Novell EDIRECTORY 8.8 SP3, Administration Manual, Page: 58 / 634

58 Novell eDirectory 8.8 Administration Guide
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Subordinate Reference Replica
Subordinate reference replicas are system-generated replicas that don’t contain all the object data of
a master or a read/write replica. Subordinate reference replicas, therefore, don’t provide fault
tolerance. They are internal pointers that are generated to contain enough information for eDirectory
to resolve object names across partition boundaries.
You can’t delete a subordinate reference replica; eDirectory deletes it automatically when it is not
needed. Subordinate reference replicas are created only on servers that hold a replica of a parent
partition but no replicas of its child partitions.
If a replica of the child partition is copied to a server holding the replica of the parent, the
subordinate reference replica is automatically deleted.
1.6.2 Filtered Replicas
Filtered replicas contain a filtered set of objects or object classes along with a filtered set of
attributes and values for those objects. For example, you might want to create a set of filtered
replicas on a single server that contains only User objects from various partitions in the eDirectory
tree. In addition to this, you can choose to include only a subset of the User objects’ data (for
example, Given Name, Surname, and Telephone Number).
A filtered replica can construct a view of eDirectory data onto a single server. To do this, filtered
replicas let you create a scope and a filter. This results in an eDirectory server that can house a well-
defined data set from many partitions in the tree.
The descriptions of the server’s scope and data filters are stored in eDirectory and can be managed
through the Server object in iManager.
A server hosting one of more filtered replicas has only a single replication filter. Therefore, all
filtered replicas on the server contain the same subset of information from their respective partitions.
The master partition replica of a filtered replica must be hosted on an eDirectory server running
eDirectory 8.5 or later.
Filtered replicas can
Š
Reduce synchronization traffic to the server by reducing the amount of data that must be
replicated from other servers.
Š Reduce the number of events that must be filtered by Novell Identity Manager.
For more information on Novell Nsure Identity Manager, see the
Novell Identity Manager 3.0.1
Administration Guide (http://www.novell.com/documentation/idm/index.html)
Š
Reduce the size of the directory database.
Each replica adds to the size of the database. By creating a filtered replica that contains only
specific classes (instead of creating a full replica), you can reduce the size of your local
database.
For example, if your tree contains 10,000 objects but only a small percentage of those objects
are Users, you could create a filtered replica containing only the User objects instead of a full
replica containing all 10,000 objects.
Other than the ability to filter data stored in a local database, the filtered replica is like a normal
eDirectory replica and it can be changed back to a full replica at any time.