Computing Technical Design Report

Contents

ATLAS Collaboration

Acknowledgements

Editorial Board

1 Introduction

1.1 Overview
1.2 Outlook

2 Computing Model

2.1 Introduction
2.2 Input Parameters for Proton-Proton Collisions
2.2.1 LHC Operational Parameters and Trigger Rates
2.2.2 Types of Data
2.2.3 Event Store
2.2.4 The Tier Structure and the Roles of the Various Tiers
2.2.5 Data Flow
2.3 Data Analysis
2.3.1 Analysis Procedures and Data Flow
2.3.2 The Analysis Model and Access to Resources
2.3.3 Distributed Analysis System
2.4 Simulation Process
2.5 Calibration and Alignment
2.5.1 Types of Processing
2.5.2 Calibration Streams
2.5.3 Prompt Reconstruction Latency
2.5.4 Offline Calibration and Alignment
2.6 Heavy Ion Data
2.7 Commissioning the System
2.8 Summary
2.9 References

3 Offline Software

3.1 Introduction and Requirements
3.2 Methodology and Domain Decomposition
3.2.1 An Object-Oriented Methodology
3.2.2 Domain Decomposition
3.3 The Athena Framework
3.3.1 Introduction
3.4 Data Access Model
3.4.1 Data Objects and Algorithms
3.4.2 StoreGate: the ATLAS Transient Data Store
3.4.3 Data Objects
3.4.4 Accessing Data Objects
3.4.5 Using DataLinks to Persistify References
3.5 Detector Description
3.5.1 ATLAS Geometry DB Schema - the Hierarchical Versioning System (HVS)
3.5.2 The Geometry Kernel (GeoModel)
3.5.3 Generic Identification Scheme Connecting Events and Detector Description
3.6 Graphics and Event Display
3.6.1 Introduction
3.6.2 Atlantis
3.6.3 HEPVis/v-atlas
3.6.4 Persint
3.7 Calibration and Alignment
3.7.1 Inner Detector
3.7.2 Liquid Argon and Tile Calorimeters
3.7.3 Muon Spectrometer
3.8 Simulation
3.8.1 The Simulation Data Flow
3.8.2 Generators
3.8.3 Fast Simulation (Atlfast)
3.8.4 ATLAS Geant4 Simulation (G4ATLAS)
3.8.5 Pile-up
3.8.6 Digitization
3.9 Event Selection and Reconstruction
3.9.1 Introduction
3.9.2 Reconstruction
3.9.3 Analysis Preparation
3.10 Physics Analysis Tools
3.10.1 Current Status
3.10.2 Short-Term Objectives
3.11 Use of Offline Software for HLT and Monitoring
3.12 Use of Offline Software for Detector Commissioning
3.13 Testing and Validation
3.13.1 Testing Aims
3.13.2 Types of Testing
3.13.3 Testing Frameworks
3.13.4 Testing Future
3.13.5 Physics Validation
3.14 Software Infrastructure
3.14.1 Introduction and Description
3.14.2 Code Management
3.14.3 External Packages
3.14.4 Platforms and Compilers
3.14.5 Releases and Release Strategy
3.14.6 Code Distribution
3.14.7 Quality Assurance and Quality Control (QA/QC)
3.14.8 Documentation
3.14.9 User Support
3.14.10 HLT Coordination
3.14.11 Mailing Lists
3.15 Integration of LCG Application Area Products
3.15.1 SEAL
3.15.2 POOL
3.15.3 PI
3.15.4 Simulation Components
3.15.5 SPI Components
3.15.6 LCGCMT
3.16 References

