Pivotal Greenplum Command CenterGreenplum Command Center 4.4.0 is a minor release that adds features and resolves some issues. See Enhancements and Changes in Greenplum Command Center

PivotalGreenplum®

CommandCenter

Version4.4.0

UserGuide

Rev:01

©2018PivotalSoftware,Inc.

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TableofContents

TableofContentsPivotalGreenplumCommandCenter4.4.0DocumentationPivotalGreenplum®CommandCenter4.4.0ReleaseNotesAboutPivotalGreenplumCommandCenterInstallingtheGreenplumCommandCenterSoftwareCreatingthegpperfmonDatabaseInstallingPivotalGreenplumCommandCenterUpgradingGreenplumCommandCenterUninstallingGreenplumCommandCenterAbouttheCommandCenterInstallationSettingtheGreenplumCommandCenterEnvironmentConnectingtotheGreenplumCommandCenterConsoleAdministeringtheCommandCenterWebServerAdministeringCommandCenterAgentsAdministeringthegpperfmonDatabasegpccConfigurationFileReferenceCommandCenterAgentParametersCommandCenterConsoleParametersSetupConfigurationFileGreenplumDatabaseServerConfigurationParametersSecuringGreenplumCommandCenterManagingGreenplumCommandCenterAuthenticationManagingGreenplumCommandCenterPermissionsSecuringthegpmonDatabaseUserEnablingAuthenticationwithKerberosMonitoringtheGreenplumDatabaseSystemDashboardGreenplumDatabaseClusterStateSegmentStatusClusterMetricsHostMetricsStorageStatusMonitoringandManagingGreenplumDatabaseQueriesQueryMonitorQueryDetailsHistoryManagingGreenplumDatabaseWorkloadsAboutGreenplumCommandCenterWorkloadManagementWorkloadManagementImportingResourceQueuestoResourceGroupsAccessingtheWorkloadConfigurationProgrammaticallyTroubleshootingEnablingResourceGroupsPivotalCommandCenterOnlineHelpTopicsCPUCPUSkewLocksMemory

©CopyrightPivotalSoftwareInc,2013-2018 2 4.4.0

99QueryPlanExecution


PivotalGreenplumCommandCenter4.4.0DocumentationPDF

GreenplumCommandCenter4.4.0ReleaseNotes

AboutGreenplumCommandCenter

InstallingGreenplumCommandCenter


AbouttheCommandCenterInstallation

SettingtheGreenplumCommandCenterEnvironment

Administration

AdministeringtheCommandCenterWebServer

AdministeringCommandCenterAgents

AdministeringthegpperfmonDatabase

gpccCommandReference

ConfigurationFileReference

SecuringGreenplumCommandCenter

UsingGreenplumCommandCenter

MonitoringtheGreenplumDatabaseSystem

OverallClusterStateSegmentStatusClusterMetricsHostMetricsStorageStatus

MonitoringandManagingGreenplumDatabaseQueries

QueryMonitorQueryDetailsQueryHistory

ManagingWorkloads

AboutWorkloadsManagingWorkloadswithCommandCenterTroubleshootingCommandCenterWorkloadManagement

CommandCenterHelpTopics

CPU

CPUSkew

Locks

Memory

QueryOptimization

SpillFiles


http://gpcc.docs.pivotal.io/pdf/GPCC-440-guide.pdf

http://gpcc.docs.pivotal.io/440/help/spill-files.html

PivotalGreenplum®CommandCenter4.4.0ReleaseNotes

AboutThisReleaseThisdocumentcontainspertinentreleaseinformationaboutPivotalGreenplumCommandCenter4.4.0.GreenplumCommandCenter4.4.0isaminorreleasethataddsfeaturesandresolvessomeissues.

SeeEnhancementsandChangesinGreenplumCommandCenter4.4.0forinformationaboutnewfeaturesandchangesinthisCommandCenterrelease.

SupportedPlatformsGreenplumCommandCenter4.4.0iscompatiblewiththefollowingplatforms.

PivotalGreenplumDatabase5.9.0andhigher

RedHatEnterpriseLinux6.xand7.x

CentOS6.xand7.x

SUSEEnterpriseLinux11SP4

IfyouuseresourcegroupsandworkloadmanagementonRedHatorCentOS6.x,upgradeyourkernelto2.6.32-696orhighertobenefitfromimprovementsintheLinuxcgroupsservice.

GreenplumCommandCenterworkloadmanagementfeaturesarenotsupportedonSUSEEnterpriseLinux11.

EnhancementsandChangesinGreenplumCommandCenter4.4.0GreenplumCommandCenter4.4.0containsthefollowingfeaturesandenhancements.

WorkloadManagementCommandCenterhasanewuserinterfacetoassistadministratorsinenablingresourcegroupsinGreenplumDatabase,importingexistingresourcequeuestoresourcegroups,andenablingworkloadmanagementwithCommandCenter.Theoptiontoimportresourcequeuestoresourcegroupsispresentedifnoresourcegroupshavebeencreated(otherthan default_group and admin_group )andGreenplumDatabasehasresourcequeuestoconvert(otherthan pg_default ).Oncetheadministratorhasimportedresourcequeues,orchosentoskipimportingresourcequeues,theoptiontoimportqueuesisnolongerpresented.

TheresourcegrouplistontheWorkloadManagementviewhasanewcolumntoshowtheminimum(fixed)amountofmemorythatwillbeallocatedtoaqueryforeachresourcegroup.Thisvalueisrecalculatedwhenyouenternewvalueswhileeditingresourcegroups.

Administratorscannowdefineresourcegroupassignmentrulesandidlesessionkillruleswithaninteractiveinterface.ItisnolongernecessarytoedittheJSONdocumentforworkloadmanagementrules.TheJSONtextfieldisremoved.

TheWorkloadManagementviewchangedtoalighttheme.

PermissionsCommandCenteruserswiththeSelfOnlypermissionlevelcan:

seeallqueriesonthequerymonitor,includingqueriesownedbyotheruserscanceltheirownqueriesaccessthequerydetailsviewfortheirownquerieshoveronaquerytoseequerytextfortheirownquerieshoveronlocking/blockingqueriesandaccessdetailsoflocking/blockingqueriesthatdonotbelongtootherusers

BeginningwithGreenplumDatabase5.11.0,youcanusehostnamesintheaddressfieldofthe pg_hba.conf configurationfile.GreenplumCommandCenterdoesnotyetsupportenteringhostnamesintheAdmin>Authorizationview.IfyouusehostnamesinGreenplumDatabase,donotusetheAdmin>AuthorizationviewinGreenplumCommandCenter4.4.0orearliertoeditthe pg_hba.conf file.


UserswithSelfOnlypermissionlevelcannotseequerytextoraccessthedetailsviewsofothers’queries.

TheGreenplumDatabaseroles gpcc_basic , gpcc_operator ,and gpcc_operator_basic arecreatedduringCommandCenterinstallationiftheydonotalreadyexist.

QueryMonitorFixedabugwherethedatabasenameandrolenameweremissingfromquerydetailswhenqueriesareexecutedinasessionafterrestartingCommandCenter.

EnhancementsandChangesinGreenplumCommandCenter4.3.0GreenplumCommandCenter4.3.0containsthefollowingenhancements.

ResourceGroupManagementTheAdmin>WorkloadMgmtviewhasanewuserinterfaceyoucanusetoaddandremoveresourcegroupsandtochangetheConcurrency,CPU%,andMemory%attributesofresourcegroups.

ResourceGroupRoleAssignmentsTheAdmin>WorkloadMgmtviewhasanewuserinterfaceyoucanusetoviewandchangeGreenplumDatabaseroles’defaultresourcegroups.

DetailsAddedtoVisualQueryPlanStepsThemetricscollectorextensioninGreenplumDatabaserelease5.9isupdatedtosubmitadditionalinformationabouteachstepinthequeryplantotheCommandCenterbackend.CommandCenterdisplaysthisinformationinthevisualqueryplanwhenyouexpandastepinthequeryplan.Thenewinformationdisplayeddependsontheoperationthestepperformsandincludesdetailssuchashashkey,mergekey,joincondition,orfiltercondition.Previously,youcouldonlyseethisinformationbygeneratingthetextualqueryplan.


VisualQueryPlanTheCommandCenterQueryDetailsviewnowincludesavisualqueryplan.

IdleSessionKillRulesIdlesessionkillrulescanincludeoptional exemptedRoles and message parameters.

Thevalueofthe exemptedRoles parameterisalistofGreenplumDatabaserolesthatareexemptedfromtherule.ThelistcanincludePosixregularexpressionstomatchGreenplumDatabaserolenames.

Thevalueofthe message parameterisastringtoincludeinthemessagethatisdisplayedwhenasessioniskilled.

CommandCenterCanRunontheMasterHostorStandbyMasterHostTheGreenplumCommandCenterwebserverandbackendmaynowbeexecutedonthemasterhostoronthestandbymasterhost.RunningGPCConthestandbymasterhostisrecommendedtoavoidaddingloadtothemasterserver,butitisnolongerarequirement.AftertheGPCCsoftwareisinstalled,log


intothehostwhereyouwanttorunGPCC,sourcethe gpcc_path.sh fileintheGPCCinstallationdirectory,andrunthe gpccstart

command.


CommandCenteradministratorscansetpermissionlevelsforCommandCenterusers.Permissionsareenforcedasdescribedinthedocumentation.

OntheQueryDetailview,clickingCopyinthequerytextorqueryplanpanelcopiesthetextinthepaneltotheclipboard.

Ahelpiconandin-apphelphavebeenaddedontheQueryMonitorandQueryDetailviews.

Thefollowingworkloadmanagementfeatures,improvements,andbugfixeshavebeenaddedintheworkloadmanagementextensionincludedwithGreenplumDatabase5.8.0.

OntheAdmin>WorkloadMgmtview,youcanaddidlesessionkillrulesforeachresourcegroup.Whenyouaddtheserules,theGreenplumDatabaseworkloadmanagementextensionkillsasessionafterithasbeenidleforthenumberofsecondsyouspecify.SeeWorkloadManagementforsyntaxandexamples.

OptimizationshavebeenimplementedtoreducetheimpactonGreenplumDatabasewhentheworkloadmanagementextensionisdisabled.

Theworkloadmanagementextensiontakesadvantageofresourcegroupname-to-idcachingaddedinGreenplumDatabase.

Fixedabugintheworkloadmanagementextensionthatcausederrorstoprinttothe psql prompt,evenwhentheextensionwasdisabled.

GreenplumCommandCenter4.1.0containsthefollowingbugfixes.

IntheHistoryDetailview,wheneitheroftheDiskRorDiskWmetricsis0,botharereportedtobe0.Thisisfixed.

WhenusingtheKerberosgpmon-onlyauthenticationmode,generatinganexplainplanfailed.Thisisfixed.

TheCommandCenteragentfailedwiththemessage“Error:can’tfindgpcc.query_metrics_port,metrics_collectorisnotcorrectlyinstalled.”ThisoccurswhenrunningCommandCenteronaGreenplumDatabasesystemthatwasupgradedfromanearlierGreenplumDatabase5.xrelease.Themetrics_collector and gp_wlm extensionsareinstalledwiththeupgrade,buttheupgradeprocessdoesnotperformtherequiredconfigurationchangesinthe postgresql.conf configurationfile.TheCommandCenterinstallationinstructionsnowincludestepstomanuallyconfigureandrestartanupgradedGreenplumDatabasesystem.

WhenCommandCenterstarts,anerrormessageiswrittenintheGreenplumDatabaselogfile:“functiongpcc_schema.read_pghba(unknown)doesnotexist.”Thisisfixed.

AchangetotimezonehandlinginGreenplumDatabase5.7cancauseGreenplumCommandCenter4.0.0todisplayanincorrecttimeifthemasterhostoperatingsystemtimeandGreenplumDatabaseusedifferenttimezones.NowCommandCentertimesaredisplayedusingthetimezoneoftheGreenplumDatabasemasterhostoperatingsystem.Thecurrenttime,lastsynctime,andtimestampsinalertlogs,clustermetrics,andqueryhistoryarealldisplayedusingthemasterhost’ssystemtimezone.

OntheAdmin>Authorizationview,whentheauthorizationmethodis gss andtheoptionsfieldcontainstext,changingthemethodto trust doesnotcleartheoptionsfieldanditisnotpossibletosavechangestothe pg_hba.conf file.

TheCommandCenterwebserver, gpccws ,spawnssshprocessesbutdoesnotreaptheminatimelymanner,leadingtomanyzombieprocesses.Thisisfixed.

OntheAdmin>Authenticationview,ifthenumberofuserslistedintheusercolumnislongerthancanbedisplayed,CommandCentertruncatesthelistandaddsellipsis( ... )totheend.Onlyadministratorscanviewthecompletevalue,byeditingthefield.Nowanyuserwithaccesstotheviewcanseethefulllistofusersbyhoveringoverthefield.

EnhancementsandChangesinGreenplumCommandCenter4.0.0

CommandCenterInstallationChangesGreenplumCommandCenter4.xsoftware,unlikepreviousreleases,isinstalledoneveryhostintheGreenplumDatabasecluster.TheCommandCenterwebserverandbackendrunonthestandbymaster,ifyourGreenplumDatabaseclusterhasastandbymaster.Ifthereisnostandbymaster,CommandCenterrunsonthemasterhostinstead.

TomodifytheCommandCenterinstallation—forexampletoenableordisableSSLorinstallCommandCenteronneworreplacedhosts—justre-execute


theinstallerandrestartCommandCenter.ItisnotnecessarytouninstallCommandCenterbeforereinstalling.

ThereisoneCommandCenterinstallationperGreenplumDatabasecluster.ItisnolongernecessarytocreateCommandCenterinstancesafterinstallingthesoftware.

The gpcmdr command-lineutilityisreplacedwiththenew gpcc utility.Usethe gpcc utilitytostartandstopCommandCenterandmetricscollectionagents,checkCommandCenterstatus,andenableordisableKerberosauthentication.

Inpreviousreleases,thegpmonrolerequiredonlylocalconnectionstodatabasesontheGreenplummasterhost.InGreenplumCommandCenter4.x,thegpmonusermustbeabletoconnecttodatabasesfromthehostrunningtheCommandCenterwebserverandbackend,whichrequiresaddingahostentrytothe pg_hba.conf authenticationconfigurationfile.

Real-timeQueryMetricsGreenplumCommandCenter4.0introducesreal-timequerymetricsforPivotalGreenplumDatabase5.7andabove.ThisnewfeaturecombinesthefollowingnewfeaturesinGreenplumDatabaseandGreenplumCommandCenter:

GreenplumDatabasesavesqueryexecutionmetricsinsharedmemorywhilequeriesexecute.

AnewGreenplumDatabasemetricscollectionextension,includedwithPivotalGreenplumDatabase,emitsthesavedmetricsasUDPdatagrams.

AnewGreenplumCommandCentermetricscollectionagentrunningoneachGreenplumDatabasehostreceivesthedatagramsandpostsmetricstotheGreenplumCommandCenterbackend.TheCommandCenterbackendstartsandmanagesthemetricscollectionagents.

TheCommandCenterQuerymonitorviewupdatesinrealtimesoyoucanseequeriesthatarewaitingtoexecuteandthecurrentstatusandresourceusageforqueriesthatarerunning.

Metricscollectionnowincludeslockandspillfileinformation.OntheQueryMonitor,youcanseewhichqueriesareblockedandwhichqueriesholdthelocksblockingthem.TheQueryMonitorshowsthetotalsizeofspillfilescreatedonallsegmentsforeachquery.

InstallingthegpperfmondatabaseremainsaprerequisiteforCommandCenter.ThegpperfmondatabaseisthesourceforqueryhistorydisplayedintheCommandCenteruserinterface.Thenewreal-timemetricsarenotpersistedandarenotdirectlyrelatedtothemetricscollectedandpersistedinthegpperfmondatabase.

