WebSphere Application Server V7.0: Concepts ... - IBM Redbooks

provided by the Service 2 Producer component has to relate a message it
receives to the corresponding message that was sent by the Service 1
Consumer component.
Technically, this message exchange pattern is the same as the one-way pattern,
with the additional requirement that there has to be a mechanism to associate
response messages with their corresponding request message. This can be
done at the application level or by using SOAP protocol.
Service 1
Consumer
Service 2
Producer
Figure 11-4 Asynchronous two-way message exchange pattern
Request-response
Probably the most common message exchange pattern, a remote procedure call
(RPC) or request-response pattern, involves a request message and a
synchronous response message (Figure 11-5). In this message exchange
pattern, the underlying transport protocol provides an implicit association
between the request message and the response message.
In situations where the message exchange pattern is truly synchronous, such as
when a user is waiting for a response, there is little point in decoupling the
consumer and producer. In this situation, the use of SOAP/HTTP as a transport
provides the highest level of interoperability. In cases where reliability or other
quality of service requirements exist (such as prioritization of requests),
alternative solutions might have to be sought.
Service
Consumer
Figure 11-5 Request-response message exchange pattern
Service 1
Producer
Service
Producer
There are numerous examples of this message exchange pattern, for example,
requesting an account balance on a bank account.
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