Replication OverviewChapter 8 Managing Replication 277• In the case of cascading replication, the hub supplier holds a read-only replicathat it supplies to consumers. For more information, refer to “CascadingReplication,” on page 283.• In the case of multi-master replication, both masters are suppliers andconsumers for the same read-write replica. For more information, refer to“Multi-Master Replication,” on page 281.In Directory Server, replication is always initiated by the supplier server, never bythe consumer. This operation is called supplier-initiated replication. It allows youto configure a supplier server to push data to one or more consumer servers.Earlier versions of the Directory Server allowed consumer-initiated replicationwhere you could configure consumer servers to pull data from a supplier server.Change LogEvery supplier server maintains a change log. A change log is a record thatdescribes the modifications that have occurred on a replica. The supplier serverthen replays these modifications to the replicas stored on consumer servers, or toother suppliers in the case of multi-master replication.When an entry is modified, a change record describing the LDAP operation thatwas performed is recorded in the change log.In Directory Server, the format of the change log has changed. It is now onlyintended for internal use by the server. If you have applications that need to readthe change log, you need to use the Retro Change Log Plug-in for backwardcompatibility. For more information, refer to “Using the Retro Change LogPlug-In,” on page 320.Unit of ReplicationIn Directory Server, the smallest unit of replication is a database. This means thatyou can replicate an entire database, but not a subtree within a database. Therefore,when you create your directory tree, you must take your replication plans intoconsideration. For more information on how to set up your directory tree, refer toNetscape Directory Server Deployment Guide.
