Specifying the Cluster Host Parameters

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

The cluster host parameters are the configuration settings that define each cluster host, including the configuration settings that are unique to each cluster host within the cluster. The cluster host parameters must be unique within a cluster and within your organization’s network.

Specify the cluster host parameters by completing the following steps:

  1. Specify the cluster host priority.

  2. Specify the dedicated IP address configuration.

  3. Specify the initial host state.

For more information about configuring the cluster host parameters, see "Network Load Balancing parameters" in Help and Support Center for Windows Server 2003.

Tip

  • Network Load Balancing Manager prevents common cluster host configuration errors, such as duplicate cluster host priorities or duplicate dedicated IP addresses. When you use other methods to configure the cluster host parameters, you must ensure that the cluster host parameters are configured appropriately for all cluster hosts within the cluster.

Specifying the Cluster Host Priority

For each cluster host, you must specify a cluster host priority that is unique within the cluster. During cluster convergence, the cluster host with the lowest numeric value for the cluster host priority triggers the end of convergence. For example, if three cluster hosts have the priorities of 3, 16, and 22, 3 is the cluster host with the highest priority and it will trigger the end of convergence.

Specify the cluster host priority for your cluster by using any unique identifier between 1 and 32. Any sequence can be used as long as the cluster host priorities are unique.

Note

  • If you specify the same cluster host priority for two cluster hosts, the last cluster host that starts fails to join the cluster. An error message describing the problem is written to the Windows system event log. The existing cluster hosts continue to operate as before.

Specifying the Dedicated IP Address Configuration

The dedicated IP address is an IP address that is assigned to each cluster host for network traffic that is not associated with the cluster, such as Telnet access to a specific host within a cluster. This IP address is used to individually address each host in the cluster; therefore, it should be unique for each host. Enter this parameter in standard Internet dotted notation (for example, w.x.y.z).

Traffic that is sent to the dedicated IP address is not load balanced by Network Load Balancing. Network Load Balancing ensures that all traffic to the dedicated IP address is unaffected by the Network Load Balancing current configuration, including:

  • When a host is running as part of the cluster.

  • When Network Load Balancing is disabled as a result of parameter errors in the registry.

Tip

  • The dedicated IP address must be the first IP address in the list of IP addresses in the TCP/IP properties. Network Load Balancing Manager automatically configures the TCP/IP properties so that the dedicated IP address is first. When you use other methods to configure the TCP/IP properties, you must ensure that the dedicated IP address is the first IP address listed in the TCP/IP properties.

Specifying the Initial Host State

The initial host state specifies whether Network Load Balancing starts and whether the cluster host joins the cluster when the operating system starts. You need to determine the correct initial host state for the applications and services running on the cluster.

Network Load Balancing starts very early in the system start sequence. As a result, a cluster host can join the cluster before the applications and services running on the cluster host are ready to handle traffic. In this situation, clients might be directed to the cluster host and experience outages.

In some instances, management software, such as MOM or Applications Center 2000, is responsible for starting Network Load Balancing. The management software monitors the applications and services running on the cluster host and starts Network Load Balancing when the applications are fully operational.

In other instances, you might decide to start Network Load Balancing manually to ensure that applications and services are running before Network Load Balancing starts.

Table 8.3 lists the possible settings for the initial host state and the reasons for selecting the specific initial host state.

Table 8.3   Selecting the Appropriate Initial Host State

Initial Host State Reasons for Selecting the Initial Host State

Started
  • The applications and services running on the cluster start before Network Load Balancing.

  • The length of time between the start of Network Load Balancing and the start of applications and services running on the cluster is negligible.

Stopped
  • Management software, such as MOM or Application Center 2000, is responsible for starting Network Load Balancing automatically.

  • The applications and services running on the cluster start after Network Load Balancing, and you want to start the cluster host manually.

Suspended
  • You have performed maintenance on the cluster host, and you want to prevent the cluster from responding to clients after a restart of the cluster host.