1. The PH-SFT Group Mandate, Organization, Achievements Software Components Software Services Summary January 31st, 2011 1

2. SFT Group Mandate The group develops and maintains common scientific software for the physics experiments in close collaboration with the PH experimental groups, the IT department and external HEP institutes The majority of the group is directly involved in projects organized as part of the Applications Area of the LHC Computing Grid Project (LCG-AA) In addition, several group members have direct responsibilities in the software projects of the LHC experiments January 31st, 2011 2 http://sftweb.cern.ch

3. Activity Organization Group activities are organized around the main products and services Baseline projects: Simulation: Geant4, Physics Validation and Event Generators ROOT: ROOT Core, ROOT Analysis, PROOF SPI: builds, tests, externals, web, Savannah R&D projects: Multicore: parallel frameworks, performance studies CernVM : image production, file system Geant: investigation of new approaches in event simulation We meet regularly with the leaders of the core software projects of the LHC experiments Architects Forum (AF), with representation from each of the experiments and IT, monitors and steers regularly these projects January 31st, 2011 3 http://lcgapp.cern.ch/project/mgmt/af.html

4. Applications Area Organization January 31st, 2011 4 AA Manager Alice Atlas CMSLHCb Architects Forum Application Area Meeting MBLHCC External Collaborations Geant4 ROOT Work plans Quarterly Reports Reviews Resources LCG AA Projects EGEE Chairs Decisions SIMULATION SPI WP1 WP2 ROOT WP3 WP1 POOL WP3 WP2 WP1 Subproject 1 IT-GD IT-FIO

5. Simulation Project Development and validation of simulation software components. Bringing together developers with physicists working on simulating the real LHC detectors Geant4. Development, maintenance and support of several modules, including the geometry and a number of physics models. Infrastructure for the collaboration for testing and releasing the software. Generator Services (Genser). Provides validated MC generators for the theoretical and experimental communities at the LHC. Physics validation. Comparisons of the main detector simulation engines for LHC (Geant4 and FLUKA) with experimental data. Meetings with the experiments: Physics Validation meetings MC Generator meetings January 31st, 2011 5

6. ROOT Project Development and maintenance of the ROOT framework and set of foundation and utility class libraries that are used as a basis for developing HEP application codes The main components are: Utilities and extensions to C++, I/O system, interpreters (CINT, Python), data visualization (2D & 3D), graphical user interface, mathematical and data analysis libraries, etc. PROOF enables distributed data sets to be analyzed in a transparent way. January 31st, 2011 6

7. Software Process & Infrastructure (SPI) Project Provides a common software development infrastructure and delivers complete and validated set of software components to the LHC experiments Software configuration External libraries (~100 open-source and public domain libraries) Software development tools and services Nightly build, testing and integration service Documentation tools (doxygen, opengrok) Quality assurance (coverity, qmtest) Collaborating tools (Savannah) Infrastructure in general (build servers, web, etc.) January 31st, 2011 7

8. R&D Multi-core - Parallelization of Software Frameworks to exploit multi-core Processors Investigate current and future multi-core architectures. Measure and analyze performance of current LHC application software Investigate solutions to parallelize current LHC physics software at application framework level and also investigate solutions to parallelize algorithms Virtualization - Portable Analysis Environment using Virtualization Technology Development the “CernVM” virtual appliance common to all the experiments Deployment of a read-only distributed file system with aggressive caching schema, as well as the pilot infrastructure to serve the software installation on demand January 31st, 2011 8

9. ROOT Consolidation and speed-up of the ROOT I/O system EVE event display for Alice, CMS and a number of non-LHC PROOF in production in Alice, tests in ATLAS and CMS. PROOF-lite widely used on multi-core machines Development of RooStats in collaboration with ATLAS and CMS SIMULATION Comparisons of 2010 MC productions and first LHC real data show an excellent agreement Implementation of FTFP and CHIPS models have been tested by ATLAS and CMS and will be production quality in 9.4 release. These lists give smoother response in transition region Alternative to parameterizations for anti-protons, kaons, hyperons etc. Main Achievements 2010 January 31st, 2011 9

10. R&D Finalized Gaudi Parallel framework (ATLAS and LHCb) Performance instrumentation of CMSSW, Gaudi and Geant4 CernVM virtual platform being taken up by ATLAS, LHCb and CMS The CernVM-FS has created a lot of interest from the Tier1,2,3 sites User Support and Training Answering in average 40 issues/requests per working day from users Provided 12 lecturers to 4 schools and tutorials (CSC, G4, INFN, etc.) Supporting Experiments Software Development Provided complete releases and a service for continuous integration and testing to ATLAS, CMS, LHCb and all AA projects Deployment of AA software for the CERN Theory group Identified and deployed a tool that is helping the experiments to eradicate many thousands of “defects” in their codes Main Achievements 2010 (2) January 31st, 2011 10

