A service-oriented architecture (SOA) allows you to govern
your processes and services in a secure and efficient way. This section
covers the concept of governance in an SOA, and how the ESB enables
this concept.
Introduction
In the business world any key
asset needs to be carefully managed in order to get the maximum business
benefit. In other words, key assets need governance.
The life
cycle of a service in an SOA requires governance processes. Governance
processes ensure that standards and policies are enforced, and that
change occurs in a controlled fashion and with the appropriate authority.
Governance
covers the following areas:
- Aligning business goals with information technology goals
- Managing resources
- Managing risk
- Managing performance
- Reducing costs
WebSphere® Service
Registry and Repository (WSRR)
The scope of governance in
an SOA environment extends beyond any single product. However, WSRR
is a powerful enabler for SOA governance, and provides a number of
mechanisms that you can use to implement the governance processes
that have been specified by your business design.
WSRR can be
used with the ESB, and provides the following governance capabilities:
- Business governance. Business governance ensures that your business
processes are legal, auditable, and correctly mapped to information
technology services. Business governance can include the following
features:
- Policy enforcement and change auditing, using a simple policy
life cycle, and status metadata, in the registry.
- Security to control who can change policies and who can register
service providers. WSRR gives you security-based and role-based access
control, to metadata managed in the registry.
- Information technology governance. Information technology governance
ensures that updated systems perform as intended, and that no other
systems are impacted. Information technology can include the following
feature:
- Life cycle management allows you to categorize services as being
in different states. For example, model, assemble, deploy, and manage.
Life cycle status is held in the registry. You can use the life cycle
status to filter the visibility of services, according to usage and
context. You can define a life cycle that includes the categories
required by your organization.
Using WSRR with the ESB
In order for the
run time to make use of an existing WSRR registry, you need to take
the following steps:
- Create and configure an SCA module that uses the registry.
The
integration developer creates a mediation flow that contains an Endpoint
Lookup mediation primitive or a Policy Resolution mediation primitive,
and exports the module in an enterprise archive (EAR) file.
Note: The
governance state is specified on the Classification property
of the mediation primitives.
- Add the appropriate service endpoints, or mediation policies,
to the registry.
The WSRR administrator loads documents (for example,
WSDL or SCA module documents) for the services and policies you want
to use.
- Make the appropriate WSRR objects governed.
After the WSRR
administrator has made an object governed, the object can be moved
from one life cycle state to another. This means that you can store
both production level and test level objects in one registry, or store
production level versions in the same registry.
- Optional: Configure the WSRR entities.
The WSRR
administrator might need to take other actions, depending on what
the integration developer has created. For example, on the Endpoint
Lookup primitive there might be user-defined properties; these properties
let mediation flows retrieve service endpoints that meet specific
conditions. In this case, the WSRR administrator would need to create
custom properties with a key and a value.
- Create and configure a registry definition in the runtime environment.
The
runtime administrator creates a WSRR definition so that the run time
knows which instance of WSRR to access. If you are using a secured
WSRR, the runtime administrator needs to specify an authentication
alias.
- Deploy the SCA module.
The runtime administrator installs the
EAR file containing the mediation flow.