figure 7.1 shows two connected Network Load Balancing clusters. The first cluster consists of two hosts and the second cluster consists of four hosts.

Each host runs separate copies of the server applications, such as those for a Web, FTP, or Telnet server. Network Load Balancing distributes incoming client requests across the hosts in the cluster. The load weight to be handled by each host can be configured as necessary. You can also dynamically add hosts to the cluster to handle the increased load. In addition, Network Load Balancing can direct all traffic to a designated single host, called the default host.

Network Load Balancing allows all of the computers in the cluster to be addressed by the same cluster IP address (but also maintains their existing unique, dedicated IP addresses). For more information about Network Load Balancing, see Help and Support Center for Windows Server 2003.

Related Topics

For more information about upgrading your FrontPage-extended Web sites, see SharePoint Team Services.