# Presentation: 268680

##     “International” ATLAS Overview: DoE/NSF Nov. 2001 

- Norman McCubbin (RAL)
- Computing Co-ordinator

- McCubbin ATLAS DoE/NSF Nov 01

## Computing: DoE/NSF Nov. 2001

- This report will concentrate on:
- Status of and progress on software components;
- US roles; effort; software agreements; Grid
- The ‘theme’ during 2001 has been increasing the usage of, and therefore the feedback’ on, the ‘new’ (OO/C++) software. This theme will continue in the future.
- 2001: Software release for ATLAS Physics workshop in September at Lund.
- This workshop resulted in ~30 new users (100 total) of software, and generated extensive feedback.

- McCubbin ATLAS DoE/NSF Nov 01

## Computing: DoE/NSF, Nov. 2001

- 2002-3: First round of Data Challenges (DC):
- DC0: December01/Jan02: ‘100k’ events as ‘continuity’ check of software chain: Geant3 plus updated detector geometry, reconstruction under Athena.
- DC1: February to July 2002:
- ‘Phase 1’: DC0 software + enhanced ‘Event Model’ to provide samples of O(10^7) events for TDAQ/High Level Trigger(HLT) community for TDR at end 2002. Also test of Athena and algorithms for use in HLT;
- ‘Phase 2’: Phase1 software + enhanced handling of Det. Description: substantial samples for a) Physics studies and b) testing of Geant4.
- Use of Grid, depending on what’s available and useful.
- DC2: First half of 2003. ‘x10’ increase in scale compared to DC2. Extensive use of Grid.
- The DCs have already had a highly beneficial ‘catalytic’ effect in concentrating minds and effort on what has to be got ready. (I see them as ‘reality checks’.)
- Detailed planning under direction of G.Poulard (CERN), Data Challenge Co-ordinator.

- McCubbin ATLAS DoE/NSF Nov 01

## Computing: DoE/NSF Nov. 2001

**Software Components:**
**Releases: ** Appointment of (‘rotating’) Release Co-ordinator has helped to sharpen planning and organisation of releases. We have just  decided to switch to CMT as ‘release tool’. Release 3.0 (December) will define the software for Data Challenge 0.
**Athena Framework (major US)**: Release 2 (‘Lund’) used successfully for full reconstruction and fast simulation. Release 3.0 features will include improved ‘StoreGate’ (access to Transient Event Store), infrastructure for ‘pile-up’ handling, prototype for handling ‘time-dependent’ conditions data (e.g. Detector Description).
**ATLAS ‘Dictionary’ (US leadership of French effort): ** Idea is to describe all classes in ‘meta-language’ (IDL) and then generate all necessary C++ code, in particular the C++ ‘header’ file and I/O ‘converters’ (for ROOT, Objectivity,..) Prototype exists and is being tested by ~6 people with real ATLAS classes. Prototype already useful and more features in Release 3.0. (picture next page.)

- McCubbin ATLAS DoE/NSF Nov 01

## CBE-Generated Files

- McCubbin ATLAS DoE/NSF Nov 01

## Computing: DoE/NSF, Nov. 2001

- Software Components (contd.)
**Simulation**: Geant4: Substantial and significant ATLAS input into Geant4 Review (end June; report still awaited.) (picture) ATLAS validation of Geant4 e.m processes now shows agreement/disagreement with data at roughly same level as Geant3. Studies of hadronic processes now started. FADS/Goofy simulation framework beta release last month. (There are some US sensitivities on this point which are being addressed.)** ** Several detectors now described in G4. Significant production test of G4 planned for phase 2 of DC1 around middle of 2002.  Geant3: geometry description updated to latest detector annd pile-up handling upgraded. (Essentially ready for DC0 and DC1.)

- McCubbin ATLAS DoE/NSF Nov 01

## Muon Spectrometer (G4)

- Shower production by muons
- Studies the production of extra particles from muon-induced electromagnetic showers in absorbers placed in front of the muon chambers and compares to test beam data:
- Gross features are fairly reproduced (at the 10% level) for light absorber material (Al), less so for heavier material (Fe):

