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Performance measurement of transferring files on the federated SRB

Performance measurement of transferring files on the federated SRB. KEK Computing Research Center Yoshimi Iida. Outline. The Belle experiment at KEK What is SRB? HEP Data Grid workshop Performance measurement Transfer measurement between sites in the Belle SRB federation

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Performance measurement of transferring files on the federated SRB

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  1. Performance measurement of transferring files on the federated SRB KEK Computing Research Center Yoshimi Iida

  2. Outline • The Belle experiment at KEK • What is SRB? • HEP Data Grid workshop • Performance measurement • Transfer measurement between sites in the Belle SRB federation • Using WAN emulator • Conclusions ISGC 2005

  3. The Belle experiment at KEK • The Belle experiment at KEK is one of several ongoing large experimental collaborations • The accumulated data up to now is about 2PB including simulation data for analysis • The large amount of data should be analyzed promptly to get statistically improved data for exploring new physics results • Large numbers of files need to be managed consistently and shared easily among the 400 collaborators ISGC 2005

  4. What is SRB? • SRB provides a uniform interface for connecting to heterogeneous data resources and accessing data sets • SRB, in conjunction with the Metadata Catalog (MCAT), provides a way to access data sets and resources based on logical attributes • http://www.sdsc.edu/srb/ ISGC 2005

  5. SRB federation • SRB zone • consist of one or more SRB servers along with one MCAT • Federated MCAT • allow users to access resources and data sets across zones Server 1.1 MCAT 1 Server 1.2 MCAT 3 Server 3.1 MCAT 2 Server 2.1 Server 2.2 ISGC 2005

  6. Logical file system Single SRB system / - Zone1/ - container/ - home/ - srbUserA.domain/ - srbUserB.domain/ data.txt - styles/ - trash/ - container/ - styles/ - trash/ Federated SRB system / - Zone1/ - container/ - home/ - styles/ - trash/ - Zone2/ - container/ - home/ - styles/ - trash/ - Zone3/ : : ISGC 2005

  7. SRB data management • Logical name space • Mapping of each logical name to physical attributes • UNIX like API and utilities for collections (directories) and data objects (files) • Data replication • replicate onto different resources ISGC 2005

  8. User management • Single Global User Name Space • Uniquely identify by their usernames combined with their domain ‘iidayo@kek' • Maintained in MCAT • Single sign-on, access all resources • No need for UNIX account at remote sites ISGC 2005

  9. HEP Data Grid workshop • Pre-workshop • 1 - 3 December, 2004 • Participants from 8 institutes at 7 countries • SDSC (US) • Australia National U., U. Melbourne (Australia) • ASCC (Taiwan) • KNU (Korea) • IHEP (China) • Krakow (Poland) • KEK (Japan) • Workshop • 6 - 7 December, 2004 • http://www-conf.kek.jp/hepdg/ ISGC 2005

  10. SRB federated MCAT Zone IHEP (China) Zone ASCC (Taiwan) Zone KNU (Korea) 10Mbps Internet 100Mbps 100Mbps Zone ANU (Australia) Zone Krakow (Poland) 100Mbps 622Mbps Zone KEK (Japan) FW FW: Firewall M: MCAT enabled SRB server S: SRB server C: SRB client C S M C ISGC 2005

  11. Belle SRB federation • Install SRB server, a storage resource and MCAT at each site • SRB version 3.2.1p • Open the KEK firewall from the fixed IP address of the other sites • After the installation, the functionality of the federation was tested and confirmed to be working ISGC 2005

  12. Transfer measurement from KEK • Copy files from KEK to the other sites • 10 files from 0.5 to 100MB in size • ‘Scp’ (SRB copy) use parallel I/O by default • Configure to allocate one thread per 2MB of the file size up to a maximum of 16 threads (i.e. 32MB) ISGC 2005

  13. Transfer rates from KEK Measured by ‘Scp’ ISGC 2005

  14. Transfer performance between sites in the Belle SRB federation Results of 100MB data file transfer in MB/s ISGC 2005

  15. WAN emulation • NIST Net • Network emulation package • NIST Net allows a single Linux PC set up as a router to emulate a wide variety of network conditions • http://www-x.antd.nist.gov/nistnet/ • Machine Specification • CPU: Pentium4 3.2GHz • Memory: 1GB • OS: Red Hat Linux 8 • NIC: GbE×2 Internet KEK network GbE GbE SRB server SRB server 100Mbps 100Mbps router NIST Net ISGC 2005

  16. Transfer measurement with various file size • Copy files on WAN emulation • 8 files from 10 to 500MB in size • Measure as a function of the RTT from 0 to 300ms • ‘Scp’ use parallel I/O by default • Configure to allocate one thread per 2MB of the file size up to a maximum of 16 threads • Measure the bandwidth with iperf • set the parallel client threads to 16 ISGC 2005

  17. Transfer performance with various file size iperf -P 16 Emulated by NIST Net ISGC 2005

  18. Transfer performance on WAN (preliminary) BW 100Mbps WAN Emulation (NIST Net) KNU ASCC ANU Krakow IHEP Measured by Scp ISGC 2005

  19. Bandwidth • The nominal bandwidth between KEK and some sites are same 100Mbps as WAN emulation • The actual bandwidth measured by iperf between KEK and other site is lower than WAN emulation • e.g. 60Mbps for ASCC with iperf • Further investigation is necessary ISGC 2005

  20. Conclusions • A federation of SRB servers was demonstrated successfully among ANU, KNU, IHEP, ASCC, Krakow and KEK • The current results are preliminary and were obtained in the limited time available in the pre-workshop session • The functionality of data sharing for analysis was proved to be stable and sufficient to be used by Belle collaboration ISGC 2005

  21. Acknowledgements • SDSC (San Diego Supercomputer Center) • M. Wan • ANU (Australia National University) • S. J. McMahon • University of Melbourne • G. Moloney • ASCC (Academia Sinica Computing Centre) • H. Lin • KNU (Kyungpook National University) • K. Kwon • IHEP (Institute of High Energy Physics) • G. Chen • Krakow (Institute of Nuclear Physics, Krakow) • P. Lason and H. Palka • Fujitsu • S. Honma and T. Nakajima • KEK (High Energy Accelerator Research Organization) • Y. Karita, T. Sasaki, S. Y. Suzuki, S. Yashiro and Y. Watase ISGC 2005

  22. Backups

  23. ‘Sls’ display data objects (file) or collections (directory) • ‘SgetD’ display information about SRB data objects • ‘SgetR’ display information about SRB resource ISGC 2005

  24. ISGC 2005

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