WorkloadManagementWorkloadmanagementisnowanintegratedCommandCenterfeatureratherthanaseparateproduct.WorkloadmanagementisavailableinCommandCenteronlyafterresourcegroupshavebeenenabledinGreenplumDatabasebychangingthe gp_resource_manager serverconfigurationparameterfrom'queue' to 'group' andenablingLinuxcontrolgroups(cgroups).

InCommandCenter4.0,workloadmanagementallowsyoutoassigntransactionstoGreenplumDatabaseresourcegroupsatexecutiontimebyevaluatingthecurrentdatabaseroleandquerytagsagainstworkloadassignmentfiltersyoudefineinCommandCenter.Querytagsareuser-definedname=value parametersthatyoudefineinthe gpcc.query_tags databasesessionparameter.Youcandefinemultiplequerytagsseparatedbysemicolons.SetquerytagsinaGreenplumDatabasesessioneitherasaparameterinthedatabaseconnectionURLorbyexecutingSETgpcc.query_tagsTO'<tag1>=<val1>;<tag2>=<val2>;...'

inthedatabasesession.

Whenatransactionisabouttoexecute,thecurrentdatabaseroleandquerytagsarecomparedtotheworkloadassignmentfiltersthatyouhavecreatedinCommandCenter.Ifamatchisfound,thetransactionisassignedtoaresourcegroupaccordingtotheworkloadmanagementfilter.Otherwise,thetransactionisassignedtothedatabaseuser’sresourcegroup,whichisthedefaultbehaviorwhenCommandCenterworkloadmanagementisnotenabled.

Workloadmanagementusesthe gp_wlm databaseextensionincludedwithPivotalGreenplumDatabase.

UnimplementedFeaturesSomefeaturesavailableinpreviousGreenplumCommandCenterreleaseshavebeenremovedorarenotyetimplementedinCommandCenter4.x.

TheabilityforaCommandCenteradmintopostamessagetotheQueryMonitorviewisnotyetimplemented.

Themulti-clusterviewhasbeenremoved.


KnownIssuesThefollowingareknownissuesinthecurrentGreenplumCommandCenterrelease.

UnabletoViewRealTimeQueriesAfterUpgradingFromaPreviousCommandCenterReleaseIfyouinstallanewversionofGreenplumCommandCenterusingthesameportnumberasthepreviousversion,andyouusetheChromewebbrowser,youmaybeunabletoviewreal-timequeriesuntilafteryouclearthebrowser’scache.SeethenoteinConnectingtotheCommandCenterConsoleforstepstoclearthebrowsercache.


AboutPivotalGreenplumCommandCenterPivotalGreenplumCommandCenterisamanagementtoolforthePivotalGreenplumDatabaseBigDataPlatform.ThistopicintroduceskeyconceptsaboutGreenplumCommandCenteranditscomponents.

GreenplumCommandCenterFeaturesGreenplumCommandCentermonitorssystemperformancemetrics,analyzesclusterhealth,andenablesdatabaseadministratorstoperformmanagementtasksinaGreenplumDatabaseenvironment.

GreenplumCommandCenterprovidesabrowser-nativeHTML5graphicalconsoleforviewingGreenplumDatabasesystemmetricsandperformingcertaindatabaseadministrativetasks.TheCommandCenterapplicationprovidesthefollowingfunctionality:

Interactiveoverviewofrealtimesystemmetrics.Drilldowntoseedetailsforindividualclusterhostsandsegments.

Detailedrealtimestatisticsfortheclusterandbyserver.

QueryMonitorviewlistsqueriesexecuting,waitingtoexecute,andblockedbylocksheldbyotherqueries.

QueryDetailviewshowsquerymetrics,querytext,andtheexecutionplanforthequery.

WorkloadManagementviewallowsadministratorsto:

CreateandmanageworkloadstomanageconcurrencyandallocateCPUandmemoryresources.ChangedefaultresourcegroupsforGreenplumDatabaseroles.Createassignmentrulestoassigntransactionstoresourcegroups.Createidlesessiontimeoutrulestosettheamountoftimebeforeanidlesessioniskilled.

Fourpermissionlevelsallowuserstovieworcanceltheirownorothers’queries,andtoviewormanageadministrativeinformation.

ClusterMetricsviewshowssynchronizedchartsofhistoricalsystemmetrics.

Historyviewlistscompletedqueriesandsystemmetricsplottedoveraselectedtimeperiod.

PermissionsviewtoseeormanageCommandCenterpermissionlevels.

Authenticationviewtoseeoreditthe pg_hba.conf host-basedauthenticationconfigurationfile.

SegmentStatusviewwithsummariesanddetailsbysegment.

StorageStatusviewwithsummariesanddetailsbysegmentdatadirectory.

GreenplumCommandCenterArchitectureThefollowingfigureillustratestheGreenplumCommandCenterarchitecture.


GreenplumCommandCenterWebServerandWebApplicationTheGreenplumCommandCenterwebserverandbackendapplicationcanrunonthemaster,standbymaster,oranysegmenthostintheGreenplumDatabasecluster—thestandbymasterhostisrecommended.Thewebserver,gpccws,isacustomHTTPserverdesignedforCommandCenter.ThewebapplicationisanHTML5andGolanguageapplication.

TheCommandCenterwebserverauthenticatesuserswiththeGreenplumDatabaseauthenticationsystem.AdministratorscanedittheGreenplumDatabasehost-basedauthenticationfile, pg_hba.conf ,intheCommandCenterConsole.CommandCentercanalsobeconfiguredtoauthenticateusersinaKerberosenvironment.

CommandCenterdefinesfouruserauthorizationlevelstomanageusers’accesstotheQueryMonitor,andtoadministrativeinformationandoperations.UserauthorizationismanagedintheAdministrativeareaoftheCommandCenteruserinterface.

GreenplumCommandCenterdisplaysinformationderivedfromseveralsources:

GreenplumDatabaseperformancemonitoringdatabase(gpperfmon)

Operatingsystemprocessaccounting

GreenplumDatabasesystemcatalogtables

Real-timequerymetricscollectionextension

Workloadmanagementextension

GreenplumDatabaseisinstrumentedtoenablecapturingperformancemetricsandtrackingqueryexecution.Theperformancemonitoringdatabaseandthequerymetricscollectionextensiondeployagents—processesrunningoneachhostlisteningforUDPpackets—tocollectmetrics.ThegpperfmonagentsforwardcollecteddatatoanagentontheGreenplumDatabasemaster.Thereal-timequerymetricsagentssubmitcollecteddatadirectlytotheCommandCenterrpcport.TheagentsalsocollectdatafromthehostoperatingsystemsothatqueryperformancecanbecorrelatedwithCPUandmemoryutilizationanddiskspacecanbemonitoredinCommandCenter.

GreenplumDatabasePerformanceMonitoringDatabaseThegpperfmonperformancemonitoringdatabasestorescurrentandhistoricalquerystatusandsysteminformationcollectedfromagentsrunningonthemasterandsegmenthosts.GreenplumCommandCenterusesgpperfmonforhistoricaldataonly;itusesthereal-timequerymetricstomonitoractiveandqueuedqueries.GreenplumDatabasesendsUDPpacketsatvariouspointsduringqueryexecution.The gpsmon processoneachsegmenthostcollectsthedata.Periodically,every15secondsbydefault,a gpmmon agentonthemasterhostsignalsthe gpsmon processtoforwardthecollecteddata.Theagentonthemasterhostreceivesthedataandaddsittothegpperfmondatabase.

TheCommandCenterdatabaseconsistsofthreesetsoftables:

nowtablesstoredataoncurrentsystemmetricssuchasactivequeries


historytablesstoredataonhistoricalmetrics

tailtablesarefordataintransition.Tailtablesareforinternaluseonlyandshouldnotbequeriedbyusers.

Thenowandtaildataarestoredastextfilesonthemasterhostfilesystem,andtheCommandCenterdatabaseaccessesthemviaexternaltables.Thehistorytablesareregulardatabasetablesstoredwithinthegpperfmondatabase.

YoucanrunSQLqueriesonthedatastoredinthegpperfmondatabase.GreenplumCommandCenterrunsqueriesonthedatabaseforinformationpresentedintheCommandCenterConsole.TheGreenplumDatabaseReferenceGuidecontainsreferencesforthetablesinthegpperfmondatabase.

GreenplumDatabaseprovidesamanagementutility, gpperfmon_install ,tocreatethegpperfmondatabaseandenablethegpperfmonagentsonthemasterandsegmenthosts.CreatingthegpperfmondatabaseisaprerequisiteforinstallingGreenplumCommandCenter.SeetheGreenplumDatabaseUtilityGuidefordetailsofrunningthe gpperfmon_install managementutility.

Real-TimeQueryMetricsCollectionThedatacollectedbyreal-timequerymetricscollectionismoredetailedandmorecurrentthanstatisticsrecordedinthegpperfmondatabase.CommandCenteruserscanobservequeriesastheyexecuteand,withsufficientpermissions,cancelproblemqueriestoallowotherqueriestocomplete.

TheGreenplumDatabasequerymetricsextensionandthemetricscollectionagentworktogethertocollectreal-timemetricsandupdatetheCommandCenterapplication.

GreenplumDatabasecallsthequerymetricsextensionwhenaqueryisfirstsubmitted,whenaquery’sstatuschanges,andwhenanodeinthequeryexecutionplaninitializes,starts,orfinishes.ThequerymetricsextensionsendsmetricsinUDPpacketstothemetricscollectionagentrunningoneachsegmenthost.Theextensionalsocollectsinformationaboutthelocksqueriesholdsothatyoucanseewhichqueriesholdlocksthatblockotherqueries.TheagentpoststhemetricstotheGreenplumCommandCenterrpcport.

The metrics_collection extensionisincludedwithPivotalGreenplumDatabase.Theextensionisenabledbysettingthe gp_enable_query_metrics serverconfigurationparametertoonandrestartingtheGreenplumDatabasecluster.ThemetricscollectionagentisinstalledoneachhostwhenyouinstallGreenplumCommandCenter.TheCommandCenterapplicationmonitorstheagentandrestartsitifneeded.

CommandCenterWorkloadManagementWorkloadssetconcurrency,memory,andCPUresourcelimitsfordatabasetransactionstheymanage.AGreenplumCommandCenterworkloadcorrespondstoaGreenplumDatabaseresourcegroup,butaddsadditionalcapabilitiesthatarenotavailablewithresourcegroups.

CommandCenterallowsadministratorsgreaterflexibilityinassigningtransactionstoworkloads.EveryGreenplumDatabaseroleisassignedtoasingleresourcegroupand,bydefault,transactionsaremanagedbytherole’sresourcegroup.WithCommandCenterworkloadmanagement,administratorscandefinecriteriatoassigntransactionstoworkloadsbasedonattributesotherthantherolesubmittingthetransaction.Currently,assignmentcriteriacanevaluatequerytagsandrolesincombinationwithquerytags.

Aquerytagisakey-valuepairdefinedinthe gpcc.query_tags parameterofadatabasesession.Theparameterhastheformat<tag1>=<value1>;<tag2>=<value2> ,wheretagsandvaluesareuser-definedvalues.Forexample,ifyouwanttorunETLoperationsinaworkloadnamed“etl”,youcoulddefineatagnamed“xact-type”andsetitto“etl”: xact-type=etl .The gpcc.query_tags parametercanbesetasaconnectionparameteronGreenplumDatabaseclientsthatallowit,orwitha SET commandinsidethesessionaftertheconnectionhasbeenestablished,forexampleSETgpcc.query_tags='xact-type=etl'

.

The gp_wlm extensioninPivotalGreenplumDatabaseprovidessupportforCommandCenterworkloads.TheextensionisincludedwithPivotalGreenplumDatabase,butisnotenabledbydefault.Initially,GreenplumDatabaseusesresourcequeuestomanageresources.UsingCommandCenterworkloadsrequiresenablingresourcegroupsinGreenplumDatabase.ResourcegroupsarebasedontheLinuxcontrolgroups(cgroups)service,whichmustfirstbeenabledintheoperatingsystem.


InstallingtheGreenplumCommandCenterSoftwareThissectioncontainsthefollowingtopics:

CreatingthegpperfmonDatabase


UpgradingGreenplumCommandCenter

UninstallingGreenplumCommandCenter

SettingtheCommandCenterEnvironment


CreatingthegpperfmonDatabaseThistopicdescribeshowtocreatetheCommandCentergpperfmondatabaseandenablethegpperfmondatacollectionagents.ThistaskmustbecompletedonetimefortheGreenplumDatabasesystem,beforeyouinstallGreenplumCommandCenter.

Whenthedatacollectionagentsareenabled,theirprocessesarestartedandstopped(using gpstart and gpstop )ontheGreenplumsegmenthostsalongwiththeGreenplumDatabaseserverprocesses.

GreenplumDatabaseincludesa gpperfmon_install utilitythatperformsthefollowingtasks:

CreatestheCommandCenterdatabase(gpperfmon).

CreatestheCommandCentersuperuserrole( gpmon ).

ConfiguresGreenplumDatabaseservertoacceptconnectionsfromthe gpmon role(editsthe pg_hba.conf and .pgpass files).

SetstheCommandCenterserverconfigurationparametersintheGreenplumDatabaseserver postgresql.conf files.

The gpperfmon_install utilityandtheagentsarepartoftheGreenplumDatabasesoftware.ThetasksinthistopiccanbeperformedbeforeoraftertheCommandCentersoftwareisinstalled.

EnablingtheCollectionAgents1. LogintotheGreenplummasterhostasthe gpadmin user.

$su-gpadmin

2. SourcethepathfilefromtheGreenplumDatabaseinstallationdirectory:

#source/usr/local/greenplum-db/greenplum_path.sh

3. Runthe gpperfmon_install utilitywiththe --enable option.YoumustsupplytheconnectionportoftheGreenplumDatabasemasterserverprocess,andsetthepasswordforthe gpmon superuserthatwillbecreated.Forexample:

$gpperfmon_install--enable--passwordchangeme--port5432

Note:The gpperfmon_install utilitycreatesentriesforthe gpmon userinthe $MASTER_DATABASE/pg_hba.conf file.SeegpmonUserAuthenticationfornotesaboutrestrictingthegpmonuser’saccesstodatabases.Thepasswordyouspecifyissavedina .pgpass fileinthe gpadmin user’shomedirectory.SeeChangingthegpmonPassword forstepstochangethe gpmon password.

4. Whentheutilitycompletes,restartGreenplumDatabaseserver.Thedatacollectionagentsdonotstartuntilthedatabaseisrestarted.

$gpstop-r

5. Usingthe ps command,verifythatthedatacollectionprocessisrunningontheGreenplummaster.Forexample:

$ps-ef|grepgpmmon

6. Runthefollowingcommandtoverifythatthe gpmon usercanauthenticateandthatthedatacollectionprocessesarewritingtotheCommandCenterdatabase.Ifallofthesegmentdatacollectionagentsarerunning,youshouldseeonerowpersegmenthost.

$psql-Ugpmongpperfmon-c'SELECT*FROMsystem_now;'

Thedatacollectionagentsarenowrunning,andyourGreenplumsystemnowhasagpperfmondatabaseinstalled.ThisisthedatabasewherehistoricalCommandCenterdataisstored.Youcanconnecttoitasfollows:

$psqlgpperfmon


http://gpcc.docs.pivotal.io/440/topics/admin-configure.html#topic_ysv_mvq_wr

ConfiguringaStandbyMasterHost(ifenabled)1. Copythe $MASTER_DATA_DIRECTORY/pg_hba.conf filefromyourprimarymasterhosttoyourstandbymasterhost.Thisensuresthattherequired

connectionoptionsarealsosetonthestandbymaster.

