A clustered system uses two or more server machines as a single virtual server machine to provide high level of availability.
In single-server machine operation, if the server machine or an application running on it stops, the machine or the application must be restarted. During this time, the operation stops.
A clustered system, however, uses two or more server machines. If a failure occurs on one server machine or an application running on it, the transaction can be resumed immediately by restarting the application on the other server machine. As a result, transaction downtime is reduced. The switching of a transaction from a server with a problem to another server that is operating normally is referred to as failover.
In the clustered system, each server machine in the clustered system is called "node".
The clustered system operation is classified into one of the following types. These types are explained in names of "PRIMECLUSTER".
Standby operation
1:1 standby
Mutual standby
N:1 standby
Cascade
Priority transfer
Scalable operation
See
The clustered system operation and the names given to those that are supported by cluster software differ from each other in different systems. Refer to the cluster software manuals for more information.
