The basic relationship in replication is that of a master
server and its replica server. The master server can contain a directory
or a subtree of a directory. You can use the information and example
provided here to know more about it.
The master is writable, which means it can receive updates from
clients for a given subtree. The replica server contains a copy of
the directory or a copy of part of the directory of the master server.
The replica is read only; it cannot be directly updated by clients.
Instead it refers client requests to the master server, which performs
the updates and then replicates them to the replica server.
A master server can have several replicas. Each replica can contain
a copy of the master's entire directory, or a subtree of the directory.
In the following example Replica 2 contains a copy of the complete
directory of the Master Server, Replica 1 and Replica 3 each contain
a copy of a subtree of the Master Server's directory. Figure 1. Master-replica replication The relationship between two servers can also be described in
terms of roles, either supplier or consumer. In the previous example
the Master Server is a supplier to each of the replicas. Each replica
in turn is a consumer of the Master Server.