2. Copyyour ~/.pgpass filefromyourprimarymasterhosttoyourstandbymasterhost.Thisfileusuallyresidesinthe gpadmin user’shomedirectory.Notethatthepermissionson .pgpass mustbesetto600(forexample: chmod 0600 ~/.pgpass ).

gpmonUserAuthenticationThe gpperfmon_install utilityaddsentriesforthe gpmon usertothe pg_hba.conf file,whichallowsthe gpmon usertomakealocalconnectiontoanydatabaseintheGreenplumcluster.

localgpperfmongpmonmd5hostallgpmon127.0.0.1/28md5hostallgpmon::1/128md5

ForGreenplumCommandCenter,the gpmon usermustalsohavehostaccessfromthehostwheretheCommandCenterwebserverandbackendrun.ThisrequiresthatyouaddanentryfortheCommandCenterhost.Editthe $MASTER_DATA_DIRECTORY/pg_hba.conf fileandaddalinelikethefollowing.

hostallgpmon<cc-host-ip>/32md5

Sincethe gpmon roleisaGreenplumDatabasesuperuser,youmaywishtorestricttherolefromaccessingotherdatabases.Edittheselines:

ListgpperfmonandthedatabasesyouwanttomonitorwithCommandCenterinthesecondfield:

localgpperfmon,userdb1,userdb2gpmonmd5hostgpperfmon,userdb1,userdb2gpmon127.0.0.1/28md5hostgpperfmon,userdb1,userdb2gpmon::1/128md5hostgpperfmon,userdb1,userdb2gpmon<cc-host-ip>/32md5

SeeChangingthegpmonPassword forstepstochangethe gpmon user’spassword.



InstallingPivotalGreenplumCommandCenterThePivotalGreenplumCommandCenterinstallationutilityinstallstheCommandCenterfilesonallhostsintheGreenplumDatabasecluster.

PrerequisitesTheGreenplumCommandCenterinstallerinstallstheCommandCentersoftwareoneveryhostintheGreenplumDatabasecluster.Youcanruntheinstalleronthemasterhost.ThelistofhoststoinstalluponisretrievedfromtheGreenplumDatabase gp_segment_configuration systemtable.

BeforeinstallingGreenplumCommandCenter,ensurethefollowingrequirementsaremet:

GreenplumDatabasemustbeinstalledandrunning.SeethePivotalGreenplumCommandCenterreleasenotesforcompatibleGreenplumDatabaseversions.

TheGreenplumDatabase MASTER_DATA_DIRECTORY environmentvariablemustbeset.

Thegpperfmondatabaseandgpmonrolemustbecreatedandthegpperfmonagentsmustberunning.SeeCreatingthegpperfmonDatabase.

ThedirectorywhereGreenplumCommandCenterwillbeinstalled, /usr/local/ bydefault,mustbewritablebythegpadminuseronallGreenplumDatabasehosts.Alternatively,youcaninstallCommandCenterasrootand,whendone,changeownershipofallfilesintheinstallationdirectorytothegpadminuser.SeeSelectingandPreparinganInstallationDirectoryforCommandCenterforoptions.

PreparetheStandbyMasterHostAftertheCommandCentersoftwareisinstalled,youstarttheCommandCenterwebserverandbackendonthestandbymasterhostoronthemasterhost.SomepreparationisrequiredtoenableCommandCentertorunonthestandbymasterhost.

1. Onthemasterhost,editthe $MASTER_DATA_DIRECTORY/pg_hba.conf fileandaddthefollowingentrytoallowthegpmonusertoauthenticatefromanyhostintheGreenplumDatabasecluster.

hostallgpmon<IP_of_host>/32md5

Run gpstop-u tohaveGreenplumDatabasereloadthefile.

2. Copythe .pgpass filefromthemasterhosttothestandbymasterhost.Runthesecommandsfromthemaster:

$sshgpadmin@<standby_host>$scpgpadmin@<master_host>:~/.pgpass~$chmod600~/.pgpass

3. IftheGreenplumCommandCenterwebserveristosupportTLS/SSL,aservercertificatemustbeobtainedandinstalledontheCommandCenterhostinalocationreadablebythegpadminuser.Thedefaultpathis /etc/ssl/certs/cert.pem .

4. IfGreenplumCommandCenteristosupportKerberosauthentication,GreenplumDatabasemusthaveKerberosauthenticationsetupandtherequiredprincipalsandkeytabsmustbeinstalledontheCommandCenterhost.SeeEnablingAuthenticationwithKerberosforKerberossetupinstructions.YoucaninstallCommandCenterwithoutKerberosauthenticationinitiallyandthenenableKerberoslaterbyrunningthe gpcckrbenable

Important!IfyouupgradedtoPivotalGreenplumDatabaserelease5.7orlaterfromanearlierGreenplumDatabase5.xrelease,youmustfollowstepsatSetUptheMetricsCollectionandWorkloadManagementExtensionsbeforeyoustartGreenplumCommandCenter.

NOTETherearetwoalternativemethodsyoucanusetosupplythegpmonuser’spasswordsothatyoudonothavetoputthe .pgpass fileonthehost.CommandCenteronlyrequiresthegpmonpasswordwhenyourun gpccstart , gpccstop ,or gpccstatus .

1. Setthe PGPASSWORD environmentvariablebeforeyourun gpcc commands.Example:

$ PGPASSWORD=changeme gpcc status

2. Addthe -W optionto gpcc commandstohavethecommandpromptyouforthepassword.Example:

$ gpcc start -W


command.

SelectingandPreparinganInstallationDirectoryforCommandCenterTheCommandCenterinstallationdirectorymustexistandbewritableoneveryhostintheGreenplumDatabaseclusterbytheLinuxuserwhorunstheCommandCenterinstaller.Thatusermustalsohavepasswordlesssshaccesstoallhostsinthecluster.TheCommandCenterinstallercreatesadirectorynamed greenplum-cc-web-<version> intheinstallationdirectoryoneveryhostintheGreenplumDatabasecluster.WhenCommandCenterinstallationiscompletethe greenplum-cc-web-<version> directoryandallofitscontentsmustbeownedbythe gpadmin user.

ThedefaultinstallationdirectoryforCommandCenteris /usr/local .InastandardLinuxsystem,the /usr/local directoryisownedby root andisonlywritableby root .Ifyouchoosethedefaultinstallationdirectoryoranotherdirectorywhere gpadmin doesnothavewritepermission,youcanuseoneofthefollowingmethodstoinstallCommandCenter.

Temporarilychangepermissionsontheinstallationdirectorytoallowthe gpadmin usertoinstallCommandCenter.

As root ,createthe greenplum-cc-web-<version> directoryintheinstallationdirectoryonallhostsintheGreenplumDatabaseclusterandchangethedirectory’sownershipto gpadmin .

RuntheCommandCenterinstalleras root andthenchangetheownershipofthe greenplum-cc-web-<version> directoryanditscontentstogpadmin .

Alloftheseoptionsrequire root toexecuteshellcommandsoneveryGreenplumDatabasehost.TheGreenplumDatabaseutilities gpssh-exkeys andgpssh makethismucheasier.

SettingupPasswordlesssshfortherootUserTherootusermusthavepasswordlesssshaccesstoallGreenplumDatabasehostsinordertoruntheCommandCenterinstallerortoexecuteshellcommandsonGreenplumhostsusingthe gpssh utility.Followthisproceduretosetuppasswordlesssshaccesswiththe gpssh-exkeys utility.

1. Logintothemasterhostasthe root user.

2. Createatextfile,forexample allhosts.txt ,containingalistofallGreenplumDatabaseclusterhosts,includingthemasterandstandbymasterhost,onenameperline.

3. SourcetheGreenplumDatabaseenvironmentsetupscriptintheGreenplumDatabaseinstallationdirectory.

#source/usr/local/greenplum-db-<version>/greenplum-db_path.sh

4. Runthe gpssh-exkeys utility,specifyingthehostsfilewiththe -f option.

#gpssh-exkeys-fallhosts.txt

CreatetheInstallationDirectoryandInstallCommandCenterSoftwareCreatetheCommandCenterinstallationdirectoryonallGreenplumDatabasehostsandassignpermissionssothatyoucanruntheCommandCenterinstallerasthe gpadmin user.

1. Logintothemasterhostasthe root user.



3. Usethe gpssh utilitytocreatethedirectoryandsetownershiponallhosts.

#gpssh-fallhosts.txt=>mkdir/opt/greenplum-cc-web-4.4.0=>chowngpadmin:gpadmin/opt/greenplum-cc-web-4.4.0=>exit

4. Asthe gpadmin user,runtheCommandCenterinstallerasdescribedinInstallationSteps.Whenpromptedfortheinstallationdirectory,enter /opt .


ChangeOwnershipoftheCommandCenterDirectoryPost-InstallationIfyouinsteadinstalledCommandCenterinstallerasthe root user,thenyoumustfollowthesestepstochangetheownershipoftheinstallationdirectoryanditscontentstothe gpadmin user.ThisexampleassumesyouhaveinstalledCommandCenteras root inthe opt directory,followingthestepsinInstallationSteps.Thefilesinthe greenplum-cc-web-<version> directoryanditscontentsarecurrentlyownedby root .

1. Logintothemasterhostas root .



3. Runthefollowingcommands,providingthepathtoyourCommandCenterinstallation.

#gpssh-fallhosts.txt=>chown-Rgpadmin:gpadmin/opt/greenplum-cc-web-<version>exit

Nowyoucanlogintothestandbymasterormasterhostas gpadmin andstartCommandCenter.

InstallationStepsYoucanruntheGreenplumCommandCenterinstallerontheGreenplumDatabasemasterhost.Thesoftwarewillbecopiedtoallotherhostsinthecluster.

Performthesestepsasthe gpadmin user,if gpadmin haswritepermissionintheinstallationdirectory,oras root .

IfyouinstallCommandCenteras root ,makesure root haspasswordlesssshaccesstoallhostsintheGreenplumDatabasecluster.(SeeSettingupPasswordlesssshfortherootUser.)Wheninstallationiscomplete,besuretochangetheownershipoftheGreenplumCommandCenterdirectoryandcontentsto gpadmin .(SeeChangeOwnershipoftheCommandCenterDirectoryPost-Installation.)

1. DownloadGreenplumCommandCenter4.xfromPivotalNetwork .

2. Extracttheinstallerfromthezipfile.

$unzipgreenplum-cc-web-<version>-LINUX-x86_64.zip

Extractingtheinstallercreatesa greenplum-cc-web-<version> directorycontainingthe gpccinstall-<version> installationutility.

3. Sourcethe greenplum_path.sh scriptintheGreenplumDatabaseinstallationdirectorytoensurethe GPHOME environmentvariableisset.

$source/usr/local/greenplum-db/greenplum_path.sh

4. RuntheGreenplumCommandCenterinstaller.

$cdgreenplum-cc-web-<version>$./gpccinstall-<version>-W

Theinstallerhasthreeoptions.

The -c <config-file> optionspecifiesthepathtoaninstallationconfigurationfiletouseforanon-interactiveinstallation.SeeInstallwithaConfigurationFile.The W optioninstructstheinstallertopromptforthegpmonuser’spassword.TheinstallerattemptstoretrievethegpmonpasswordfromthePGPASSWORD environmentvariable,ifset,orfromthe ~gpadmin/.pgpass file,ifpresent.Ifneitheroftheseoptionsisavailable,includethe-W optiontoinstructtheinstallertopromptforthepassword.The --ssh_path optionallowsyoutospecifythefullpathtoacustomsshprogram.Ifyoudonotsupplythisoption,theinstallerusesthesshcommandonthepath.

$./gpccinstall-<version>--ssh_path/usr/local/bin/ssh-W

5. Readthroughthelicenseagreementandenter y toaccept.

6. WherewouldyouliketoinstallGreenplumCommandCenter?


https://network.pivotal.io

Thedefaultinstallationdirectoryis /usr/local .PressEntertoacceptthedefaultorenterthedesiredpath.ThedirectorymustexistonallhostsintheGreenplumDatabaseclusterandmustbewritablebygpadmin.

7. WhatwouldyouliketonamethisinstallationofGreenplumCommandCenter?EnteranametodisplayonCommandCenterwebpagestoidentifythisGreenplumDatabasesystem.

8. OnwhichportwouldyouliketoinstalltheGreenplumCommandCenterwebserver?ThedefaultCommandCenterlistenportis28080.PressEntertoacceptthedefaultorenteranotherportnumber.

9. WouldyouliketoenableSSL?Enter y ifyouwanttoenableSSL/TLS(HTTPS)encryptionforclientconnectionstotheCommandCenterwebserver.TheinstallationutilitypromptsforthelocationoftheSSLcertificate.ProvidethefilepathfortheSSLcertificateEnterthepathtothecertificateinstalledontheCommandCenterhost.Thedefaultis /etc/ssl/certs/cert.pem .Thecertificatemustbereadablebythegpadminuser.

10. WouldyouliketoenableKerberos?Enter y ifyouwanttoenableclientauthenticationwithKerberos.KerberosmustalreadybeenabledforGreenplumDatabase.(Ifyouenter n ,youcansetupKerberosauthenticationlaterusingthe gpcckrbenable command.)TheinstallerpromptsforinformationaboutyourKerberosinstallation.ChooseKerberosmode(1.normal/2.strict/3.gpmon_only)GreenplumCommandCentersupportsthreedifferentKerberosauthenticationschemes.

1-normalmode(default)–TheCommandCenterKerberoskeytabfilecontainstheCommandCenterprincipalandmaycontainprincipalsforCommandCenterusers.Iftheprincipalintheclient’sconnectionrequestisintheCommandCenter’skeytabfile,CommandCenterusestheclient’sprincipalfordatabaseconnections.Otherwise,CommandCenterusesthe gpmon userfordatabaseconnections.2-strictmode–CommandCenterhasaKerberoskeytabfilecontainingtheCommandCenterserviceprincipalandaprincipalforeveryCommandCenteruser.Iftheprincipalintheclient’sconnectionrequestisinthekeytabfile,thewebservergrantstheclientaccessandthewebserverconnectstoGreenplumDatabaseusingtheclient’sprincipalname.Iftheprincipalisnotinthekeytabfile,theconnectionrequestfails.3-gpmon_onlymode–CommandCenterusesthe gpmon databaseroleforallGreenplumDatabaseconnections.NoclientprincipalsareneededintheCommandCenter’skeytabfile.

ProvidethepathtothekeytabfileEnterthepathtothekeytabfilecontainingtheKerberosprincipalfortheCommandCenterwebserverand,optionally,CommandCenteruserprincipals.WhatisthenameoftheGPDBKerberosservice?ThedefaultservicenameforGreenplumDatabaseis postgres .YoucancheckthevalueoftheservicenameforyourGreenplumDatabaseclusterwiththe gpconfig utility:

$gpconfig-skrb_srvname

WhatistheURLoftheCommandCenterwebserver?TheKerberoskeytabfilemustcontainaprincipalfortheCommandCenterwebserver.Theprincipalnameisoftheformat HTTP/<gpcc-host>@<realm> ,where <gpcc-host> isthehostnameclientsuseinURLswhenconnectingtotheCommandCenterwebserver.

Ifyourantheinstalleras root ,changetheownershipoftheGreenplumCommandCenterdirectoryandcontentsto gpadmin .SeeChangeOwnershipoftheCommandCenterDirectoryPost-installation.

InstallWithaConfigurationFileYoucanprovideaconfigurationfiletotheGreenplumCommandCenterinstallertoperformanon-interactiveCommandCenterinstallation.Notethatyoumuststillviewandacceptthelicenseagreement.

$cdgreenplum-cc-web-<version>$./gpccinstall-<version>-c<config-file>-W

Thefollowingtablecontainsthenamesoftheparameterscorrespondingtotheinteractiveinstallationpromptsandtheirdefaultvalues.Defineparametersinaconfigurationfileforanyparametersthathavenodefaultvalueortooverridedefaultvalues.

InstallerPrompt Default Parameter

WherewouldyouliketoinstallGreenplumCommandCenter? /usr/local path

WhatwouldyouliketonamethisinstallationofGreenplumCommandCenter? gpcc display_name


OnwhichportwouldyouliketoinstalltheGreenplumCommandCenterwebserver? 28080 web_portWouldyouliketoenableSSL? false enable_ssl

PleaseprovidethefilepathfortheSSLcertificate: /etc/ssl/certs/cert.pem ssl_cert_file

WouldyouliketoenableKerberos? false enable_kerberos

ChooseKerberosmode(1.normal/2.strict/3.gpmon_only): 1 krb_mode

Pleaseprovidethepathtothekeytabfile: keytab

WhatisthenameoftheGPDBKerberosservice? postgres krb_service_name

WhatistheURLoftheCommandCenterwebserver? gpcc webserver_url

InstallerPrompt Default Parameter

Ifthe enable_ssl parameteristrue,the ssl_cert_file parameterisrequired.

