December 10,1999: MONARC Plenary Meeting Harvey Newman (CIT) MONARC Plenary December 9 Agenda u Introductions HN, LP15’ è Status of Actual CMS ORCA databases and relationship to MONARC Work: HN u Working Group Reports (by Chairs or Designees)40’ u Simulation Reports: Recent Progress AN, LP,IL 30’ u Discussion 15’ u Regional Centre Progress: France, Italy, UK, 45’ US, Russia, Hungary; Others u Tier2 Centre Concept and GriphyN: HN 10’ u Discussion of Phase 330’ u Steering Group 30’

December 10,1999: MONARC Plenary Meeting Harvey Newman (CIT) To Solve: the HENP “Data Problem” While the proposed future computing and data handling facilities are large by present-day standards, They will not support FREE access, transport or reconstruction for more than a Minute portion of the data. While the proposed future computing and data handling facilities are large by present-day standards, They will not support FREE access, transport or reconstruction for more than a Minute portion of the data. è Need effective global strategies to handle and prioritise requests (based on both policies and marginal utility) è Strategies must be studied and prototyped, to ensure Viability: acceptable turnaround times; efficient resource utilization  Problem to be Explored in Phase 3; How to Use Limited Resources to è Meet the demands of hundreds of users who need “transparent” (or adequate) access to local and remote data, in disk caches and tape stores è Prioritise hundreds to thousands of requests from local and remote communities è Ensure that the system is dimensioned “optimally”

December 10,1999: MONARC Plenary Meeting Harvey Newman (CIT) Phase 3 Letter of Intent (1/2)  Short: N Pages è May Refer to MONARC Internal Notes to Document Progress  Suggested Format: Similar to PEP Extension è Introduction: deliverables are realistic technical options and the associated resource requirements for LHC Computing; to be presented to the experiments and CERN, in support of Computing Model development for the Computing TDRs. è Brief Status; Existing Notes è Motivations for a Common Project --> Justification (1) è Goals and Scope of the Extension --> Justification (2) è Schedule: Preliminary estimate is 12 Months from completion of Phase 2, that will occur with the submission of the final Phase 1+2 Report. Final report will contain a proposal for the Phase 3 milestones and detailed schedule k Phase 3A: Decision on which prototypes to build or exploit u MONARC/Experiments/Regional Centres Working Meeting k Phase 3B: Specification of resources and prototype configurations u Setup of simulation and prototype environment k Phase 3C: Operation of prototypes and of simulation; analysis of results k Phase 3D: Feedback; strategy optimization

December 10,1999: MONARC Plenary Meeting Harvey Newman (CIT) Phase 3 Letter of Intent (2/2)  Equipment Needs (Scale specified further in Phase 3A) è MONARC Sun E450 server upgrade k TB RAID Array, GB memory upgrade k To act as a client to the System in CERN/IT, for distributed system studies è Access to Substantial system in the CERN/IT infrastructure consisting of a Linux farm, and a Sun-based data server over Gigabit Ethernet è Access to a Multi-Terabyte robotic tape store è Non-blocking access to WAN links to some of the main potential RC (e.g. 10 Mbps reserved to Japan; some tens of Mbps to US) è Temporary use of a large volume of tape media  Relationship to Other Projects and Groups è Work in collaboration with CERN/IT groups involved databases and large scale data and processing services è Our role is to seek common elements that may be used effectively in the experiments’ Computing Models è Computational Grid Projects in US; Cooperate in upcoming EU Grid proposals è US other National Funded efforts with R&D components  Submitted to Hans Hoffmann for Information on our Intention to Continue è Copy to Manuel Delfino

December 10,1999: MONARC Plenary Meeting Harvey Newman (CIT) Phase 3 LoI Status  Monarc has met its milestones up until now è Progress Report è Talks in Marseilles: General + Simulation è Testbed Notes: 99/4, 99/6, Youhei’s Note --> MONARC number è Architecture group notes: 99/1-3 è Simulation: Appendix of Progress Report è Short papers (Titles) for CHEP 2000 by January 15

December 10,1999: MONARC Plenary Meeting Harvey Newman (CIT) MONARC Phase 3: Justification (1) General: TIMELINESS and USEFUL IMPACT  Facilitate the efficient planning and design of mutually compatible site and network architectures, and services è Among the experiments, the CERN Centre and Regional Centres  Provide modelling consultancy and service to the experiments and Centres  Provide a core of advanced R&D activities, aimed at LHC computing system optimisation and production prototyping  Take advantage of work on distributed data-intensive computing for HENP this year in other “next generation” projects [*] è For example in US: “Particle Physics Data Grid” (PPDG) of DoE/NGI; + “Joint “GriPhyN” proposal on Computational Data Grids by ATLAS/CMS/LIGO/SDSS. Note EU Plans as well. [*] See H. Newman,

December 10,1999: MONARC Plenary Meeting Harvey Newman (CIT) MONARC Phase 3 Justification (2A) More Realistic Computing Model Development (LHCb and Alice Notes)  Confrontation of Models with Realistic Prototypes;  At Every Stage: Assess Use Cases Based on Actual Simulation, Reconstruction and Physics Analyses; è Participate in the setup of the prototyopes è We will further validate and develop MONARC simulation system using the results of these use cases (positive feedback) u Continue to Review Key Inputs to the Model k CPU Times at Various Phases k Data Rate to Storage k Tape Storage: Speed and I/O  Employ MONARC simulation and testbeds to study CM variations, and suggest strategy improvements

December 10,1999: MONARC Plenary Meeting Harvey Newman (CIT) MONARC Phase 3 Justification (2B) u Technology Studies u Data Model u Data structures k Reclustering, Restructuring; transport operations k Replication k Caching, migration (HMSM), etc. è Network k QoS Mechanisms: Identify Which are important è Distributed System Resource Management and Query Estimators k (Queue management and Load Balancing)  Development of MONARC Simulation Visualization Tools for interactive Computing Model analysis (forward reference)

December 10,1999: MONARC Plenary Meeting Harvey Newman (CIT) MONARC Phase 3: Justification (3) Meet Near Term Milestones for LHC Computing  For example CMS Data Handling Milestones: ORCA4: March 2000 ~1 Million event fully-simulated data sample(s) è Simulation of data access patterns, and mechanisms used to build and/or replicate compact object collections è Integration of database and mass storage use (including caching/migration strategy for limited disk space) è Other milestones will be detailed, and/or brought forward to meet the actual needs for HLT Studies and the TDRs for the Trigger, DAQ, Software and Computing and Physics  ATLAS Geant4 Studies  Event production and and analysis must be spread amongst regional centres, and candidates è Learn about RC configurations, operations, network bandwidth, by modeling real systems, and analyses actually with è Feedback information from real operations into simulations è Use progressively more realistic models to develop future strategies

December 10,1999: MONARC Plenary Meeting Harvey Newman (CIT) MONARC: Computing Model Constraints Drive Strategies u Latencies and Queuing Delays è Resource Allocations and/or Advance Reservations è Time to Swap In/Out Disk Space è Tape Handling Delays: Get a Drive, Find a Volume, Mount a Volume, Locate File, Read or Write è Interaction with local batch and device queues è Serial operations: tape/disk, cross-network, disk-disk and/or disk-tape after network transfer u Networks è Useable fraction of bandwidth (Congestion, Overheads): 30-60% (?) Fraction for event-data transfers: 15-30% ? è Nonlinear throughput degradation on loaded or poorly configured network paths. u Inter-Facility Policies è Resources available to remote users è Access to some resources in quasi-real time