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London Tier2 Status

London Tier2 Status. Olivier van der Aa. LT2 Team M. Aggarwal, D. Colling, A. Fage, S. George, K. Georgiou, W. Hay, P. Kyberd, A. Martin, G. Mazza, D. McBride, H. Nebrinsky, D. Rand, G. Rybkine, G. Sciacca, K. Septhon, B. Waugh. Outline. LT2 Usage LT2 Sites updates LT2 SC4 activity

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London Tier2 Status

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  1. London Tier2 Status Olivier van der Aa LT2 Team M. Aggarwal, D. Colling, A. Fage, S. George, K. Georgiou, W. Hay, P. Kyberd, A. Martin, G. Mazza, D. McBride, H. Nebrinsky, D. Rand, G. Rybkine, G. Sciacca, K. Septhon, B. Waugh

  2. Outline • LT2 Usage • LT2 Sites updates • LT2 SC4 activity • Conclusion London Tier 2 Status

  3. Number of Running Jobs January February London Tier 2 Status

  4. Number of running jobs March April London Tier 2 Status

  5. Number of running jobs May • Increase of the infrastructure usage by LHCB last month • Has stressed the system. Caused very slow mds responses. London Tier 2 Status

  6. Usage and efficiency per VO[2006-01-01,2006-04-30] BIOMED ATLAS LHCB CMS • WallTime consumption • ATLAS, LHCB, BIOMED, CMS are the top consumers • Efficiency: Fraction of total time which result in a successful state. • Efficiency by order: BIOMED, ATLAS, LHCB, CMS. • Efficiency pattern is notyet understood. Why is BIOMED more efficient (ie causes less middleware failures) London Tier 2 Status

  7. Usage and efficiency per CE[2006-01-01,2006-04-30] ucl-central ucl-central Brunel QMUL RHUL IC-HEP IC-LESC UCL-HEP brunel ucl-central ucl-central IC-LESC IC-HEP QMUL Brunel RHUL UCL-HEP • WallTime • QMUL provides 55% of the total WallTime • Delicate to provide the Service Level Agreement of 95% availability of the LT2 with 1FTE at QMUL • Efficiency • UCL-CENTRAL the most efficient in job successes rate. • Can be explained because they mainly attract biomed jobs Brunel London Tier 2 Status

  8. CE / VO view • In London we support18 VO. (sixt has not been used) • Right Plots shows the relative VO usage for each CE. • Size of the box is proportional to the total Wall Clock Time Brunel Brunel IC-LESC QMUL RHUL IC-HEP UCL-HEP ucl-central ucl-central London Tier 2 Status

  9. GridLoad https://gfe03.hep.ph.ic.ac.uk:4175/cgi-bin/load • Tool to monitor the sites: • -Updates every 5minutes • -Uses the RTM data and stores it in rrd files • Shows theNumber of Jobs in any state • VO view. Stacks the Jobs by VO • CE view. Stacks the Jobs by CE • Still a prototype. Will add • View by GOC and ROC. • Error checking. • Add usage (running cpu/total cpu). • Improve look and feel • Could interface with NAGIOS for raising alarms (high abort rate) London Tier 2 Status

  10. GridLoad (cont) • The GridLoad plots can be useful to spot problems. • Example: Observed High Abort rate at one site for LHCB jobs • It helped to be proactive for the VO. Could spot that there is a problem before we receive a ticket # Aborted Jobs #Running Jobs London Tier 2 Status

  11. LT2 Usage: Conclusions • We have now an additional tool to monitor the LT2 cpu activity on real time. • The overall usage is increasing. • We need to understand the efficiency patterns. What causes those differences between the VO. • We need similar real time monitoring tools for the storage. Jan - May London Tier 2 Status

  12. Outline • LT2 Usage • LT2 Sites updates • LT2 SC4 activity • Conclusion London Tier 2 Status

  13. Brunel site update • New Cluster provided by Streamline Computing: • Supermicro dual processor dual core AMD Opteron nodes • 40x1.8 GHz, 4GB memory, 80 GB disk • Head node 2 GHz 8GB memry, 320 GB disk • Total 164 Cores • Is in the process of being configured • Gb connection ? • 1Gb wan at Brunel in 65 days from now. • They are currently buying appropriates switches and related hardware. • Will have a throttling router that limits the LCG traffic if the university demand is high. If the university demand is low then the LCG will have higher allocation • The Brunel site is expected to have a 10 times faster connection (200Mb) by September. • SRM: • best rate was 59Mb/s . • Will remove any nfs mounted filesystem. No real showstopper there. London Tier 2 Status

  14. IC Sites update • HEP: • Old IBM (60CPU) cluster running smoothly, almost full of jobs for the last two month. • Will build a new cluster with off the shelf boxes • 40 Dual Core AMD • 40 TB of disk (non raid) • Will use SGE for the job manager. London Tier 2 Status

