2.7.5 Directory Replication
The use cases in this category represent replication of directory data that is maintained by the Active Directory system. Domain and forest data have to be replicated among disparate physical storage devices to maintain the integrity of the abstract logical structure of the directory. Replication can happen at various levels within a directory and under varying circumstances. Consider the following examples:
If copies of domain data, or replicas, exist on multiple servers within the domain, that is, if there are multiple domain controllers (DCs) within the domain, new objects and modifications to existing objects are replicated to all of the domain's DCs by using normal replication cycles.
A forest typically consists of multiple domains, each of which is maintained by one or more domain controllers. Some of the data that is stored in the directory is considered to be forest-wide data, which is replicated to all of the domain controllers in the forest.
Some of the values that are stored in the directory, such as user password and account status, are of such a nature that propagation of changes in these values is time-critical. Replication of these values has to happen outside of normal replication cycles to allow for rapid propagation of the changes throughout the directory.
The following use case diagram shows the use cases of directory replication that are described in this document.
Figure 31: Use cases for directory replication