Federation is the term used to describe how metadata can be copied and kept up to date between two related Aristotle Metadata Registries. Once a "Federation rule" is configured in an Aristotle Metadata Registry, it means that content held within a different registry can be copied into this registy, and any changes in the external system will be periodically updated.
Because different registries may have content that is related, it is useful to set up federations to ensure that metadata can be copied and kept up to date. And because every federation uses a Universally Unique Identifier (UUID), the same UUID will refer to the same metadata item, regardless of the registry it is stored in.
What can be federated?
The Aristotle Metadata Registry only supports the federation of metadata objects - that is any item in the registry that can be endorsed by a Registration Authority. Metadata must also be published for non-authenticated users and publically accessible to be federated. However, endorsement information, such as Registration statuses or Registation Authority information is not copied.
When a Federation rule is set up and run for a given metadata item, it will copy all related component metadata items. For example:
When copying a Data Element, its components (i.e. the Data Element Concept, Value Domain, Object Class and Property) will be copied.
When copying an Indicator, all of its related Data Elements and their components will be copied.
When copying a Distribution, all of its related Data Elements and their components will be copied.
If any of the related items or components are not available, Federation will not be available.