[cddlm] Comment on BPEL option

[Takashi Kojo]

> Vanish: What about BPEL
>
> Stuart: BPEL is a very rich syntax. (Steve: it was made for humans;
> Stuart: it was also done for automation). BPEL has much more that is not
> needed.
>
> Vanish: BPEL already provides many things in case 2, especially if you
> want conditionals, parallel, sequence, etc.
>
> Stuart: I can do an implementation in BPEL and check on Monday. I
> already have a lot of infrastructure

We have experience with BPEL in our project, too. I would compare
BPEL with Java in the sense that BPEL is procedural description in XML
for composing Web Services, while Java is procedural description
(in Java syntax of cause) composing objects. BPEL procedure context
is persistent, while Java context is transient.

In Stuart's scenario of 3 or 5 in which the policy implementation is 
detached
from CDL or platform, policy objects can be implemented either in Java
or BPEL. Assuming appropriate API between platform, I think, both can be
compatible alternatives. There should be no difference with the CDL syntax,
other than body or attribute of PolicyCodeBase.

Becuase BPEL context it parsistent, policy object with BPEL has advantage
when it has long life of policy execution and expected to be persistent
after the fault, while Java is suited in many cases with smaller and lighter
policy execution.


> In a summary, Stuart did a great job with the design options.

Indeed!


Kojo