Ifthe enable_kerberos parameteristrue,the keytab parameterisrequiredandthe webserver_url , krb_mode ,and krb_service_name mustbesettovaluesfromyourKerberosinstallation.

Thefollowinginstallationconfigurationfileexamplesetsallparameterstotheirdefaultvalues.

path=/usr/local#Setthedisplay_nameparamtothestringtodisplayintheGPCCUI.#ThedefaultisthehostnameoftheGreenplummasterhost#display_name=localhost

master_port=5432web_port=28080rpc_port=8899enable_ssl=false#Uncommentandsetthessl_cert_fileifyousetenable_ssltotrue.#ssl_cert_file=/etc/certs/mycertenable_kerberos=false#Uncommentandsetthefollowingparametersifyousetenable_kerberostotrue.#webserver_url=<webserver_service_url>#krb_mode=1#keytab=<path_to_keytab>#krb_service_name=postgres

SetUpCommandCenterandWorkloadManagementExtensionsYoumustfollowthestepsinthissectiononlyifyouhaveupgradedyourPivotalGreenplumDatabasesystemfroma5.xreleaseearlierthan5.7.0.

TheGreenplumDatabasemetricscollectionandworkloadmanagementextensionsareinstalledwhenyouupgradetoPivotalGreenplumDatabase5.7.0orlater.However,theupgradeprocedurepreservesyourprevious postgresql.conf configurationfile,soyoumustmanuallysettheserverconfigurationparametersthatenabletheextensions.YoumustrestartGreenplumDatabaseifyouchangeanyconfigurationparameters.

TosetuptheCommandCenterandworkloadmanagementextensions,logintothemasterhostasgpadminandfollowthesesteps.

1. Addthemetricscollectorandworkloadmanagementsharedlibrariestothe shared_preload_libraries configurationparameter.Checkthecurrentvalueofthe shared_preload_libraries configurationparameter.

$gpconfig-sshared_preload_librariesValuesonallsegmentsareconsistentGUC:shared_preload_librariesMastervalue:Segmentvalue:

AddtheCommandCenterandworkloadmanagementlibrariestotheparameter.(Iftherewereexistinglibrariesintheparameter,appendthenewlibraries,separatedwithacomma.)

$gpconfig-cshared_preload_libraries-v'\$libdir/metrics_collector,\$libdir/gp_wlm'

2. Makesurethe gp_enable_query_metrics configurationparameterison.

gpconfig-sgp_enable_query_metricsgpconfig-cgp_enable_query_metrics-von

3. Ifyouchangedanyconfigurationparameters,restartGreenplumDatabase.


gpstop-r

NextStepsSettingtheGreenplumCommandCenterEnvironment

StartingandStoppingGreenplumCommandCenter

ConnectingtoGreenplumCommandCenter


UpgradingGreenplumCommandCenterToupgradeGreenplumCommandCenter,youinstallthenewCommandCentersoftwarerelease,stoptheoldversion,andstartthenewversion.YoucanthenremovetheolderCommandCenterreleasefromyourGreenplumDatabasehosts.

ToupgradetoanewreleaseofGreenplumCommandCenter4.x:

1. DownloadandinstallthenewCommandCenterreleasebyfollowingtheinstructionsinInstallingGreenplumCommandCenter.

2. StopthecurrentCommandCenterrelease.CommandCenter3.x:

$gpcmdr--stop<instance_name>

CommandCenter4.x:

$gpccstop

3. Sourcethe gpcc_path.sh scriptinthenewCommandCenterinstallationdirectory.

$source/usr/local/greenplum-cc-web-<version>/gpcc_path.sh

Note:Alsoupdatethesourcecommandinyourshellstart-upscript,forexample ~/.bashrc.sh or ~/.bash_profile.sh .

4. StartthenewCommandCenterrelease.

$gpccstart

5. UninstalltheolderCommandCenterrelease.See“UninstallingGreenplumCommandCenter”intheGreenplumCommandCenterdocumentationforthereleaseyouareuninstalling.

UpgradingFromGreenplumCommandCenter3.xto4.x

TheGreenplumCommandCenterarchitecturechangedbetweenCommandCenter3.xand4.x.

WithCommandCenter3.x,youinstalledtheGreenplumCommandCentersoftwareonetimeontheCommandCenterhost.YouthencreatedaCommandCenterinstanceforeachGreenplumDatabaseclusteryoumonitoredwithCommandCenter.

CommandCenter4.xdoesnothaveinstances;youinstalltheCommandCentersoftwareonthemasterorstandbymasteroftheGreenplumDatabaseclusteryouwanttomonitorwithCommandCenter.TheinstallercopiesthesoftwaretoeveryhostintheGreenplumDatabasecluster.TomonitoradditionalGreenplumDatabaseclustersyoumustinstalltheCommandCentersoftwareagain,onadifferentmasterorstandbyhost.MonitoringmultipleGreenplumDatabaseclustersrunningonthesamehardwareclusterisnotsupported.


UninstallingGreenplumCommandCenterTouninstallGreenplumCommandCenter,youmuststopboththeCommandCenterConsoleanddisablethedatacollectionagents.Optionally,youmayalsoremoveanydataassociatedwithGreenplumCommandCenterbyremovingyourCommandCenterConsoleinstallationandthegpperfmondatabase.

1. StopCommandCenterConsoleifitiscurrentlyrunning.Forexample:

$gpcc--stop

2. RemovetheCommandCenterinstallationdirectoryfromallhosts.Forexample:

$rm-rf/usr/local/greenplum-cc-web-version

3. Disablethedatacollectionagents.

a. LogintothemasterhostastheGreenplumadministrativeuser( gpadmin ):

$su-gpadmin

b. Disablethedatacollecitonagentsbysettingthe gp_enable_gpperfmon serverconfigurationparameteroff:

$gpconfig-cgp_enable_gpperfmon-voff

c. Removeorcommentoutthegpmonentriesin pg_hba.conf .Forexample:

#localgpperfmongpmonmd5#hostgpperfmongpmon0.0.0.0/0md5

d. DroptheCommandCentersuperuserrolefromthedatabase.Forexample:

$psqltemplate1-c'DROPROLEgpmon;'

e. RestartGreenplumDatabase:

$gpstop-r

f. CleanupanyuncommittedCommandCenterdataandlogfilesthatresideonthemasterfilesystem:

$rm-rf$MASTER_DATA_DIRECTORY/gpperfmon/data/*$rm-rf$MASTER_DATA_DIRECTORY/gpperfmon/logs/*

g. IfyoudonotwanttokeepyourhistoricalCommandCenterdata,dropthegpperfmondatabase:

$dropdbgpperfmon


AbouttheCommandCenterInstallationTheinstallationprocedurecreatesasoftwareinstallationdirectoryforGreenplumCommandCenter.ThisdirectoryiscopiedtoallhostsintheGreenplumCluster.VersionsofGreenplumDatabasethatarecompatiblewithGreenplumCommandCenterincludepre-packagedfilesthatsupporttheCommandCenterreal-timemetricsandworkloadmanagementfeatures.

SoftwareInstallationDirectoryThefollowingfilesandfirst-levelsubdirectoriesarecopiedintotheinstallationdirectoryyouspecifywhenyouinstallGreenplumCommandCenter.Thislocationcanbereferencedwiththe $GPCC_HOME environmentvariablewhenyouhavesettheCommandCenterenvironment.

gpcc_path.sh –filecontainingenvironmentvariablesforGreenplumCommandCenter

bin/ –programfilesforGreenplumCommandCenter

gpcc-agent -real-timequerymetricscollectionagentgpccws -theGreenplumCommandCenterwebserverstatic/ -staticfilesfortheCommandCenterapplication

conf/

app.conf -configurationfilefortheCommandCenterwebserver

logs/ -webserveraccessanderrorlogfiles

open_source_licenses_GPCC.txt –licensesforopensourcecomponentsusedbyGreenplumCommandCenter

GreenplumDatabaseArtifactsTheCommandCenterreal-timemetricsandworkloadmanagementfeaturesdependonthe gp_wlm and metrics_collection GreenplumDatabaseextensions.TheseextensionsareincludedwithcompatibleversionsofGreenplumDatabase.


SettingtheGreenplumCommandCenterEnvironmentToenablethe gpadmin usertoexecuteCommandCenterutilitiessuchas gpcc atthecommandline,sourcethe gpcc_path.sh fileintheGreenplumCommandCenterinstallationdirectory.Forexample:

$source/usr/local/greenplum-cc-web-<version>/gpcc_path.sh

The gpcc_path.sh scriptsetsthe GPCC_HOME environmentvariabletotheCommandCenterinstallationdirectoryandaddsthe $GPCC_HOME/bindirectorytothepath.

Toautomaticallysourcethe gpcc_path.sh eachtimeyoulogin,addtheabovesourcecommandtoyourstart-upscript,forexample ~/.bashrc or~/.bash_profile .


ConnectingtotheGreenplumCommandCenterConsoleSignintotheCommandCenterConsolewithanameandpassword.IftheGuestAccesstoQueryMonitorfeatureisenabled,youcansigninanonymouslytoseejusttheQueryMonitorview.

OpentheCommandCenterConsoleinasupportedbrowserusingthehostnameandportconfiguredfortheCommandCenterwebserver.Forexample,toopenasecureCommandCenterconnectiononahostnamed smdw atport28080,enterthisURLintoyourbrowser:

https://smdw:28080

IftheViewQueryMonitorlinkispresent,youcanclickittoviewtheQueryMonitorpagewithoutsigningin.ThistakesyouimmediatelytotheQueryMonitorview.ToaccessadditionalCommandCenterfeatures,clickSignInontheQueryMonitorviewandsigninwithavalidCommandCenterusernameandpassword.Ifthelinkisnotpresentonthesign-inpage,aCommandCenteradministratorhasdisabledtheanonymousquerymonitorfeature.

TosigninasaCommandCenteruser,entertheusernameandpasswordofaGreenplumrolethathasbeenconfiguredtoallowauthenticationtoGreenplumCommandCenter,thenclickSignIn.ThisopenstheDashboardpageoftheCommandCenterConsole,whichprovidesagraphicalsystemsnapshotandasummaryviewofactivequeries.SeetheDashboardforinformationabouttheDashboardview.

NotetoChromeBrowserUsers

IfyouinstallanewversionofGreenplumCommandCenterusingthesameportnumberasthepreviousversion,andyouusetheChromewebbrowser,youmaybeunabletoviewreal-timequeriesuntilafteryouclearthebrowser’scache.Followthesesteps.

1. ChooseSettingsfromtheChromemenu.

2. ScrolltothebottomandclickAdvanced.

3. UnderPrivacyandsecurity,clickClearbrowsingdata.

4. ClicktheBasictabandselectCachedimagesandfiles.YoudonothavetoclearBrowsinghistoryorCookiesandothersitedata.

5. ClickCLEARDATAandthenlogintoCommandCenter.


AdministeringtheCommandCenterWebServerThegpccwswebserverbinaryandwebapplicationfilesareinstalledinthe bin directoryofyourGreenplumCommandCenterinstallation.

StartingandStoppingtheWebServerStartingtheCommandCenterWebServerrunsthegpccwswebserver,startsthemetricscollectionagentsonthesegmentservers,andstartsalistenerontheCommandCenterrpcport.

Youcanrunthe gpcc commandasthegpadminuseronthestandbymasterhost(recommended)oronthemasterhost.

Toensurethe gpcc commandisonyourpath,sourcethe gpcc_path.sh fileintheCommandCenterinstallationdirectoryoraddittothestartupscriptforyourcommandshell.SeeSettingtheGreenplumCommandCenterEnvironmentforinstructions.

TostartGreenplumCommandCenter

Logontothestandbymasterhostorthemasterhost.

Tologontothestandbyfromthemasterhost:

$ssh<standby-host>

SourcetheCommandCenterenvironmentvariables.

$source/usr/local/greenplum-cc-<version>/gpcc_path.

StarttheCommandCenterwebserverandthemetricscollectionagents.

$gpccstartStartingthegpccagentsandwebserver…2018/03/2217:35:06Agentsuccessfullystartedon7/8hosts2018/03/2217:35:06ViewGreenplumCommandCenterathttp://smdw:28080

TostopGreenplumCommandCenter

$gpccstop2018/03/2217:36:23Gpccwebserverandmetricscollectionagentshavebeenstopped.Usegpccstarttostartthemagain

TochecktheGreenplumCommandCenterstatus

$gpccstatusStartingthegpccagentsandwebserver…2018/03/2217:36:55Agentsuccessfullystartedon7/8hosts2018/03/2217:36:55ViewGreenplumCommandCenterathttp://smdw:28080

Seethe gpcc referencepageforfullsyntaxforthe gpcc command.

ConfiguringtheCommandCenterWebServerThewebserverconfigurationfileisstoredin $GPCC_HOME/conf/app.conf .TheparametersinthisconfigurationfilearesetwhenyouinstallGreenplumCommandCenter.TheinstallercopiestheCommandCenterinstallationdirectory,includingthisconfigurationfile,toeveryGreenplumDatabasehost.

SeetheWebServerParameterssectionofConfigurationFileReferenceforadescriptionoftheparametersinthisfile.

NOTEThe gpcc commandusesthegpmonroletoconnecttoGreenplumDatabase.Itlooksforthegpmonpasswordinthe PGPASSWORD environmentvariableorinthe .pgpass fileinthegpadminuser’shomedirectory.Youcaninsteadappendthe -W flagtothe gpcc commandsbelowtohavegpcc promptyoutoenterthepassword.


Youcanseeasummaryofthecurrentconfigurationusingthe gpcc--settings

command.

$gpcc--settingsInstallpath:/usr/localDisplayName:gpccGPCCport:28080Kerberos:disabledSSL:disabled

Ifyoumodifythefileononehostyoushouldcopyittoeveryotherhost.Besuretorestartthewebserverafteryouchangetheconfiguration.Ratherthanmodifyingtheconfigurationdirectly,youcanjuststopCommandCenterandre-runthe gpccinstall-<version> installationcommand.Thisensurestheconfigurationisconsistentonallhosts.

Youcanusethe gpcckrbenable commandtoaddKerberosauthenticationtotheCommandCenterconfiguration.SeeEnablingAuthenticationwithKerberosfordetailsaboutsettingupKerberosontheCommandCenterhost.The gpcckrbenable commandpromptsfortheKerberosprincipalnamesandartifactsandupdatestheconfiguration.

The gpcckrbdisable commandremovesKerberosparametersfromtheCommandCenterconfiguration.

ViewingandMaintainingWebServerLogFilesWebserveraccessanderrorlogmessagesarewrittento $GPCC_HOME/logs/gpccws.log .

IfyouexperienceerrorsviewingtheGreenplumCommandCenterConsole,refertothisfileformoreinformation.

Topreventthewebserverlogfromgrowingtoexcessivesize,youcansetuplogfilerotationusing logrotate or cronolog .


AdministeringCommandCenterAgentsTheCommandCentermetricscollectionagent, cc_agent ,runsonsegmenthostsandlistensonaUDPportforreal-timemetricsemittedbythemetricscollectiondatabaseextension.StartingGreenplumCommandCenterwiththe gpcc

startcommandstartstheCommandCenteragentoneachsegment

host.StoppingCommandCenterwith gpccstop endstheseprocesses.TheCommandCenterbackendmonitorstheseagentsandrestartsthemwhennecessary.

