Cluster Nodes

A cluster node is a machine running both the Solaris operating environment and Sun Cluster software, and is either a current member of the cluster (a cluster member), or a potential member. The Sun Cluster software enables you to have from two to eight nodes in a cluster. See Sun Cluster Topology Examples for the supported node configurations.

Cluster nodes are generally attached to one or more multihost disks. Nodes not attached to multihost disks use the cluster file system to access the multihost disks. For example, one scalable services configuration allows nodes to service requests without being directly attached to multihost disks.

In addition, nodes in parallel database configurations share concurrent access to all the disks. See Multihost Disks and Chapter 3, Key Concepts for Administration and Application Development for more information on parallel database configurations.

All nodes in the cluster are grouped under a common name, known as the cluster name. The cluster name is used to access and manage the cluster.

Public network adapters attach nodes to the public networks, providing client access to the cluster.

Cluster members communicate with the other nodes in the cluster through one or more physically independent networks. This set of physically independent networks is referred to as the cluster interconnect.

Every node in the cluster is aware when another node joins or leaves the cluster. Additionally, every node in the cluster is aware of the resources that are running locally as well as the resources that are running on the other cluster nodes.

Nodes in the same cluster should have similar processing, memory, and I/O capability to enable failover to occur without significant degradation in performance. Because of the possibility of failover, every node must have enough excess capacity to take on the workload of all nodes for which they are a backup or secondary.

Each node boots its own individual root (/) file system.

Software Components for Cluster Hardware Members

To function as a cluster member, the following software must be installed:

• Solaris operating environment

• Sun Cluster software

• Data service application

• Volume management (Solaris Volume Manager^TM or VERITAS Volume Manager)

  An exception is a configuration that uses hardware redundant array of independent disks (RAID). This configuration may not require a software volume manager such as Solaris Volume Manager or VERITAS Volume Manager.

See the Sun Cluster 3.1 System Administration Guide for information on how to install the Solaris operating environment, Sun Cluster, and volume management software.

See the Sun Cluster 3.1 Data Service Collection for information on how to install and configure data services.

See Chapter 3, Key Concepts for Administration and Application Development for conceptual information on the preceding software components.

The following figure provides a high-level view of the software components that work together to create the Sun Cluster software environment.

Figure 2–2 High-Level Relationship of Sun Cluster Software Components

See Chapter 4, Frequently Asked Questions for questions and answers about cluster members.