Re: Asynchronous service invocation question

[Jim Alateras <ji...@comware.com.au>]

Jiang Liu wrote:
> Hi BPEL experts,
> 
> I do apologize if this is not the place to ask any BPEL general questions. :-)
> 
> I get quite confused about asynchronous service invocations, here are my questions, They might be out of scope for Ode, anyway, i really want to get clear of the whole picture.
> 
> 1), in partner link, any "myRole" is (supposed to) implemented by BPEL with BPEL service's concrete EPR, any "partnerRole" is (supposed to) implemented by external services with service's EPR, am I right?
> 
> 2), say in a BPEL process it makes asynchronous invocation to an external Web service (not another BPEL service, just a simple service). BPEL applies callback role, service for call role respectively. When BPEL invokes service's call, how exactly the service can callback to BPEL? I mean since the callback is defined as "myRole" and must be implemented by BPEL, in service's skeleton, there is no logic for callback operation. When external service finish the long-term function, he will call back to BPEL immediately? or 5 mins later or blah blah? And how does service knows BPEL's EPR? This seems like it has lots of "secrets" behind. :)
> 
> I know call/callback is "packed" from partner links's perspective, also in Ode it requires concrete bindings in configuration file, but for external service's perspective, how actually it works? 
> I think this is even more complex when we have service skeleton and stub generated and functioned seperately.
I am taking a stab here but I suspect that WS-Addressing is used and the 
Reply-To element is set with the EPR that the external service should 
use for the callback.

cheers
</jima>