[ogsa-wg] RE: Modeling State for BES

[Fred Maciel]

Hi all,

> But that's not the topic of the recent thread.

So I'm changing the subject... :-)

> > What WS-RF and WS-Transfer and REST are doing is require that each
> > message be directed to only one resource. As a result, when it comes to
> > defining groups of resources, additional resources (representing
> > collections) have to be created. Populating and managing the collections
> > require additional messages.
>
> I think your email misses the point of the current discussion.
>
> Of course, as you point out, if I have a handle of some sort for a job (a
WS-Addressing EPR, as in WSRF/WS-Transfer, or a job-id, as you advocate
below), then I can include several of these in a request to the job factory
asking for some operation to be performed on them all. I don't believe that
anyone's debating that.

I think that a *part* of this discussion can be summarized as "what is the
level of abstraction of the interfaces you use"? Which between a low-level
resource-oriented (probably per-resource) interface and a high-level
abstract interface is the best one? My answer so far is "both". You want to
deal both with resources ("deploy this OS on this specific host"), and to
have a high-level interface ("start me these zillion jobs, wherever and
whenever suitable"). Operations in the high-level interface will generate
operations in the low-level interfaces (when you start a job with the
high-level one, you might deploy the OS beforehand). The high-level
interface might show some of the operations of the low-level interface
("what is the state of this specific job?").

Which takes me to the execution management in OGSA. We are now doing the
container, which for me seems to be a resource with low-level interfaces
(not as low as the bare metal though). But I think the container's
interfaces, while needed, are not the high-level interfaces yet, and these
too are needed.

Do you have any wisdom (*) on this issue, for OGSA as a whole? BTW, the
issue above applies to other OGSA capabilities also.

By the way, I'm not including angle brackets, SOAP and WSA issues on the
above. What will be put in resource properties is affected, but I'm not
going down to these details yet.

Regards,

Fred Maciel.

(*) No conscious reference to WSDM intended, only subconscious and
subliminal ones :-).