I am still struggling to understand the relationships between WS-
BusinessActivity, WS-AtomicTransaction and BPEL.

BPEL has a concept of compensation handlers. From what I understand,
if the parent activity of the compensation handler is invoked, the
state of the process is saved at that point. If the compensation
handler is triggered, that saved state is made available to the
compensation handler which can then use it to effect
the 'compensation'.

With multiple BPEL processes interacting in a B2B collaboration, you
would want the right compensation handlers to be triggered more or
less simultaneously. The idea is that you want state changes across
business partners to be synchronized (all-or-nothing).

WS-BA/WS-AT provide the protocols to synchronized state changes. How
exactly are these hooked to BPEL is still unclear (to me).


Faisal
http://objectpeddler.blogspot.com/