Two clusters where each cluster is both the primary cluster for some services and the secondary cluster for other services.
An application that is managed as a resource to its increased availability.
A Sun Cluster resource group that is configured by the user to make an application highly available on Sun Cluster. An application resource group can be configured into a protection group to make it disaster tolerant and highly available.
A cluster that supports data replication between geographically separate nodes within one cluster. The maximum distance between nodes is limited.
The copying of data from data storage devices in a primary cluster to data storage devices in a secondary cluster. Through data replication, the secondary cluster has a recent copy of the data on the primary cluster. The primary and secondary clusters can be geographically separated.
In a campus cluster, the two data storage devices are on the same cluster. In a geographically separated cluster that runs the Sun Cluster Geographic Edition software, the two data storage devices are on different clusters.
A Sun Cluster resource that monitors the state and status of data replication.
The ability of a system to restore an application on a secondary cluster when the primary cluster fails. Disaster tolerance is based on data replication and failover.
An error scenario in which two clusters in a protection group act as the primary cluster. In a disconnected partnership, the system administrator must execute a takeover, making one cluster the primary cluster and the other cluster the secondary cluster.
A resource that enforces the switchover of the device group when the replication resource group is switched over or failed over.
A signal that is emitted from a cluster and detected by its partner cluster. Heartbeats enable a cluster to monitor the presence and failure of its partner cluster.
A primary cluster where an application is not running and data is not being replicated to a secondary cluster. Alternatively, a secondary cluster where data is not being replicated from the primary cluster.
A relationship between two geographically separated clusters that are installed with the Sun Cluster software and Sun Cluster Geographic Edition software. These two clusters monitor each other's health by exchanging heartbeats.
A cluster that is in a cluster partnership, that hosts the application resources, and that holds the primary copy of replicated data. Protection groups define whether a cluster is primary or secondary. For example, the primary cluster of one protection group can also be the secondary cluster for another protection group.
An entity that manages application resource groups for services that are protected from disaster. Clusters in a protection group must be defined as partners. A cluster can have different roles in different protection groups. For example, the primary cluster of one protection group can also be the secondary cluster for another protection group.
A protection group has the following characteristics:
A set of resource groups and resources for services that are protected from disaster
Device group entries
A primary cluster that hosts the protection group
A secondary cluster that is able to host the protection group
A data replication service
A resource group that contains data replication resources.
A Sun Cluster resource.
A Sun Cluster resource group. A resource group can be an application resource group or a replication resource group.
An application that runs on several nodes of one cluster to create a single, logical service. If a node that is running a scalable application fails, failover does not occur. The application continues to run on the other nodes of the cluster.
A cluster in a cluster partnership that is capable of hosting a protection group. The secondary cluster receives mirrored data from the primary cluster. If the primary cluster fails, the secondary cluster can become the new primary cluster.
A secondary cluster can be associated with a protection group. If a primary cluster fails, the protection group is migrated to a secondary cluster. Protection groups define whether a cluster is primary or secondary. For example, the primary cluster of one protection group can also be the secondary cluster for another protection group.
A node that is in a cluster, but does not host the application services. If the primary node fails, the secondary node becomes the new primary node.
A location that houses one or more clusters that run the Sun Cluster Geographic Edition software. To participate in the disaster recovery environment, a cluster must have a partner cluster on a geographically separated site.
A cluster with a minimal configuration that acts as a secondary cluster. A standby cluster can take over from the primary cluster in an emergency situation, but supports a reduced service only. A standby cluster is a low-cost alternative to a secondary cluster.
The planned migration of services from the primary cluster to the secondary cluster.
Unlike a takeover, the primary cluster is connected to the secondary cluster during a switchover. During a switchover, the primary cluster is connected to the secondary cluster and coordinates the migration of services with the secondary cluster. This coordination enables the data replication to be completed and ensures that services can be transferred from the primary cluster to the secondary cluster with minimal loss or corruption of data.
The emergency migration of services from the primary cluster to the secondary cluster. A system administrator can initiate a takeover to recover from a disaster scenario.
Unlike a switchover, the primary cluster is not connected to the secondary cluster during a takeover. Therefore, the primary cluster cannot coordinate with the secondary cluster to migrate the services. Because of this lack of coordination, the risk of data loss and data corruption is higher than with a switchover. During a takeover, dedicated recovery procedures are used to minimize data loss and data corruption.