The activties of the Off-line Project include the development of the ALICE Off-line framework and the central coordination, maintenance and distribution of the software. This in order to allow an easier and more productive access for all the physicists to the Software tools needed to realise the physic potential of the ALICE experiment.
In particular the Off-line Project has been concentrating on the following activities
- Framework development
- Simulation Framework
- Reconstruction Framework
- Raw Data
- Condition Database
- Analysis Framework
The development of the ALICE Off-line framework started at the beginning of 1998, and at that time few strategic choices were taken
- Burn the bridges, i.e. migrate immediately to an OO environment
- Collaborate closely with physicists and provide them with working tools (ROOT, GEANT3)
- Support and train the user community
The membership of the Offline Computing Board is here.
Off-line development is a transversal as well as a vertical activity. It has specific items, such as mass storage or visualisation that are developed according to the user requirements by few experts, and that are usually seen as internal Off-line activities. But all the physicists involved in ALICE are users of these tools. Moreover, a large part of the software will eventually come from the physicists themselves, and will have to be integrated in the framework.
This natural logical distribution of the Off-line project is accompanied by a geographical de-localization. The number of software developers present at CERN will be very limited at each moment, so that the development will be geographically distributed. The Off-line Project will have to play complementarity and concentrate on
- Framework development
- Central co-ordination
- Release control and distribution
and it should delegate to the detector groups
- Detector code development and integration
- Detector code release control
- Contact with CERN software team
To achieve this goal, the Off-line Project needs a different management structure from the other projects, which could reflect its special nature.
During the ALICE week of September 20-23 1999, a proposal for the organisation of the ALICE Off-line Project has been accepted by the Management Board.
The Off-line Project is steered by an Off-line Computing Board. Every Project (detector) formally commits to name one or two full time Off-line co-ordinators, depending on the size of the Project. These are intended to be medium term nominations (of the order of 3 years), with a substantial overlap between one person and its successor.
Members of the Computing Board will be also one representative of the Physics Board and of the Off-line Project, representatives of the Regional Centres, when those will be established, and lead developers of the major software packages.
ALICE has recently joined the Monarc project and its computing centre policy is being defined. Representatives from major computing centres will be completed as soon as those interested are identified.
Main tasks of the Board will be
- Plan development of the Off-line
- Ensure communication with Detectors
- Define and review milestones
- Define and monitor progress of workpackages
While the CERN Off-line group will develop the global infra-structure, the representatives of the different projects will concentrate on the software of the project, making sure that it all fits in a coherent ensemble. In particular the tasks of the representatives are:
- Physically manage the insertion and update of the code into the central repository
- Participate in the planning of the global Off-line Project. In particular participate in defining goals and milestones that are realistic and relevant to the collaboration
- Find and coordinate the necessary resources within their project to meet the agreed milestones
- Interface Off-line activities with the other activities in the project, such as test beams, DAQ and detector design
- Provide front line support for Off-line users in the project, filtering trivial problems and reporting the others to the Off-line project
- Maintain and develop the project-specific Off-line code, In particular this means providing adequate documentation for the code and a test suite.