ATLAS Software and Computing Week April 4-8, 2011 General News

Transcription

1 ATLAS Software and Computing Week April 4-8, 2011 General News Refactor requests for resources (originally requested in 2010) by expected running conditions (running in 2012 with shutdown in 2013) 20% more CPU required at T0 which will be redeployed from CAF No extra CPU for T2 in 2012 but 11% more disk requested T1 CPU up 15%, disk and tape OK Expect Group and User activities to increase as the experiment matures Change in data distribution model: 1 disk copy of RAW at T1 s Rolling buffer of 10% of ESD at T1 s + small streams 10 copies of AOD over the clouds (3 copies of previous version) 2 copies of DESD at T1, 4 at T2 Larger pileup means ~double the event size Work done already to reduce the reconstruction time New version of Oracle (11g) to be introduced at end of 2011 (somewhat disruptive move from current 9g)

2 Data Movement and Cloud Model Break original cloud and DDM model as network architectures have evolved away from the original MONARC model Allow DDM to transfer data freely between all sites T2D (D=Directly connected) are an attempt to break the cloud boundaries where it makes sense In the new model, every T1 is topologically close with the other T1s, its T2s and all the T2Ds Requirements for being/becoming a T2D Need satisfy transfer metrics with all T1s Strictly quantifiable via SONAR tests Need to provide a certain level of commitment and reliability Not quantifiable at the moment, up to ATLAS central ops to decide Number of files transferred SMALL Avg(Byterate)+StD(Byterate) SMALL <0.05MB/s <0.1MB/s 0.1MB/s MEDIUM LARGE MEDIUM <1MB/s <2MB/s 2MB/s LARGE <10MB/s <15MB/s 15MB/s

3 ATLAS clouds and T2Ds Many T2Ds commissioned in less than 2 months Represent over 80% of ATLAS resources But many clouds have no T2Ds and less than 50% of T2 s represented LHCONE should address some of these issues Proposal that only T2Ds participate in multicloud production activities and even hosting GROUPDISK T2Ds could become primary replica sites esp. for GROUPDISK replication Strongly urged to get as many T2Ds as possible in a cloud but up to squads and sites to do the commissioning perfsonar and independent FTS tests at US sites has been immensely helpful in commissioning and monitoring Won t discuss LHCONE here but refer you to slides =0&resId=1&materialId=slides&confId= Intercloud transfers may need direct T2-T2 new feature in DDM based on measurements

4 15.6.X.Y last of 2010 analyses 16.0.X.Y recommended for all pp analyses 16.2.X.Y HI reprocessing Software 16.6.X.Y (latest ) for 2011 MC and data Rel 17 due out begin May, validate July for Sept reprocessing Hope for significant cleanup (compilation warnings, savannah bugs, etc) 64-bit builds maybe in Y CPU performance gain but 1.5x more memory (reco ~3.5 GB) Cleanup of releases needed before deployment on CVMFS People needed to help the effort (2-3 people at 30-50% FTE)

5 MC Production MC10a production (for 2011 data) Starting now Reprocess (digi+reco) all MC10 HITS ( Y) 800M events, ~6 weeks to reprocess MC11 Geant4 in validation now (16.6.X.Y) All 800M samples redone from scratch ~ 3 months HITS go to TAPE until reconstruction in summer with rel Multi-cloud working reasonably well with a few mostly local concerns Monitoring, foreign T2s stealing jobs Clouds tend to empty at the same time this is good

6 R&D and Task Forces NoSQL database (e.g. MongoDB, Cassandra, Hbase) Cloud Computing xrootd Federation and File Level Caching Event Data Caching Tier-3 Monitoring CVMFS Multicores AthenaMP reduce memory footprint Reco prototype working in with caveats Network and Transfer Monitoring New ATLAS Development Meeting Wed s 17:00 CET Open meeting with people invited from outside of ATLAS Discuss future computing projects atlas-project-adc-development@cern.ch

