2016 WLCG Collaboration Workshop

ISCTE-IUL - University Institute of Lisbon

ISCTE-IUL - University Institute of Lisbon

Av. das Forças Armadas, 1649-026 Lisboa, Portugal

The 2016 WLCG Workshop in Lisbon will be devoted to in-depth discussions of the current issues and how to solve them in the medium term, and to have a common brainstorming on the long term future of WLCG over the coming 10 years.

Immediately after the WLCG workshop, a DPHEP workshop will take place and cross-participation is encouraged (agenda).

  • Alberto Aimar
  • Alberto Di Meglio
  • Alessandra Forti
  • Alexei Klimentov
  • Andrea Chierici
  • Andrea Manzi
  • Andrea Sciabà
  • Andrea Valassi
  • Andreas Haupt
  • Andreas Joachim Peters
  • Andreas Petzold
  • Andrej Filipcic
  • Andrew Bohdan Hanushevsky
  • Andrew McNab
  • Andrey Kirianov
  • Antonio Delgado Peris
  • Antonio Perez-Calero Yzquierdo
  • Artem Petrosyan
  • Benedikt Hegner
  • Bernd Panzer-Steindel
  • Brian Davies
  • Carlos Fernando Gamboa
  • Catherine Biscarat
  • Christoph Wissing
  • Claudio Grandi
  • Concezio Bozzi
  • Daniele Bonacorsi
  • Danilo Piparo
  • David Britton
  • David Kelsey
  • David Lange
  • David Michael South
  • Dietrich Liko
  • Dirk Duellmann
  • Domenico Elia
  • Edith Knoops
  • Edoardo Martelli
  • Elizabeth Sexton-Kennedy
  • Enrico Fattibene
  • Enrico Mazzoni
  • Eric Christian Lancon
  • Eric Fede
  • Eva Dafonte Perez
  • Federico Stagni
  • Fons Rademakers
  • Frank Berghaus
  • Frank Wuerthwein
  • Frederique Chollet
  • gaetano maron
  • Gareth Smith
  • Gavin McCance
  • Gerardo GANIS
  • German Cancio
  • Gianfranco Sciacca
  • Gianpaolo Carlino
  • Go Iwai
  • Guenter Grein
  • Hannah Short
  • Helge Meinhard
  • Hironori Ito
  • Ian Bird
  • Ian Fisk
  • Ian Neilson
  • Ian Peter Collier
  • Ikuo Ueda
  • James Letts
  • Jamie Shiers
  • Jean-Michel Barbet
  • Jeff Templon
  • John Gordon
  • Jordi Casals
  • Jorge Gomes
  • Jose Hernandez
  • Josep Flix Molina
  • Julia Andreeva
  • Kyle Gross
  • Latchezar Betev
  • Laurent Duflot
  • Luc Poggioli
  • Maarten Litmaath
  • Manfred Alef
  • Marco Cattaneo
  • Maria Alandes Pradillo
  • Maria Dimou
  • Maria Girone
  • Mario David
  • Markus Schulz
  • Matthias Schroder
  • Mattias Wadenstein
  • Michel Jouvin
  • Miguel Coelho dos Santos
  • Mike Hildreth
  • Miron Livny
  • Nathalie Rauschmayr
  • Nicolo Magini
  • Nilo Segura Chinchilla
  • Oliver Gutsche
  • Oliver Keeble
  • Oxana Smirnova
  • Patrick FUHRMANN
  • Peter Clarke
  • Peter Gronbech
  • Philippe Charpentier
  • Predrag Buncic
  • Rachid Lemrani
  • Raja Nandakumar
  • Randall Sobie
  • Reda Tafirout
  • Renaud Vernet
  • Rob Quick
  • Robert William Gardner Jr
  • Rodney Walker
  • Roger Jones
  • Romain Wartel
  • Ron Trompert
  • Ryan Taylor
  • Samuel Ambroj Pérez
  • Samuel Cadellin Skipsey
  • Sebastien Gadrat
  • Shawn Mc Kee
  • Sigve Haug
  • Simone Campana
  • Stefan Roiser
  • Stefano Bagnasco
  • Stefano Zani
  • Sven Gabriel
  • Takashi Sasaki
  • Tanya Levshina
  • Tibor Kurca
  • Tigran Mkrtchyan
  • Tim Bell
  • Tommaso Boccali
  • Tony Cass
  • Ulf Bobson Severin Tigerstedt
  • Vanessa Acín
  • Vladimir Sapunenko
  • Walter Lampl
  • Wei Yang
  • Xiaofei Yan
    • 9:00 AM 10:00 AM
      Software topics 1h
      • What is actually useful to do in common?
      • Tools or support for common automated and intelligent build/test/validation services?
      • More ? Common libraries etc? Role of HSF
      • What is usefully shareable?
      • Detailed software performance analysis and tools for analysis
      • All this should be in the context of the HSF. Some activities towards common (lower-level) build tools was started already. Organise a dedicated HSF workshop on this?-
      • Do experiments actually want to commit to the HSF for common software interests?
      • Given today's (and expected evolution of) processor and machine architecture, is today's data architecture (i.e. ROOT) appropriate - do we need to re-think completely?
      Speaker: Benedikt Hegner (CERN)

      Benedikt Hegner showed 6 slides.

