Hi; I agree that exact matching on cpu and os isn't the most important issue. What IS important is being able to say "all the same": this is really important for various kinds of MPI applications. I suspect you'll see more specification of binary executable as time goes on. As people purchase multiple clusters with somewhat different hardware and as they add new hardware to existing clusters they end up with heterogeneous environments where the exact choice of hardware really does matter. For example, running numerical libraries that have been optimized for Intel or AMD on the opposite chip type can yield substantial performance penalties. Marvin. -----Original Message----- From: owner-ogsa-bes-wg@ggf.org [mailto:owner-ogsa-bes-wg@ggf.org] On Behalf Of Donal K. Fellows Sent: Wednesday, June 07, 2006 1:24 AM To: Peter Lane Cc: ogsa-bes-wg@ggf.org; Ed Lassettre Subject: Re: [ogsa-bes-wg] Questions and potential changes to BES, as seen from HPC Profile point-of-view Peter Lane wrote:
Right, I meant something a little different when I mentioned JSDL. JSDL doesn't allow for describing complex requirements. For example, one might need a complex set of resources to run a distributed application on a cluster. The best JSDL can do, IIRC, is to allocate N homogenous
resources. There's no way you can say, for example, "give me two IA64
machines, two x86_64 machines, and two i386 machines". This is a very
real requirement by users of GRAM.
Hmm, that's not something I've ever seen in our job flows. On the other hand, we've found that our users aren't interested in specifying what sort of processor they use at all. They focus on the application instead and if that's part of the set described as supported by the container (ignoring questions of how this is discovered for the moment) then it hardly matters what the underlying CPU or OS is. (OK, both of those can certainly make a difference to the relevant performance metrics, but we'd rather state that we support a certain level of performance instead of providing some information that people can use to try to infer what they're really interested in.) The only real use for matching on CPU and OS is if you're staging in the binary executable to run as part of the job. Physicists seem to like to do that; seems to be a peculiarity of that community. We don't see the same thing to anything like as great an extent among other scientists and engineers (and we have very little CS in our usage profile, though if we did I'd expect them to be similar to the physicists). On the other hand, the physicists seem to prefer to buy their own clusters too. Oh, you're supporting physicists? :-) Donal.