Arbitration for Data Integrity in Serviceguard Clusters
Arbitration in
Arbitration in Disaster-Tolerant Clusters
Extended Distance Clusters
In extended distance (campus) clusters, the nodes are divided into two separate data centers in different buildings, which can be as far as 100 km apart. A dual cluster lock disk may be used for arbitration, with the two lock disks located in the two different data centers. This affords protection against the loss of one of the data centers. If a quorum server is used, it must be in a different location from either of the two data centers, thus providing additional protection against data center loss. Similarly, if arbitrator nodes are used, they must be in a different location from the two data centers.
An extended distance cluster is no different from a standard Serviceguard cluster except that components are subdivided by data center. This means that groups of nodes are located in different buildings, and storage units with mirrored data are placed in separate facilities as well.
Metropolitan Clusters
Arbitration in a MetroCluster configuration has traditionally followed a different model than that of the single arbitrator device (originally this was a lock disk). Because a MetroCluster configuration contains two distinct data centers at some distance from one another, the main protection has been against a partition that separates the two data centers into
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