  15. IC Sites update • Investigated FTS performance issues with dCache<->dCache transfers • FTS using urlcopy causes high iowait iowait FTS/urlcopy (130Mb/s) FTS/srmcp (179Mb/s) Block Block Time Time London Tier 2 Status

  16. IC Sites update • LESC: • 33% of 400 1.8 GHz opterons. • Running RHEL3 64 bit. • SGE job manager. • DPM storage with small disk partition • Currently porting DPM to SOLARIS to avoid nfs mounting file systems used for the SRM. • See the progressing work at http://www.gridpp.ac.uk/wiki/DPM-on-Solaris • Difficulties: Improving usage. Several VO not comfortable with 64bit arch even if 32 bit libraries are there • ICT: • Deploying a new 200 Xeon cluster running PBS for College Use. • Will have a share of 30% in that cluster for LCG • 30TB of raid storage that will be shared. • Difficulties: They want to use GT 3.2.1 London Tier 2 Status

  17. QMUL site update • Lots of activity with the commissioning of their new cluster provided by Viglen • 280 Dual Core Opterons (270) 2GHz • All nodes have 2x250 Gb disks =140TB ! • What filesystem to use with that environment. Will consider lustre. • All nodes are 1Gb connected. With 10Gb inter switch links. • Now online with ~1600 job slots • Problems: • Site stability under high job load: nfs mounted software area not coping • Raid boxes giving hardware errors. Seemed to be due to loose sata connectors. The disks where tested ok with smart. Not yet clear what it is due to. • Reliability of DPM on Poolfs London Tier 2 Status

  18. UCL sites update • CCC • Have successfully moved to SGE job manager to service364 Slots (91 dual cpu + hyper threading) • Improved their SRM performance by using direct fiberchannel link to the raid array from the head node. • Write bandwidth moved from 90Mb/s to 238Mb/s • Will have 40 additional nodes (160 slots) soon. • Moving their cluster from one building to another one will start on July 3 for 1 week. • HEP • New Gb switches have been bought. Need to cable them to the head node. • Will have 1,2 boxes with mirrored 120Gb disks with dpm pool installed on them to support non Atlas vo • Atlas will still be using nfs mounted • Problem: Performance for Atlas storage London Tier 2 Status

  19. RHUL siteupdate • Cluster running smoothly • 142 Job slots almost full for two month. All VO targetting that site. • No more nfs mounted disks with write access from DPM . • Broad VO usage • Update on the 1Gb connection: • Purchase order was signed yesterday. • Discussions are now starting as to when it will be installed. • Problems: • Need to be able to drain Pool to remove the read-only nfs mounted filesystem London Tier 2 Status

  20. Transfers throughput status London Tier 2 Status

  21. Outline • LT2 Usage • LT2 Sites updates • LT2 SC4 activity • Conclusion London Tier 2 Status

  22. SC4 Activity • CMS: Target is CSA06 (Computing Software and Analysis Challenge) • CSA06 Objective=“A 50 million event exercise to test the workflow and dataflow associated with the data handling and data access model of CMS “ • Will test the new cms reconstruction framework for large production • Need 20MB/s bandwidth to T2 storage • Will start on 15 Sept • More information can be found at:https://twiki.cern.ch/twiki/bin/view/CMS/CSA06 • IC-HEP and IC-LESC preparing for CSA06 • Strategy is to help other sites when IC is ok. • New PheDex installed that uses FTS • Need to solve the FTS performance issues • ProdAgent configuration prepared for IC-LESC and IC-HEP • Brunel Involved in PheDex. • ATLAS: • No commitment yet. London Tier 2 Status

  23. Conclusions • Real Time monitoring of the LT2 job states in place • The usage is increasing • Site evolution • SGE deployed at UCL-CENTRAL • QMUL more than doubled the number of job slots • Brunel: Gb connection on the right track, Commissioning a new cluster (160 cores) • IC: spotted FTS performance issues, Porting of DPM under solaris ongoing, Will commission a new cluster at HEP • RHUL: very stable site, Gb connection signed. General storage evolution: In the process of removing nfs mounts. • SC4: Involvement in the CMS SC4 activity is going on. Need to have a volunteer in the atlas sc4. London Tier 2 Status

  24. LT2 Thanks to all of the Team M. Aggarwal, D. Colling, A. Fage, S. George, K. Georgiou, M. Green, W. Hay, P. Hobson, P. Kyberd, A. Martin, G. Mazza, D. McBride, H. Nebrinsky, D. Rand, G. Rybkine, G. Sciacca, K. Septhon, B. Waugh, London Tier 2 Status

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