Retrieving federated data stored externally by creating federated classes

You can federate data stored externally, such as a in a table in a database, by creating BMC CMDB classes and mapping them to the external data. This method of federation is also called the retrieval method. When you define federated data classes mapped to represent external data, you must make sure that they are subclasses of the BMC_FederatedBaseElement class.

The federated data class represents a portion of the information about the external source of data so that data can be viewed within the context of the data model.

After you complete the following procedure, in the Explorer, you can directly view the federated data that is related to specific CIs.

Before you begin

• You must have AR Administrator permissions to create or edit classes.
• You must define the federation plug-ins as described in Creating AR or JDBC federated data plug-ins to access data external to the CMDB.

To retrieve federated data stored externally by creating federated classes

As an administrator, you want to create a new federated data class for information stored on an external database. It is assumed that you have already created a plug-in and data store for this database. 

1. Open Class Manager.
   Select Class Management > Classes.
2. Click Federated, and then click Create.
   
   The Create Federation page opens.

3. Enter the details of the class you want to create:

    Steps (4)

   1. In the Namespace list, select the namespace to which you want the new class to belong.

   2. In the Name field, enter the name of the new class.
      If your organization follows any naming conventions when extending the data model, apply those conventions to this class. You can optionally enter the author name and description in the respective fields.

   3. From the Select Plug-in list, select the plug-in that you want to use to connect to the federated data.
      For example, the Calbro Services administrator would select the banking server plug-in. 
      For more information about federated data plug-ins, see Creating AR or JDBC federated data plug-ins to access data external to the CMDB.

   4. You must specify the data that you want to retrieve through the federated class:

      • (For AR plug-ins) From the Select Form list, select the AR form that you want to access.

      • (For JDBC plug-ins) From the Select Table list, select the table that you want to access.

   5. From the Form Fields list, add the fields that you want available in the new class.

   6. From the Key Attribute list, select a field as the key identifier for the new class.
      You can only select fields that have the Data Type as CHAR in the Key Attribute list. You cannot add fields of non-character data types such as ENUM as a key attribute for a federated class. For example, the Status attribute is of ENUM data type and you cannot add it as a key attribute.

4. In the Relationship section, select the relationship 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. You can define multiple relationships to a single class.

    Steps (6)

   1. In the Namespace list, select the namespace to which you want the new relationship class to belong.
   2. In the Class Name field, enter the name of the new class.
      If your organization follows any naming conventions when extending the data model, apply those conventions to this class. You can optionally enter the author name and description in the respective fields.
   3. (Optional) In the Author field, enter a name according to the convention in your organization.
   4. (Optional) In the Description field, enter a description that would help understand the purpose of the class.
   5. In the Qualification field, click the Launch Expression Builder button and define a qualification.
      The qualification must help you associate a CI with the federated data related to that CI. For example, if you want to search for a Printer with an Account ID 111, enter the qualification $PRINTERID$ = 'AccountID'. This qualification relates a specific printer CI to a federated data from the database with a matching attribute.
   6. Click Add/Edit Class Permissions, to provide permissions to various groups and roles.
      

Example of a federated data class definition

The following example values are for a Calbro Services administrator who wants to create a new federated data class for computer system information stored on a Microsoft SQL Server database.

Where to go from here

• In the Explorer, you can view the CIs and the retrieved federated data.
• You can view and verify the class properties in the Class Manager.
  For information about the Class Manager, see Class Manager interface to view CDM and extensions.
• You can also view the federated information through Impact Simulator. 
  For more information about simulating impact, see Simulating the impact of changes to CIs.