HP-UX Directory Server 8.1 administrator guide

Figure 8-3 Multi-master replication (four masters)
Multi-master configurations have the following advantages:
• Automatic write failover when one supplier is inaccessible.
• Updates are made on a local supplier in a geographically distributed environment.
NOTE:
The speed that replication proceeds depends on the speed of the network. Plan changes and
directory configuration accordingly, and realize that changes to one directory may not be quickly
replicated to other directories over slow links, such as wide-area networks, in geographically
distributed environments.
For the procedure to set up multi-master replication, see “Configuring multi-master replication”.
8.2.3 Cascading replication
In a cascading replication scenario, one server, a hub, acts both as a consumer and a supplier. It
holds a read-only replica and maintains a changelog, so it receives updates from the supplier
server that holds the master copy of the data and, in turn, supplies those updates to the consumer.
Cascading replication is very useful for balancing heavy traffic loads or to keep master servers
based locally in geographically-distributed environments.
Figure 8-4 “Cascading replication” shows an example of a simple cascading replication scenario,
though it is possible to create more complex scenarios with several hub servers.
324 Managing replication