      Frank Wuerthwein:  Go where the money is. KNL will be relevant in the US. For CMS Reconstruction will be the most cpu intensive data processing activity, and of that Tracking is the biggest part

      Marco Cattaneo: C++14 is coming, we all need to become familiar and develop expertise, need for common support

      Michel Jouvin  : HSF TN’s were started in order to address this, so that expertise can be shared

      Mattias Wadenstein : easier to deal with small projects; validation - use state of the art compilers, haven’t done anything yet on behalf of the entire community

      Fons Rademakers :

      • Need to keep tracking new (software) technologies such as Apple/Swift
      • Fast memories will have an impact - build a demonstrator to study them
      • ROOT format is used for storage model but this may be outdated - need to look at new technologies such as Kudu, C++ Object Storage
      • Interesting results coming out of taking a fresh look - Intel competition on Xenon Phi - student managed to increase the speed of neurobiology code by a factor of  x320
      • Make HSF a legal entity (cf Apache Foundation), handle Copyright in a better way, helps to get funding from industry, profit from work done in Machine Learning

      Benedikt Hegner :

      • several comments to make..
      • legal entity : this is a chicken/egg situation, HSF started small by a few volunteers, need to reach a critical mass and demonstrate feasibility of initiative, now need more participation from the community
      • Concurrency Forum fosters 1st round of demonstrators, now need to start a second round e.g. fast memories
      • Different languages have been looked at e.g. Go, but no real outcome, take a look at Julia, ….

      Ian Bird :

      • profiling tools were mentioned, it would be good to have measures of what can be achieved.
      • savings of 10% here and there are crucial since they have a big impact on costs. If they exist they should be used
      • I’d like to see some metrics of what can be done

      Danilo Piparo : we need to build a matrix of costs, for example see what we are prepared to give up; one example is precision, floating point give up IEEE performance

      Liz Sexton-Kennedy : we have one person to do it for the experiment, this is a fundable model, have developer and user work closely together to achieve results

      Latchezar Betev : for simulation code is focused in one place, therefore optimisation can be done for whole community, surprised more emphasis has not been given to this in the discussion

      Marco Cattaneo :

      • careers are important, need to raise the profile of developers
      • not a part-time job for a student, engineers are important
      •  middleware is not a job for a physicist, get this on the radar of management

      Stefan Roiser : try to involve SE institutes - those close to our physics depts. and collaborate with computer scientists; in LHCb we need to change our framework and in particular the data model in order to exploit vectorisation for example, currently we are not using SIMD

      Ian Bird: there are ways of giving recognition (see mail thread that was circulating earlier this year; idea is to look at code that is accessed/used in git repositories such that articles can reference what has been used in a piece of work, this allows developers to build their CVs

      Danilo Piparo:

      • I agree its important to work with computer scientists, however the biggest role is still played by physicists;
      • have to understand the impact of any software change on physics results

      Benedikt Hegner : yes we need physicists for validating impact on physics results, but this shouldn’t prevent us for being outward-looking and learning from other fields, there is a place for non-physicists and this will help us to avoid re-inventing the wheel

      Miron Livny : From experience, solutions owned by experiment(s) don’t become common, only solutions that are owned outside the experiments have a good chance to become common solutions.

      Liz Sexton-Kennedy : Disagrees. Frontier and xrootd were solutions that grew out of a single experiment (CDF, BaBar). The solution has to be proven to work at scale for somebody before it is accepted by another. Common solutions need to be open source because it increases the trust between developers from different organizations.


      Jeff :

      • Here in Netherlands we benefit from participation of non-physicists
      • However experience shows it is hard to rethink an algorithm if you are not a physicist
      • Try community building i.e. one good place where people can talk to each other 

      Oxana : we need to lower the threashold for invoving non-physicists who would like to help

      Frank Wuerthwein : If I look in CMS, the biggest contribution to tracking came from 5 people, 3 of whom have permanent jobs; I’d suggest that physicists have a harder time becoming permanent

      Benedikt Hegner :

      • HSF is everybody, you are all invited to contribute, need to assemble people who are keen to do technology tracking
      • In reply to question from John, the HSF Workshop will take place at LAL, Orsay, Paris and the current favoured time is first week of May, time hopefully to be fixed early next week


      note taker :    John Harvey

    • 10:00 AM 10:30 AM
      Coffee 30m
    • 10:30 AM 12:30 PM
      Future work and actions
      Convener: Ian Bird (CERN)
    • 2:00 PM 6:00 PM
      DPHEP Workshop (click the link on the right for the agenda)