Java Reference
In-Depth Information
While Oracle/BEA's list may not be the one you choose (you might collapse Data and
Connectivity Services and you might throw out Presentation Services altogether, or add
another layer of your own), the point is that it is useful to conceptualize your services on
this level, and not simply on the level of Entity, Process, or Functional, as these are com-
plementary classifications.
Promote best practices
Promote best practices
The RA can declare that services and clients must be created and consumed following cer-
tain guidelines. Perhaps there are design patterns that you want consistently implemented
in certain situations. Perhaps you want to require a set of acceptable methods for service
creation, messaging, encoding, and so forth.
By declaring guidelines, standards, and conventions, the RA will help to ensure consisten-
cy across the board in service implementation. Architects have an easier task in enforcing
the guidelines when they are spelled out clearly in a living public document. Once every-
one is used to consistently implementing services in a given manner, this will mean quick-
er time to market. Developers can create new assemblies with confidence that the services
they are reusing will fit well together.
The RA should address how to deal with cross-cutting concerns such as security and rules
engines, which are sometimes themselves implemented as services.
Clarify trade-of
Clarify trade-offfs
You cannot do everything. Certain requirements are always at odds with each other. Re-
conciling terrific performance with strong security is a continual struggle.
Enable governance
The governance of your SOA is highly dependent on the creation of an RA. The RA serves
as a constitution of sorts for your SOA Center of Excellence or governance board to fol-
low.
Reference architecture site
Your SOA reference architecture can be a deliverable, a living set of resources that can be used
for a variety of purposes, and not simply some documentation that accompanies your code. As
a deliverable in its own right, it works well when implemented within a website that is easy
to update, such as a wiki. Members of the SOA team or governance board or the architects
involved at your organization can create a site that they populate with architectural models,
standards and conventions documents, and resources for evangelizing and education, and that
can perhaps serve as a gateway to runtime tools.
