Example: Migrating to the Target Cluster

Applies To: Windows Server 2003, Windows Server 2003 R2, Windows Server 2003 with SP1, Windows Server 2003 with SP2

The fictitious organization Contoso, mentioned in examples earlier in this chapter, is now ready to migrate their existing applications running on the four IIS Web farms to the target IIS 6.0 Web farm (and subsequently the target Network Load Balancing cluster). Contoso’s target Web farm has been installed and their applications have been verified to work with Windows Server 2003 and Network Load Balancing.

Figure 9.14 illustrates Contoso’s network environment after the migration of the existing applications to the target Web farm and Network Load Balancing cluster.

Figure 9.14   Network Environment After Migrating Applications and Services

Table 9.7 lists the applications, the Web farms that run the applications, and the DNS entries that correspond to the Web applications.

Table 9.7   Applications, Web Farms, and DNS Entries

In this step, Contoso creates the port rules on the target cluster based on the port rules from each of the existing clusters (IISNLB-01, IISNLB-02, IISNLB-03, and IISNLB-04). Table 9.8, Table 9.9, Table 9.10, and Table 9.11 lists the port rules for the existing clusters.

Table 9.8   Port Rules for IIS Applications on IISNLB-01

Table 9.9   Port Rules for IIS Applications on IISNLB-02

Table 9.10   Port Rules for IIS Applications on IISNLB-03

Table 9.11   Port Rules for IIS Applications on IISNLB-04

The port rules are recorded for each of the source clusters. Because each of the clusters has different port rules, virtual clusters are created to facilitate the consolidation of the applications onto the target cluster IISNLB-05. Table 9.12 lists the port rules that were created to support the applications on IISNLB-05.

Table 9.12   Port Rules Created for IIS Applications on IISNLB-05

The port rules on IISNLB-01 and IISNLB-02 are combined into a pair of port rules on IISNLB-05 because IISNLB-01 and IISNLB-02 support the same application. The two clusters, IISNLB-01 and IISNLB-02, were created to provide scaling in the original design. Because the application — www.contoso.com — is being consolidated onto one Web farm on a single cluster, the port rules can be consolidated as well.

The virtual clusters on IISNLB-03 are created on IISNLB-05 to provide separate virtual IP addresses for support.contoso.com and sales.contoso.com.

A virtual cluster, 10.0.0.154, was created to support the application on IISNLB-04, www.treyresearch.net.

After the applications are migrated to the target cluster, IISNLB-05, and are verified for proper operation, DNS entries are created to direct clients to the applications running on the target cluster. Table 9.13 lists the applications, the Web farms that run the applications, and the DNS entries that correspond to the Web applications that include the target cluster, IISNLB-05.

Table 9.13   Applications, Web Farms, and DNS Entries

After a few days of operation, clients are experiencing no difficulty with IISNLB-05, so Contoso modifies the DNS entries to remove the original Web servers (IISNLB-01, IISNLB-02, IISNLB-03, and IISNLB-04). Table 9.14 reflects the DNS entries after the removal of the original Web servers.

Table 9.14   Applications, Web Farms, and DNS Entries

To finalize the completion of the migration, Contoso performs the following tasks:

1. Contoso monitors the source clusters for client traffic.

2. After all client traffic ceases on the source clusters, Contoso decommissions the computers in the source clusters.