Outline Oxana Smirnova, Particle Physics 2

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2 Outline Oxana Smirnova, Particle Physics 2

3 Oxana Smirnova, Particle Physics 3

4 Short-list of open questions for LHC Can gravity be included in a theory with the other three interactions? How many space-time dimensions do we live in? Are the known elementary particles fundamental or do they possess structure? Why are there 3 generations of quarks and leptons? Why are protons stable, or are they? Why is the electrical charge of the proton equal and opposite to that on the electron? Why is there overwhelmingly more matter than anti-matter in the Universe? What is the nature of the dark matter and dark energy that pervade our Galaxy? Why are the neutrinos so light, and which is the heaviest? Are there new states of matter at exceedingly high density and temperature? Oxana Smirnova, Particle Physics 4

5 LHC is a data generator Graphics by CERN Oxana Smirnova, Particle Physics 5

6 A data sample: collision event at LHC ATLAS video Oxana Smirnova, Particle Physics 6

7 An instrument at LHC: ATLAS Graphics by QED AB Oxana Smirnova, Particle Physics 7

8 Does LHC produce Big? Oxana Smirnova, Particle Physics 8

9 How big is Big Oxana Smirnova, Particle Physics 9

10 Do we need to store all this data? Oxana Smirnova, Particle Physics 10

11 Trigger is a powerful system itself Typical number of pieces Detector Custom links from the detector Readout Units for protocol adaptation Powerful Core routers Edge switches Servers for event filtering to to 8 50 to 100 > 1000 Slide from ISOTDAQ16 TDAQ for LHC - Niko Neufeld, CERN Oxana Smirnova, Particle Physics 11

12 Example: Acquisition system for the CMS experiment Slide from ISOTDAQ16 TDAQ for LHC - Niko Neufeld, CERN Oxana Smirnova, Particle Physics 12

13 There are several levels of triggers # Level-0,1,2 Event Network Storage Trigger Rate (khz) Size (Byte) Bandw.(GB/s) MB/s(Event/s) LHCb CMS ATLAS ALICE 4 Pb-Pb 5 5x (10 2 ) p-p 1 2x (10 2 ) 3 LV x ~1000 (>400) LV LV ~1000 (10 3 ) 2 LV x >600 (1.2x10 4 ) Slide from ISOTDAQ16 TDAQ for LHC - Niko Neufeld, CERN Oxana Smirnova, Particle Physics 13

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15 Statistical analysis of ever increasing samples Oxana Smirnova, Particle Physics 15

16 Some real data volumes CERN Nordic share (3 countries) Oxana Smirnova, Particle Physics 16

17 Stored and analysed around the World Graphics by isgtw Oxana Smirnova, Particle Physics 17

18 Why distribute data? Oxana Smirnova, Particle Physics 18

19 Changing data access concepts Traditional Distributed data Researcher Researcher Researcher Researcher Researcher Researcher Researcher Oxana Smirnova, Particle Physics 19

20 Computing infrastructure for LHC Oxana Smirnova, Particle Physics 20

21 WLCG Grid sites Oxana Smirnova, Particle Physics 21

22 For comparison: Hazel Hen from HLRS HPC: focus on data generation, less on data processing Oxana Smirnova, Particle Physics 22

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24 So, what is Grid? Oxana Smirnova, Particle Physics 24

25 What problems does middleware solve? Problem Where is my data? Every cluster has different batch system (PBS, GE, LSF, SLURM ), what do I do? How do I describe my task? I don t even know what is available! I can t remember 200+ passwords! Where am I authorised? How do I know about my resource usage? Solution Common catalogues using logical names and unique identifiers for data sets Common execution interface is provided by Grid services; each job has a unique ID Common job description language Common information schema and services Single sign-on infrastructure based on certificates; delegation by proxy Common authorisation and policy decision services Common accounting service Oxana Smirnova, Particle Physics 25

26 We develop middleware ourselves Oxana Smirnova, Particle Physics 26

27 Move jobs or move data? Jobs to data: Slow network Large local storage Trivial Grid to jobs: Fast network Small local storage Complex Grid Researcher Researcher ARC is optimized to move data Oxana Smirnova, Particle Physics 27

28 Nordic Grid infrastructure: NDGF-T1 Scientists Authorised users directory (VOMS) ARC Indexing servers Cache Cache Cache Cache Copenhagen Oslo Linköping Umeå Site-BDII servers SGAS accounting server Cache Cache Helsinki Bergen ARC computing services Cache Lund Operators dcache storage cloud CERN dcache server FTS server Oxana Smirnova, Particle Physics 28

29 From the many-logins world Cluster SSH Researcher Cluster SSH Researcher Oxana Smirnova, Particle Physics 29

30 to the single Grid system Application database Certificate Certificate Authorised users directory Certificate Policies Grid job management service Certificate Certificate Researcher Information services Certificate Grid tools Certificate Researcher Certificate Grid job management service Many alternative and complementary software solutions exist for each service or tool Grid tools Oxana Smirnova, Particle Physics 30

31 Summary Oxana Smirnova, Particle Physics 31