Clusters give your applications more capacity and higher
availability than a single server.
A Cluster is a set of managed servers that provide
high availability and workload balancing for applications. Members
of a cluster can be servers located on various hosts or servers located
on the same host (the same node). To best achieve high availability
and workload balancing, place each cluster member on different host
machines.
A clustered environment provides the following benefits:
- Workload balancing: By running application images on multiple
servers, a cluster balances an application workload across the servers
in the cluster.
- Processing power for the application: You can add processing power
to your application by configuring server hardware as cluster members
to support the application.
- Application availability: When a server fails, the application
continues to process work on other servers in the cluster. This allows
recovery efforts to proceed without affecting the application users.
- Maintainability: You can stop a server for planned maintenance
without stopping application processing.
- Flexibility: You can add or remove capacity as needed by using
the administrative console of the deployment manager.
By nature, the z/OS® environment
is clustered and can provide a highly scalable environment without
all the complexities of separate clustered servers. Separate clustered
servers can be used for multisystem nodes to provide additional availability.