IES Sabadell visits PIC (outreach activity)

Yesterday we had the visit of around 80 students and 5 professors from IES Sabadell to PIC installations. Their academic field based in Informatics ("Cicles formatius de grau mig/superior") made the tour to be exciting and full of questions. The visit, conducted by Dr. Josep Flix, started with two talks held in the IFAE Seminar Room (next to PIC). The first talk was entitled "The LHC and its 4 experiments: a data stream to understand the Big Bang" and was presented by Dra. Elisa Lanciotti, who is the LHCb contact at PIC. The students placed very interesting questions related to Physics and the techonology used on the LHC, during and after the talk. The level of curiosity was amazing! Maybe, in part related to the preparation sessions prior the visit the professors made and the comprenhesive Elisa's talk. Well after, Dr. Josep Flix presented "The use of Grid Computing by the LHC". He is currently the CMS contact at PIC and the CMS Facilities/Integration coordinator. The talk also raised questions from the attentive audience.


After the talks we made a visit to PIC installations, so they could see how a Computing Center is built and managed. In groups of 15 people we showed them first the real-time views of what's actually occurring on the Grid: the nice visualization of the WLCG grid activity on Google Earth, the ATLAS concurrent jobs running at all their Tiers, the CMS overall data transfer volumes, the LHCb job monitor display, and a few local monitoring plots, like the batch system and LAN/WAN usages.

Then, the visit to the Computing Area itself started: we showed them the different kind of disk pools we have installed, which covered the SUN X4500 (we opened one, so they could see how disks are installed and can be easily replaced) and the new powerful DDN system that offers 2 PBs of disk space; our computational power based on brand new HP Blade systems; plus the two tape robots we have at PIC (around 3 PBs of data stored) and which are the tapes available on the market and how we use them. The students were impressed as well on the WAN and LAN capabilities, the latest improved with the acquisition of two new 10 Gbps switches.


So far, the morning was extremely fruiful. From PIC we want to thank the Professors (Gregorio, Fernando, Lino, Alberto, Alexandra) for their dedication and motivation they offer to their students. They enjoyed the visit and want to repeat it with other students from the school in two months from now. We are happy to receive them again! ;)

Last day of LHC running this year

After so much celebration of first days of LHC running, it is time today to celebrate the last day of LHC running... this year. In few hours the LHC will be switched of and accelerated protons will go on holidays until next year.
I has been a very nice and long awaited time since last 23rd November the experiments started taking collision data. Today the LHC goes on holidays, but the WLCG does not. This piece of distributed infrastructure we have been building in the last six years should stay up and running 24x7 so that the precious data taken can be processed, re-processed, re-re-processed and so on. Somebody said that "data can be equated with money that has value only if it is used and circulated". So this is what we will be doing in the next weeks: giving value to the LHC data. This will not yet be haunting the Higgs, but less sexy minimum bias soft QCD events... but still, LHC physics after all.
At PIC Tier-1 we will carefully look to the services to ensure maximum availability and efficiency.
For the moment, what can we say about PIC's performance during "the month in which the LHC started" (aka November 2009)? We just received this Christmas gift from the official WLCG availability reports:

• PIC availability and reliability for OPS VO = 100%
  
• For ATLAS VO: 98% availability and 100% reliability (only ATLAS Tier-1 with max score)
• For CMS VO: 100% availability and reliability (FZK also got max score for CMS)
• For LHCb: 98% availability and 99% reliability (only CERN got 100% for LHCb)
  

Outreach in the school

Last week it was the "week of science" in Spain. This happens every year around mid November and consists of one week where plenty of activities oriented to explain science to the people are scheduled. In Catalonia, one of the organised activities are talks of scientists in the schools. Last wednesday there were 100 simultaneous talks carried out in different schools all around Catalonia. I visited a secondary school in Badalona where I had a great time talking about the LHC and the origin of the Universe to around 70 students. I see now that they even posted an etry in the blog of the school!
Nice to see that Catalan schools are in the blogosphere... and that they had a nice time listening to my LHC stories.

Real data flowing through PIC

ATLAS has provided a nice monitoring page where we can follow the progress of data distribution in these so exciting moments of first circulating beam in the LHC. This is not collisions yet, but real data indeed. After so many years of simulations, we are happy to see the first Megabytes of real stuff. In the picture, I have just captured the current status of the datasets distribution to Tier-1s and from there to the associated Tier-2s. The overall picture looks pretty green, which is good news. PIC received the subscribed data with no problems and promptly redistributed it to the Tier-2s. It looks the data movement went mostly smooth. Let's keep an eye on this. We will see the rates growing in the next days.

Circulating beam in the LHC (take two)

So, there we go. Last friday 20th November beams circulated again inside the LHC, after one long year of reparations. Everyone is happy and bottles of champain (or cava) are being opened in the control rooms. In the picture you can see, besides the party atmosphere at the LHC control room, the first event displays from ATLAS, CMS and LHCb . The hundreds of tracks coming from the collimators where beams are splashed can be clearly seen in all of them. We are watching the first LHC data.
Commencing countdown, engines on...

LHC beam approaching CMS!

Last Saturday evening, the 7th of November 2009, at around 8 p.m., after passing through the LHCb detector, for the first time since last year's incident, protons arrived at the doorstep of the CMS experiment, thus completing half the journey around the LHC's circumference.

Low energy protons from the LHC were dumped in a collimator just upstream of the CMS cavern. The calorimeters and the muon chambers of the experiment saw the tracks left by particles coming from the dumping point (a so-called 'splash event', see images). During the rest of the weekend, bunches of protons were also sent in the clockwise direction passing through the ALICE detector and were dumped at point 3.

All detectors saw 'splash' events on their monitoring pages. Castor and the Preshower detectors saw particles for the first time! Some beautiful pictures from the events seen:

Data loss

These days we are hearing more often about data loss events at the WLCG sites. Today it was the NL-T1 site that reported some data loss in the daily Operations meeting. Apparently, the tape drive loaded the tape and, instead of reading it, it just destroyed it. A similar event happened to us at PIC at the end of September, when we lost a tape containing 214 files from CMS. Nothing could be done with that piece of hardware... not even rewinding it! Luckily for us, all of those files were replicated in some other Tier-1 or at CERN, so we could fix the problem quite straightaway.
We were used to think in tapes as a safe media for data... but these episodes of tape destruction show that this is not always the case. A bit scary.
Anyhow, even ig it does not solve anything but it is nice to see that WLCG sites we are not the only ones losing data. Even Microsoft loses some data eventually!