Re: [ws-caf] Multiple contexts

[Guy Pardon <guy@atomikos.com>]

Thanks Jim,

Please see my comments below...

On woensdag, mei 26, 2004, at 03:09 Europe/Brussels, Jim Webber wrote:
> > What happens if there are both security and transaction 
> > contexts for the same activity (if this is possible at all)? 
> > Will they appear as two different context headers or will 
> > they be nested within each other? 
>
> Application choice. You know the context can have arbitrary content
> through extensibility.  However I think in the general case transaction
> and security contexts are different and would therefore be separate
> headers.

Since it is the ALS that extends the context, and there is only one ALS per activity, security and transactions would have to have _different_ contexts (probably nested for the reason outlined below?)...

> > The clarification text defines an activity as operations 
> > being executed within a valid context (or something similar) 
> > (fine). A context can only belong to one activity (fine). 
> > But if there can be multiple contexts for one particular 
> > activity, which context is the one that actually _defines_ 
> > the activity (and, consequently, its outcome)? 
>
> I'm afraid I don't understand this. In my mind activity scope matches
> context scope and nesting of contexts, and thus activities, it
> permitted.

What I meant: if there are different top-level contexts for the same activity, then how can they reach the same completion state (Success or fail)?
In other words, is there some rule that says that different CTX services will reach the same completion state if they are for the same activity (and yet not nested in each other)?

I assume that this should be the case, since the activity is defined by means of a context, and therefore the completion state of an activity would correspond to the completion state of some context?
Or have I misunderstood this part? I guess it all depends on how you look at the notion of activity.

The alternative would be to say that there is one top-level context that defines the activity (and its completion state) and there are different nested contexts, such as one for transactions and one for security.
This would imply that a transaction context could be a child of a security context.

I guess that last alternative makes the most sense?

Guy

Dr. Guy Pardon ( guy@atomikos.com )
Atomikos: Your Partner for Reliable eBusiness Coordination
http://www.atomikos.com/

The information in this email is confidential and only meant for the addressee(s). The content of this email is informal and will not be legally binding for Atomikos.