Each Directory Server has an embedded replication server that is responsible
for transmitting updates to other replication servers. Each replicating base distinguished
name (DN), such as cn=schema, dc=example,dc=com, has a separate component
called a replica. Each replica connects to the embedded replication server running within
the Directory Server Java virtual machine (JVM) process.
When a client application updates an entry on the Directory Server, the
replica sends an update message to its embedded replication server. The replication server
applies the change to the replicationChangelog backend repository and then
sends an update message to the connected replication server on another directory server. The replication server on other directory servers then passes the change to the
appropriate replica, which in turn applies the change to its backend after performing
conflict resolution.
The following figure shows the standard setup.