I am wondering if the current BPEL draft is
making an incorrect assumption about WSDL 1.1 MEPs. The assumption that
the spec seems to make is that a WSDL operation with
Request/Response MEP will necessarily have the request and response in the
same network connection, regardless of the binding. My questions
are:
1. Is the spec making this assumption? (I think
it is.)
2. Is this assumption correct? (I think it is
not.)
My reading this assumption in to the spec comes
largely from Section 6.5. The current draft contains the following
paragraph, where I interpret "synchronous" to mean "in the same network
connection":
The example makes the implicit assumption
that the customer request can be processed in a reasonable amount of time,
justifying the requirement that the invoker wait for a synchronous response
(because this service is offered as a request-response operation). When that
assumption does not hold, the interaction with the customer is better
modeled as a pair of asynchronous message exchanges. In that case, the
"sendPurchaseOrder" operation is a one-way operation and the asynchronous
response is sent by invoking a second one-way operation on a customer
"callback" interface. In addition to changing the signature of
"sendPurchaseOrder" and defining a new portType to represent the customer
callback interface, two modifications need to be made in the preceding
example to support an asynchronous response to the customer. First, the
partner link type "purchasingLT" that represents the process-customer
connection needs to include a second role ("customer") listing the customer
callback portType. Second, the <reply> activity in the process needs
to be replaced by an <invoke> on the customer callback
operation.
I don't think you can correctly infer whether
or not a request/response pair will be on a single network connection based
solely on an abstract WSDL. If I'm either
misreading the spec or misunderstanding WSDL, could someone clarify this for me? If not, I'll submit this as an
issue to be resolved. Thanks.
Jim Clune
Parasoft
Corporation email:
jim.clune@parasoft.com101 E.
Huntington Ave. voice: (626)
256-3680
Monrovia, CA.
91016 fax
: (626) 256-6884