InstallingthegpperfmondatabaseconfiguresGreenplumDatabasetorunagentsonthemasterhostandeachsegmenthost.Theagentsarestartedautomaticallywhenthedatabasesystemstartsup.TheGreenplumDatabasepostmasterprocessmonitorstheagentsandrestartsthemwhennecessary.

gpmmon

The gpmmon agentrunsontheGreenplumDatabasemasterhost.Itcollectsinitialqueryinformationfromthemaster.Every15seconds,bydefault,itpromptsthe gpsmon agentstosendtheiraccumulateddata.The gpmmon processsavesthemetricsdataandlogstoCSVtextfilesthatfeedtheexternaltablesinthegpperfmondatabase.

gpsmon

The gpsmon agentrunsoneachGreenplumDatabasesegmenthost.ItlistensonaUDPportformetricsemittedbyGreenplumDatabase,gathersadditionalmetricsfromtheoperatingsystem,andforwardsdatatothe gpmmon agentwhenrequested.

Thistopicdescribesbasicagentadministrationtasks,includingaddinghostsandviewingagentlogfiles.

AddingandRemovingHostsWhenyouaddorreplaceGreenplumDatabasehosts,youmustreinstalltheGreenplumCommandCentersoftwaretoensurethesoftwareisinstalledonthenewhosts.ItisnotnecessarytouninstallCommandCenterbeforereinstalling.StopCommandCenterandrestartittostartagentsonthenewhosts.

Thegpperfmon gpsmon agentsonnewhostsaredetectedautomaticallybythemasteragent, gpmmon .Wheneverthe gp_enable_gpperfmon serverconfigurationparameterisenabledonthemaster,the gpmmon agentautomaticallydetects,starts,andbeginsharvestingdatafromnewsegmentagents.

ViewingandMaintainingAgentLogFilesLogmessagesfortheCommandCentermetricscollectoragentsaresavedinthe logs directoryoftheCommandCenterinstallationdirectory.

Logmessagesforthegpperfmonmasteragentarewrittentothefollowingfilebydefault:

$MASTER_DATA_DIRECTORY/gpperfmon/logs/gpmmon.log

Tochangethegpperfmonlogfilelocation,editthe log_location parameterin gpperfmon.conf .

Onthesegmenthosts,gpperfmonagentlogmessagesarewrittentoa gpsmon.log fileinthesegmentinstance’sdatadirectory.Forahostwithmultiplesegments,theagentlogfileislocatedinthedatadirectoryofthefirstsegment,aslistedinthe gp_configuration tablebydbid.Ifthesegmentagentisunabletologintothisdirectory,itwilllogmessagestothehomedirectoryoftheuserrunningCommandCenter(typically gpadmin ).

ConfiguringgpperfmonLogFileRolloverAthigherlogginglevels,thesizeofthegpperfmonlogfilesmaygrowdramatically.Topreventthelogfilesfromgrowingtoexcessivesize,youcanaddanoptionallogrolloverparameterto gpperfmon.conf .Thevalueofthisparameterismeasuredinbytes.Forexample:

max_log_size=10485760

Withthissetting,thelogfileswillgrowto10MBbeforethesystemrollsoverthelogfile.Thetimestampisaddedtothelogfilenamewhenitisrolledover.Administratorsmustperiodicallycleanoutoldlogfilesthatarenolongerneeded.


AdministeringthegpperfmonDatabaseDatacollectedbygpmmonandgpsmonagentsisstoredinadedicateddatabasecalledgpperfmon.Thisdatabaserequiresthetypicaldatabasemaintenancetasks,suchascleanupofoldhistoricaldataandperiodic ANALYZE .

SeethegpperfmonDatabaseReference sectionforareferenceofthetablesandviewsinthegpperfmondatabase.

ConnectingtothegpperfmonDatabaseDatabaseadministratorscanconnectdirectlytothegpperfmondatabaseusinganyGreenplumDatabase-compatibleclientprogram(suchas psql ).Forexample:

$psql-dgpperfmon-hmaster_host-p5432-Ugpadmin

BackingUpandRestoringthegpperfmonDatabaseThehistorytablesofthegpperfmondatabasecanbebackedupandrestoredusingtheGreenplumDatabasebackupandrestoreutilities.SeetheGreenplumDatabaseUtilityGuideformoreinformation.

MaintainingtheHistoricalDataTablesAllofthe *_history tablesstoredinthegpperfmondatabasearepartitionedintomonthlypartitions.AJanuary2010partitioniscreatedatinstallationtimeasatemplatepartition.Itcanbedeletedoncesomecurrentpartitionsarecreated.TheCommandCenteragentsautomaticallycreatenewpartitionsintwomonthincrementsasneeded.Administratorsmustperiodicallydroppartitionsforthemonthsthatarenolongerneededinordertomaintainthesizeofthedatabase.

SeetheGreenplumDatabaseAdministratorGuideformoreinformationondroppingpartitionsofapartitionedtable.


http://gpdb.docs.pivotal.io/latest/ref_guide/gpperfmon/dbref.html

gpccManagestheGreenplumCommandCenterwebserviceandmetricscollectionagents.

gpcc<action>[-W]

gpcc[--version|-v]

gpcc[--help|-h]

gpcc[--settings]

Actionsstart

StartstheCommandCenterwebserviceandmetricscollectionagents.Addthe -W flagtoforceapromptforthegpmonuserpassword.

stop

StopstheCommandCenterwebserviceandmetricscollectionagents.Addthe -W flagtoforceapromptforthegpmonuserpassword.

status

Displaysthestatus,either Running or Stopped ,ofthewebserverandmetricscollectionagents.Addthe -W flagtoforceapromptforthegpmonuserpassword.

krbenable

EnablesKerberosauthenticationforCommandCenter.

Usethe gpcckrbenable commandtosetupKerberosauthenticationforCommandCenterusersifCommandCenterwasinitiallyinstalledwithoutenablingKerberos.Whenyourun gpcckrbenable , gpcc promptsfor:

thewebservername

thenameoftheGreenplumDatabaseKerberosservice

theCommandCenterKerberosauthenticationmode

thepathtothekeytabfileontheCommandCenterhost.

Beforeyourun gpcckrbenable ,seeEnablingAuthenticationwithKerberostocheckprerequisitesandforhelppreparingtheCommandCenterhosttoallowKerberosauthentication.

krbdisable

DisablesKerberosauthenticationforCommandCenter.

help

Displayssyntaxandhelptextforthe gpcc command.

Options--settings

DisplaysthecurrentvaluesoftheCommandCenterconfigurationparameters.SeeSetupConfigurationFileforalistoftheconfigurationparameters.

--version or -vDisplaystheGreenplumCommandCenterversion.

-W <password>

Theoptional -W optionspecifiesthepasswordforthegpmonuser.The gpcc commandnormallygetsthepasswordfromthe $PGPASSWDenvironmentvariableorthe .pgpass fileinthegpadminuser’shomedirectory.Ifthepasswordisnotavailablewitheitherofthesemethods,the-W optionmustbeincludedtospecifythepasswordwheneveryourun gpcc .


DescriptionOncestarted,theCommandCenterbackendmonitorsthemetricsagentswithaheartbeat.Ifafailedagentisdetected,thebackendspawnsanewagentprocess.

ExamplesStartCommandCenterandthemetricsagents,promptingforthegpmonpassword.

$gpccstart-WPasswordforGPDBusergpmon:Startingthegpccagentsandwebserver…2018/03/2217:51:51Agentsuccessfullystartedon7/8hosts2018/03/2217:51:51ViewGreenplumCommandCenterathttp://smdw:28080


ConfigurationFileReferenceConfigurationparametersforGreenplumCommandCenterarestoredinthefollowingfiles.

$MASTER_DATA_DIRECTORY/gpperfmon/conf/gpperfmon.conf ,onGreenplumDatabasemasterhostStoresconfigurationparametersfortheGreenplumCommandCenteragents.

$GPCC_HOME/conf/app.conf ,onCommandCenterhost.StoresconfigurationparametersfortheCommandCenterwebapplicationandwebserver.

$MASTER_DATA_DIRECTORY/postgresql.conf

StoresconfigurationparameterstoenabletheGreenplumCommandCenterfeaturesforGreenplumDatabaseserver.Theseparametersarenormallysetusingthe gpconfig GreneplumDatabasemanagementutility.

$GPCC_HOME/bin/ssh-wrapper

GreenplumCommandCenternormallyfindsthe ssh commandonthepath.Ifyourenvironmenthasanincompatibleimplementationofthiscommandonthepath,youcanprovidetheabsolutepathtoyourversioninthe ssh-wrapper script,locatedat $GPCC_HOME/bin/ssh-wrapper .

Forexample:

ssh="/opt/bin/myssh"


CommandCenterAgentParametersThe $MASTER_DATA_DIRECTORY/gpperfmon/conf/gpperfmon.conf fileontheGreenplumDatabasemasterhoststoresconfigurationparametersfortheCommandCenteragents.Forconfigurationchangestotheseoptionstotakeeffect,youmustsave gpperfmon.conf andthenrestartGreenplumDatabaseserver( gpstop-

r).

ToenabletheCommandCenteragentswithinGreenplumDatabaseserver,youmustalsosettheGreenplumDatabaseServerConfigurationParameters.Seethe gpperfmon_install referenceintheGreenplumDatabaseUtilityGuidefordetails.

log_locationSpecifiesadirectorylocationforCommandCenterlogfiles.Defaultis $MASTER_DATA_DIRECTORY/gpperfmon/logs .

min_query_timeSpecifiestheminimumqueryruntimeinsecondsforstatisticscollection.CommandCenterlogsallqueriesthatrunlongerthanthisvalueinthequeries_historytable.Forquerieswithshorterruntimes,nohistoricaldataiscollected.Defaultsto20seconds.

Ifyouknowthatyouwanttocollectdataforallqueries,youcansetthisparametertoalowvalue.Settingtheminimumqueryruntimetozero,however,collectsdataevenforthenumerousqueriesrunbyCommandCenteritself,creatingalargeamountofdatathatmaynotbeuseful.

min_detailed_query_timeSpecifiestheminimumiteratorruntimeinsecondsforstatisticscollection.CommandCenterlogsalliteratorsthatrunlongerthanthisvalueintheiterators_historytable.Foriteratorswithshorterruntimes,nodataiscollected.Minimumvalueis10seconds.

Thisparameter’svaluemustalwaysbeequalto,orgreaterthan,thevalueof min_query_time .Setting min_detailed_query_time higherthanmin_query_time allowsyoutologdetailedqueryplaniteratordataonlyforespeciallycomplex,long-runningqueries,whilestillloggingbasicquerydataforshorterqueries.

Giventhecomplexityandsizeofiteratordata,youmaywanttoadjustthisparameteraccordingtothesizeofdatacollected.Iftheiterators_* tablesaregrowingtoexcessivesizewithoutprovidingusefulinformation,youcanraisethevalueofthisparametertologiteratordetailforfewerqueries.

max_log_sizeThisparameterisnotincludedingpperfmon.conf,butitmaybeaddedtothisfileforusewithGreenplumCommandCenter.

Topreventthelogfilesfromgrowingtoexcessivesize,youcanaddthe max_log_size parameterto gpperfmon.conf .Thevalueofthisparameterismeasuredinbytes.Forexample:

max_log_size=10485760

Withthissetting,thelogfileswillgrowto10MBbeforethesystemrollsovertoanewlogfile.

partition_ageThenumberofmonthsthatGreenplumCommandCenterstatisticsdatawillberetained.Thedefaultitis0,whichmeanswewon’tdropanydata.

quantumSpecifiesthetimeinsecondsbetweenupdatesfromCommandCenteragentsonallsegments.Validvaluesare10,15,20,30,and60.Defaultsto15seconds.

Ifyoupreferalessgranularviewofperformance,orwanttocollectandanalyzeminimalamountsofdataforsystemmetrics,chooseahigherquantum.Tocollectdatamorefrequently,choosealowervalue.

ignore_qexec_packetWhensettotrue,GreenplumCommandCenteragentsdonotcollectperformancedatainthegpperfmondatabase queries_* tables: rows_out ,cpu_elapsed , cpu_currpct , skew_cpu ,and skew_rows .Thedefaultsetting,true,reducestheamountofmemoryconsumedbythegpmmonprocess.Setthisparametertofalseifyourequirethisadditionalperformancedata.

smdw_aliasesThisparameterallowsyoutospecifyadditionalhostnamesforthestandbymaster.Forexample,ifthestandbymasterhastwoNICs,youcanenter:

smdw_aliases=smdw-1,smdw-2

ThisoptionalfaulttoleranceparameterisusefuliftheGreenplumCommandCenterlosesconnectivitywiththestandbymaster.Insteadofcontinuouslyretryingtoconnecttohostsmdw,itwilltrytoconnecttotheNIC-basedaliasesof smdw-1 and/or smdw-2 .ThisensuresthattheCommandCenterConsolecancontinuouslypollandmonitorthestandbymaster.



CommandCenterConsoleParametersTheCommandCenterConsoleconfigurationfileisontheCommandCenterhostat $GPCC_HOME/webserver/conf/app.conf .

Aftereditingthisfile,reloadtheconfigurationbyrestartingtheCommandCenterConsole.

$gpcc--stop$gpcc--start

appname = gpccws

Thewebserverbinaryfile.Donotchange.

listentcp4 = [true | false]

When true ,theaddresstypeistcp4.Thedefaultis true .

runmode = [prod | dev | test]

Theapplicationmode,whichcanbe dev , prod or test .Thedefaultis dev .In dev modeCommandCentershowsuserfriendlyerrorpages.Userfriendlyerrorpagesarenotrenderedin prod mode.

session = [true | false]

Usesessionstomanageuserexperience.Thedefaultis true .Sessionsarestoredinmemory.

enablexsrf = [true | false]

EnableCSRFprotection.

xsrfexpire = <seconds>

CSRFexpiretime.Thedefaultis 2592000 seconds.

xsrfkey = <token_string>

TheCSRFtoken.

rendertype = json

Therendertypeofwebserver.Donotchange.

printallsqls = [true | false]

PrintallbackendgpperfmonSQLtothewebserverconsole.Thedefaultis false .

path = /usr/local

PathtothedirectorywhereGreenplumCommandCenterisinstalled.

display_name = <display_name>

Thedisplaynameforconsole.

enable-kerberos = [true | false]

TrueifKerberosauthenticationisenabledforCommandCenter.Thedefaultis false .

HTTPSCertFile = </path/to/cert.pem>

Thefullpathtotheserver’sSSLcertificate,ifSSLisenabled.

HTTPSKeyFile = </path/to/cert.pem>

Theserver’sprivatekeyfileifSSLisenabled.

EnableHTTPS = [true | false]

EnablelisteningonthesecureSSLport.Thedefaultis true .

EnableHTTP = [true | false]

EnablelisteningontheHTTPport.Defaultis false .

httpport = <port>

Thewebserverport.Thedefaultis28080.

rpcport = <port>

TheportonwhichtheCommandCenterbackendreceivesdatafrommetricscollectoragents.Thedefaultis8899.

master_host = <hostname>


TheGreenplumDatabasehostname.Thedefaultis localhost .

master_port = <port>

TheGreenplumDatabasemasterport.Thedefaultis 5432 .


SetupConfigurationFileAsetupconfigurationfilecontainspropertiesusedtoconfigureGreenplumCommandCenterwhenyouperformanon-interactiveCommandCenterinstallation.Thefileispassedtothe gpccinstall commandwiththe -c option:

$./gpccinstall-<version>-c<config_file>

Theconfigurationfilecontains name:value or name=value entries,oneperline.Commentsbeginwitha # or ; characterandcontinuethroughtheendoftheline.

SeeInstallingPivotalGreenplumCommandCenterformoreinformationaboutinstallingCommandCenterwithaconfigurationfile.

