BPEL and transactions - part 4

And here is part 4 of "BPEL and transactions". This time I write about BPEL and error detection in a transactional enviroment.

BPEL and error detection

To trigger a compensation action, every service has to return a fault in case of error. In case of synchronous services faults are returned by default. With asynchronous services no fault is returned. A "receive element" would wait forerver for the result of the service (endless loop).

Pick element

The pick element contains the two cases "on Message" and "on Alarm". It waits until the called asynchronous process returns a result ("on Message") or the maximum waiting time ("on Alarm") is reached and then executes the corresponding block.