This past Monday we had our annual US CMS Tier-2 computing workshop. Once again, we held our workshop as part of the Open Science Grid All-Hands Meeting. Those of you who have been reading the blog for more than a year will remember that last year this meeting was held at the totally neat LIGO facility in Louisiana. This year the meeting was at totally neat…Fermilab! OK, I’ve been to Fermilab before, so no travelogue this time, but as usual it was good to meet so many collaborators face to face.
I don’t want to jinx ourselves, but I’m feeling pretty good about the state of the computing for the experiment right now. As we reviewed the status of the seven CMS Tier-2 sites in the United States and two in Brazil, we generally saw that everyone is operating pretty stably and happily. A year ago, there was a lot of discontent with existing large-scale disk storage systems. But since then we’ve developed and implemented some new systems, and there have been a lot of improvements in the existing systems, so it all just looks a lot better.
That being said, this all just dress rehearsal — we’ll see how it really goes when thousands of physicists start using the system to do hundreds of data analyses. Now that the LHC running schedule has been defined for the coming three years, we have a much better handle on the needed computing resources for for this period. Overall, we’re going to be running at lower collision rates than previously anticipated, but with pretty much the same livetime. This means that we’ll be recording the same number of events we would have at higher collision rates, implying that the density of interesting physics will be smaller. It creates a more challenging situation for the computing, but at least we now know what has to be done, and have a reasonably good idea of how to get there.
As for the second half of the title — the real excitement was on my trip home. I had an 8:10 AM flight out of O’Hare, which would arrive in Lincoln around 9:40, giving me plenty of time to be ready for my 12:30 PM class. But there was fog in Chicago, and an aircraft was late, and then the crew was swapped, and then the aircraft was sent to Peoria instead while we waited for the crew, and in the end we didn’t leave until around 10:45. The plane touched down on the runway in Lincoln at 11:57. And I was in my classroom just on time. Ah, lovely Lincoln, where the airport is small, you park right next to the airport, and you can drive to campus in minutes!
