RE: [wsbpel] Assumptions about WSDL 1.1 MEPs

This was discussed in Issue 118 and Issue 122, and resolved in Issue 122.

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.com
101 E. Huntington Ave.      voice: (626) 256-3680
Monrovia, CA. 91016           fax : (626) 256-6884

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