HP-UX Directory Server 8.1 administrator guide

8.2 Replication scenarios
This section describes the most commonly used replication scenarios:
• “Single-master replication”
• “Multi-master replication”
• “Cascading replication”
These basic strategies can be combined in a variety of ways to create the best replication
environment.
NOTE:
Whatever replication scenario is implemented, consider schema replication. To avoid conflict
resolution loops, the Referential Integrity Plug-in should only be enabled on one supplier replica
in a multi-master replication environment. The plug-in is off by default.
8.2.1 Single-master replication
In the simplest replication scenario, the master copy of directory data is held in a single read-write
replica on one server called the supplier server. The supplier server also maintains changelog
for this replica. On another server, called the consumer server, there can be multiple read-only
replicas. Such scenarios are called single-master configurations. Figure 8-1 “Single-master
replication” shows an example of single-master replication.
Figure 8-1 Single-master replication
In this particular configuration, the ou=people,dc=example,dc=com suffix receives a large
number of search requests. Therefore, to distribute the load, this tree, which is mastered on Server
A, is replicated to two read-only replicas located on Server B and Server C.
322 Managing replication