HP Reliable Transaction Router - Manual (Page 42)

Broadcasts
Broadcasts
Sometimes an application has a requirement to send unsolicited
messages to multiple recipients.
An example of such an application is a commodity trading
system, where the clients submit orders and also need to be
informed of the latest price changes.
The RTR broadcast capability meets this requirement.
Recipients subscribe to a class of broadcasts; a sender broadcasts
a message in this class, and all interested recipients receive
the message. However, broadcast reception is not guaranteed;
network or node outages can cause a particular client to fail to
receive a broadcast message.
RTR permits clients to broadcast messages to one or more
servers, or servers to broadcast to one or more clients. If a server
needs to broadcast a message to another server, it must open a
second channel as a client.
Flexibility and Growth
RTR allows you to cope easily with changes in:
• Network demand
• User access patterns
• Volume of data
Because an RTR-based system can be built using multiple
systems at each functional tier, it easily lends itself to step-by-
step growth, avoiding unused capacity at each stage. With your
system still up and running, it is possible to:
• Create and delete concurrent server processes.
• Add or remove nodes (frontend, router or backend).
This means you do not need to provide spare capacity to allow
for growth.
2–4 Architectural Concepts