Atlas:Analysis HC beyond STEP09

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--Chollet 15:56, 19 octobre 2009 (CEST)

Distributed Analysis Stress Tests - HammerCloud beyond STEP09

Lessons learnt from STEP09

  • Sites may identify reasonable amount of analysis they can assume and set hard limits on number of analysis running jobs
  • Balancing data across many disk servers is essential.
  • Very high i/o required by analysis (5 MB/s per job). Sites should review LAN architecture to avoid bottlenecks.

Results

HC web interface

ATLAS STEP09 summary

Some conclusions about DB access HC tests

ATLAS Info & Contacts

  • Information via mailing list ATLAS-LCG-OP-L@in2p3.fr
  • LPC : Nabil Ghodbane - Nabil.Ghodbane@cern.ch
  • LAL : Nicolas Makovec
  • LAPP : Stéphane Jézéquel
  • CPPM : Emmanuel Le Guirriec
  • LPSC : Sabine Crepe
  • LPNHE : Tristan Beau
  • CC-T2 : Catherine, Ghita
  • IRFU : Nathalie Besson

HC Tests

ATLAS-HC-small.jpg

Objectives

  • Improve Cloud readiness by following site&ATLAS problems week by week (SL5 migration, site upgrades)
  • Identify best data access method per site by comparing the event rate and CPU/Walltime

https://twiki.cern.ch/twiki/bin/view/Atla/HammerCloudDataAccess#FR_cloud

  • Exercise Analysis with Conditions DB access (see where squid caching is needed) and Tag analysis

Data Access methods

Multiple data access methods are exercised

  • via Panda : A copy-to-WN access mode using rfcp is used (xrootd in ANALY-LYON)
  • via gLite WMS : 2 data access modes available
    • DQ2_LOCAL mode is a direct access mode using rfio or dcap
    • FILE_STAGER mode : data staged in by a dedicated thread running in // with Athena

Week 40

29/09/09 Test 649

  Bad efficiency - all sites affected all sites 
  Failed jobs with error : exit code 1137
  Put error: Error in copying the file from job workdir to localSE
  due to LFC ACL problem : write permissions in /grid/atlas/users/pathena
  for pilot jobs /atlas/Role=pilot and /atlas/fr/Role=pilot (newly activated)

30/09/09 Test 652, 653, 656, 657

http://lcg.in2p3.fr/wiki/images/ATLAS-HC300909.gif

Week 41

08/10/09 Test 663

  • Cosmics DPD Analysis (Release 15.5.0)
  • Input DS - DATADISK : data09_cos.*.DPD*
  • Cond DB access to Oracle in Lyon T1
  • via Panda (mode copy-to-WN using ddcp/rfcp - xrootd in ANALY-LYON)
  • http://gangarobot.cern.ch/hc/663/test/
  • Sites problems or downtime :
    • LAL : downtime
    • RO : DS unavailable
    • LYON (T2) : release 15.5.0 unavalaible. No performances comparison possible with other T2s
    • TOKYO, BEIJING : Poor performance for foreign sites compared to french sites. Squid installation in progress. Tests to be performed afterwards
    • IRFU, LAPP, LPNHE : 2 peak structure observed on Nb events/Athena(s)

http://lcg.in2p3.fr/wiki/images/HC663-081009-GRIF-Irfu-CPU.png http://lcg.in2p3.fr/wiki/images/HC663-081009-GRIF-Irfu-rate.png http://lcg.in2p3.fr/wiki/images/HC663-081009-GRIF-Irfu-EventsAthena.png
http://lcg.in2p3.fr/wiki/images/HC663-081009-Tokyo-CPU.png http://lcg.in2p3.fr/wiki/images/HC663-081009-Tokyo-rate.png http://lcg.in2p3.fr/wiki/images/HC663-081009-Tokyo-EventsAthena.png

Week 42

15/10/09 Test 682

  • Muon Analysis (Release 15.3.1)
  • Input DS (STEP09) : mc08.*merge.AOD.e*_s*_r6*tid*
  • via Panda (mode copy-to-WN using ddcp/rfcp - xrootd in ANALY-LYON)
  • http://gangarobot.cern.ch/hc/682/test/
  • Sites problems or results to be followed-up :
    • GRIF-IRFU : failures due to release 15.3.1 installation (has run fine last week but needed to be patched)
  gcc version 4.1.2 used instead of gcc 3.4...
  See GGUS ticket 52483
    • LYON (T2) : both queues ANALY_LYON (xrootd) and ANALY_LYON_DCACHE exercised at the same time
  limitation due to BQS resource (u_xrootd_lhc)  
  ANALY_LYON_DCACHE : limited number of jobs but good performances (effect of dcache upgrade ?)
  ANALY_LYON : many failures - problems followed by J.Y Nief (root version used by ATLAS ?

Week 43

21/10/09 Test 720

  • Cosmic DPDs Analysis (Release 15.5.0)
  • Input DS - DATADISK : data09_cos.*.DPD*
  • Dedicated test to Tokyo and Beijing with access via Squid
  • via Panda (mode copy-to-WN using ddcp/rfcp)
  • http://gangarobot.cern.ch/hc/720/test/

http://lcg.in2p3.fr/wiki/images/HC720-211009-Tokyo-CPU.png http://lcg.in2p3.fr/wiki/images/HC720-211009-Tokyo-rate.png http://lcg.in2p3.fr/wiki/images/HC720-211009-Tokyo-EventsAthena.png


Recent talks & Documents

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