LargeSynopticSurveyTelescop
    QservFall16LargeScale
    VaikunthThukral
    DMTR-16
    LatestRevision:2017-05-09
    Abstract
    Thisdocumentcontainsresultsofthelargescaletests
    runonCC-IN2P3clusterduringFebruary-March2017.
    Forcomparisons,thepreviouslargescaletestcanbefoundDMTR-13.
    LARGESYNOPTICSURVEYTELESCOPE

    LARGESYNOPTICSURVEYTELESCOPE
    QservTestFall2016DMTR-16LatestRevision2017-05-09
    Contents
    1DatasetInformation1
    2Hardware1
    3Testingmethodologyandsummary2
    3.1Shortqueries..........................2
    3.2Fulltablescans,singlequeryatatime...................2
    3.3Fulltablejoins,singlequeryatatime...................3
    3.4Concurrentscansandstresstest.....................3
    3.5Typicalloadtest60LV+10HV(+10%ifpossible)............3.....
    3.6Heavyloadtest100LV+20HV(+10%ifpossible)...........6.....
    4NotesandObservations7
    5QueryTemplatesUsed7
    ii

    LARGESYNOPTICSURVEYTELESCOPE
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    QservFall16LargeScaleTests/KPMs
    1DatasetInformation
    TableRowCount.MYDsize[TB].MYIsize[TB]
    Object3,777,968,8804.60.1
    Source69,744,689,07233.6
    ForcedSource344,034,271,38011.08.7
    TotalMySQLdatadirsize:62.4TB
    DR1numbersareavailableinDocument-16168under“DataReleases”
    ObjectandSourcearenowat~20%ofDR1levelandForcedSource
    DR1.
    2Hardware
    •50nodes:
    –DELLPowerEdgeR620(DellSpecSheet)fornodes1-25
    –DELLPowerEdgeR630(DellSpecSheet)fornodes26-50
    •2xProcessorsIntelXeonE5-2603v2@1.80Ghz4core
    •10MBcache,6.4GT/s,80W
    •Memory16GBDDR-3@1600MHz(2x8GB)
    •2xharddrive250GBSATA7200Rpm2,5”-hotplug=>OS
    •8xharddrive1TBNearlineSAS6Gbps7200Rpm2,5”
    •hotplug=>DATA
    •1xcardRAIDH710pwith1GBnvram
    1

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    •1xcard1GbE4portsBroadcom®5720Base-T
    •1xcardiDRAC7Enterprise
    3Testingmethodologyandsummary
    Theclusterisdividedintotwosetsof25nodeseach,and
    datasetloadedin.TheseKPMtestswereperformedonthesecond
    ccqserv125
    -
    ccqserv149
    (DR1 is expected to be on 92 nodes)
    Queries are selected from a query pool that is divided into
    age patterns as well as expected support for baseline requirements.
    number of simultaneous queries to be tested are spawned,
    tion to the qserv proxy and repeatedly picking random queries
    sleeping when required.
    The actual program that we used to
    drive
    runQueries.py
    the testing can be
    3.1 Short queries
    •Single object selection by ID: 0.18 sec
    SELECT
    *
    FROM
    Object
    WHERE
    deepSourceId = 1696835327229975
    •Small spatial area selection from Object: 0.52 sec
    SELECT COUNT
    ( *
    F
    )
    ROM
    Object
    WHERE
    qserv_areaspec_box (42.247
    38.874077, 42.273855, 39.034748)
    3.2 Full table scans, single query at a time
    •Object: ~7 min
    SELECT
    ra , decl , u_psfFlux , g_psfFlux
    FROM
    Object
    , r_psfFlu
    WHERE
    y_shapeIxx
    BETWEEN
    20
    AND
    20.2
    2

