A cluster is a collection of one or more nodes that belong exclusively to that collection. In a cluster that runs on the Solaris 10 OS, a global cluster and a zone cluster are types of clusters. In a cluster that runs on any version of the Solaris OS that was released before the Solaris 10 OS, a node is a physical machine that contributes to cluster membership and is not a quorum device. In a cluster that runs on the Solaris 10 OS, the concept of a node changes. A node is a Solaris zone that is associated with a cluster. In this environment, a Solaris host, or simply host, is one of the following hardware or software configurations that runs the Solaris OS and its own processes:
A “bare metal” physical machine that is not configured with a virtual machine or as a hardware domain
A Sun Logical Domains (LDoms) guest domain
A Sun Logical Domains (LDoms) I/O domain
A hardware domain
In a Solaris 10 environment, a voting node is a zone that contributes votes to the total number of quorum votes, that is, membership votes in a cluster. This total determines whether the cluster has sufficient votes to continue operating. A non-voting node is a zone that does not contribute to the total number of quorum votes, that is, membership votes in a cluster.
In a clustered environment, the nodes are connected by an interconnect and work together as a single entity to provide increased availability and performance.
In a Solaris 10 environment, a global cluster is a type of cluster that is composed only of one or more global-cluster voting nodes and optionally, zero or more global-cluster non-voting nodes.
A global cluster can optionally also include solaris8, solaris9, lx (Linux), or native brand, non-global zones that are not nodes, but high availability containers (as resources).
A global-cluster voting node is a native brand, global zone in a global cluster that contributes votes to the total number of quorum votes, that is, membership votes in the cluster. This total determines whether the cluster has sufficient votes to continue operating. A global-cluster non-voting node is a native brand, non-global zone in a global cluster that does not contribute votes to the total number of quorum votes, that is, membership votes in the cluster.
In a Solaris 10 environment, a zone cluster is a type of cluster that is composed only of one or more cluster brand, voting nodes. A zone cluster depends on, and therefore requires, a global cluster. A global cluster does not contain a zone cluster. You cannot configure a zone cluster without a global cluster. A zone cluster has, at most, one zone cluster node on a machine.
A zone-cluster node continues to operate only as long as the global-cluster voting node on the same machine continues to operate. If a global-cluster voting node on a machine fails, all zone-cluster nodes on that machine fail as well.
The Sun Cluster software enables you to have one to sixteen Solaris hosts in a cluster, depending on the hardware configuration. Contact your Sun representative for information about the number of Solaris hosts that are supported on your particular hardware configuration.
Solaris hosts in a cluster are generally attached to one or more disks. Solaris hosts that are not attached to disks use the cluster file system to access the multihost disks. Solaris hosts in parallel database configurations share concurrent access to some or all disks.
Every node in the cluster is aware when another node joins or leaves the cluster. Also, 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.
Solaris hosts 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, each host should have sufficient capacity to meet service level agreements if a node fails.