1. CMS STEP09 C. Charlot / LLR LCG-DIR 19/06/2009

2. Réunion LCG-France, 19/06/2009 C.Charlot STEP09: scale tests STEP09 was: A series of tests, not an integrated challenge To investigate performance of the computing systems while overlapping with the other VOs, june 1-14 Emphasis on tape performance at T0 and T1s and analysis performance at T2s Postmortem document in preparation, there will be a STEP09 parallel session during (next week) CMS week Full results planed for WLCG STEP09 post-mortem workshop july 9/10

3. Réunion LCG-France, 19/06/2009 C.Charlot STEP09: T0 tests Goal: investigate castor tape write performance and explore write limits in parallel to other VOs Tested repacking without prompt reco in several T0 instances CMS time windows limited due to Mid-Week-Global-Runs Atlas planned to write during two weeks continuously Preliminary results We saw write rates up to 1.5GB/s, quite larger than what we need Also Atlas and LHCb have conducted tape write tests Write rates cannot be confirmed easily because CERN-IT lacks tape performance monitoring tools for castor Comments Activity overlap was limited by experiments activities CERN-IT seems to be happy with overlap achieved

4. Réunion LCG-France, 19/06/2009 C.Charlot STEP09: T1 pres-staging tests Goal: investigate tape system performance and develop rolling re- reconstruction Staging to be done manualy, via SRM scripts or via PhEDEx Expected rates:  below 100MB/s for 6 of the 7 T1s and 240MB/s for FNAL Preliminary results We saw pre-staging rates in excess of 100MB/s at most of the sites; FNAL reached 400MB/s during pre-staging in the second week We measured CPU efficiencies with and without pre-staging  Promising results.. Need more analysis Comments Several site specific issues observed, detailed analysis needed to solve No general and commissioned tools and infrastructure exists to handle this consistently and in automated way at the T1 sites

5. Réunion LCG-France, 19/06/2009 C.Charlot STEP09: T1 transfer tests Goal: synchronize 50TB of AODs data during (or after) re- reconstruction between all the T1s Higher scale than CCRC08 Preliminary results Overall sucessful Need to avoid congestion in transfer queues 2nd AOD synchronisation was sucessfully completed on saturday Comments Transfer latency is very important PhEDEx will roote the files more efficiently than we tested  takes advantage of lower latency netwotrk connections (in theory, a file only has to cross the atlantic once)

6. Réunion LCG-France, 19/06/2009 C.Charlot STEP09: T1-T2 transfer tests Goal: to check additional tape loads, selected datasets were transfered from T1 sites to T2 sites Dataset had been purged from the disk before so that they had to be recalled from tapes A selection of T1 and T2 to participate:  T1_FR_CCIN2P3->T2_FR_GRIF_IRFU, T1_FR_CCIN2P3->T2_FR_IPHC, T1_US_FNAL->T2_FR_GRIF_LLR Preliminary results In general worked Latencies are currently investigated Post mortem analysis is ongoing

7. Réunion LCG-France, 19/06/2009 C.Charlot STEP09: Analysis at T2 Goal, tests and schedule: T2 analysis test: sustain analysis scale at 50% of T2 level resources (ie full analysis pledges) Backfill normal analysis load with artificial analysis jobs to sustain this load  Jobs of ~1-2h duration Preliminary results 1 244 242 jobs had been terminated 903 478 were successful Success rate: 73%, failures to be understood Post mortem analysis ongoing Comments Atlas ran ~same load through the « hammerclouds » tests during STEP

8. Réunion LCG-France, 19/06/2009 C.Charlot STEP09: Analysis at T2 01-07/06 week

9. Réunion LCG-France, 19/06/2009 C.Charlot STEP09: Site readiness T1 site readiness during STEP was mixed CC Lyon: was in shutdown for HPSS, will be corrected

10. Réunion LCG-France, 19/06/2009 C.Charlot STEP09: T2 site readiness Overal good performance for french sites

11. Réunion LCG-France, 19/06/2009 C.Charlot Conclusions Overall CMS succeeded with the tests. We gain very valuable experience. CMS did not have an automated pre-staging mechanism at T1s Post-mortem is starting, first results at CMS week next week Then post-mortem WLCG workshop july 9/10 STEP09 was an intensive activity Daily reports, 276 emails over ~2weeks + 10 days preparation Thanks to all!