HP-UX Directory Server 8.1 deployment guide

Figure 6-4 “Multi-master replication configuration B (four suppliers)” illustrates a topology
where each supplier server feeds data to two other supplier servers (which also function as
consumers). Only eight replication agreements exist between the four supplier servers, compared
to the twelve agreements shown for the topology in Figure 6-3 “Multi-master replication
configuration A (four suppliers)”. This topology is beneficial where the possibility of two or
more servers failing at the same time is negligible. Because each supplier only supplies two other
servers, such a configuration is useful in reducing the network traffic and reducing server load.
Figure 6-4 Multi-master replication configuration B (four suppliers)
NOTE:
HP-UX Directory Server supports a maximum of four supplier servers in any replication
environment. However, the number of consumer servers that hold the read-only replicas is
unlimited.
The following diagram illustrates the replication traffic in an environment with two suppliers
(read-write replicas in the illustration), and two consumers (read-only replicas in the illustration).
This figure shows that the consumers can be updated by both suppliers. The supplier servers
ensure that the changes do not collide.
78 Designing the replication process