OpenEdge Getting Started: Installation and Configuration - Product ...

Appendix E: NameServer and NameServer Load Balancing Details
Note that while NameServer neighbors provide the most benefit when using UDP
broadcast, there is no requirement to do so. The hostName properties for NS2 and NS3
in Figure 11 can explicitly specify 172.20.7.4 and 172.22.7.4. You might want to use
NameServer neighbors without broadcasting when you must tie together preconfigured
NameServers, but where the performance implications of broadcasting outweigh the
benefits. For more information, see the “Performance implications of broadcasting”
section on page 500.
Performance implications of broadcasting
When you use UDP to send a specific host request, only the specified host examines
the message to determine what port it was sent to and whether an application (like the
NameServer) is running and listening to that port on the host. However, when you use
UDP broadcasting, either for NameServer replication or to provide location
transparency for a single NameServer, every host in the specified subnet examines the
message for this same information.
Thus, using UDP broadcast might have a significant impact on the performance of your
network if you have a large number of client applications that frequently connect to
Unified Brokers. In deciding whether to use UDP broadcasting, you must weigh the
benefits of location transparency for a single NameServer or replication of multiple
NameServers against the impact on your Unified Broker and network performance.
500 OpenEdge Getting Started: Installation and Configuration