RE: [wsbpel] Removing "compensating a process as a whole"

["Satish Thatte" <satisht@microsoft.com>]

The problem for BPEL is that it either goes into monolithic "I specify
everything" mode which we have all seen fail in the past, or it sticks
to its factored role and takes dependencies on things like WSDL,
admittedly moving targets, that will define the aspects it leaves
unspecified.  If we make interoperability dependent on platform-level
deployment modes I would argue that we have failed to maintain the loose
coupling implicit in the web services architecture.

As for interop with WS-TX, specifically with the BA protocol(s), my
personal opinion is that this is something we should look at very
closely and do whatever is needed to make it happen.

Satish

-----Original Message-----
From: Assaf Arkin [mailto:arkin@intalio.com] 
Sent: Friday, June 20, 2003 9:59 AM
To: Satish Thatte
Cc: Yuzo Fujishima; wsbpel@lists.oasis-open.org
Subject: Re: [wsbpel] Removing "compensating a process as a whole"

Is it fair to assume that the specification is intended to foster 
interoperability between systems? Can we do that and still leave a lot 
of things unspecified?

Satish Thatte wrote:

>Consider also the BA protocol in WS-Transaction which shows how the
compensation of a subordinate instance would be invoked by a controlling
instance, if we were to specify such a subordinate-controller
relationship in BPEL, effectively "remoting" a scope as a separate
instance (without implicit state sharing).  The BA protocol messages
could be handled by implicit event handlers that maintain the BA
protocol semantics.
>  
>
>I am not saying yet that we should actually do this, just throwing out
some interesting possibilities to think about.
>  
>
It's a very interesting possibility. At least I'm interested in that 
possibility ;-)

The current spec seems to suggest in one place that it could be done 
(the appendix), and it seems to suggest in another place that it is 
permitted (implementation specific manner). Yet it does not define how 
it would be done in an interoperable fashion, leaving open the question 
of how would you go about using WS-TX, if you so choose to, and use it 
in an interoperable manner. Again, while most of the grunt work should 
be left up to the WS-TX spec, there's a few requirements placed on BPEL 
to actually clarify how things should be done.

So right now BPEL is in a limbo state where as an interoperable 
specification it does not allow you to use WS-TX (I can point out to 
specific issues, if you are interested), the only way to go about doing 
it is with something similar to the pattern described by Yuzo.

Is there any intent for BPEL to provide an interoperable way to use 
WS-TX (or similar protocol) to invoke compensation of a process as per 
its abstract definition?

arkin

> 
>
>Satish
>  
>