Report PROOF session ALICE Offline FAIR Grid Workshop

Report PROOF session ALICE Offline FAIR Grid Workshop #1 Kilian Schwarz GSI

PROOF Session • Title: CAF/GSIAF status/experience • PROOF roadmap (Ganis) – – – New Xrd. Proofd plugin Dynamic worker startup/removal Input data optimally distributed to nodes Memory monitor PROOF Lite (test setup before sending jobs to large cluster) – Updated v 5 -21 -05 (trunk instabilities in Xrd. Prood plugin) – Processing small number of large files with many workers (new packetiser strategy needed)

PROOF (2) • Merging: – File backup on master – Workers send result when above certain size • Ongoing work: – Killing of memory eating sessions

PROOF related topics • Ali. Root raw-data reco in parallel via PROOF • CAF: – New CAF – Certificate based authentication – Cmsd – 8 Core machines, 2 TB staging space /WN – 6. 5 times faster than old CAF

PROOF related activities • GSIAF – Merging (memory limit on master): being addressed – PROOF cluster with submasters (should work in principle ) – Authorised access to SEs from PROOF nodes should work when GSI authentication is used – PROOF instability (xrd master infrastructure affected) should be solved with new ROOT – Lack of PROOF documentation also mentioned by Latchezar

PROOF related activities • Virtual analysis facility (Bagnasco) – 1 WNs runs via Xen 1 virtual LCG WN and 1 virtual PROOF slave – More flexibility than only renice

FAIR Grid Workshop #1 • New features in Ali. En: – Physical deletion of files in SEs • Working currently too fine • Tested intensively by Panda • Implementation: – SE optimiser looks for PFNs which have no corresponding LFNs anymore (e. g. after user deleted the entry in the FC) – Files to be deleted are put to extra table – Here SEs will look if there is something to delete for them – If yes, SE will go to action

FAIR Grid workshop • List only files in specific SE – set. SElimit ALICE: : GSI: : SE • Displays only files of selected SE • Working for „ls“, to be implented in „find“ • „get“ collections of multiple files and maintain directory structure of FC – get –c (all files will be retrieved with their original lfn name) – get –c –b

FAIR Grid workshop • Many new Ali. En users – Panda, CBM, Romanian Air and Space, more projects in the Philippines – New central Wiki has been setup as inter VO discussion forum for the setup of new central Ali. En services – ALICE profites a lot from new VOs debugging new Ali. En features before they go into production for ALICE – Ali. En developments also outside of ALICE

Xrd global redirector • Tests with test clusters at GSI and Subatech: – Fetch files from CERN – Delete/access files – No transfer failures – Performance: • 80 MB/s at GSI • 45 MB/s at Subatech • Limit seems to be disk saturation