170 likes | 282 Views
LHCb Distributed Computing and the Grid V. Vagnoni (INFN Bologna). D. Galli, U. Marconi, V. Vagnoni INFN Bologna N. Brook Bristol K. Harrison Cambridge E. Van Herwijnen, J. Closier, P. Mato CERN A. Khan Edinburgh A. Tsaregorodtsev Marseille
E N D
LHCb Distributed Computingand the GridV. Vagnoni (INFN Bologna) D. Galli, U. Marconi, V. Vagnoni INFN Bologna N. Brook Bristol K. Harrison Cambridge E. Van Herwijnen, J. Closier, P. Mato CERN A. Khan Edinburgh A. Tsaregorodtsev Marseille H. Bulten, S. Klous Nikhef F. Harris, I. McArthur, A. Soroko Oxford G. N. Patrick, G. Kuznetsov RAL V. Vagnoni BEAUTY 2002
Overview of presentation • Current organisation of LHCb distributed computing • The Bologna Beowulf cluster and its performance in distributed environment • Current use of Globus and EDG middleware • Planning for data challenge and the use of Grid • Current LHCb Grid/applications R/D • Conclusions V. Vagnoni BEAUTY 2002
History of distributed MC production • Distributed System has been running for 3+ years & processed many millions of events for LHCb design. • Main production sites: • CERN, Bologna, Liverpool, Lyon, NIKHEF & RAL • Globus already used for job submission to RAL and Lyon • System interfaced to GRID and demonstrated at EU-DG Review and NeSC/UK Opening. • For 2002 Data Challenges, adding new institutes: • Bristol, Cambridge, Oxford, ScotGrid • In 2003, add • Barcelona, Moscow, Germany, Switzerland & Poland. V. Vagnoni BEAUTY 2002
LOGICAL FLOW Submit jobs remotely via Web Analysis Execute on farm Data quality check Update bookkeeping database Transfer data to mass store V. Vagnoni BEAUTY 2002
Monitoring and Control of MC jobs • LHCb has adopted PVSS II as prototype control and monitoring system for MC production. • PVSS is a commercial SCADA (Supervisory Control And Data Acquisition) product developed by ETM. • Adopted as Control framework for LHC Joint Controls Project (JCOP). • Available for Linux and Windows platforms. V. Vagnoni BEAUTY 2002
Example of LHCb computing facility:the Bologna Beowulf cluster • Set up at INFN-CNAF • ˜100 CPUs hosted in Dual Processor machines (ranging from 866 MHz to 1.2 GHz PIII), 512 MB RAM • 2 Network Attached Storage systems • 1 TB in RAID5, with 14 IDE disks + hot spare • 1 TB in RAID5, with 7 SCSI disks + hot spare • Linux disk-less processing nodes with OS centralized on a file server (root file-system mounted over NFS) • Usage of private network IP addresses and Ethernet VLAN • High level of network isolation • Access to external services (afs, mccontrol, bookkeeping db, java servlets of various kinds, …) provided by means of NAT mechanism on a GW node V. Vagnoni BEAUTY 2002
Disk-less node Red Hat 7.2 (kernel 2.4.18) Mirrored disks (RAID 1) CERN Red Hat 6.1 DNS Kernel 2.2.18 NAT (IP masquerading) PBS Master MC control server Gateway Farm Monitoring NAS NAS 1TB RAID 5 1TB RAID 5 Private Public VLAN VLAN Uplink Control Node Fast Ethernet Processing Node 1 Switch Disk-less nodes CERN Red Hat 6.1 Processing Node n Kernel 2.2.18 PBS Slave Master Server Red Hat 7.2 Ethernet OS file-systems Link Home directories Various services: Power Control Power Distributor PXE remote boot, Mirrored disks (RAID 1) DHCP, NIS Farm Configuration V. Vagnoni BEAUTY 2002
Fast ethernet switch Rack (1U dual-processor MB) NAS 1TB Ethernet controlled power distributor V. Vagnoni BEAUTY 2002
Farm performance • Farm capable to simulate and reconstruct about (700 LHCb-events/day)*(100 CPUs)=70000 LHCb-events/day • Data transfer over the WAN to the CASTOR tape library at CERN realised by using bbftp • very good throughput (up to 70 Mbits/s over currently available 100 Mbits/s) V. Vagnoni BEAUTY 2002
