Federation methods in BMC Helix CMDB

BMC Helix CMDB enables you to configure federation through retrieval and cross-launch methods.

• The retrieval method enables you to view federated data as if it were stored in BMC Helix CMDB.
• The cross-launch method enables you to view federated data in another application, such as a AR System form.

These methods enable you to retrieve data in the context of a configuration item (CI). That is, you want data that is relevant to a particular CI, not every piece of data that an external source has to offer.

Retrieval method of federation

With the retrieval method of federation, you create BMC Helix CMDB classes to represent data that is stored outside of BMC Helix CMDB. You can also create federated relationship classes that join classes that are already part of the BMC Helix CMDB data model with the new federated data classes. This method enables you to view the relationships between federated data and BMC Helix CMDB data through such tools as CMDB Explorer and CMDB Impact Simulator.

Federation objects for the retrieval method

A federated data class represents a set of information on the external source of data (such as a table on a database), so that data can be viewed within the context of the data model. As part of the process of creating a federated data class, BMC Helix CMDB creates attributes to represent the fields from the external repository. Federated data classes that you create are subclasses of the BMC_FederatedBaseElement class.

A federated relationship class establishes a relationship between CIs stored in BMC Helix CMDB and external data. Federated relationship classes that you create are added to the data model as subclasses of the BMC_FederatedBaseRelationship class. The source class of the relationship must be in the BMC_BaseElement hierarchy of classes, and the destination class of the relationship must be a federated data class.

Cross-launch method of federation

In the cross-launch method of federation, you define the method of viewing the data (such as opening the data on a AR System form), and then create a link between that data and CIs in BMC Helix CMDB. For example, in CMDB Portal in Federation Manager > Access Method, use the URL option to link a database through a browser, and use the AR System option to link the data through an AR System form.

BMC Helix CMDB uses several types of objects to implement federation. The following figure illustrates these objects, each of which is represented by a class in the BMC Helix CMDB metadata.

Federation objects for the cross-launch method

A CI class or instance has a cross-launch link relationship to a launch interface, which defines the information necessary to access a particular piece of federated data.

The launch interface contains a federated product link relationship from a federated data store, which names an external source of data. Because an external source of data might offer several types of federated data, each federated data store can be linked to multiple launch interfaces.

If foreign key substitution is used, the federated data store also has one or more federated key link relationships to CIs. This relationship carries the key value that identifies the federated data for the CI.

BMC Helix CMDB offers attribute substitution and foreign key substitution as ways to implement the cross-launch method of federation.