| Article found | Fact |
|---|
|
Secure, Reliable, Transacted Web Services [FS03]
|
- Using WS-Policy, services describe their service assurance capabilities and requirements in the form of a machine-readable policy expression containing combinations of assertions. This allows service to select each other based on "how" or "with what quality" they deliver their contracts.
-
Policy assertions are identified by stable and globally unique names whose meaning is consistent in time and space no matter which service the assertion is applied to. Policy assertions may also have parameters that qualify the exact interpretation of
the assertion.
- WSDL and XSD definitions often do not provide enough information to call a Web service. WSDL and XSD define the service's interface syntax but they do not express information about how the service delivers its interface or what the service expects of the caller. For example, does the service require security or implement transactions?
- enables a service to specify what it expects of callers and how it implements its interface
- WS-Policy is critical to achieve interoperability at the higher-level functional operation of the service. Security, transactions, reliable messaging and other specifications require concrete WS-Policy schema. These allow services to describe the functional assurance that they expect from and provide to callers.
- provides a base model for defining policy expressions
- supports a grammar for aggregating policy statements and allows the construction of more flexible and complete
sets of policy
- WS-PolicyAttachment specifies how to associate a policy set with XML messages and WSDL elements (operations and portTypes).
- Together WS-Policy and WS-PolicyAttachment provide the framework. Individual specifications define their domain specific policy statements and schema.
- WS-PolicyAssertions provides a foundational set of common policy statements that can be used to achieve interoperability.
|
