OSG Newsletter, January 2010

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ATLAS Analysing Real Data After LHC Start-up

ATLAS (A Toroidal Lhc ApparatuS) is one of the four particle physics experiments located at the Large Hadron Collider at CERN. With the first sustained operation of the LHC in December, ATLAS has finally taken substantial amounts of real collision data—ultimately at record-setting energy (2.36 TeV).

Subsequently, in late December and early January, U.S. ATLAS made heavy use of its sites on the OSG to perform reconstruction and initial analysis of this data. During these processing runs, the ATLAS Tier 1 Center at Brookhaven National Lab, along with 5 Tier 2 sites (and a growing number of Tier 3s) typically ran 10-13,000 jobs at a time, with a maximum throughput of almost 50,000 jobs over a 24-hour period.

Thanks to the OSG, this work was accomplished quickly and with very high efficiencies (~99%). ATLAS plans to perform another reprocessing run (which means re-analysing the December data with refined calibration information) before the LHC restarts in February.

~ John Hover

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Production Report from CMS

CMS continues to shift focus from exercising the computing system at full load to analyzing the roughly 15 terabytes of real collision data from the 2009 run. The emphasis is on checking how well Monte Carlo simulations match the data collected by the detector, and so far they are in fantastic agreement! At the well-understood center-of-mass energy of 900 GeV, the detector energy loss, particle spectra, and reconstructed masses and widths for well-known particles, such as lambdas and K^0 shorts (to name but a few quantities of interest), have matched up well to expectations.

~ Burt Holzman

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Native Packaging VDT Work

The VDT team at the University of Wisconsin-Madison has been working hard to be able to ship the OSG Software Stack as native packages (RPMs and Debian packages) in addition to the existing Pacman distribution. There has been strong demand from VOs and users for native packages because they would interact well with the OS distribution mechanisms that site administrators already use.

The work has been challenging because we are becoming experts in two native packaging systems, and because much of our internal infrastructure for producing the OSG Software Stack relies on features in Pacman that do not match well with native packaging systems.

Right now, the VDT team is focusing on a subset of the VDT needed by the LIGO experiment, which has the most pressing needs for native packaging. After this, we hope to provide native packages, first for glexec (because it must be installed on a local disk), and then software needed on the worker nodes. Once that is done, we’ll gradually increase the set of available native packages.

We anticipate continuing to support Pacman installations for at least a while. Users have already installed software with Pacman, and should not need to re-install from scratch just to get a new style of packaging. We’ll support Pacman for the foreseeable future.

We look forward to working with all of you as we proceed with support for native packages.

~ Alain Roy

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Early LHC Measurements from the Large Hadron Collider Depend on the Distriburted Computing Contributions of the Open Science Grid

In November and December 2009, the LHC delivered over one million collisions to the four detectors at energies of 900 GeV and 2,360 GeV, please view the US LHC Blog Entry. Many physicists having been poring over the data during and since that data run. Early measurements are already being validated, reviewed, and presented by the experiments. These measurements look at detection and distribution of known particles, masses, and distributions; they check the performance of each of the millions of channels of the detector and compare the actual data to that from the years of simulation.

You can catch some of the excitement locally at the US LHC Blog entry from Edgar Carrera of Boston University. We give two publicly available plots to whet your apetitite!

Angular distribution of Events with two jets with pT> 7 GeV (Courtesy of ATLAS publicly available plots)	First physics distributions: The green band represents the measurement uncertainty (Courtesy of Fermilab Today, Don Lincoln)

~ OSG Executive Team

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iSGTW Survey: January 2010

As you know, the SGTW (Science Grid This Week) was created by us in OSG, then grew to include the “i” in partnership with EGEE and GridPP in Europe. iSGTW now has 5,684 subscribers. We need your feedback to continue to make this publication worthwhile and useful.

Please take a few moments to fill out the survey. The editors welcome opinion pieces as well as news. Let’s make sure we keep articles coming and the many subscribers informed and up-to-date.

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From the Executive Director

Your many contributions were key to the comprehensive annual report that I submitted to the DOE this week. Well done! Do take a moment to read some of the OSG 2009 Annual Report.

This month’s focus in several areas is usability, scalability, usability, scalability…. Usability was a theme echoed throughout the ID Management Workshop, please view the report. If you want to know more and want to help, come to the All Hands Meeting in March!

Another new OSG satellite project—the Advance Network Initiative (INI) research project at DOE funded by ARRA—has kicked off with work at UCSD. The goals and initial activities will make use of a local testbed in collaboration with SDSC and then with NERSC, while the wide-area 100 Gigabit fabric is being built.

And don’t forget to register for the All Hands Meeting. See you there!

~ Ruth

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December ATLAS & CMS Thumbnails

Recent change in profile of US LHC usage on OSG reflects increased attention to analysis jobs and  temporary reduction of large scale simulation jobs.

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Documents Modified in the Last 20 Days

OSG-doc-#	Title	Author(s)	Topic(s)	Last Updated
931-v2	OSG-ESnet Joint Identity Management Workshop report	Mine Altunay et al.	Security Plans Work Orders	15 Jan 2010
932-v2	OSG Annual Report to DOE (December 2009)	Paul Avery et al.	Reports	15 Jan 2010
930-v2	Vignettes to ASCR	Miron Livny et al.	Outreach	11 Jan 2010
813-v2	The Value of OSG	Executive Board	Reports	08 Jan 2010
887-v1	Year 3 Metrics	Brian Bockelman	Metrics	08 Jan 2010
928-v0	RSV (Draft)	Rob Quick	Agreements	06 Jan 2010
927-v0	CA Distribution	Rob Quick	Agreements	06 Jan 2010
926-v0	MyOSG Service Level Agremeent	Rob Quick	Agreements	06 Jan 2010
925-v0	BDII Service Level Agreement	Rob Quick	Agreements	06 Jan 2010

 

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