The Oracle Solaris Cluster environment extends the Oracle Solaris Operating System into a cluster operating system. A cluster is a collection of one or more nodes that belong exclusively to that collection. The nodes can be different model machines, as long as they are either all SPARC based systems or all x86 based systems.
A cluster offers several advantages over traditional single-server systems. These advantages include support for failover and scalable services, capacity for modular growth, the ability to set load limits on nodes, and low entry price compared to traditional hardware fault-tolerant systems.
Additional benefits of the Oracle Solaris Cluster software include the following:
Reduce or eliminate system downtime because of software or hardware failure
Ensure availability of data and applications to end users, regardless of the kind of failure that would normally take down a single-server system
Increase application throughput by enabling services to scale to additional processors by adding nodes to the cluster and balancing load
Provide enhanced availability of the system by enabling you to perform maintenance without shutting down the entire cluster
In a cluster that runs on the Oracle Solaris OS, a global cluster and a zone cluster are types of clusters. A global cluster consists of a set of Solaris global zones, while a zone cluster consists of a set of non-global zones (one per global-cluster node), which are configured to behave as a separate "virtual" cluster. For more information about global and zone clusters, see Overview of Administering Oracle Solaris Cluster in Administering an Oracle Solaris Cluster 4.4 Configuration and Working With a Zone Cluster in Administering an Oracle Solaris Cluster 4.4 Configuration.