Parameterspath

ThepathtothedirectorywhereGreenplumCommandCentersoftwarewillbeinstalled.ThedirectorymustbewritablebythegpadminuseronallhostsintheGreenplumCluster.

display_name

ThenametodisplayintheCommandCenteruserinterface.Thedefaultdisplaynameis gpcc .

master_port

TheGreenplumDatabasemasterport.Default: 5432 .

web_port

ThelistenportfortheCommandCenterwebserver.Thedefaultis 28080 .

enable_ssl

True ifclientconnectionstotheCommandCenterwebserveraretobesecuredwithSSL.Thedefaultis false .If true the ssl_cert_fileparametermustbesetandtheSSLcertificatemustbeinstalledonthehostwhereyourunCommandCenter.

ssl_cert_file

If enable_ssl is true ,setthisparametertothefullpathtoavalidcertificateinPEMfileformat.ThecertificatemustbeinstalledonthehostwhereyourunCommandCenter.

enable_kerberos

Setto true toenableKerberosauthentication.

krb_mode

TheKerberosauthenticationschemetouse.Thedefaultis 1 .

1-normalmode(default)-TheCommandCenterKerberoskeytabfilecontainstheCommandCenterprincipalandmaycontainprincipalsforCommandCenterusers.Iftheprincipalintheclient’sconnectionrequestisintheCommandCenter’skeytabfile,CommandCenterusestheclient’sprincipalfordatabaseconnections.Otherwise,CommandCenterusesthegpmonuserfordatabaseconnections.

2-strictmode-CommandCenterhasaKerberoskeytabfilecontainingtheCommandCenterserviceprincipalandaprincipalforeveryCommandCenteruser.Iftheprincipalintheclient’sconnectionrequestisinthekeytabfile,thewebservergrantstheclientaccessandthewebserverconnectstoGreenplumDatabaseusingtheclient’sprincipalname.Iftheprincipalisnotinthekeytabfile,theconnectionrequestfails.

3-gpmon_onlymode-CommandCenterusesthegpmondatabaseroleforallGreenplumDatabaseconnections.NoclientprincipalsareneededintheCommandCenter’skeytabfile.

webserver_url

Thewebserverhostname,fromtheKerberosHTTPserviceprincipal.

keytab

PathtothekeytabfilecontainingKerberosprincipalsfortheCommandCenterwebserverandusers.

Examples


######GPCC4.0setupconfigurationfile#####path=/optdisplay_name=GreenplumDatabaseProductionClustermaster_port=5432webserver_port=28081EnableHTTP=true;allowbothHTTPandHTTPSEnableHTTPS=truessl_cert_file=/etc/ssl/cert.pemenable_kerberos=false


GreenplumDatabaseServerConfigurationParameters

GreenplumDatabasegpperfmonDatabaseThefollowingGreenplumDatabaseconfigurationparametersmustbeuncommentedandsetintheserverconfigurationfile( postgresql.conf )toenabletheCommandCenterdatacollectionagents:

gp_enable_gpperfmon and gpperfmon_port mustbesetinboththemasterandsegment postgresql.conf files.

gp_enable_gpperfmon and gp_enable_gpperfmon onlyneedtobesetinthemaster postgresql.conf file.

Afterchangingthesesettings,theGreenplumDatabaseinstancemustberestartedforthechangestotakeeffect.

gp_enable_gpperfmonTurnsontheCommandCenterdatacollectionagentforasegment.Mustbesetinall postgresql.conf files(masterandallsegments).

gpperfmon_portThedefaultportfortheCommandCenteragentsis8888,butyoucansetthisparametertoadifferentportifrequired(masterandallsegments).

gp_gpperfmon_send_intervalSetsthefrequencyinsecondsthattheGreenplumDatabaseserverprocessessendqueryexecutionupdatestotheCommandCenteragentprocesses.

gp_external_enable_execThisparameterisenabledbydefaultandmustremainenabled.ItallowstheuseofexternaltablesthatexecuteOScommandsorscriptsonthesegmenthosts.TheCommandCenteragentsusethistypeofexternaltablestocollectcurrentsystemmetricsfromthesegments.

gpperfmon_log_alert_levelControlswhichmessagelevelsarewrittentothegpperfmonlog.Eachlevelincludesallthelevelsthatfollowit.Thelaterthelevel,thefewermessagesaresenttothelog.Thedefaultvalueiswarning.

shared_preload_librariesAcomma-separatedlistofsharedlibrariesthataretobepreloadedwhenGreenplumDatabasestarts.TheworkloadmanagementandquerymetricsextensionlibrariesmustbeincludedinthisconfigurationparametertouseGreenplumCommandCenter.

gp_enable_query_metricsWhenon,enablesquerymetricscollection.Thedefaultisoff.Aftersettingthisconfigurationparameter,GreenplumDatabasemustberestartedforthechangetotakeeffect.

gp_instrument_shmem_sizeTheamountofsharedmemory,inkilobytes,allocatedforquerymetrics.Thedefaultis5120andthemaximumis131072.Atstartup,ifgp_enable_query_metrics issettoon,GreenplumDatabaseallocatesspaceinsharedmemorytosavequerymetrics.Thismemoryisorganizedasaheaderandalistofslots.Thenumberofslotsneededdependsonthenumberofconcurrentqueriesandthenumberofexecutionplannodesperquery.Thedefaultvalue,5120,isbasedonaGreenplumDatabasesystemthatexecutesamaximumofabout250concurrentquerieswith120nodesperquery.Ifthe gp_enable_query_metrics configurationparameterisoff,oriftheslotsareexhausted,themetricsaremaintainedinlocalmemoryinsteadofinsharedmemory.


SecuringGreenplumCommandCenterGreenplumCommandCenterConsolecanbesecuredbyencryptingnetworktrafficbetweenthewebserverandusers’browsers,authenticatingCommandCenterusers,andmanagingusers’permissionstoaccessCommandCenterfeatures.

SSL/TLSEncryptionGreenplumCommandCentersupportsSSL/TLSencryptiontosecureconnectionsbetweenbrowsersandtheCommandCenterwebserver.WhenSSLisenabled,CommandCenterusestheWebSocketsAPI,enablinglong-lived,full-duplexconnections,inadditiontoencryption.

ToenableSSL,youshouldhaveasignedcertificatefortheCommandCenterwebserverinplacewhenyouinstallCommandCenter.PlaceyourcertificateontheserverwhereCommandCenterisinstalled,forexampleinthe /etc/ssl/certs directoryoftheGreenplummasterhost.YouimportthecertificatewhenyouinstallCommandCenter.Thelocationsofthecertificateandprivatekeyfilesaresavedinthe $GPCC_HOME/conf/app.conf configurationfilefortheCommandCenter.SeeCommandCenterConsoleParametersfordetails.

Youcanrequestacertificatefromyourorganization’sinternalcertificateauthorityoracommercialcertificateauthority,oryoucanuseaself-signedcertificateyoucreateyourselfwithacryptographysuitesuchasOpenSSL.Ifyoucreateaself-signedcertificate,notethatclientswillhavetooverrideasecuritywarningwhentheyfirstconnecttotheCommandCenterwebserver.

AuthenticationOptionsUsersloggingintoGreenplumCommandCenterareauthenticatedwiththeGreenplumDatabasehost-basedauthenticationsystem.Userscanentercredentialsasausernameandpasswordor,ifKerberosauthenticationisconfigured,byauthenticatingwithKerberosontheirworkstationbeforebrowsingtotheCommandCenterwebserver.

Note:GreenplumCommandCenterdoesnotacceptloginsfromthegpadminuser,orfromusersconfiguredwithtrustauthenticationinthe pg_hba.conffile.

DatabaseusersmustfirstbeaddedtotheGreenplumDatabasebyusingcommandssuchas CREATEROLE or CREATEUSER .The LOGIN privilegeisrequired.Thisexamplecreatesaloginuserwithanencryptedpassword:

CREATEROLEcc_userWITHLOGINENCRYPTEDPASSWORD'changeme';

The pg_hba.conf configurationfiledetermineshowauthenticationwillproceed.Thisfilecontainsalistofentriesthatarecomparedtoattributesoftheuser’sconnectionrequest,includingthetypeofconnection,networklocationoftheoriginatinghost,databasename,andloginusername.Whenamatchisfound,theauthenticationmethodspecifiedintheentryisapplied.

The pg_hba.conf filecanbeviewedbyOperatorsandeditedbyAdminsintheCommandCenterconsoleontheAdmin>Authenticationpage.

The md5 and password authenticationmethodsauthenticatetheusernameandpasswordwiththeGreenplumDatabase pg_roles systemtable.Themd5 methodrequiresthepasswordtobeMD5-encodedwhensentoverthenetwork,soitispreferredoverthe password method,whichsendsthepasswordincleartext.

The ldap authenticationmethodauthenticatestheusernameandpasswordwithanLDAPserver.TheLDAPserverandparametersarespecifiedintheoptionsfieldofthe pg_hba.conf entry.SeethePostgreSQLLDAPauthentication documentationfortheformatoftheLDAPoptions.

The gss authenticationmethodisusedforKerberosauthentication.TouseKerberoswithCommandCenter,KerberosauthenticationmustbeenabledfortheGreenplumDatabasesystemandCommandCentermustalsobeconfigured.UsersauthenticatewiththeKerberosKDContheirworkstations(using kinit ,forexample)beforeconnectingtotheCommandCenterwebserver.TherolenameinCommandCenteristheuser’sKerberosprincipalname.

FordetailsaboutsettingupKerberosauthentication,seeEnablingKerberosAuthenticationwithGreenplumCommandCenter.

SeethePostgreSQLAuthenticationmethods documentationforadditionaldetailsoftheauthenticationoptions.

Authorization

Note:ThefunctionalitydescribedinthissectionhasnotbeenfullyimplementedinGreenplumCommandCenter4.0.0.OnlyAdminandSelfOnly


https://www.postgresql.org/docs/8.3/static/auth-methods.html

https://www.postgresql.org/docs/8.3/static/auth-methods.html#AUTH-PASSWORD

CommandCentermanagespermissionlevelsusingGreenplumDatabaserolesandgroups.TheBasic,OperatorBasic,andOperatorpermissionlevelscorrespondtothe gpcc_basic , gpcc_operator_basic ,and gpcc_operator grouprolesinthedatabase.TheAdminpermissionlevelisconferredtorolesthathavethe SUPERUSER privilege.Auserwhohasnotbeenaddedtoanyofthegroupsanddoesnothave SUPERUSER privilegehasthemostrestrictivepermissionlevel,SelfOnly.

GreenplumDatabasesuperuserscanmanagepermissionlevelsontheCommandCenterAdmin>Permissionspage.Superuserscanalsodirectlyassignusersrolesinthedatabasebyusingthe ALTERUSER , ALTERGROUP ,andrelatedcommandstoaddorremoveusersfromgroupsandaddorremovetheSUPERUSER privilege.Ifaroleisconfiguredformorethanonepermissionlevel,CommandCenterusesthehighestpermissionlevel.

CommandCenterusershavethefollowingcapabilities,accordingtotheirpermissionlevels:

SelfOnlyUserscanviewmetricsandviewandcanceltheirownqueries.

AnyGreenplumDatabaseusersuccessfullyauthenticatedthroughtheGreenplumDatabaseauthenticationsystemcanaccessGreenplumCommandCenterwithSelfOnlypermission.Higherpermissionlevelsarerequiredtoviewandcancelother’squeriesandtoaccesstheSystemandAdminControlCenterscreens.

BasicAllowsuserstoviewmetrics,viewallqueries,andcanceltheirownqueries.

UserswithBasicpermissionaremembersoftheGreenplumDatabase gpcc_basic group.

OperatorBasicAllowsuserstoviewmetrics,viewtheirownandothers’queries,canceltheirownqueries,andviewtheSystemandAdminscreens.

UserswithOperatorRead-onlypermissionaremembersoftheGreenplumDatabase gpcc_operator_basic group.

OperatorAllowsuserstoviewtheirownandothers’queries,canceltheirownandother’squeries,andviewtheSystemandAdminscreens.

UserswithOperatorpermissionaremembersoftheGreenplumDatabase gpcc_operator group.

AdminAllowsusersaccesstoallviewsandcapabilitiesintheCommandCenter.

GreenplumDatabaseuserswiththe SUPERUSER privilegeinGreenplumDatabasehaveSuperuserpermissionsinCommandCenter.

permissionlevelsareavailable.


ManagingGreenplumCommandCenterAuthenticationTheSystem>AuthenticationscreenallowsuserswithOperatorBasic,Operator,andAdminpermissiontoviewtheGreenplumDatabasehost-basedauthenticationfile, pg_hba.conf .

UserswithAdminpermissioncanadd,remove,change,andmoveentriesinthefile.TheCommandCenterUIvalidatesentriestoensurecorrectsyntax.Previousversionsofthefilearearchivedsothatyoucanrestoreanearlierversionorauditchanges.

SeeAuthenticationOptionsforanoverviewofuserauthenticationoptionsforGreenplumDatabaseandGreenplumCommandServer.

Seepg_hba.conffile inthePostgreSQLdocumentationforadetaileddescriptionofthecontentsofthe pg_hba.conf file.

ViewingtheHost-BasedAuthenticationFileChooseAdmin>AuthenticationtodisplaythecontentoftheGreenplumDatabase pg_hba.conf file.

The pg_hba.conf filecontainsalistofentriesthatspecifythecharacteristicsofdatabaseconnectionrequestsandauthenticationmethods.WhenGreenplumDatabasereceivesaconnectionrequestfromaclient,itcomparestherequesttoeachentryinthe pg_hba.conf entryinturnuntilamatchisfound.Therequestisauthenticatedusingthespecifiedauthenticationmethodand,ifsuccessful,theconnectionisaccepted.

EditingtheHost-BasedAuthenticationFileCommandCenteruserswiththeAdminpermissioncaneditthe pg_hba.conf file.Notethatanychangesyoumakearelostifyoumovetoanotherscreenbeforeyousavethem.

Tochangeanexistingentry,clickanywhereontheentry.EditthefieldsandclickSavetosaveyourchanges,orCanceltorevertchanges.

Tomoveanentryupordowninthelist,clickonthe symbol,dragthelinetothedesiredlocation,andrelease.

Toaddanewentrytotheendofthefile,clickAddNewEntryatthebottomofthescreen.EditthefieldsandclickSavetosaveyourchanges,orCanceltoabandonthenewentry.

Toaddanewentryafteranexistingentry,highlighttheexistingentryandclick .EditthefieldsandclickSavetosaveyourchanges,orCanceltoabandonthenewentry.

Tocopyanentry,selecttheentryandclick .Acopyoftheselectedentryisaddedbelowtheselectedentryanddisplayedforediting.EditthefieldsandclickSavetosaveyourchanges,orCanceltoabandonthecopy.

Toaddacommenttothefile,addanentrybyclickingAddNewEntry andthenchoose # fromthe Type list.or


https://www.postgresql.org/docs/8.3/static/auth-pg-hba-conf.html

Totoggleanentrybetweenactiveandinactive,selectthelineandclicktheactive/inactivetogglecontroltotheright.Thisactionaddsorremovesacommentcharacter( # )atthebeginningoftheentry.

Toremoveanentry,highlightthelineandclick .Theentryisdisplayedwithstrikethroughtext.Youcanrestoretheentrybyhighlightingitandclickingundelete.TheentryispermanentlyremovedwhenyouclickSaveconfigandupdateGPDB.

Tofinishediting,clickSaveconfigandupdateGPDB.ThenclickSaveandUpdatetosaveyourchangesorclickCanceltoreturnwithyoureditsintact.

WhenyouselectSaveandUpdate,the pg_hba.conf fileissavedandrefreshedinGreenplumDatabase.Notethatexistingclientconnectionsareunaffected.

LoadingaPreviousVersionoftheHost-BasedAuthenticationFileWhenyousaveanewversionofthe pg_hba.conf file,acopyissavedintheGreenplumDatabase $MASTER_DATA_DIRECTORY/pg_hba_archive directoryaspg_hba.conf-<timestamp> .

Toviewanarchivedversionofthe pg_hba.conf file,clickLoadversions…andclickthetimestampfortheversiontodisplay.

Toreverttoapreviousversionofthefile,loadthepreviousversionandthenclickSaveconfigandupdateGPDB.TheconfigurationisrefreshedinGreenplumDatabaseandsavedasanewversioninthearchivedirectory.