4 Databases and Data Management

4.1 Introduction
4.2 Approach and Architecture
4.3 Technical Data
4.3.1 Technical Coordination Databases
4.3.2 Detector Production Data
4.3.3 Installation Data
4.3.4 Survey Database
4.4 Conditions and Configuration Data
4.4.1 Introduction
4.4.2 Conditions Database Architecture
4.4.3 Conditions Database Online Model
4.4.4 Supporting Tools
4.4.5 Athena Access to Conditions Data
4.4.6 Performance, Scalability and Distribution
4.4.7 Detector Description
4.5 Event Data
4.5.1 Introduction
4.5.2 Persistence Services
4.5.3 Storage Technology and Technology Selection
4.5.4 Persistence of the Event Data Model
4.5.5 Automatic Persistence
4.5.6 Navigational Infrastructure
4.5.7 Schema Evolution
4.5.8 Event-level Metadata
4.5.9 Event Selection and Input Specification
4.5.10 Event Store Services
4.5.11 Summary
4.6 Distributed Data Management
4.6.1 Introduction
4.6.2 DC2 Experience
4.6.3 Precepts and Requirements
4.6.4 Scenarios and Use Cases
4.6.5 System Architecture
4.6.6 Implementation
4.6.7 Organization of System Development, Deployment and Operation
4.6.8 DQ2 Development and Deployment Timeline
4.7 Book-keeping for Production and Analysis
4.7.1 Production Database
4.7.2 Offline Book-keeping
4.7.3 Provenance and Related Metadata
4.8 Database and Data Management Services
4.8.1 Distributed Database Services
4.8.2 Caching Tiers for Distributed Database Access
4.8.3 Operational Experience
4.8.4 Monitoring
4.8.5 Roles
4.8.6 Database Authentication
4.9 Development Processes and Infrastructure
4.9.1 Milestones, Planning, Manpower
4.10 References

5 Grid Tools and Services

5.1 Introduction
5.2 Relations with the LCG Project and with Grid Middleware Providers
5.3 Integration of Grid Tools
5.3.1 The ATLAS Virtual Organization
5.3.2 Data Management on the Grid
5.3.3 Job Submission to the Grid
5.4 The Distributed Production System
5.4.1 Architecture
5.4.2 Job Transformations
5.4.3 Production Database
5.4.4 Supervisor
5.4.5 Executors
5.4.6 Experience with the Production System
5.4.7 Evolution of the Production System
5.5 Distributed Analysis on the Grid
5.5.1 The ATLAS Distributed Analysis Model
5.5.2 Data Management
5.5.3 Workload Management
5.5.4 Prototyping Activities
5.5.5 The ADA Project
5.6 Testing and Commissioning of the System
5.7 References

6 Computing Operations

6.1 Introduction
6.2 Software Distribution and Deployment
6.2.1 Preparation and Distribution of ATLAS Software
6.2.2 ATLAS Software Deployment on the Grid
6.3 Production Operations
6.3.1 Operations at Tier-0
6.3.2 Operations at Tier-1s
6.3.3 Operations at Tier-2s
6.3.4 Production and Databases
6.3.5 Monitoring and Book-Keeping
6.4 Productions
6.4.1 Distributed Production and Analysis Operations
6.4.2 Management of the ATLAS Virtual Organization
6.5 Experience with Data Challenges and other Mass Productions
6.5.1 Data Challenge 1
6.5.2 Data Challenge 2
6.5.3 Production for the ATLAS Physics Workshop
6.5.4 Combined Test Beam
6.6 Summary
6.7 References

7 Resource Requirements

7.1 Introduction
7.2 Ramp-up and Resource Requirement Evolution
7.3 Networking Requirements

8 Project Organization and Planning

8.1 Organizational Structure
8.1.1 The Computing Management Board
8.1.2 The Computing Oversight Board
8.1.3 The International Computing Board
8.1.4 The Software Project
8.1.5 The Database and Data Management Project
8.1.6 Grid Tools and Services
8.1.7 Computing Operations
8.1.8 Computing Resources Management
8.1.9 Relations with other ATLAS-wide Projects
8.1.10 Relations with the LCG Project
8.2 Work Plan, Schedule and Milestones
8.2.1 Planning Methodology
8.2.2 Data Challenge 3: Computing System Commissioning
8.2.3 High-Level Milestones
8.3 Manpower and Hardware Resources
8.3.1 Manpower Resources
8.3.2 Hardware Resources
8.4 References

A Glossary

A.1 Acronyms and Terms
A.2 Definitions


4 July 2005 - WebMaster

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