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News from ALICE Calibration Workshop

News from ALICE Calibration Workshop. Peter Chochula. Calibration workshop held Oct 04 Agenda: http://indico.cern.ch/conferenceDisplay.py?confId=a056304 All detector presentations available from this page General information about the calibration progress can be found here:

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News from ALICE Calibration Workshop

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  1. News from ALICE Calibration Workshop Peter Chochula 17th DCS Workshop, P.Chochula

  2. Calibration workshop held Oct 04 • Agenda: • http://indico.cern.ch/conferenceDisplay.py?confId=a056304 • All detector presentations available from this page • General information about the calibration progress can be found here: • http://aliceinfo.cern.ch/Collaboration/Boards/Computing/Planning/index.html 17th DCS Workshop, P.Chochula

  3. Please pay attention to the XLS file containing detector requirements (published on the web page referenced in previous slide) • DCS Detector experts were requested to provide feedback/corrections • NO reply! • You will be asked to provide some details during your presentation later today or tomorrow (missing numbers, milestones) • We assume, that the quoted numbers are complete • Data volumes are very important for infrastructure (FES , DB) • Last minute corrections will be expensive (both in terms of manpower and hardware! 17th DCS Workshop, P.Chochula

  4. Ways to provide calibration data to offline • 5 cases identified • Calibration is performed only by DAQ • Calibration is performed only by HLT • Calibration is performed only by DCS • Calibration is performed by DAQ and DCS either in dedicated runs or during physics runs • Calibration data is already stored in ConfDB and needs to be provided to offline 17th DCS Workshop, P.Chochula

  5. Communication between online systems and offline • Online systems are synchronized by ECS • Data exchange via DIM, Amanda or File Exchange Systems (FES or sometimes also called FXS) • DCS provides data to offline via Shuttle • Archived data is published by Amanda and collected by Shuttle • Some data is written to FES and collected by Shuttle 17th DCS Workshop, P.Chochula

  6. File Exchange Systems DAQ HLT FES FES DCS FES allow for exchange of huge data files between ALICE systems FES OFFLINE 17th DCS Workshop, P.Chochula

  7. DCS Calibration Data Flow for Cases 3,4,5 • Case 3 (all data prepared by DCS) • Data is written to Archive and/or FES and collected by Shuttle • Case 4 (combined run with DAQ) • Data is contained in the DCS Archive, made available to Shuttle by Amanda • This mechanism is also used by HLT during the normal run • Case 5 (copy of configuration data is needed) • Data will be provided via FES • Involved detectors need to provide more details • Configuration data will not go into DCS Archive (only version number is archived) 17th DCS Workshop, P.Chochula

  8. DCS Calibration Data Flow DAQ HLT FES FES Pendolino DCS Archive FES Shuttle OFFLINE 17th DCS Workshop, P.Chochula

  9. More DCS Calibration Data Flow DAQ HLT DIM FES FES Pendolino DCS Archive FES Shuttle OFFLINE 17th DCS Workshop, P.Chochula

  10. Typical Questions and Answers • Can be the ConfDB accessed by Shuttle? • No • How are the configuration parameters calculated by DAQ, Offline or HLT transferred to the DCS? • Via FES, dedicated software is needed (to be developed by detectors) • Can I transfer any data via Shuttle? • Technically yes, but offline will store only data needed for analysis • Use case needs to be described before we can provide more details 17th DCS Workshop, P.Chochula

  11. Typical Problems to be Answered • Which approach is used for the calibration in your detector? • What is the exact size of the data and what is the refresh rate? • Is all the data really needed for archival? • Sometimes we see attempts to archive all what is measured at highest possible rate • Please try to provide really realistic answer, the archive has limited size and very high cost • Is really all data listed in the referenced XLS document? 17th DCS Workshop, P.Chochula

  12. Actions for ACC • Implement the FES • Provide framework for accessing the FES • Work to be done in October, existing DAQ FES architecture will be used as a basis for DCS FES • Assist detectors in implementation • Please contact us well in advance • The sooner we start the better implementation we can prepare • We are late already now! • Computing infrastructure is now available 17th DCS Workshop, P.Chochula

  13. Conclusions • Visible progress, all detectors provided information during the calibration • Are we really sure that you talked to your offline experts? • Still some uncertainties in provided numbers • Missing data size and rate • Extremely demanding requirements – thousands of channels to be refreshed at ~Hz rate and archived without smoothing • Unclear procedures for obtaining the data • Strange data formats expected to be provided directly by the DCS (AliRoot Objects) which is not possible 17th DCS Workshop, P.Chochula

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