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Offline Week HLT Plans Thorsten Kollegger

Offline Week HLT Plans Thorsten Kollegger. CERN | 26 .03.2013. HLT Status. A few words on the HLT operational status… More details in the HLT presentation during the Workshop on Run 1 Conclusions and Run 2 Outlook https://indico.cern.ch/conferenceDisplay.py?confId= 240668.

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Offline Week HLT Plans Thorsten Kollegger

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  1. Offline WeekHLT PlansThorsten Kollegger CERN | 26.03.2013

  2. HLT Status A few words on the HLT operational status… More details in the HLT presentation during the Workshop on Run 1 Conclusions and Run 2 Outlook https://indico.cern.ch/conferenceDisplay.py?confId=240668 HLT Plans | Offline Week | 26.03.2013 | Thorsten Kollegger

  3. Run 1 Conclusions Operation Run participation: > 97% EOR percentage: <≈ 5%- dominated by hardware issues, can we get better? Performance Full online TPC tracking for maximum TPC read-out rate demonstrated Efficiency comparable to offline tracking Limited by “online calibration” HLT Plans | Offline Week | 26.03.2013 | Thorsten Kollegger

  4. Tracking Performance HLT GPU tracking – speed comparison It’s fast… HLT Plans | Offline Week | 26.03.2013 | Thorsten Kollegger

  5. Tracking Performance HLT GPU tracking – physics performance Similar performance as offline… … if we have the same calibration (need online calibration) HLT Plans | Offline Week | 26.03.2013 | Thorsten Kollegger

  6. LS1 – HLT Farm Availability QA Two use cases HLT development Offline usage Cloud Gateway Private CERN Cloud AliEn CAF On Demand CernVM/FS Cloud Agent HLT Public Cloud HLT Plans | Offline Week | 26.03.2013 | Thorsten Kollegger

  7. LS1 – HLT Farm Availability From Technical Coordination No power starting week 22 for two months No cooling weeks 22-40 Implications Testing and development capabilities for HLT limited Offline usage of farm not feasible/worthwhileDevelopment of tools continuing in view of Run 2 downtimes, general use HLT Plans | Offline Week | 26.03.2013 | Thorsten Kollegger

  8. HLT Offline Plans LS1 ? HLT Plans | Offline Week | 26.03.2013 | Thorsten Kollegger

  9. HLT Offline Plans LS1 Group responsible for HLT offline integration left HLT project Can maintain current software, but no development/restructuring Need to concentrate on core efforts,e.g. HLT Event Display only on best-effort basis Have been in this mode since ≈ summer 2012 What can still be done in/with offline? HLT Plans | Offline Week | 26.03.2013 | Thorsten Kollegger

  10. To be finished… There are many HLT-related developments waiting to be finished/back-ported to offline Fast (TPC) transformations (calibration, > factor 10 speed-up) HLT tracks as offline reconstruction TPC seeds HLT tracking performance evaluation A more general remark: Need to converge as-much-as-possible towards common code, very good experience working with TPC group HLT Plans | Offline Week | 26.03.2013 | Thorsten Kollegger

  11. Event Display Event Display for nice pictures…… not only, but also very useful for fast feed-back for shift-crew, displaced vertex runs “by eye” HLT can support this only on abest-effort basis: Can we converge towardsa common event display? HLT Plans | Offline Week | 26.03.2013 | Thorsten Kollegger

  12. Start of Run (SOR) Strong push from TC/RC to SOR time to 10 s HLT engage times currently around 100 s 25 s – Pendolino prepare calibration/HCDB <5 s – Start of HLT processes 60 s – Initialization of processes (CDB access, map preparation) <5 s - Subscriptions (Configured->Running+Subscribed+....) <5 s - Network connections (Running... -> Connected) Can AliROOT go from “off” to first event reco from in 2 s? (incl. building geometry, updating calibrations…) HLT Plans | Offline Week | 26.03.2013 | Thorsten Kollegger

  13. LS1 – HLT Farm Replacement Full replacement of computing farm beginning of 2014 Switch from H-RORC to C-RORC 12 DDLs/board vs 2 DDLs/boardreduced number of FEP nodes Test-Setup in CR2 working Tracking/Compute node hardware to be decided move tracker from CUDA to OpenCL to gainvendor independence HLT Plans | Offline Week | 26.03.2013 | Thorsten Kollegger

  14. Run 2 Outlook All detectors available in HLT Use requires development (not HLT core) If we want to do this, major software development effort by detectors needed HLT “core” focused on improvement of online software Data transport and process control/monitoring framework HLT specific detector software HLT Plans | Offline Week | 26.03.2013 | Thorsten Kollegger

  15. Run 2 Outlook Full TPC reconstruction available TPC cluster finding for data reduction TPC seeding Online calibration of TPC, replacement of CPass0? Additional data reduction? Towards online calibration porting of DAs to HLT started, massive changes required (TPC, MUON) “CPass0” feasibility study with TPC Need to know NOW computing requirements after LS1 HLT Plans | Offline Week | 26.03.2013 | Thorsten Kollegger

  16. Online Calibration There are two running modes in the HLT Guaranteed analysis of every event -> main chain “best-effort” event delivery -> monitoring chain The choice of chain defines requirements on your code! HLT Plans | Offline Week | 26.03.2013 | Thorsten Kollegger

  17. Online Calibration Requirements Stability Can your code run on >100M events?(memory consumption?) How well can you handle detector errors?In offline you are too a large extend shielded already by online (DAQ/HLT) How stable is your code?Online code changes require verification, only possible without beam HLT Plans | Offline Week | 26.03.2013 | Thorsten Kollegger

  18. Online Calibration Requirements Processing What are the computing resources you need to process1000 Hz of minimum bias Pb+Pb collisions? Does your code allow for parallelization of event processing?How do you handle merging of process output? Input data format: ROOT adds huge overhead… An examplewhy this matters: Your code takes 1 second to process 1 event No parallel code  1Hz Parallel code  1000 Hz However:  1000 cores  100 additional nodes  >500k€ HLT Plans | Offline Week | 26.03.2013 | Thorsten Kollegger

  19. Online Calibration Requirements Need to know NOWcomputing requirements after LS1 This defines the infrastructure, there are no fast changes possible Reminder: All detectors available in HLTSome limited computing power available for local processing Resources available for TPC tracking (and limited calibration)Everything beyond requires additional resources… HLT Plans | Offline Week | 26.03.2013 | Thorsten Kollegger

  20. Run 3 Outlook Developments towardsthe upgrade… Reconstruction Calibration Re-reconstruction Online Raw Data Store HLT DAQ AliEn O2 Online-Offline Facility HLT Plans | Offline Week | 26.03.2013 | Thorsten Kollegger

  21. Run 3 Outlook … to make this a reality 2 HLT Plans | Offline Week | 26.03.2013 | Thorsten Kollegger

  22. Backup HLT Plans | Offline Week | 26.03.2013 | Thorsten Kollegger

  23. Tracking Performance HLT uses GPUs for TPC tracking Unique at LHC, other experiments following now with R&D Factor 4 in total tracking time: factor 3 less nodes in system HLT Plans | Offline Week | 26.03.2013 | Thorsten Kollegger

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