7 ATLAS Monitoring and Reporting Dashboard e.g. Historical Views for Job accounting, DDM Dashboard 2.0, Global Job monitoring Some still in validation so report features and bugs ADC Monitoring ATLAS Grid Information System development: Discussions on converging monitoring tools within Dashboard framework Some useful new pages Data Distribution (T0 T1, T1 T1) Site Status Board or shifter view Autopyfactory monitoring Talk about implementing more stringent criteria on site availability to avoid flip-flopping (e.g. from CMS: site OK >5 days in last 7 or in last 2 days)

8 DQ2/DDM Evolution 50 PB, 2.5M datasets, 185M files, 800 end-points and growing 14/0.6M reads/writes per day (162/7Hz), 500k deletes/day New accounting service dq2-list-accounting E.g. Count all data10 datasets at CERN by datatype: dq2-list-accounting project=data10* location=cern* datatype Automatic notification to squads of suspicious files and tagging datasets Multi-hop/direct transfer services being worked on for T2D s Dropping python 2.3/2.4 support currently 2.5/2.6 dq2 Stable release (tested with Python 2.6) Few name changes to maintain compatibility e.g. dq2-put2 replaces old dq2-put Python files now in /opt/dq2/lib Working on DQ3 code-named Rucio More hooks for group datasets, symlinks, multiple replicas, cloud computing, etc

9 Distribute read-only binaries (immutable, sha-1 hashed) Files/meta-data downloaded on demand and locally cached (fuse) Self-contained (e.g. /cvmfs/atlas.cern.ch/) Local load-balanced squids with fail-over capability In deployment at few sites already (RAL, QMUL, Wuppertal) V2.0 end of May Recommended for grid sites for ease of installation, no local repo to worry about space or performance, do need squid proxy Caveat is need local disk cache (at least 8GB recommended) or can use shared memory KV works transparently Cern VM File System (CVMFS) Installation DB recognizes CVMFS site and removes concurrent job restrictions VO_ATLAS_SW_DIR= /cvmfs/atlas.cern.ch/repo/sw Athena software will be installed in $VO_ATLAS_SW_DIR/software/<version> /cvmfs/atlas.cern.ch Production Software 5 release managers, 24 releases SLC releases SLC5 590 GB, 11 Million files, 16 Million entries (shadow) 85 GB and 1.5 Million files (repository) /cvmfs/atlas-condb.cern.ch ATLAS Condition Flat Files Release manager machine hosted by CERN IT Automatic update several times a day 30 GB, files, 7000 directories, 3000 symlinks (shadow tree) 30 GB, files (repository) Only fraction of all conditions data /cvmfs/atlas-nightlies.cern.ch ATLAS Nightlies to be done

10 Merging of output files for analysis jobs Event picking in PD2P Optimize rebrokerage of jobs (general agreement to reduce from 3 days to 1 day for analysis jobs) LFC registration by panda server PanDA Developments Pilot changes to support new functionality T1 T1 PD2P for secondary copies based on usage Split dataset containers based on MOU shares Further copies made to T2s based on job backlogs (log10 function) Algorithm will be tuned with experience Maybe add popularity and history (needs additional tables in db)

11 Backups

12 Revise model due to 200 Hz 400 Hz trigger rate No long term storage of ESDs on disk for physics streams Muon, JetTauEtmiss, Egamma, MinBias Do not store any ESD on tape Data Distribution for 2011 This removes the possibility of reprocessing from ESD Provide 2 replicas of ESD from all physics streams for ~10% of the data Last 2 months rolling buffer for Tier0 produced ESDs Specific data period corresponding to ~10% of the data for ESDs from reprocessing Provide 2 replicas of ESD for some small streams CosmicCalo, ZeroBias, Standby & express Reduce the ESD size by ~30% by dropping unused or redundant information Provide 1 copy of RAW data on disk for the physics stream for data taken in the last year In addition to copy of RAW on tape Compress RAW data on disk (can achieve a factor of ~2)

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