Current Use of Grid Middleware in development system • Authentication • grid-proxy-init • Job submission to DataGrid • dg-job-submit • Monitoring and control • dg-job-status • dg-job-cancel • dg-job-get-output • Data publication and replication • globus-url-copy, GDMP V. Vagnoni BEAUTY 2002
Example 1:Job Submission dg-job-submit /home/evh/sicb/sicb/bbincl1600061.jdl -o /home/evh/logsub/ bbincl1600061.jdl: # Executable = "script_prod"; Arguments = "1600061,v235r4dst,v233r2"; StdOutput = "file1600061.output"; StdError = "file1600061.err"; InputSandbox = {"/home/evhtbed/scripts/x509up_u149","/home/evhtbed/sicb/mcsend","/home/evhtbed/sicb/fsize","/home/evhtbed/sicb/cdispose.class","/home/evhtbed/v235r4dst.tar.gz","/home/evhtbed/sicb/sicb/bbincl1600061.sh","/home/evhtbed/script_prod","/home/evhtbed/sicb/sicb1600061.dat","/home/evhtbed/sicb/sicb1600062.dat","/home/evhtbed/sicb/sicb1600063.dat","/home/evhtbed/v233r2.tar.gz"}; OutputSandbox = {"job1600061.txt","D1600063","file1600061.output","file1600061.err","job1600062.txt","job1600063.txt"}; V. Vagnoni BEAUTY 2002
Example 2: Data Publishing & Replication Compute Element Storage Element MSS Local disk Job Data globus-url-copy Data register-local-file publish CERN TESTBED Replica Catalogue NIKHEF - Amsterdam REST-OF-GRID replica-get Job Data Storage Element V. Vagnoni BEAUTY 2002
LHCb Data Challenge 1 (July-September 2002) • Physics Data Challenge (PDC) for detector, physics and trigger evaluations • based on existing MC production system – small amount of Grid tech to start with • Generate ~3*10**7 events (signal + specific background + generic b and c + min bias) • Computing Data Challenge (CDC) for checking developing software • will make more extensive use of Grid middleware • Components will be incorporated into PDC once proven in CDC V. Vagnoni BEAUTY 2002
GANGA: Gaudi ANd Grid AllianceJoint Atlas (C. Tull) and LHCb (P. Mato) project,formally supported by GridPP/UK with 2 joint Atlas/LHCb research posts at Cambridge and Oxford • Application facilitating end-user physicists and production managers the use of Grid services for running Gaudi/Athena jobs. • a GUI based application that should help for the complete job life-time: • - job preparation and • configuration • - resource booking • - job submission • - job monitoring and control GANGA GUI Collective & Resource Grid Services Histograms Monitoring Results JobOptions Algorithms GAUDI Program V. Vagnoni BEAUTY 2002
Required functionality • Before Gaudi/Athena program starts • Security (obtaining certificates and credentials) • Job configuration (algorithm configuration, input data selection, ...) • Resource booking and policy checking (CPU, storage, network) • Installation of required software components • Job preparation and submission • While Gaudi/Athena program is running: • Job monitoring (generic and specific) • Job control (suspend, abort, ...) • After program has finished: • Data management (registration) V. Vagnoni BEAUTY 2002
Conclusions • LHCb already has distributed MC production using GRID facilities for job submission • We are embarking on large scale data challenges commencing July 2002, and we are developing our analysis model • Grid middleware will be being progressively integrated into our production environment as it matures (starting with EDG, and looking forward to GLUE) • R/D projects are in place • for interfacing users (production + analysis) and Gaudi/Athena software framework to Grid services • for putting production system into integrated Grid environment with monitoring and control • All work being conducted in close participation with EDG and LCG projects • Ongoing evaluations of EDG middleware with physics jobs • Participate in LCG working groups e.g. Report on ‘Common use cases for a HEP Common Application layer’ http://cern.ch/fca/HEPCAL.doc V. Vagnoni BEAUTY 2002