11. Software Components January 31st, 2011 11

12. 12 Simplified Software Structure non-HEP specific software packages Experiment Framework Event Det Desc. Calib. Applications Core Libraries Simulation Data Mngmt. Distrib. Analysis Every experiment has a framework for basic services and various specialized frameworks: event model, detector description, visualization, persistency, interactivity, simulation, calibrarion Many non-HEP libraries widely used (e.g. Xerces, GSL, Boost, etc.) Applications are built on top of frameworks and implementing the required algorithms (e.g. simulation, reconstruction, analysis, trigger) Core libraries and services that are widely used and provide basic functionality (e.g. ROOT, HepMC,…) Specialized domains that are common among the experiments (e.g. Geant4, COOL, Generators, etc.) January 31st, 2011

13. Foundation Libraries Basic types Utility libraries System isolation libraries Mathematical Libraries Special functions Minimization, Random Numbers Data Organization Event Data Event Metadata (Event collections) Detector Description Detector Conditions Data Data Management Tools Object Persistency Data Distribution and Replication 13 Software Components  Simulation Toolkits Event generators Detector simulation  Statistical Analysis Tools Histograms, N-tuples Fitting  Interactivity and User Interfaces GUI Scripting Interactive analysis  Data Visualization and Graphics Event and Geometry displays  Distributed Applications Parallel processing Grid computing One or more implementations of each component exists for LHC January 31st, 2011

14. C++ used almost exclusively by all LHC Experiments LHC experiments with an initial FORTRAN code base have completed the migration to C++ long time ago Large common software projects in C++ are in production for many years ROOT, Geant4, … FORTRAN still in use mainly by the MC generators Large developments efforts are being put for the migration to C++ (Pythia8, Herwig++, Sherpa,…) Java is almost non-existent for LHC Exception is the ATLAS event display ATLANTIS 14 Programming Languages January 31st, 2011

15. Scripting has been an essential component in the HEP analysis software for the last decades PAW macros (kumac) in the FORTRAN era C++ interpreter (CINT) in the C++ era Python is widely used by 3 out of 4 LHC experiments Most of the statistical data analysis and final presentation is done with scripts Interactive analysis Rapid prototyping to test new ideas Scripts are also used to “configure” complex C++ programs developed and used by the experiments “Simulation” and “Reconstruction” programs with hundreds or thousands of options to configure 15 Scripting Languages January 31st, 2011

16. Python language is really interesting for two main reasons: High level programming language Simple, elegant, easy to learn language Ideal for rapid prototyping Used for scientific programming (www.scipy.org) Framework to “glue” different functionalities Any two pieces of software can be glued at runtime if they offer a “Python interface” With PyROOT any C++ class can be easily used from Python 16 Role of Python January 31st, 2011

17. Standard Data Formats HepMC- Event record written in C++ for HEP MC Generators Many extensions from HEPEVT (the Fortran HEP common block) Agreed between MC authors and clients (LHC exp., Geant4, …) I/O support (ASCII files and ROOT I/O) GDML - Geometry Description Markup Language (XML) Low level (materials, shapes, volumes and placements) Quite verbose to edit directly Directly understood by Geant4 and ROOT Standard Event Data models? Within an experiment the Event model spans all applications Algorithms can be easily re-used between reconstruction, high-level trigger, simulation, etc. Sharing of Event Data models between LHC expts. has not happened On the contrary, LCIO is a very successful Event Model (and I/O system) for the ILC community January 31st, 2011 17

18. Highly optimized (speed & size) platform independent I/O system developed for more than 10 years Able to write/read any C++ object (event model independent) Almost no restrictions (default constructor needed) Make use of ‘dictionaries’ Self-describing files Support for automatic and complex ‘schema evolution’ Usable without ‘user libraries’ All the LHC experiments will rely on ROOT I/O for years to come 18 ROOT I/O January 31st, 2011

19. Experiments have developed Application Frameworks General architecture of any event processing applications (simulation, trigger, reconstruction, analysis, etc.) To achieve coherency and to facilitate software re-use Hide technical details to the end-user Physicists Help the Physicists to focus on their physics algorithms Applications are developed by customizing the Framework By the “composition” of elemental Algorithms to form complete applications Using third-party components wherever possible and configuring them ALICE: AliROOT; ATLAS+LHCb: Athena/Gaudi; CMS: CMSSW 19 Data Processing Frameworks January 31st, 2011

20. GAUDI is a mature software framework for event data processing used by several HEP experiments ATLAS, LHCb, HARP, Fermi, Daya Bay, Minerva, BES III, LBNE/WCD The same framework is used for all applications All applications behave the same way (configuration, logging, control, etc.) Re-use of ‘Services’ (e.g. Det. description) Re-use of ‘Algorithms’ (e.g. Recons -> HTL) 20 Example: GAUDI Framework January 31st, 2011

