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AliEn development

AliEn development. Miguel Martinez Pedreira. Contents. Basics and concepts CVMFS migration Recent changes ToDos / Ideas. What is AliEn ?.

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AliEn development

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  1. AliEn development Miguel Martinez Pedreira

  2. Contents • Basics and concepts • CVMFS migration • Recent changes • ToDos / Ideas AliEn development - Miguel Martinez Pedreira

  3. What is AliEn ? • AliEn (ALICE Environment) is a lightweight Open Source Grid Framework built around other Open Source components using the combination of a Web Service and Distributed Agent Model • designed to comply with the offline world of a HEP experiment • massive amounts of data implies distributing its storage and processing • It started within the ALICE Off-line Project at CERN and constitutes the production environment for simulation, reconstruction, and analysis of physics data of the ALICE Experiment • The current status of the ALICE grid operation can be found at the MonALISA Grid Monitoring AliEn development - Miguel Martinez Pedreira

  4. Virtual Organisations • Users (jobs submission for data analysis) + Central management (the “brain” of the GRID) + Sites (the “muscle” of the GRID) • ALICE numbers: ~35K avg running jobs (~200K/day), ~80sites, ~60SE, ~1000M entries in the catalogue AliEn development - Miguel Martinez Pedreira

  5. Distributed Analysis AliEn development - Miguel Martinez Pedreira

  6. ALICE Grid AliEn development - Miguel Martinez Pedreira

  7. AliEn summary • 3-layer system that leverages thedeployed resources of the underlying WLCG infrastructures and services • Interfaces to AliRoot via ROOT plugin (TAlien) that implements AliEn API • Complex workflows including distributed analysis built on top of AliEn API • Used by ALICE and PANDA AliEn development - Miguel Martinez Pedreira

  8. CVMFS AliEn development - Miguel Martinez Pedreira

  9. CVMFS migration • Started in second half of August 2013 • First sites: test CE at CERN (local) and BITP (grid) • Running production-like JDLs (alitrain/aliprod) • CVMFS setup tested then over ‘real’ site • Combination of packages were showing problem with the environment of the process that was being set First fix • IP list from APISCONFIG • Paths • Wiki created with steps to follow before starting migration AliEn development - Miguel Martinez Pedreira

  10. CVMFS migration • Then started with some other sites • Mainly big sites, 1 by 1, overall quite smooth • Decided to push everyone • Spam-time ( sorry  ) • haven’t counted myself, 7 November ~800 mails had been sent ( according to Maarten ) • Reactions • Many sites reinstalling to WLCG SL6 • Sites pending CVMFS being installed for quite a while... • Several interface updates: CONDOR, ARC • CREAM was updated also to add robustness and deal with specific setups AliEn development - Miguel Martinez Pedreira

  11. CVMFS migration • Deadline modified after October push: end 2013 AliEn development - Miguel Martinez Pedreira

  12. CVMFS migration • PackMan service not needed anymore • Issues • Fix for the ROOT/AliRoot paths when local ROOT installed (conflict) • Missing libraries: libtcl, gfortran, libtermcap... • Some sites don’t use HEP_OS_libs • ‘Warm-up’ time with ERROR_E ? • I/O Error • squid and cache misconfigurations? not easy to debug... • Efficiencies ? • Thanks to admins ;-) ! AliEn development - Miguel Martinez Pedreira

  13. CVMFS migration AliEn development - Miguel Martinez Pedreira

  14. CVMFS migration AliEn development - Miguel Martinez Pedreira

  15. CVMFS migration AliEn development - Miguel Martinez Pedreira

  16. Recent changes: /tmp issue • Detected some jobs that were analyzing the wrong data • From the file ‘wn.xml’ • Job tokens • Not unique  • Using a new service creating unique tokens • Other ideas led to a more robust JobAgent • Check sandbox use, creation • Check chdir • Printing more info • Unique open/read of the XML file • Problem resulted not to be in AliEn • jobs waiting for same CVMFS content writing concurrently • helped to create a model of the JobAgent flow: to be ‘digitalized’ AliEn development - Miguel Martinez Pedreira

  17. Recent changes • Investigating the errors • ERROR_E • TTL • Memory • Idle • Couldn’t get Catalogue... • Still the winner is ERROR_V • Focusing on what we don’t understand or the problems that affect more the system overall AliEn development - Miguel Martinez Pedreira

  18. Recent changes: ERROR_E • Many jobs failing for running over the TTL • ProxyTTL=“1” • Job runtime to proxy timeleft on the job – 10 minutes • Still some continue failing... • Proxy timeleft unavailable • Memory issues (or other) • Saving the output to check logs • OutputErrorE, same as output • then registerOutput <jobId> AliEn development - Miguel Martinez Pedreira

