LT 2 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

LT 2 Jan 27 th June 2006London Tier 2 Status Outline LT2 Usage LT2 Sites updates LT2 SC4 activity Conclusion

LT 2 Jan 27 th June 2006London Tier 2 Status Number of Running Jobs January February

LT 2 Jan 27 th June 2006London Tier 2 Status Number of running jobs March April

LT 2 Jan 27 th June 2006London Tier 2 Status Number of running jobs May Increase of the infrastructure usage by LHCB last month Has stressed the system. Caused very slow mds responses.

LT 2 Jan 27 th June 2006London Tier 2 Status Usage and efficiency per VO [ , ] 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 not yet understood. Why is BIOMED more efficient (ie causes less middleware failures) BIOMED ATLASLHCBCMS

LT 2 Jan 27 th June 2006London Tier 2 Status ucl-central Brunel QMUL RHUL IC-HEP UCL-HEP ucl-central IC-LESC Usage and efficiency per CE [ , ] 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 ucl-central Brunel brunel QMUL RHUL IC-HEP UCL-HEP ucl-central IC-LESC

LT 2 Jan 27 th June 2006London Tier 2 Status CE / VO view In London we support 18 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 ucl-central Brunel QMUL RHUL IC-HEP UCL-HEP ucl-central IC-LESC Brunel

LT 2 Jan 27 th June 2006London Tier 2 Status GridLoad 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)

LT 2 Jan 27 th June 2006London Tier 2 Status 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

LT 2 Jan 27 th June 2006London Tier 2 Status 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

LT 2 Jan 27 th June 2006London Tier 2 Status Outline LT2 Usage LT2 Sites updates LT2 SC4 activity Conclusion

LT 2 Jan 27 th June 2006London Tier 2 Status 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.

LT 2 Jan 27 th June 2006London Tier 2 Status 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.

LT 2 Jan 27 th June 2006London Tier 2 Status IC Sites update Investigated FTS performance issues with dCache dCache transfers FTS using urlcopy causes high iowait FTS/urlcopy (130Mb/s) FTS/srmcp (179Mb/s) iowait Time Block Time

LT 2 Jan 27 th June 2006London Tier 2 Status LESC: –33% of 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 –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 IC Sites update

LT 2 Jan 27 th June 2006London Tier 2 Status 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

LT 2 Jan 27 th June 2006London Tier 2 Status UCL sites update CCC –Have successfully moved to SGE job manager to service 364 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

LT 2 Jan 27 th June 2006London Tier 2 Status RHUL site update 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

LT 2 Jan 27 th June 2006London Tier 2 Status Transfers throughput status Rate (Mb/s) SiteInboundOutboundUpdate Brunel5759Gb connection signed (200Mb by september) IC-HEP80190FTS performance problem not yet understood IC-LeSC15695DPM being build for solaris QMUL Poolfs need to be recompiled with round robin feature RHUL5958Gb connection signed UCL-HEP7163Gb switches there. UCL- CENTRAL90309 Move to direct fiberchannel connection. Rate is now 238Mb/s

LT 2 Jan 27 th June 2006London Tier 2 Status Outline LT2 Usage LT2 Sites updates LT2 SC4 activity Conclusion

LT 2 Jan 27 th June 2006London Tier 2 Status 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: –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.

LT 2 Jan 27 th June 2006London Tier 2 Status 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.

LT 2 Jan 27 th June 2006London Tier 2 Status 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, LT 2