ATLAS Software Installation at UIUC “Mutability is immutable.” - Heraclitus ~400 B.C.E. D. Errede, M. Neubauer Goals: 1) ability to analyze data locally (with constraints) 2) ability to connect to other machines around the world 3) ability to contribute to the detector commissioning and calibration locally 4) ability to store reasonable quantities of data for ease of analysis 1) - not completely. 2) - not completely. 3) presently done at CERN(Irene Vichou); effort to make contributions locally. (see S. Errede’s talk) 4) Discussion with local UIUC computing center on access to available disk space ?

Ability to analyze data locally 1)Accomplished: *installation of ATLAS release software locally and also installed per machine. ( Restrictions on NFS type installation. ) Reduces disk-space usage. *ROOT software for ntuple/tree analysis exists. We do not expect to be able to generate large data sets locally of complete monte carlo data for instance because of the well known restrictions of generation time. Perhaps fast MC data can be generated locally (?). *installation of Scientific Linux 3 and 4 platform on several local linux machines *installation of Open Science Grid User Interface allowing access to large farms(as clients, not as a Computing Element). Software installed and simple condor submission tested, however all local idiosyncrasies not yet understood. Installed as User, not globally for group, yet. *installation of dq2 software to access data files from OSGrid

Ability to analyze data locally Not accomplished: *installation of OSG UI centrally for all users ability to connect to other machines around the world 2) Accomplished: *security issues related to logging into CERN lxplus machines ( LCG access, dq2 working, ROOT is prohibitively slow), SLAC linux machines, BNL linux machines. *OSG UI installation allowing access to large OSG farms, simply tested but not fully tested. ability to contribute to the detector commissioning and calibration locally 3)See Steve Errede’s talk. Presumably dealing with ROOT ntuples is the primary requirement here. ROOT exists and is usable. ability to store reasonable quantities of data for ease of analysis 4) Discussion with CITES and NCSA on access to some fraction of petabyte disk. NCSA has resources that perhaps we can tap into in the future. We already have 10 Gbit/s connection to CITES and then Chicago’s “hub”.

ARE WE DONE? ARE WE CLOSE TO BEING DONE? NO. We will be establishing a systematic analysis effort locally. (see Mark Neubauer’s talk) The HECA state of Illinois grant (D. Errede P.I.) contributed over $200k toward computing equipment etc from which will be used by the ATLAS group here, though in limited fashon due to memory constraints. 16 dual-processor boxes for muon collaboration use Next project: *setting up 3 linux machines locally (OSG00,01,X0) with SL3/4 platforms on which to install ATLAS software for testing. The software changes and is updated constantly hence we will be starting with a ‘clean slate’ on which to work. We know that some software doesn’t work ‘on top of’ other software, for instance. Important to this effort will be the authority to use root privileges on our machines. The addition of Mark Neubauer to this effort is a tremendous contribution given his background in installing the CONDOR batch queue system at CDF and hence his knowledge in other required languages such as Python and as can be seen from this good idea for the next step/project. Overall comment: because of the evolving nature of the ATLAS software what is easy at the present time would have been quite difficult earlier on.

Toward a UIUC: The “Problem” The scale of computing requirements for the LHC experiments is unprecedented in HEP’s history  ATLAS: ~3x10 3 collaborators spread across the globe  3 PB / year RAW + 1 PB / year ESD Much progress has been made on pieces necessary to get ATLAS physics done on globally distributed computing (GRID)  Many complex pieces to handle authentication, VOs, job submission/handling/monitoring, data handling, etc System needs to be exercised from the perspective of a physicist “just trying to get their physics done” (I.e. end user)  Convenient and flexible interface to authentication, dataset creation/consumption, job submission, monitoring, output retrieval  Support and reliability of service, deserving of a production system These goals have not yet been fully achieved in ATLAS but need to be for the experiment to be successful! “ The world according to Mark “

Toward a UIUC: A “Solution”? Deploy a “large” computing cluster configured as a Tier-3 and operated as a model Tier-3 in terms of reliability and utilization for doing a home institution  Q: How large is “large” A: Large enough for ATLAS computing organization to pay attention and for UIUC to get our physics done. Could be as large as most Tier-2 sites Why do this at UIUC?  We have an enormous amount of high-end computing infrastructure and technical expertise to pull this off!  Infrastructure includes HEP & MRL computing, NCSA, recent availability of 10 GB/s network pipe to Chicago (ATLAS Tier-2 Center)  Technical expertise includes HEP group, networking experts, new addition: Mark Neubauer  Neubauer: At MIT then UCSD with F. Wurthwein:  lead complete redesign of CDF analysis computing -> CDF Analysis Facility (CAF)  CAF Project Leader ( )  Involved in subsequent to migration to Condor and utilization of offsite computing (one of, if not the, first operating GRIDs in HEP) Goals: Drive ATLAS into a successful computing model from the analysis end Get our physics done, and strengthen our collaborations (e.g. FTK)

Toward a UIUC: A Prototype Have recently assembled a prototype system to begin work on ATLAS Tier- UIUC (many thanks to Dave Lesny) 3 Dual Xeon dual processor boxes, 2 Gbytes memory coming out of existing equipment.

Toward a UIUC Proto-CAF (Oct 2001) FNAL CAF + 9 DCAFs (now) Insert Picture ?

Toward a UIUC “The time to repair the roof is when the sun is shining” – JFK