HP-UX Directory Server 8.1 deployment guide

Figure 9-12 Server topology for Example Corp. International's extranet
The hub servers replicate data to two consumer servers in each of the data centers in Europe,
the US and Asia.
9.2.5 Multinational enterprise replication design
Example Corp. considers the following points when designing replication for its directory:
• Data will be managed locally.
• The quality of network connections varies from site to site.
• Database links will be used to connect data on remote servers.
• Hub servers that contain read-only copies of the data will be used to replicate data to
consumer servers.
The hub servers are located near important directory-enabled applications such as a mail server
or a web server.
Hub servers remove the burden of replication from the supplier servers, so the supplier servers
can focus on write operations. In the future, as Example Corp. expands and needs to add more
consumer servers, the additional consumers do not affect the performance of the supplier servers.
For more information on hub servers, see “Cascading replication”.
9.2.5.1 Supplier architecture
For the Example Corp. intranet, each locality stores the master copy of its data and uses database
links to chain to the data of other localities. For the master copy of its data, each locality uses a
multi-master replication architecture.
The following diagram illustrates the supplier architecture for Europe, which includes the
dc=example, dc=com and dc=com information:
9.2 Design example: A multinational enterprise and its extranet 137