The sun sets later and later, the temperatures are getting warmer, and the plants in the yard are starting to grow. Rapidly. (We’re already losing control of the yard, which has me worried. Don’t get me started — this is supposed to be about particle physics.) But most importantly, we are almost done with the school year. This is finals week here, and I give my final on Friday. I’ve been teaching the graduate-level particle physics course this term, and while I have enjoyed it (and learned and re-learned a lot), it’s also been a lot of work. But by early next week, I will be done with my teaching duties until August, which means that I’ll only be holding down one job instead of two. At long last, more time to focus on particle physics! There are a lot of things I want to be working on this summer — we’re trying to get new equipment running in our silicon-pixel lab, and we need to be getting our act together on how exactly we are going to look at the LHC data when they arrive this summer. But my concern at the moment needs to be the big computing exercise that we’re running in May, the Combined Computing Readiness Challenge. I suppose that I’ll write about CMS’s distributed computing system in pieces over many postings (if nothing else so you don’t have to read it all in one go), but let’s say at the outset that the CMS data processing is going to be taking place at computing centers spread around the world. Making that function is going to take a lot of technical work and also a lot of operational focus. Many of the computing sites serve more than one LHC experiment. Thus, not only do we want to exercise the CMS computing system at full scale in advance of LHC startup, we want to exercise the systems of the three other experiments at the same time — the “combined” in the name of the challenge. Since I look after the Tier-2 sites in US CMS (and to some extent CMS as a whole), I’m focused on what those sites have to do in the challenge. We have to transfer datasets from Tier-1 sites, and show that we can host jobs that are submitted to run on these datasets. Right now we’re trying to push a few datasets through the network to the sites in preparation for job submission this week. The results have been so-so so far; with the May Day holiday in Europe, some Tier-1 sites are not fully up and running (grumble grumble). But I’m hoping that we can get that fixed up early in the week, and push forward. I’ll let you know how it’s going in my next post.
