It looks like the event processing blogosphere is about to be energized with a lively discussion. Opher has opined that SOA is not inherently request-reply. Pen to paper! Let the lively debates begin!
Kindly turn your attention to IBM’s discussion of SOA and their figure below.
The IBM figure was derived from the original W3.org view of SOA, Register-Find-Bind, found here in a figure titled “SOA”.
Kindly notice that Bind, as defined by W3.org, and also represented by IBM in a similar way, has a two-way arrow. This is a request-reply architecture where the client binds to the server.
In addition, IBM (from the link referenced above) also defines these properties of an SOA:
|Loosely coupled interactions||Services are invoked independently of their technology and location|
|One-to-one communications||One specific service is invoked by one consumer at a time. The communications are bidirectional|
|Consumer-based trigger||The flow of control is initiated by the client (the service consumer)|
|Synchronous||Replies are sent back to the consumer in a synchronous way|