LHC-B Computing Computing Tasks Computing Model Software Strategy Objectives Technology People Project Plan for LHC-B Computing Project organization Development phases and major milestones John Harvey - October 29, 1997 LHCB Status Report

LHC-B Computing Group Pavel Binko Olivier Callot Lola Camacho Marco Cattaneo Jean-Pierre Dufey Yuri Ermoline Markus Frank Frank Harris John Harvey Eric van Herwijnen Irakli Mandjavidze Pere Mato Hans Muller Andreu Pacheco Florence Ranjard Wolfgang Tejessy Andrei Tsaregorodtsev John Harvey - October 29, 1997 LHCB Status Report

Introduction New software for a new experiment intense use of software in triggering (Levels 1,2, and 3) many orders of magnitude more data and CPU power Need better quality Control better designs, better control procedures, more manpower intensive Resources scarce improve efficiency - use engineering practices and modern technologies strategy must encourage all members of collaboration to participate Need experienced people LHC-B staff active in current experiments - big advantage Need to close culture gap Long lead times Important to have a well-defined strategy and investment in project management and planning John Harvey - October 29, 1997 LHCB Status Report

Software Strategy Objectives Reuse put effort into building high quality components become economic by extracting more use out of components Architecture-driven approach identify basic building blocks - 3 levels : patterns, components, frameworks reuse spans across application domains event display, geometry DB, data storage models, controls, GUI Common Infrastructure standardise on a set of working principles, process, development environment minimise diversity of hardware and software Commercial software Licensing model to minimise cost and ensure collaboration-wide availability Evolution development and maintenance span ~20 years plan for changes in needs and technology John Harvey - October 29, 1997 LHCB Status Report

Software Strategy Technology Why Object Technologies (OTs) ? Evolved from sound principles of software engineering Young staff with some training in computing familiar with OTs Technical prerequisites are in place development environments (languages etc.), ODBMS, communication standards, frameworks Widespread use and support by computing industry Adoption by HEP collaborations (BaBar, STAR, LHC,…) Object modeling leads naturally to reusability encapsulation, design patterns, component-ware, frameworks John Harvey - October 29, 1997 LHCB Status Report

Software Strategy Technology - Languages John Harvey - October 29, 1997 LHCB Status Report

Software Strategy Technology - Distributed Computing OMG Application Objects Common Facilities Object Request Broker Object Services Different standards CORBA, IDL (OMG - ODMG) DCOM, OLE (Microsoft) Javabeans / RMI (Javasoft) John Harvey - October 29, 1997 LHCB Status Report

Current LHC++ components John Harvey - October 29, 1997 LHCB Status Report

Manpower - Profiles Architects Software Engineers Software Toolsmiths experienced in design of large software systems, familiar with standards. deliver architectural design documents and frameworks Software Engineers develop basic building blocks , apply quality control require formal training in software engineering practices deliver reference documents and user guides Software Toolsmiths select and maintain software tools used to build our software install software tools and give support to programmers in their use manage the codebase and production processing on real and simulated data keeping track of all LHCB datasets Application Programmers must be familiar with software development environment and follow quality procedures when appropriate trained in use of supported languages, design methods and tools John Harvey - October 29, 1997 LHCB Status Report

Migration Strategy Harvest knowledge in legacy systems - dump legacy thinking LHC-B has limited software production activity now - this will change Longer we delay the more difficult it will be to make the transition Hands-on experience best way to learn Need a framework equipped with basic tools before people can start Intensive training can start once this framework is ready Need mentors and knowledge transfer between staff Technology still evolving and must be tracked - choices at appropriate times Benefit from support groups - news services, library, seminars, in-house training, support for engineering tools, joint projects John Harvey - October 29, 1997 LHCB Status Report

Other issues addressed in report Software development process Documentation Collaborative Computing Training John Harvey - October 29, 1997 LHCB Status Report

Organization of Computing Projects Steering Group • coordination • planning • architecture • budget OFF-LINE ON-LINE Computing Recon- Analysis Simul- ation DAQ DCS OPS SEG Facilities struction • Level 2 • Framework • Framework • Event • DCS • Control Tools & methods • Computing • Level 3 • Tools • Tools Builder • LHC room Model • Prompt • Production • Interfaces • Safety • SDE • CPU farms • Full • Crates • CASE • Desktop • DAQware • Code • Storage management • Network • Quality Re-usable Components Control • Event Display • Document. • Frameworks • Data Quality • Training • CORBA,DCOM • Bookkeeping • Licenses • OS • Librarian Collab Tools • Data management (DBMS) • Controls • Event Storage (HPSS) • GEANT4 • Graphical User Interfaces • CLHEP • Histograms John Harvey - October 29, 1997 LHCB Status Report

Links to Sub-detector Groups Application Project (e.g. DAQ) RICH Computing Team Project Leader Vertex RICH Inner Tracker Outer Tracker ECAL HCAL MUON Trigger L0 Trigger L1 Trigger L2/L3 John Harvey - October 29, 1997 LHCB Status Report

Development Phases Identify phases by boundaries which correspond to major decisions Plan for technology change Move to OTs which will have major impact FORTRAN to C++ Important to prototype gain experience study behaviour and performance After prototype phase take final decisions on technology Boundary of prototype and production phase should have less major impact design review, C++ to JAVA? John Harvey - October 29, 1997 LHCB Status Report

Software Planning for Transition Phase (1) John Harvey - October 29, 1997 LHCB Status Report

Software Planning for Transition Phase (2) John Harvey - October 29, 1997 LHCB Status Report

Global Software Planning Showing Main Development Phases John Harvey - October 29, 1997 LHCB Status Report

Global Planning For DAQ System John Harvey - October 29, 1997 LHCB Status Report

Summary Immediate challenge is a change of software paradigm Plan to make transition as painless as possible Relatively good position since we start later and have less investment in legacy code We have a kernel of experienced people - to be complemented by outside help Long term strategy involves a prototyping (learning) phase and a production phase Organise all computing as one project minimise barriers between on-line and off-line maximise reuse of software components John Harvey - October 29, 1997 LHCB Status Report

Software Strategy Architecture-driven development Patterns well engineered systems are full of patterns means of leveraging expertise of experienced architects provide a common vocabulary and understanding for design principles Components systems constructed out of re-usable tested components, with known characteristics and well-defined interfaces take longer to build, cost is higher often can be commercially obtained Frameworks set of pre-fabricated building blocks used, extended or customised for a particular application. ~half code in a typical application dedicated to routine operations, that can be built once and canned for reuse…frameworks give high level of reuse e.g. framework that provides histogramming, statistical analysis, visualisation can be used for interactive analysis, data quality monitoring, …. John Harvey - October 29, 1997 LHCB Status Report