Overview#NDS Read-Write Replica
eDirectory can access and change object information in a read/write replica as well as the master replica. All changes are then automatically propagated to all replicas.
If eDirectory responds slowly to users because of delays in the network infrastructure (such as slow WAN links or busy routers), you can create a read/write replica closer to the users who need it. You can have as many read/write replicas as you have servers to hold them, although more replicas cause more traffic to keep them synchronized.