A topology is the connection scheme that connects the cluster nodes to the storage platforms that are used in the cluster. Sun Cluster supports any topology that adheres to the following guidelines.
If a cluster runs Oracle Real Application Clusters (RAC), Sun Cluster software supports from one to eight nodes in that cluster. If a cluster does not run Oracle RAC, Sun Cluster software supports from one to four nodes in that cluster.
Shared storage devices must connect to both nodes.
Sun Cluster does not require you to configure a cluster by using specific topologies. The following clustered pair topology, which is a topology for clusters that are composed of x86 based nodes, is described to provide the vocabulary to discuss a cluster's connection scheme. This topology is a typical connection scheme.
The following section includes a sample diagram of the topology.
A clustered pair topology is two nodes that operate under a single cluster administrative framework. In this configuration, failover occurs only between a pair. However, all nodes are connected by the cluster interconnect and operate under Sun Cluster software control. You might use this topology to run a parallel database or a failover or scalable application on the pair.
The following figure illustrates a clustered pair configuration.