Databases Reference
In-Depth Information
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Universality
: All components can be approached from a service perspective.
For example, a business process may also be considered a service that,
despite its complexity, provides inputs and outputs.
Thinking of everything as a service leads us to another key benefit of service-oriented
architecture, namely
composability
, which is the ability to compose a service out of
other services.
Composing new services out of existing services allows
easy reasoning about the availability and performance
characteristics of the composite service.
By building composite services out of existing services, we can reduce the amount
of effort required to provide new functionality as well as being able to build
something with prior knowledge of its availability and scalability characteristics.
The latter can be derived from the availability and performance characteristics of
the component services.
Architecture
Architecture implies a consistent and coherent design approach. This implies a need
to understand the inter-relationships between components in the design and ensure
consistency in approach. Architecture suggests that we adopt some of the
following principles:
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Consistency
: The same challenges should be addressed in a uniform way.
For example, the application of security constraints needs to be enforced in
the same way across the design. Patterns or proven design approaches can
assist with maintaining consistency of design.
Reliability
: The structures created must be fit to purpose and meet the
demands for which they are designed.
Extensibility
: A design must provide a framework that can be expanded in
ways both foreseen and unforeseen. See the break-out-box on extensions.
Scalability
: The implementation must be capable of being scaled to
accommodate increasing load by adding hardware to the solution.
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