ManagingGreenplumCommandCenterPermissionsThePermissionsLevelsforGPCCAccessscreenallowsuserswithOperatorBasic,Operator,orAdminpermissiontoviewCommandCenteruserpermissionsforGreenplumDatabaseusers.UserswithAdminpermissioncansetpermissionsforanyuser.

UserswithOperatorBasic,Operator,andAdminpermissioncanalsoseeiftheGuestAccesstoQueryMonitorfeatureisenabledordisabled,andAdminuserscantogglethisfeatureonandoff.

ViewingUserPermissionsInitially,allGreenplumDatabaseloginusersareincludedinthelistofroleswiththeircurrentpermissionlevels.

Tofilterbyrolename,enterallorpartoftheuser’sdatabaserolenameintheRoleNamefield.Thefilterperformsasimplesubstringsearchanddisplaysuserswithmatchingrolenames.ClicktheRoleNamelabeltoreversethesearchorder.

Tofilterforuserswithaspecificpermissionlevel,choosethepermissionlevelfromthePermissionLevellist.

RoleNameandPermissionLevelfilterscanbeusedtogether.

Toresetthefilters,removealltextfromtheRoleNamefieldandchooseFilterby…fromthePermissionLevellist.

ChangingUserPermissionLevelsUserswithAdminpermissioncanchangepermissionlevels.

1. UsetheRoleNameandPermissionLevelfilterstodisplaytherolesyouwanttochange.

2. Checktheboxnexttoarolenametoselecttheuser,orchecktheboxintheheadingtoselectalldisplayedusers.

3. SelectthenewpermissionslevelforeachuserfromthelistinthePermissionLevelcolumn,orselectanewpermissionlevelforallselectedusers


http://gpcc.docs.pivotal.io/440//graphics/ui-admin-permissions-full.png

fromtheChangeSelectedto…list.

EnablingorDisablingGuestAccesstoQueryMonitorWhenenabled,theGuestAccesstoQueryMonitorfeatureallowsanyonewithaccesstotheGreenplumCommandCenterwebservertoclickViewQueryMonitorontheCommandCentersign-inscreenandseetheQueryMonitorpagewithoutloggingin.TheseanonymoususerscannotcancelqueriesandcannotaccessanyotherCommandCenterfeatures.

Whenthisfeatureisoff,theViewQueryMonitorlinkdoesnotappearonthesign-inscreenandanonymoususerscannotseetheQueryMonitorpage.

CommandCenteruserswithAdminpermissioncantogglethefeatureonanoffwithamouseclick.UserswithOperatororOperatorBasicpermissionseeamessagereportingifthefeatureisonoroff.


SecuringthegpmonDatabaseUserTheGreenplumDatabase gpmon userisasuperuserroleusedtomanagethegpperfmondatabase.The gpperfmon_install utility,whichmustberunbeforeyouinstallGreenplumCommandCenterConsole,createsthe gpmon role.

GreenplumDatabaseusesthe gpmon roletoupdatethegpperfmondatabasewithdatacollectedbyagentsrunningonthesegmenthosts.TheCommandCenterwebserverusesthe gpmon roletoconnecttothegpperfmondatabaseaswellasdatabasesmonitoredbytheCommandCenter.

When gpperfmon_install createsthe gpmon role,itpromptsforapassword,whichitthenaddstothe .pgpass fileinthe gpadmin user’shomedirectory.Theentryinthe .pgpass fileissimilartothefollowing:

*:5432:gpperfmon:gpmon:changeme

SeeThePasswordFile inthePostgreSQLdocumentationfordetailsaboutthe .pgpass file.

The .pgpass fileisrequiredontheGreenplumDatabasemasterhosttostartthegpperfmondatacollectionagents.IfyourunGreenplumCommandCenteronadifferenthost,youcancopythe .pgpass filetothathost,oryoucanruntheCommandCenter gpcc managementutilitywiththe -W optiontorequestpasswordentryeachtimeyoustartorstopCommandCenterorrequeststatus.

Inthe $MASTER_DATA_DIRECTORY/pg_hba.conf authenticationfile, gpperfmon_install createstheseentries:

localgpperfmongpmonmd5hostallgpmon127.0.0.1/28md5hostallgpmon::1/128md5

IfyouauthenticateuserswithKerberos,youcanalsosetupKerberosauthenticationforthe gpmon roleontheGreenplummasterandstandbyhosts.KerberosauthenticationissupportedwithTCPconnectionsonly; local entriesuseLinuxsocketsandauthenticatewiththe .pgpass filepassword,evenifyouhaveenabledKerberosfor host entries.

ChangingthegpmonPasswordTochangethe gpmon password,followthesesteps:

1. LogintoGreenplumDatabaseasasuperuserandchangethe gpmon passwordwiththe ALTERROLE command:

#ALTERROLEgpmonWITHENCRYPTEDPASSWORD'new_password';

2. OntheGreenplummasterhost,updatethepasswordinthe .pgpass fileinthe gpadmin homedirectory( ~/.pgpass ).Replacetheexistingpasswordinthelineorlinesfor gpmon withthenewpassword.

*:5432:gpperfmon:gpmon:new_password

3. Ensurethatthe .pgpass fileisownedby gpadmin andRW-accessibleby gpadmin only.

$chowngpadmin:gpadmin~/.pgpass$chmod600~/.pgpass

4. RestartGreenplumCommandCenterwiththe gpcc utility.

$gpccstop$gpccstart

AuthenticatinggpmonwithKerberosIfyouauthenticateGreenplumDatabaseandCommandCenteruserswithKerberos,youcanalsoauthenticatethe gpmon userwithKerberos.

Besuretoalsoupdatethe .pgpass fileonthestandbymasterhost.


https://www.postgresql.org/docs/8.3/static/libpq-pgpass.html

ToprepareforinstallingCommandCenterwithKerberosauthentication,followthesesteps:

1. CreatethegpperfmondatabaseusingtheGreenplumDatabase gpperfmon-install managementutility.SeeCreatingthegpperfmonDatabase.

2. OntheKDC,createakeytabfilecontainingtheKerberosprincipalforthe gpmon user,justasyouwouldforanyKerberos-authenticatedclient.InstallthefileontheGreenplummasterandstandbyhosts.

3. Updatetheentriesfor gpmon inthe $MASTER_DATA_DIRECTORY/pg_hba.conf filetousethe gss authenticationmethod.

hostallgpmon0.0.0.0/0gssinclude_realm=0krb_realm=GPDB.EXAMPLE.COM

Notethat local entriesin pg_hba.conf cannotbeauthenticatedwithKerberos.Ifthereisa local entryforthe gpmon user,itwillusethe .pgpass filetoauthenticatewiththedatabase.SeeThepg_hba.conffile inthePostgreSQLdocumentationforcomplete pg_hba.conf filedocumentation.

4. Logintothemasterhostas gpadmin andauthenticatethe gpmon user.

$kinitgpmon

5. InstallGreenplumCommandCentertosetuptheKerberos-enabledCommandCenter.


https://www.postgresql.org/docs/8.4/static/auth-pg-hba-conf.html

EnablingAuthenticationwithKerberosIfyouhaveenabledKerberosauthenticationforGreenplumDatabase,youcansetupGreenplumCommandCentertoacceptconnectionsfromKerberos-authenticatedusers.

GreenplumDatabaseandCommandCenterincludesupportfortheGenericSecurityServiceApplicationsProgramInterface(GSS-API)standard.Arelatedstandard,SimpleandProtectedGSS-APINegotiationMechanism(SPNEGO),describestheprotocolGSS-APIclientsandserversusetoagreeonthemethodofauthentication.

WithaSPNEGO-compliantwebapplicationsuchasCommandCenter,theclientandserveragreeontheauthenticationmethodontheclient’sinitialHTTPrequest.IfKerberosauthenticationisnotsupportedonbothendsoftheconnectiontheserverfallsbacktobasicauthentication,anddisplaysaloginformrequestingausernameandpassword.IfauserhasauthenticatedontheworkstationwithKerberosandhasavalidticketgrantingticket,thewebbrowserofferstheuser’scredentialtotheCommandCenterwebserver.AKerberos-enabledCommandCenterwebserverisconfiguredtohandletheauthenticateduser’sconnectionrequestinoneofthreemodes,calledstrict,normal,orgpmon-only.

StrictCommandCenterhasaKerberoskeytabfilecontainingtheCommandCenterserviceprincipalandaprincipalforeveryCommandCenteruser.Iftheprincipalintheclient’sconnectionrequestisinthekeytabfile,thewebservergrantstheclientaccessandthewebserverconnectstoGreenplumDatabaseusingtheclient’sprincipalname.Iftheprincipalisnotinthekeytabfile,theconnectionrequestfails.

NormalTheCommandCenterKerberoskeytabfilecontainstheCommandCenterprincipalandmaycontainprincipalsforCommandCenterusers.Iftheprincipalintheclient’sconnectionrequestisinCommandCenter’skeytabfile,itusestheclient’sprincipalfordatabaseconnections.Otherwise,CommandCenterusesthe gpmon userfordatabaseconnections.

gpmon-onlyTheCommandCenterusesthe gpmon databaseroleforallGreenplumDatabaseconnections.NoclientprincipalsareneededintheCommandCenter’skeytabfile.

IfyouhavesetupKerberosauthenticationforGreenplumDatabase,mostoftheconfigurationrequiredtoenableCommandCenterKerberosauthenticationhasbeendone.TheCommandCenterKerberosconfigurationbuildsupontheGreenplumDatabaseKerberossetup.

KerberosauthenticationcanbeenabledbyrespondingtopromptswhenyouinstallCommandCenter,oryoucanusethe gpcc--krbenable

commandto

enableKerberosafterCommandCenterhasbeeninstalled.

BeforeYouBeginKerberosauthenticationmustbeenabledforGreenplumDatabase.SeeUsingKerberosAuthentication forinstructions.Makesurethefollowingprerequisitesaremetbeforeyoucontinue:

The krb5-workstation packageandassociatedlibraries( libkrb5* )mustbeinstalledontheGreenplummasterhostandeachclientworkstation.

ThedateandtimeontheGreenplummasterhostandallclientworkstationsmustbesynchronizedwiththeKDC.

The krb5.conf configurationfilemustbethesameontheKDChost,theGreenplumDatabasemasterhost,andclientworkstations.

TheKDCdatabasemusthaveaserviceprincipalforGreenplumDatabase.ThedefaultservicenameforGreenplumDatabaseispostgres/<master-host>@<realm> .Youcanchooseaservicenameotherthan postgres ,butitmustmatchthevalueofthe krb_srvnameparameterinthe $MASTER_DATA_DIRECTORY/postgresql.conf file.

AkeytabfilewiththeGreenplumDatabaseprincipalmustbeinstalledontheGreenplummasterhostandidentifiedbythe krb_server_keyfileparameterinthe $MASTER_DATA_DIRECTORY/postgresql.conf file.

EachclientworkstationcanhaveakeytabfilecontainingtheirKerberosprincipal, <username>@<realm> .

AddCommandCenterPrincipalstotheKDCDatabaseBeforeyouconfigureCommandCenterforKerberosauthentication,youmustcreatetherequiredKerberosprincipals.AlloftheprincipalsusedwithCommandCenterarecreatedintheGreenplumDatabaseKerberosrealm.CommandCenteruserscanusethesameKerberosprincipaltoauthenticatewithCommandCenterandGreenplumDatabase.

CommandCenterServicePrincipal

AserviceprincipalisneededfortheCommandCenterwebserver.Thisprincipalhastheformat HTTP/<host>@<realm> .Forexample,ifusersaccess


http://gpdb.docs.pivotal.io/latest/admin_guide/kerberos.html

CommandCenterattheURL http://mdw.example.com:28080 ,the <host> partoftheservicekeyis mdw.example.com andthe <realm> partistheGreenplumDatabaseKerberosrealm,forexample GPDB.KRB .

NotethatKerberosauthenticationonlyworksifCommandCenterusersenterthehostinthesameformatspecifiedintheKerberosserviceprincipal.IftheprincipalspecifiestheFQDN,forexample,usingthehost’sIPaddressinthebrowserURLwillnotwork;thewebserverwillfallbacktobasicauthentication.

GreenplumDatabasegpmonUser

CommandCenterusesthe gpmon Greenplumroletoaccessthegpperfmondatabase,whichcontainsdatapresentedintheCommandCenterUI.

Youcanchoosetoauthenticatethe gpmon userwithKerberosorwithbasicauthentication.TouseKerberos,youmustcreateaprincipalforthegpmon user.

IfyouchoosetousebasicauthenticationyoudonotneedaKerberosprincipalforthe gpmon user.The gpmon userwillauthenticatewithGreenplumDatabaseusingthepasswordsavedinthe ~gpadmin/.pgpass fileonthehostrunningCommandCenter.IfyourunCommandCenteronahostotherthantheGreenplumDatabasemasterhost,youmustcopythe ~gpadmin/.pgpass filefromthemasterhosttotheCommandCenterhost.SeeChangingthegpmonPassword forinstructionstomanagethe gpmon password.

CommandCenterUsers

AddKerberosprincipalsforanyCommandCenteruserswhodonotalreadyhaveprincipalsintheKDCforGreenplumDatabase.

AddingKerberosPrincipalsToaddtherequiredprincipals,performthefollowingstepsasrootontheKDCserver.

1. AddaprincipalfortheCommandCenterwebservice.Besuretospecifythe <gpcc-host> inthesameformatthatusersshouldenterthehostintheirbrowsers.

#kadmin.local-q"addprinc-randkeyHTTP/<gpcc-host>@<realm>"

2. Ifyouwantthe gpmon databaseusertouseKerberosauthentication,adda gpmon principal.

#kadmin.local-q"addprincgpmon@<realm>"

3. AddprincipalsforanynewCommandCenterusers.

#kadmin.local-q"addprinccc_user1@<realm>"

RepeatforeachnewCommandCenteruser.

SetUpKeytabFilesAfteryouhavecreatedalloftheKerberosprincipalsneeded,youcreateanddistributekeytabfiles.KeytabfilescontainKerberosprincipalsandencryptedkeysbasedontheprincipals’Kerberospasswords.KeytabfilesareneededfortheGreenplumDatabasemasterandstandbyhostsandtheCommandCenterhost.

YoucanalsocreateakeytabfileforeachGreenplumDatabaseorCommandCenterusercontainingjusttheuser’sprincipal.Thiskeytabfileisinstalledontheuser’sworkstationtoenabletheusertoauthenticatetoKerberos.Notethatallkeytabfilesmustcontainthemostrecentversionsoftheprincipals’keys.

CommandCenterRunningontheGreenplumMasterHostIftheGreenplumCommandCenterwebserverisrunningontheGreenplumDatabasemasterhost,CommandCentercansharetheGreenplumDatabasekeytabfile.Youneedtocreateakeytabfilethatcontainsthefollowingprincipals:

Servicekeyforthe postgres processontheGreenplumDatabasemasterhost,forexample postgres/[email protected] .

ServicekeycreatedforCommandCenterintheprevioussection,forexample HTTP/[email protected].

AprincipalforeveryKerberos-authenticatedGreenplumDatabaseorCommandCenteruser.



AllservicekeysandprincipalsshouldbeintheGreenplumDatabaserealm.

TocreateakeytabfileforGreenplumDatabaseandCommandCenter,performthefollowingstepsasrootontheKDCserver.

1. CreateakeytabfilecontainingtheGreeplumDatabaseservicekey,thecommandcenterservicekey,andalldatabaseandCommandCenterusers.

kadmin.local-q"ktadd-kgpdb-kerberos.keytabpostgres/[email protected]/[email protected]"

Youcanenteroneormoreprincipalswitheach ktadd command.Youcanspecifyawildcardusingthe -glob option.Forexamplethiscommandaddsallprincipalsinthe GPDB.KRB realm,includingserviceprincipalsandadminusers.

kadmin.local-q"ktadd-kgpdb-kerberos.keytab-glob*@GPDB.KRB"

2. CopythekeytabyoucreatedtotheGreenplumDatabasemasterhost,replacingtheoldkeytabfile.Thelocationofthefileisgivenbythekrb_server_keyfile parameterinthe $MASTER_DATA_FILE/postgresql.conf file.Setthepermissionsonthefilesothatitcanbereadonlybythe gpadmin

user.

