[ogsa-wg] Re: [ogsa-rss-wg] Re:[RSS Architecture Discussion]

[Soonwook Hwang]

I was wondering whether you meant "divided single apps" by "parameter 
sweep types of apps." If that is the case, I don't think that it's less 
common than "multiple coupled apps," and that it's a rare application.
I think that it's in fact the kind of applications that will perhaps benefit

most from exploiting the Grid with the current limitations in
network bandwidth and latercy between WAN interconnections.
As we see in case of Condor, Nimrod and other systems. 
there are many existing systems aiming at tackling "parameter sweep apps."
In addition, we might be able to consider a collection of single job
submitted from different job managers to EPS/CSG to be a kind (?) of
parameter sweep apps that EPS/CSG needs to make mapping plans. In brief,

the point I am trying to make here is that when it comes to the design of 
EPS/CSG interface and protocol, having the matching/scheduling of parameter 
sweep type of apps (i.e., a set of independent tasks of job type) in mind 
is important as well. 

Soonwook
-----Original Message-----
From: owner-ogsa-rss-wg at ggf.org [mailto:owner-ogsa-rss-wg at ggf.org] On Behalf
Of Donal K. Fellows
Sent: Wednesday, December 14, 2005 8:57 PM
To: Karl Czajkowski
Cc: ogsa-wg at ggf.org; ogsa-rss-wg at ggf.org
Subject: Re: [ogsa-wg] Re: [ogsa-rss-wg] Re:[RSS Architecture Discussion]

Karl Czajkowski wrote:
> However, I think you would quickly want a more rich resource language
> extension---beyond JSDL v1---where you could describe network
> connectivity requirements (possibly hierarchically) and heterogeneous
> resource requirements.  For example, describing a job where you need a
> certain number of "large memory" nodes with a good interconnect, a
> certain number of "fast CPU" nodes with a separate good interconnect,
> and a less stringent WAN connection between the two node sets for some
> coupled numerical code.  This is definitely beyond the scope of the
> JSDL v1 resource language, though a nice extended language could
> encapsulate multiple v1 resource clauses, one for each homogeneous
> node set...

That's the sort of situation I'd prefer to describe as two (or more)
applications within a workflow with some kind of coupling constraint,
rather than as a single distributed app. In any case, the "multiple
coupled apps" case is probably going to be more common than the "divided
single app" case, simply because it is a rare application that can be
chopped apart that way without horrible performance penalties.

Apart from this clarification, (I think) I agree with the rest of what
you say.

(The OGSA-RSS-WG is not going to tackle Workflow Language problem, but
it must be done. I'm not at all sure that BPEL is the answer, but half
the problem is finding recent versions of the BPEL spec; the only
readable one I've ever seen was obviously not powerful enough and does
not seem to be what people are using these days anyway. But this a topic
for some other group/time.)

Donal.