Product or Service Cluster Aware Cluster Independent Cluster Incompatible Comment
Active Directory (AD)
Not recommended; availability is provided through multi-master replication
Active Directory in Application Mode (ADAM)
Not recommended; availability is provided through ADAM's replication services
BizTalk Server
BizTalk 2004 can now take advantage of a clustered environment
COM+
Component Load Balancing clusters preferred
Commerce Server
Component Load Balancing clusters preferred
Content Management Server
Only the SQL Server portion can run on a cluster server
DFS
Standalone DFS roots only
DHCP-WINS
Compliant, but should run as a single instance
Distributed Transaction Coordinator
Fully compliant
DNS
Compliant, but not recommended; availability is provided through replication, especially if integrated to AD
Exchange 2000 and above
Fully compliant
File sharing
Fully compliant
Identity Integration Server
Fully compliant
Internet Information Server
NLB clusters are preferred
Internet Security and Acceleration Server 2000
NLB clusters are preferred, but supports its own clustering through server arrays
Microsoft Message Queuing
Fully compliant
Microsoft Operations Manager
Not supported
Network Load Balancing
Network Load Balancing should not be installed on a MSCS cluster
Print services
Fully compliant
Project Central
Fully compliant
Live Communication Server
Not supported
Remote Installation Services
Not supported
SharePoint Portal Server 2001
Not supported; coexistence with SQL or Exchange not recommended
Windows SharePoint Services
Only the SQL Server portion is supported; IIS portion should use NLB
Systems Management Server 2003
Fully compliant
SQL Server 2000
Fully compliant
Terminal Services
For Windows Server 2003 only; NLB clusters preferred; incompatible in Windows 2000

Table 1 To Cluster or Not to Cluster?
Server consolidation and server availability go hand in hand. But before you can decide if you are going to cluster different services on Windows Server 2003, you need to understand which products run on which cluster services. Windows Server supports three clustering technologies (see Figure 2). Network Load Balancing (NLB) clusters are clusters that use identical servers to provide the same service. A network redirection scheme is used to provide availability and load balancing. All versions of Windows Server include the NLB service. The second clustering service is the component load balancing (CLB) that is found in Microsoft Application Center Server. This is usually reserved for COM+ load balancing. The final clustering mode is the Microsoft Clustering Service (MSCS). This service provides load balancing and application failover by sharing the resources of multiple cluster nodes. Clustering Service is available by default in both the Enterprise and the DataCenter Editions of Windows Server 2003.

Use this table to identify which applications can use which clustering service. The table is focused on the Microsoft Clustering Service. It indicates if applications are cluster aware—designed for the clustering service; cluster independent—not designed for the service, but able to operate on a cluster node with no impact; or cluster incompatible—unable to run on a cluster node.