Wednesday's session, a placeholder

Wednesday's AM sessions were on the PGRADE system, and then we talked about the semantic web.

PGRADE is a Hungarian based project that is similar to UNICORE. What PGRADE does is it helps to provide a more graphically oriented approach to monitoring an application on the grid. It also collects trace information as the programs run to help tweak future runs, and to understand what the project is doing on the grid at the time. The system also allows the user to access some pre-formed templates to assist in writing more coherent code, and code that should perform better in a parallel environment.

PGRADE is not a meta-scheduler or a resource handler, instead, it works "on top of" Globus or Condor, for example. It uses the same mechanisms for job submission and reconciliation as any of the command-line-only apps would use; PGRADE helps the user to use those utilities. In an environment where grid specialists can't help develop every application, this is a really handy utility, and the only room I can suggest for improvement is a standard reporting mechanism built into the Globus or Condor models (again, for instance) that would allow program tracing to be more effective. This is not a light endeavour - especially given as how neither the standard Linux nor Windows kernels offer such tracing by default - so I would have to say it appears they are doing the best they can to offer tracing.

As for the semantic web and it's relation to Grid. As a computer professional, I tend to get all choked up when people talk about "the semantic web" because it seems so self-pretentious. I just thought I might toss that out there, to kind of catch the attention of my readers. (And since some of the presenters and attendees felt the same way)

However, in this regard, I would have to say that I firmly believe that the OGSA ontological semantic model is doing exactly what semantic web was designed/intended to do. I'm not going to go into a huge number of specifics on what OGSA nor the semantic web are, because both are easily googlable. Instead I just wanted to mention that they were the topics of discussion.

I will say now that the concept of semantic data is best summed up as this: All data in modern systems is inherently binary, and as such, a binary blob has no distinct characteristics. Sure, a certain binary blob may correspond to ASCII text, and we may be able to read it, but the fact that it's ASCII does us no good, until we can associate, for instance, an author, or even a title for the file. That may sound too simple to the casual reader, but that's exactly what we're talking about. The trick is how does one go about attaching the metadata to the file? That's what the OGSA semantic ontological model is all about, giving us a defined format and model.

Further details are best left up to specific questions, in my mind, but perhaps that's because I also feel comfortable answering the question "what's the difference between a database and a filesystem". - Cheers!