Failover Cluster Instances

To access a network application or resource in a non-clustered environment, network clients must connect to a physical server (that is, a specific computer on the network identified by a unique network name and IP address). If that server fails, access to the application or resource is impossible.

Failover clusters, however, allow the creation of failover cluster instances. A failover cluster instance is a group that contains:

• A Network Name resource.
• An IP Address resource, an IPv6 Address resource, and/or an IPv6 Tunnel Address resource.
• The resources to be accessed by the clients of the failover cluster instance. Each resource on a failover cluster instance must establish a dependency on the failover cluster instance's Network Name resource type.

A failover cluster instance acts like a physical server in the following ways:

• It allows access to network resources.
• It is published to network clients under a unique server name.
• It is associated with a network name and an IP address.

However, a failover cluster instance is not associated with a specific computer and can be failedover like any other group. If the node hosting the failover cluster instance fails, clients can still access the failover cluster instance's resources using the same server name.

For procedures and an example of creating a failover cluster instance, see Creating a Failover Cluster Instance.