Many are comparing notes on two well-publicized paths to achieving SOA. The
bottom-up approach is currently the most common variety, where Web services
are created on an "as need" basis to fulfill mostly integration-related
requirements. These services are typically application specific and simply
re-create traditional integration channels over the open Web services
The top-down approach, on the other hand, is one of analysis, deep thought,
and patience. Service-orientation is infused into the business process layer
so that services can be modeled in alignment with business models. The models
themselves may need to be built or further refined in order to fully
incorporate service-orientation principles.
Then, of course, there's the middle ground - an approach that tries to
balance the requirements of the top-down strategy with the efficiency... (more)
With the unwavering prominence of service-oriented architecture (SOA) there
is an increasing interest in understanding what exactly it means for
something to be considered "service-oriented." Thomas Erl recently completed
a lengthy research project for SOA Systems Inc. into the origins of SOA and
the current state of service-orientation among all primary SOA technology
platforms. This body of work contributed to the mainstream SOA methodology
developed by SOA Systems and was also documented in Thomas's new book,
Service-Oriented Architecture: Concepts, Technology, and Design. We ... (more)
One of the fundamental goals when designing service-oriented solutions is to
attain a reduced degree of coupling between services, thereby increasing the
freedom and flexibility with which services can be individually evolved.
Achieving the right level of coupling "looseness" is most often considered a
design issue that revolves around the service contract and the consumer
programs that form dependencies upon it.
However, for the service architect there are opportunities to establish
intermediate layers of abstraction within the service implementation that
further foster reduced... (more)
Like data normalization, the Service Normalization pattern is intent on
reducing redundancy and waste in order to avoid the governance burden
associated with having to maintain and synchronize similar or duplicate
bodies of service logic."
You can see it introduces the Pattern on our publisher page.
When designing data architectures, you can easily end up with different
databases or even different database tables containing the same or similar
data. This has been the root of many well documented data maintenance and
quality issues that helped establish data normalization as widel... (more)
For a complete list of the co-authors and contributors, see the end of the
The following section demonstrates the creation of a simple "Hello World"
service in a Windows Azure hosted application.
Note: If you are carrying out the upcoming steps with Visual Studio 2008, you
will need to be in an elevated mode (such as Administrator). A convenient way
of determining whether the mode setting is correct is to press the F5 key in
order to enter debug mode. If you receive an error stating "the development
fabric must be run elevated," then you will need to restart Visual Studi... (more)