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>
