1. 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

2. 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

3. 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

4. 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

5. 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

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

7. 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

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

9. 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

10. 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

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

12. 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

13. 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

14. 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

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

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

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

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

19. 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

20. 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