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