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    Qserv Test Fall 2016
    DMTR-16
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    •Source: ~41 min
    SELECT COUNT
    ( *
    F
    )
    ROM
    Source
    WHERE
    flux \ _sinc
    BETWEEN
    1
    AND
    1.1
    •ForcedSource: ~26 min
    SELECT COUNT
    ( *
    F
    )
    ROM
    ForcedSource
    WHERE
    psfFlux
    BETWEEN
    0.
    A
    1
    ND
    0.2
    3.3 Full table joins, single query at a time
    •Object x Source: ~564min
    for(See
    details)
    section
    SELECT
    o. deepSourceId , s . objectId , s . id , o. ra ,
    FROM
    Object o, Source
    WHERE
    o . deepSourceId=s . objectId
    AND
    s. flux_sinc
    BETWEEN
    0.
    A
    3
    ND
    0.31
    •Object x ForcedSource: ~38 min
    SELECT
    o.deepSourceId ,
    FROM
    f .Object
    psfFlux
    o, ForcedSource f
    WHERE
    o . deepSourceId= f . deepSourceId
    AND
    f . psfFlux
    BETWEEN
    0.13
    AND
    0.14
    3.4 Concurrent scans and stress test
    •2 Object scans: ~8 min
    •5 Object scans: ~8 min (this shows that shared scans implemented
    tended)
    •Able to run up to 35 (30 on Object, 3 on Source and 2 on ForcedSource)
    — Object scans < 1h and Source scans < 1.5h
    •Attempt to run 50 scans causes the proxy to fail, solution
    ployment in the future
    3.5Typicalloadtest60LV+10HV(+10%ifpossible)
    •60lowvolumeand10highvolumequeries(4scansforObject,
    forForcedSource,2Object-Sourcejoins,1Object-ForcedSource
    3

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    query),allrunningsimultaneouslywithappropriate
    themixweareaimingfor.Wealsointroduceanewmetric
    mance,QueryThroughPut,orQTP
    •During24hourswecompleted:
    –571,029LowVolumequeriesfinished—Baseline:~10sec
    in24h
    *AchievedLowVolumeQTP:396queries/minute
    –108Objectscans—Baseline:~1hperquery,or96in
    –2Sourcescans—Baseline:~12hperquery,or2in24h
    –2ForcedSourcescans—Baseline:~12hperquery,or
    –4Object-Sourcejoins—Baseline:~12hperqueryor
    –2Object-ForcedSourcejoins—Baseline:~12hperquery
    –27NearNeighborqueries—Baseline:~1hperquery,
    *AchievedHighVolumeQTP:6queries/hour
    •Averageoutput:
    –OverallsizeofLowVolumeresultswas~70GB:128kB/query
    –OverallsizeofHighVolumeresultswas~7GB:48MB/query
    •Averagetimes:
    –LowVolumequeries3.23sec/query—Baseline:shouldbeunder10sec.1.
    –Object15.15scansmin/query—Baseline:shouldbeunder1hour
    –Sourcescans2.7hr/query—Baseline:shouldbeunder12hours
    –ForcedSourcescans2.7hr/query—Baseline:shouldbeunder12hours
    –Object-Sourcejoins2.7hr/query—Baseline:shouldbeunder12hours
    –Object-ForcedSourcejoins2.7hr/query—Baseline:shouldbeunder12
    –NearNeighborqueries16.6min/query—Baseline:shouldbeunder12hours.
    Fig.2.
    •Observations:
    4

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    Figure1:HistogramforallLowVolumequerytimes,notethelog
    Figure2:HistogramforallHighVolumequerytimes,notetheclear
    Sourcescans.
    5

