Clustering IIS 6.0
Updated: August 22, 2005
Applies To: Windows Server 2003, Windows Server 2003 with SP1
IIS 6.0 Web servers can be made highly available by failover using a Server cluster; however, Microsoft recommends that you use Network Load Balancing (NLB). In addition to providing high availability for IIS, NLB is a good cluster solution for a Web farm scenario because it also offers load balancing capabilities. NLB is generally less expensive to implement than Server cluster, which has additional hardware requirements. Windows Server 2003 Web Edition supports NLB.
Upgrading to IIS 60 from an IIS 5.0 Cluster
In Windows 2000, IIS 5.0 Web sites and FTP services used the IIS Server Instance resource type to achieve high availability with Microsoft Cluster Service (MSCS).
In Windows Server 2003, the IIS Server Instance resource type is now a Generic Script resource.This new resource type allows you to implement start/stop and health monitoring functions as scripts rather than as C or C++ programs. To manage IIS in a Windows Server 2003 cluster, you must use this Generic Script resource.
Windows Server 2003 provides a script called Iis_switch.vbs, which is located by default in the systemroot\system32\inetsrv directory. Iis_switch.vbs allows you to upgrade to IIS 6.0 from a Windows 2000 Server cluster with IIS 5.0 installed. First, upgrade all nodes except the node containing the IIS instance resource from Windows 2000 to Windows Server 2003, Enterprise Edition. Then, you can either use the script or perform the upgrade manually.
For step-by-step instructions about upgrading IIS from a clustered Windows 2000 Server configuration, see Server Clusters: Rolling Upgrades—Upgrading to Windows Server 2003.