Administrative Domain

The administrative domain in PowerHA synchronizes security and configuration resources across cluster nodes in the environment. The system requires these objects at all times, so they do not make sense in an independent auxiliary storage pool (IASP). Common examples of these resources include User Profiles, Authorization Lists, Job Descriptions, Subsystem Descriptions, and Printer Device Descriptions.

When a cluster administrative domain is created, a list of nodes is supplied to indicate which nodes in the cluster make up the administrative domain. By default, all nodes will be automatically selected.

Monitored Resources

An administrative domain is made up of monitored resources, which are system resources and objects that are managed by the administrative domain. Changes that are made to a monitored resource are synchronized across nodes in the cluster administrative domain and applied to the resource on each active node. Monitored resources can be system objects like user profiles or job descriptions, or a monitored resource can also be a system resource that is not represented by a system object, such as a single system value or a system environment variable. These monitored resources are represented in the cluster administrative domain as monitored resource entries (MREs). The PowerHA administrative domain can monitor up to 200,000 MREs.

MRE Synchronization

When a change to a monitored resource is made on any node within the administrative domain, that change is propagated to other nodes within the administrative domain. When a node within a cluster administrative domain is inactive, the synchronization option controls the way changes are propagated throughout the cluster.

When the synchronization option is set to Last Change (the default), changes made to the resource on the inactive node are only discarded if there was a more recent change to the resource propagated in the cluster administrative domain.

When the synchronization option is set to Active Domain, any changes made to the resource on the inactive node are discarded when the node rejoins the cluster, and the changes are replaced with information from the administrative domain.

Supported MREs

Each supported monitored resource has specific attributes on the resource that can be monitored for changes. By default, when a resource is added to the administrative domain, all supported attributes for a resource are monitored. However, the administrative domain provides the flexibility of only monitoring specific attributes when adding a monitored resource.

See the following pages for additional information on configuring and managing the Administrative Domain: