TCP/IPv6 Configuration and Management Manual (G06.24+)

Maximize the Benefit of the NonStop TCP/IPv6
Architecture
HP NonStop TCP/IPv6 Configuration and Management Manual—524523-008
3-10
Broker Listener Model
allowing reactive distribution. The servers have direct access to the TCP/IP library in
their own processors, eliminating both the remote IPC hops and local IPC hops. All the
distributors share the same port and present a single IP host to the outside world.
Figure 3-6 shows a configuration (simplified for comparison) with two distributors: one
in processor 0 and one in processor 2. The distributors hand off connections to servers
in their own processor and in one remote processor. All connections go through the
same G4SA LIF and the G4SA round-robin distributes connections among the
distributors. A single IP host is presented to the outside world and the inter process
hop between the remote processors (1 and 3) is eliminated as data flows directly to the
local TCP/IP library and then out to the adapter.
A similar configuration example is shown in Configuration Example for the Hybrid
Listening Model on page 3-19.
Broker Listener Model
The broker server model has become common, with the advent of multi-tiered server
architectures, especially within the distributed object paradigm (see Figure 3-7 on
page 3-11). With this approach, the initial connection is from the client to a broker. The
broker participates in a back-end, load-distribution algorithm which can be distributed.
The broker decides which of a family of server objects is the best one to serve the
object request, and the broker responds to the client with the address of the server to
contact. The client then makes a new connection to the server to complete the object
request. In some cases, the respective connections are cached for efficiency.
Figure 3-6. Hybrid Listening Model in NonStop TCP/IPv6
Distributor
Server
Server
Server
Processor 0 Processor 1 Processor 2 Processor 3
Server
Server
Server
Data
flow
Distributor
Server
Server
Server
G4SA
Server
Server
Server
One IP Host
TCP/IPv6
Library
No IPC
hop
VST112.vsd
TCP/IPv6
Library
TCP/IPv6
Library
TCP/IPv6
Library