21. Services January 31st, 2011 21

22. Windows (XP) Mac OSX (10.5) Software Configurations 22 LCG / AA external software LCG / AA external software Python Boost Qt Xerces GSL valgrind Grid … ~70 pack ages LCG / AA projects LCG / AA projects ROOT POOL COOL CORAL RELAX Linux (slc4, slc5) X gcc 4.0 icc 11 gcc 3.4 gcc 4.3 llvm 2.4 vc 7.1 vc 9 32 bit 64 bit = ~ 20 different platforms LCG Configuration Java LHC Experiment Software LHC Experiment Software AliRoot CMSSW Gaudi Athena MacOSX 10.6 LHC Experiment Software LHC Experiment Software AliRoot CMSSW Gaudi Athena Windows LHC Experiment Software LHC Experiment Software AliRoot CMSSW Gaudi Athena Linux (slc4, slc5) LCG 60

23. Continuous Integration &Testing 23 Every day Different platforms Build & Test All LCG/AA projects Different Configurations Test History

24. LHC Software Testing Stack 24

25. Benefits Self-consistent sets of basic software packages Use of recent packages / tools HEP specific patches when needed Tested in complete configurations Several deployment methods possible Virtual Machine, LCG/AA binaries or recompilation Multi platform / architecture / compiler Continuous performance / unit / integration testing Adding to overall software stability 25

26. Tools and Services January 31st, 2011 26 http://sftweb.cern.ch/devtools

27. Savannah January 31st, 2011 27

28. Coverity Coverity is a professional, high quality tool that finds problems in C++ code by simply looking at that code (static code analysis) It is used by several projects within or connected to PH-SFT, as well as by most of the LHC experiments, to track down bugs in code before anybody ever runs it. January 31st, 2011 28

29. Summary The group is developing a number of software components mainly in the area of Simulation and data Analysis Report problems, feature requests, special needs using the information channels in place (savannah, meetings, AF) Good standardization in the use of tools With the LHC experiments we have managed to keep diversity rather low while being open to evolutions and new suggestions Using common tools and libraries reduces the effort that the experiment has to invest in the long term Contact us if you need any advise on packages or tools January 31st, 2011 29

30. Additional Slides January 31st, 2011 30

31. Predefined component ‘vocabulary’ E.g. ‘Algorithm’, ‘Tool’, ‘Service’, ‘Auditor’, ‘DataObject’, ‘Property’, ‘DetectorCondition’, etc Separation from interfaces & implementation Allowing for evolution of implementations Plug-in based (dynamic loading) Homogenous configuration, logging and error reporting Built-in profiler, monitoring, utilities, etc. Interoperable with other languages (e.g. Java, Python, etc.) 31 Features of an ideal Framework January 31st, 2011

32. Separation between “data” and “algorithms” Three basic categories of “data” event data, detector data, statistical data Separation between “transient” and “persistent” representations of data Data store-centered (“black-board”) architectural style “User code” encapsulated in few specific places Well defined component “interfaces” with plug-in capabilities 32 Gaudi: Principal Design Choices January 31st, 2011

33. 33 Gaudi: Algorithms & Transient Store Algorithm A Algorithm B Algorithm C Transient Event Data Store Data T1 Data T2, T3 Data T2 Data T3, T4 Data T4 Data T5 Data T1 Data T5 Real dataflow Apparent dataflow January 31st, 2011

34. Gaudi: Control Sequences Concept of sequences of Algorithms to allow processing based on physics signature Avoid re-calling same algorithm on same event Different instances of the same algorithm possible Event filtering Avoid passing all the events through all the processing chain 34 Event Input/Output Algorithm Filter Decision Single Instances January 31st, 2011

35. Typically the execution of Algorithms are explicitly specified by the initial sequence and and sub-sequences Avoid too-late loading of components (HTL) Easier to debug For some use-cases it is necessary to trigger the execution of a given Algorithm by accessing an Object in the Transient Store The DataOnDemand Service is can be configured to provide this functionality Gaudi: Data On Demand 35 January 31st, 2011

36. Other Gaudi Services JobOptions Service Message Service Particle Properties Service Event Data Service Histogram Service N-tuple Service Detector Data Service Magnetic Field Service Tracking Material Service Random Number Generator Chrono Service (Persistency Services) (User Interface & Visualization Services) (Geant4 Services) 36 January 31st, 2011

37. Each Framework component can be configured by a set of ‘properties’ (name/ value pairs) In total thousands of parameters need to be specified to fully configure a complex HEP application Using Python to facilitate the task Python ”configurables” generated from C++ Build-in type checking Gaudi: Configuring the Application 37 January 31st, 2011

38. 38 Worker Transient Event Store Reader Transient Event Store Algorithm Event Input Queue Input Event Data Writer Transient Event Store output OutputStream Event Output Queue gaudirun –-parallel=N optionfile.py Configuration January 31st, 2011