  19. Recent changes: ERROR_E • Some jobs fail getting a catalogue instance • Found race-condition • Jobs WAITING for a while, and being moved to ZOMBIE just after ASSIGNED • Optimizer using DB field based on timestamp • that wasn’t properly updated... • A small portion still fail • Added full trace of the catalogue creation in the JobAgent • “Bad hostname” or “Host undefined” • Stuck after getting JDL • Under investigation AliEn development - Miguel Martinez Pedreira

  20. Recent changes: INSERTION Inserting Submit Job Man copyInput Check JDL, inserting `whereis` per file Splitting sizes check Analyse split fields InputDownload-Workdirectorysize Inserting Opt add SE requirements Create baskets Splitting Opt Getting all files check SE-CE compatibility `whereis` per file sizes check If maxsize, `ls` per file insert jobagent Submit subjobs Waiting Split AliEn development - Miguel Martinez Pedreira

  21. Recent changes: INSERTION Submit Job Man Check JDL, inserting Splitting Analyse split fields Create baskets Getting all files Splitting Opt `whereis` per file (and cached!) sizes check (no InputDownload or InputBox) add/check SE-CE compatibility Subjobs to WAITING Split Waiting AliEn development - Miguel Martinez Pedreira

  22. Recent changes: INSERTION AliEn development - Miguel Martinez Pedreira

  23. Recent changes: INSERTION AliEn development - Miguel Martinez Pedreira

  24. Recent changes: baskets • Some months ago, file/job distribution found to be very ugly • Issue in catalogue: entries with duplicated pfns • cleanup ? • fix on the optimizer deals with it • Improved the basket creation • Step 1: file transfers to have data in same SEs (Markus/Jan) • not so good for the grid balance • Step 2: creating big collections for several runs (Costin) • balanced grid • FileBroker not needed anymore... AliEn development - Miguel Martinez Pedreira

  25. File Catalogue AliEn development - Miguel Martinez Pedreira

  26. File Access Monitoring Service • FAMoS provides a facility to monitor the attributes of the accesses to the files and to record in an organized manner the values of attributes to a database • Counts the accesses not only to individual files but also to set of AOD and ESD files of the LHC periods, called categories (e.g. LHC10f6a_ESD, LHC10h_AOD) • It provides also information on the categories accessed by individual users (like: alidaq, aliprod, alitrain) • Information gathered from Authen’s and API servers • since August • Web interface under development • http://aligrid.yerphi.am/famos/monitoring AliEn development - Miguel Martinez Pedreira

  27. File Access Monitoring Service AliEn development - Miguel Martinez Pedreira

  28. File Access Monitoring Service AliEn development - Miguel Martinez Pedreira

  29. File Access Monitoring Service AliEn development - Miguel Martinez Pedreira

  30. ToDos / Ideas • Unifying AliEn versions  • v2-19, v2-20, v2-21, trunk, central, API • Also making installations/tests work • JDL optimization • Millions of jobs, big JDL text • Done in v2-21 • Storing compressed JDL • and only diff tags in resultsJdl • We could also create the subjobs JDL from the father’s • Optimizers investigations • periodicity ? • jobs not expiring (SPLIT without pending subjobs e.g.) • queries failing ? • Catalogue cleanups/modifications • orphan entries, duplicated pfns • unused tables • new solutions (EOS?), apply (v2-20?) improvements • more caching AliEn development - Miguel Martinez Pedreira

  31. ToDos / Ideas • zip64 • currently using standard zip • can’t deal with >4GB • IPv6 readiness • this summer • Broker queries • packages matching queries, long list • JSON services • SOAP used in production: but JSON is ready since v2-20 and being used by PANDA • + performance – backward incompatibility (in critical parts...)  AliEn development - Miguel Martinez Pedreira

  32. ToDos / Ideas • find • new flag to sort files according to the position of the request • for better reading • Long desired commands fixes • ps, top, masterjob... • glExec • utility allowing user separation in multi-user pilot jobs • let each user task run under a corresponding account • PayLoad + user certs? • Supercomputing...? • interfacing with PanDA AliEn development - Miguel Martinez Pedreira

  33. ToDos / Ideas • Machine/Job features Task Force • aiming to adapt to virtualized environments (including cloud) • also related to multi-core slot queues, cpu dynamic availability... • concerns about overloading the meta-service when communicating features via “magic-IP” • Expand to more Iaas systems AliEn development - Miguel Martinez Pedreira

  34. jAlien AliEn development - Miguel Martinez Pedreira

  35. jAlien AliEn development - Miguel Martinez Pedreira

  36. jAlien AliEn development - Miguel Martinez Pedreira

  37. Sorry if I bored you ;-) Any questions ? AliEn development - Miguel Martinez Pedreira

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