VCS Global Clusters: The Building Blocks

VCS extends clustering concepts to wide-area high availability and disaster recovery. It is enabled by the following:

• Visualization of Remote Cluster Objects
• Global Service Groups
• Global Cluster Management
• Serialization–The Authority Attribute
• Resiliency and "Right of Way"
• VCS Framework
• The Steward Process: Handling Split-brain in Two-Cluster Global Clusters

Visualization of Remote Cluster Objects

VCS enables you to visualize remote cluster objects using the VCS command-line, the Java Console, and the Web Console.

You can define remote clusters in your configuration file, main.cf. The Remote Cluster Configuration wizard provides an easy interface to do so. The wizard updates the main.cf files of all connected clusters with the required configuration changes. See Adding a Remote Cluster for more information.

Global Service Groups

A global service group is a regular VCS group with additional properties to enable wide-area failover. The global service group attribute ClusterList defines the list of clusters to which the group can fail over. The service group must be configured on all participating clusters and must have the same name on each cluster. The Global Group Configuration wizard provides an easy interface to configure global groups. See Administering Global Service Groups for more information.

Replication during cross-cluster failover is managed by VCS agents, as described in VCS Framework. You can configure a resource of type DNS to perform a canonical name update, if cross-cluster failover spans subnets. See DNS Agent for more information.