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    –Testswereabletorunexactly10%fasterthantheattempted
    queriesandObjectscans(duetotheshorttimeframe
    –ScanschedulingimplementedinW16workswithscans
    inapproximatelythesameamountoftime
    *Forcorrectscanschedulingandqueryplanning,mysql
    erated.Futureworkforthisisplanned
    *Issueswereuncoveredwithreturninglargeresult
    thisintoaccount
    *Duetoorder-of-magnitudeincreaseinoutputsize,
    umequerieshasincreasedduetotestsrunningfrom
    *Fortheseissues,seeDM-9757,DM-10360,andDM-10366.
    3.6Heavyloadtest100LV+20HV(+10%ifpossible)
    •100lowvolumeand20highvolumequeries(8scansfor
    scansforForcedSource,4Object-Sourcejoins,2Object-ForcedSource
    borqueries),allrunningsimultaneouslywithappropriate
    enforcethemixweareaimingfor
    •During24hourswecompleted:
    –814,989LowVolumequeries
    –129Objectscans
    –4Sourcescans
    –4ForcedSourcescans
    –8Object-Sourcejoins
    –2Object-ForcedSourcejoins
    –54NearNeighborqueries
    •AverageOutput:
    –OverallsizeofLowVolumeresultswas~130GB:160kB/query
    –OverallsizeofHighVolumeresultswas~8GB:38MB/query
    •Averagetimes:
    6

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    –LowVolumequeries9.98sec/query
    –Object24scansmin/query
    –Sourcescans4.44hr/query
    –ForcedSourcescans4.44hr/query
    –Object-Sourcejoins4.44hr/query
    –Object-ForcedSourcejoins4,44hr/query
    –NearNeighborqueries24min/query
    •Observations:
    –DidnotfinishexpectednumberofObjectscans
    –AveragesizeofHighVolumequeryresultslowereddue
    scans
    –LowVolumequeriesstillfinishedunderthebaseline
    4NotesandObservations
    •Concurrencymaintained:WithdoublethedatafromS15wesuccessfully
    ousqueriesuptoandmorethanthebaselinerequirements
    •RobustnessAlthoughimproved:thetestswererunfor24hoursinS15
    havebeenperformedmultipletimesandcontinuously
    servicesfailingorneedingrestarts
    •SharedScanimplementation:Qservisabletohandlesuccessivelylarger
    onthesametableandperformthemforasimilarcost/time.
    5QueryTemplatesUsed
    Theactualquerypoolusedinthesetestsisavailablefromgitrepositoryassociated
    thisdocument.Asampleofthequerytypesusedineachcategory
    •Trivialquerythatretrievesonerow,usingindex
    7

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    SELECT*FROMObjectWHEREobjectId=<objId>
    •Counts
    SELECTCOUNT(*F)ROMObject
    SELECTCOUNT(*F)ROMSource
    SELECTCOUNT(*F)ROMForcedSource
    •Spatiallyrestrictedquery,smallareaofsky,should
    <100)
    SELECTCOUNT(*)
    FROMObject
    WHEREra_PSBETWEEN1AND2
    ANDdecl_PSBETWEEN3AND4
    •Fulltablescan,usesomecolumninWHEREthatisnotindexes,
    ofresultsreturnedissane(egthousands,notmillions)
    SELECTobjectId,ra_PS,de\c_PS,<fewothercolumns>
    FROMObject
    WHEREfluxToAbMag(iFlux_PS)−fluxToAbMag(zFlux_PS)>4
    •Aggregation
    SELECTCOUNT(*A)Sn,
    AVG(ra_PS),
    AVG(decl_PS),chunkId
    FROMObject
    GROUPBYchunkId
    •Nearneighbor
    SELECTCOUNT(*)
    FROMObjecto1,Objecto2
    WHEREqserv_areaspec_box(−5−,5,5,−5)
    ANDscisql_angSep(o1.ra_PS,o1.decl_PS,o2.ra
    8

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    •Joins
    SELECTo.objectId,s.sourceId,ra_PS,decl_PS,
    FROMObject
    JOISNOURCEUSIN(GobjectId)
    WHEREfluxToAbMag(iFlux_PS)−fluxToAbMag(zFlux_PS)>4
    AND<somerestrictionfromsourcetable>
    References
    [1][DMTR-13],Becla,J.,2015,QservSummer15LargeScaleTests,DMTR-13,URLhttps://ls.
    st/DMTR-13
    [2][Document-16168],LSSTSystemsEngineering,2014,LSSTKeySystemParameters
    mary,Document-16168,URLhttps://ls.st/Document-16168
    9

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