SOA Ecosystem–Interconnected Principles, Patterns, and Frameworks - Applied SOA Patterns on the Oracle Platform - page 45

<wsdl:input message="tns:TerminateSequence"
wsam:Action="http://docs.oasis-open.org/ws-rx/wsrm/200702/
TerminateSequence"/>
<wsdl:output message="tns:TerminateSequenceResponse"
wsam:Action="http://docs.oasis-open.org/ws-rx/wsrm/200702/
TerminateSequenceResponse"/>
</wsdl:operation>
</wsdl:portType>

</wsdl:definitions>

Policy and metadata

The service metadata describes what is needed for the service consumers, including com-
position controllers to establish successful interchange sessions with service provider(s).
Some of the WS specifications are described in the following sections.

WS-MetadataExchange

Almost all elements of WSDL can be perceived as metadata: XSD structures, and also
as message data types, policies, provider's capabilities, requirements for transaction con-
trol, or reliable messaging. The details of WS-MetadataExchange are as shown in the fol-
lowing table:

Authority Primarily addresses Latest release

W3C Discoverability, Composability, Loose Coupling http://www.w3.org/TR/ws-metadata-exchange/

These metadata elements can be pushed or pulled as a whole or partially from the service
provider's contract. In general, these standards describe the way of encapsulating this data
and the extraction protocols. Some elements responsible for pulling or pushing data and
its encapsulation are presented in the following table:

Element Description

A requester may send a GetMetadata request message to an endpoint to retrieve the metadata associated
with that endpoint. This operation may be supported by the WS-MetadataExchange compliant service
endpoints.

mex:GetMetadata