- McCubbin ATLAS DoE/NSF Nov 01

## Computing: DoE/NSF, Nov. 2001

- Software Components (contd.)
**DataBase (major US,  D.Malon now co-ordinator):** Athena I/O with Objy and ROOT I/O now possible, with some limitations (e.g. ROOT ‘blobs’). Focus of DC0 will be Objy. ROOT I/O will be upgraded (‘trees’) for DC1. Technology evaluation is part of DC1 Phase2. Evaluation criteria being planned. We are of course in contact with other LHC experiments on this important topic.
- DataBase group has produced architecture document: _[http://atlas.web.cern.ch/Atlas/GROUPS/DATABASE/event_store/ev-arch-index.html](http://atlas.web.cern.ch/Atlas/GROUPS/DATABASE/event_store/ev-arch-index.html)_ and this was announced to ATLAS ‘s/w’ and ‘physics’ lists recently. Aim is to review this architecture early in 2002.
- Detector Description: Coherent (across Sim. and Reco.) treatment of detector description from single (‘xml’) source essential for G4 tests in Phase 2 DC1. Work in progress.

- McCubbin ATLAS DoE/NSF Nov 01

## Computing: DoE/NSF Nov. 2001

- Software components (contd.)
**Event Data Model**: New version needed for Phase 1 DC1 (HLT production). Being addressed vigorously. Impetus from HLT community enormously valuable.
**Reconstruction Codes**: Essentially ready for old (PhysicsTDR) geometry. Some small changes being done to for updated geometry. Expected (and required) to be ready for DC0. Detailed planning in release schedule.
**‘****Book-keeping’**: (‘what was run when and where and how, and where is it now...’) Encouraging collaboration of ATLAS, EU-DataGrid and PPDG (US). Something could be ready for DC0 and certainly needed for DC1.

- McCubbin ATLAS DoE/NSF Nov 01

## Computing: DoE/NSF, Nov. 2001

- Reviews:
- Architecture Review Committee (ARC): Lengthy (1 year!) but valuable process. Athena endorsed, but with many wide-ranging recommendations. Most recommendations non-controversial and acted on (e.g. dBase architecture document.) ARC also spent some time, and recommendations, on the Athena/Simulation issue.
- Geant4: already mentioned.
- LHCC: Concentration (at referees’ request) on Athena and G4/G3. Quite lengthy discussion of our overall Geant strategy, which was understood.
- Lund Physics w/shop: already mentioned.

- McCubbin ATLAS DoE/NSF Nov 01

## Computing: DoE/NSF, Nov. 2001

- Effort: Effort in ‘core’ s/w around 40 today, and similar in ‘non-core’. US around is 10+2.5 fte, but this underestimates importance of US contribution.  Still some (~6 fte) critical ‘infrastructure’ posts vacant (toolsmith, documentation, training, web pages, planning... also graphics) Some key personnel have been lost to burgeoning Grid projects.
- Software Agreements:
- Signed in September 2001 with US and France on Framework and Data Dictionary. (8fte)
- With France (signed October) and UK (being prepared) on Quality Assurance. (1 fte)
- In preparation: swa to cover support for CMT. (<1fte)
- Next: DataBase

- McCubbin ATLAS DoE/NSF Nov 01

## The LHC Computing Grid Project Structure

- The LHC Computing Grid Project

**LHCC**

**Project Overview Board**

**Project****Execution****Board**

**Software and****Computing****Committee****(SC2)**

**Reports**

**Reviews**

**Common****Computing****RRB**

**Resource Matters**

**Other****Computing****Grid****Projects**

**EU****DataGrid****Project**

- implementation teams

**Other HEP****Grid****Projects**

**Requirements,**
**Monitoring**

**Other**
**Labs**

- McCubbin ATLAS DoE/NSF Nov 01

## Computing: DoE/NSF, Nov. 2001

- LHC Computing Grid Project (LCGP): See Les Robertson talk earlier this week.
- ATLAS considers that the success of the LCGP is crucial to the success of LHC, and therefore ATLAS, computing. Note that it differs from the other Grid projects in that it is primarily about  ***Grid deployment*** for the LHC experiments. The LCGP must make use of the products of the other Grid projects. It therefore has a natural co-ordinating role.

- McCubbin ATLAS DoE/NSF Nov 01

## Computing: DoE/NSF, Nov. 2001

- LHC Computing Grid Project (LCGP): (contd.) Note also that it NOT just a CERN project: it is for the LHC as a whole. Although initial negotiations imposed some distinction between Member States and NMS, ATLAS has urged, and will continue to urge, that this distinction be as small as possible, ideally zero.
- The experiments have a crucial role here: see for example ATLAS effort (D.Malon) on book-keeping which has input from Atlas, EUDataGrid WP1, and PPDG. The experiments are the ‘glue’.

- McCubbin ATLAS DoE/NSF Nov 01