3. UpdateanyentriesrequiredfornewGreenplumDatabaseprincipalsinthe pg_hba.conf fileand pg_ident.conf files.SeeUpdatetheGreenplumDatabase pg_hba.conf Filefordetails.

CommandCenterRunningontheStandbyMasterIftheCommandCenterwebserverisonadifferenthostthantheGreenplumDatabasemaster,youneedseparatekeytabfilesforGreenplumDatabaseandCommandCenter.ThekeytabfileforGreenplumDatabasemaynotrequireanyupdates,butyouwillneedtocreateakeytabfileforCommandCenter.

TheGreenplumDatabasekeytabfilemustcontaintheGreenplumDatabaseservicekeyandallprincipalsforuserswithdatabaseaccess.

TheCommandCenterkeytabfilecontainstheCommandCenterservicekeyandprincipalsforusersthathaveCommandCenteraccess.UserswithCommandCenteraccessmustalsohaveGreenplumDatabaseaccess,souserprincipalsintheCommandCenterkeytabfilemustalsobeintheGreenplumDatabasekeytabfile.

UpdatetheGreenplumDatabasekeytabifyoucreatednewdatabaserolesandprincipalsforCommandCenter.Forexample,ifyouwanttouseKerberosauthenticationforthe gpmon user,youmustcreateaprincipalandaddittoboththeGreenplumDatabaseandCommandCenterkeytabfiles.

TocreatethekeytabfileforCommandCenter,performthefollowingstepsasrootontheKDChost.

```

1. CreateakeytabfileandaddtheCommandCenterservicekey.

kadmin.local-q"ktadd-kgpcc-kerberos.keytabHTTP/[email protected]"

2. Ifyouwanttoauthenticatethe gpmon userwithKerberos,addthe gpmon principal.

kadmin.local-q"[email protected]"

3. AddprincipalsforallCommandCenterusers:

kadmin.local-q"[email protected][email protected]"

Youcanenteroneormoreprincipalswitheach ktadd command.

4. Enter quit toexit kadmin.local .

5. CopythekeytabyoucreatedtothethehostrunningCommandCenter,forexample:

$scpgpcc-kerberos.keytabgpadmin@<host-name>:/home/gpadmin

6. Updateanyentriesrequiredfornewprincipalsinthe pg_hba.conf fileand pg_ident.conf filesontheGreenplummaster.SeeUpdatetheGreenplumDatabasepg_hba.confFile.


UpdatetheGreenplumDatabasepg_hba.confFileTheGreenplumDatabase $MASTER_DATA_DIRECTORY/pg_hba.conf configurationfiledetermineswhichauthenticationmethodstousetoallowdatabaseaccess.

IfyoucreatednewCommandCenterusers,youmayneedtoaddanentrytoallowaccessviaCommandCenter.Theentryforanindividualuserhasthisformat:

hostdatabase<user-name><gpccCIDR>gss[options]

Authenticationforthe gpmon userneedstobesetupinthe pg_hba.conf fileinoneofthefollowingways.

Basicauthentication

The /home/gpadmin/.pgpass filecontainsthepasswordfor gpmon touse.SeeChangingthegpmonPassword fordetails.Anentryinthe pg_hba.conffilespecifiesthemd5authenticationmethodfor gpmon :

localallgpmonmd5

Trustauthentication

OntheGreenplumDatabasemasterhostonly,the gpmon usercanaccessdatabaseswithoutauthentication:

localallgpmontrust

The /home/gpadmin/.pgpass fileisnotneeded.

Kerberosauthentication

AKerberosprincipalhasbeencreatedforthe gpmon userandaddedtotheGreenplumDatabaseandCommandCenterkeytabfiles.

hostallgpmon<gpccCIDR>gss[options]

Removeanyexistingrejectrulesfor gpmon :

hostallgpmon<auth-method>reject

SeeUsingKerberosAuthentication formoreinformationaboutthe pg_hba.conf file.

EnableKerberosforCommandCenterSetupCommandCentertousetheCommandCenterkeytabfileyoucreated.

IfyouareaddingKerberosauthenticationtoanexistingCommandCenter,usethe gpcc command.Forexample:

$gpcc--krbenable

EntertheCommandCenterhostnameandpathtothekeytabfileattheprompts.SeethegpccReferenceformoreinformation.

AuthenticatingWithKerberosontheClientWorkstationTouseKerberosCommandCenterauthentication,theusermusthaveauthenticatedwithKerberosusingthe kinit command-linetool.

TheuserthenaccessestheCommandCenterwebserverwithaURLcontainingthehostnameintheformatspecifiedintheCommandCenterserviceprincipalandtheportnumber,forexample http://mdw.example.com:28080 .

Theuser’swebbrowsermustbeconfiguredtousetheSPNEGOprotocolsothatitofferstheuser’sKerberosprincipaltothewebbrowser.Themethodforconfiguringwebbrowsersvarieswithdifferentbrowsersandoperatingsystems.SearchonlinetofindinstructionstoenableSPNEGOwithyourbrowserandOS.



http://gpdb.docs.pivotal.io/latest/admin_guide/kerberos.html


MonitoringtheGreenplumDatabaseSystemDashboard

ClusterState

SegmentStatus

ClusterMetrics

HostMetrics

StorageStatus


DashboardTheDashboarddisplayswhenyoufirstsignintoPivotalGreenplumCommandCenter.TheDashboardprovidesaquickviewofthecurrentsystemstatus,SegmentHealth,Queries,CPU,Memory,andDiskusage.

Clickingonapanelprovidesmoredetailedinformationaboutthemetric.TheAlertspanelshowsthemostrecentmessagesfromtheGreenplumDatabaselogfile.SomeinformationisavailableonlytoCommandCenteruserswithAdminorOperatorpermissionlevel.

SystemInformationThefollowingsysteminformationisdisplayedatthetopofthepage.

UptimeTheelapsedtimesincetheGreenplumDatabasesystemwaslaststarted.

GPDBVersionTheversionoftheGreenplumDatabasesoftwarethemonitoredclusterisrunning.

GPCCVersionTheversionoftheGreenplumCommandCentersoftware.

ConnectionsThenumberofactiveGreenplumDatabasesessions(clientconnections).

ServerThedisplaynameforthisGreenplumCommandCenter.

LastSyncDateandtimethedatawaslastsynchronized.TheCommandCenteruserinterfaceupdatesviewswithlivedataevery15seconds.

SegmentHealthTheSegmentHealthsectionoftheDashboardprovidesaquickoverviewofthestatusofthedatabasesystemandsegmentsthisCommandCentermonitors.

DatabaseStateDatabaseStateisthecurrentstateoftheGreenplumDatabasesystem.Thestatecanbeoneofthefollowing:


Normal:Thedatabaseisfunctioningwithnomajorerrorsorperformanceissues.

Segment(s)Down:Thedatabaseisinchange-trackingmodeorresyncmode.Overallperformanceandsystemreliabilityisgreatlyreduced.SeethePivotalGreenplumDatabaseSystemAdministratorGuideforinformationaboutresolvingthiscondition.

DatabaseUnreachable:TheGreenplumPerformanceMonitoragentcannotconnecttothedatabase.Thedatabaseislikelydown.SeethePivotalGreenplumDatabaseSystemAdministratorGuidefortroubleshootinginformation.

Unbalanced:Somesegmentsarenotrunningintheirpreferredroles.Thatis,primariesarerunningasmirrorsandmirrorsarerunningasprimaries,resultinginunbalancedprocessing.

Resyncing:Thedatabaseisperformingarecoveryorrebalanceoperation.

SegmentStatusThebargraphintheSegmentStatussectionshowstheupordownstatusofalldatabasesegmentsinyourPivotalGreenplumDatabasesystem.Acolorindicatorandassociatednumberindicatethenumberofdatabasesegmentsthatarecurrentlyinthatparticularstate.Segmentscanhavethefollowingstates:

Up(Green)

Down(Red)

ClickingtheSegmentStatuspaneldisplaystheSegmentStatusCommandCenterpage.

DiskUsageSummaryThischartdisplaystotaldiskusageanddiskavailablefortheGreenplummasterhostandsegmenthostsatthelastsynchronization.Hoveroverthecharttoseetheamountofdiskused,free,andtotal.

QueriesThisgraphdisplaysasummaryviewofactiveandqueuedqueriesforthelast60minutes.ClickonthecoloreddotnexttotheRunningorQueuedlabeltotogglethelineonoroff.Atleastonelinemustbevisibleatalltimes.Hoveroverthegraphtodisplaythenumberofqueriesforeachvisiblelineatthatpointintime.

CPUThisgraphdisplaysaverageCPUusageacrosstheentirecluster,forthelast60minutes.Thegraphdisplaysseparatelinesforsystemprocessesanduserprocesses.TheuserCPUusageincludestheGreenplumdatabasemaster,standby,andsegmentprocesses.ClickonthecoloreddotnexttotheSystemorUserlabeltotogglethatlineonoroff.Atleastonelinemustbevisibleatalltimes.

HoveringthecursoroveralineinthegraphdisplaysasmallwindowwiththepercentageofCPUusedatthatpointintimeforthevisiblelinesandthetotalifboththesystemanduserlinesarevisible.

MemoryThisgraphdisplaystheaveragepercentofmemoryusedacrosstheentireclusteroverthelast60minutes.Hoveroverthelinetodisplaythepercentofmemoryusedatthatpointintime.

AlertsAdminandOperatorpermissionlevelsonly

TheAlertspaneldisplaysrecentmessagesfromtheGreenplumDatabase pg_log logfile.Thepanelisupdatedateachsynchronization.Filterthemessagesbyseveritylevelusingthecontrolsatthetoprightofthepanel.



GreenplumDatabaseClusterStateTheGreenplumCommandCenterDashboardprovidesaquickviewofthecurrentsystemstatus,SegmentHealth,Queries,CPU,Memory,andDiskusage.Clickingonapanelprovidesmoredetailedinformationaboutthatmetric.TheAlertspanelshowsthemostrecentmessagesfromtheGreenplumDatabaselogfile.SomeinformationisavailableonlytoCommandCenteruserswithAdminorOperatorpermissionlevel.

SystemInformationThefollowingsysteminformationisdisplayedatthetopofthepage.

UptimeTheelapsedtimesincetheGreenplumDatabasesystemwaslaststarted.

GPDBVersionTheversionoftheGreenplumDatabasesoftwarethemonitoredclusterisrunning.

GPCCVersionTheversionoftheGreenplumCommandCentersoftware.

ConnectionsThenumberofactiveGreenplumDatabasesessions(clientconnections).

ServerThedisplaynameforthisGreenplumCommandCenter.

LastSyncDateandtimethedatawaslastsynchronized.TheCommandCenteruserinterfaceupdatesviewswithlivedataevery15seconds.

SegmentHealthTheSegmentHealthsectionoftheDashboardprovidesaquickoverviewofthestatusofthedatabasesystemandsegmentsthisCommandCentermonitors.

DatabaseStateDatabaseStateisthecurrentstateoftheGreenplumDatabasesystem.Thestatecanbeoneofthefollowing:






Resyncing:Thedatabaseisperformingarecoveryorrebalanceoperation.

SegmentStatusThebargraphintheSegmentStatussectionshowstheupordownstatusofalldatabasesegmentsinyourPivotalGreenplumDatabasesystem.Acolorindicatorandassociatednumberindicatethenumberofdatabasesegmentsthatarecurrentlyinthatparticularstate.Segmentscanhavethefollowingstates:

Up(Green)

Down(Red)

ClickingtheSegmentStatuspaneldisplaystheSegmentStatusCommandCenterpage.

DiskUsageSummaryThischartdisplaystotaldiskusageanddiskavailablefortheGreenplummasterhostandsegmenthostsatthelastsynchronization.Hoveroverthecharttoseetheamountofdiskused,free,andtotal.

QueriesThisgraphdisplaysasummaryviewofactiveandqueuedqueriesforthelast60minutes.ClickonthecoloreddotnexttotheRunningorQueuedlabeltotogglethelineonoroff.Atleastonelinemustbevisibleatalltimes.Hoveroverthegraphtodisplaythenumberofqueriesforeachvisiblelineatthatpointintime.

CPUThisgraphdisplaysaverageCPUusageacrosstheentirecluster,forthelast60minutes.Thegraphdisplaysseparatelinesforsystemprocessesanduserprocesses.TheuserCPUusageincludestheGreenplumdatabasemaster,standby,andsegmentprocesses.ClickonthecoloreddotnexttotheSystemorUserlabeltotogglethatlineonoroff.Atleastonelinemustbevisibleatalltimes.

HoveringthecursoroveralineinthegraphdisplaysasmallwindowwiththepercentageofCPUusedatthatpointintimeforthevisiblelinesandthetotalifboththesystemanduserlinesarevisible.

MemoryThisgraphdisplaystheaveragepercentofmemoryusedacrosstheentireclusteroverthelast60minutes.Hoveroverthelinetodisplaythepercentofmemoryusedatthatpointintime.

AlertsAdminandOperatorpermissionlevelsonly

TheAlertspaneldisplaysrecentmessagesfromtheGreenplumDatabase pg_log logfile.Thepanelisupdatedateachsynchronization.Filterthemessagesbyseveritylevelusingthecontrolsatthetoprightofthepanel.


SegmentStatusTheSegmentStatuspageprovidesahealthoverviewfortheGreenplumDatabasesegmentsanddetailsforeachprimaryandmirrorsegment.

SegmentSummaryGreenplumDatabaseismostefficientwhenallsegmentsareoperatingintheirpreferredroles.TheSegmentSummarypaneltellsyoutheoverallsegmentstatusandifanymirrorsareactingasprimaries.

TheSegmentSummarypanelprovidesthefollowinginformation:

DatabaseStateThedatabasestatecanbeoneofthefollowing:





Resyncing:Thedatabaseisperformingarecovertyorrebalanceoperation.

MirrorsActingasPrimaryThenumberofmirrorsegmentsactingasprimarysegments.

RecommendedActionsSuggestsactionstoperformtorestoretheclustertobalance.Theseinclude:

RecoverandRebalance

Rebalance

Theseactionsareexecutedfromthecommandlineusingthe gprecoverseg Greenplummanagementutility.See gprecoverseg inthePivotalGreenplumDatabaseUtilityReferenceformoreinformation.

TotalSegments


ThetotalnumberofprimaryandmirrorsegmentsintheGreenplumcluster.

SegmentHostsThetotalnumberofsegmenthostsintheGreenplumcluster.

SegmentHealthTheSegmentHealthpanelcontainschartsforGreenplumDatabasesegments’status,replicationmode,andpreferredroles.

StatusNumbersofsegmentsthataredownandup.

ReplicationModeAchartthatshowsthenumberofsegmentsineachofthepossiblereplicationmodes.

NotSyncing:Theprimarysegmentandmirrorsegmentareactiveandallchangestotheprimarysegmenthavebeencopiedtothemirrorusingafileblockreplicationprocess.

ChangeTracking:Ifaprimarysegmentisunabletocopychangestoitsmirrorsegmentusingthefilereplicationprocess,itlogstheunsentchangeslocallysotheycanbereplicatedwhenthemirroragainbecomesavailable.Thiscanhappenifamirrorsegmentgoesdownorifaprimarysegmentgoesdownanditsmirrorsegmentautomaticallyassumestheprimaryrole.

Resyncing:Whenadownsegmentisbroughtbackup,administratorsinitiatearecoveryprocesstoreturnittooperation.Therecoveryprocesssynchronizesthesegmentwiththeactiveprimaryandcopiesthechangesmissedwhilethesegmentwasdown.

Synced:Onceallmirrorsandtheirprimariesaresynchronized,thesystemstatebecomessynchronized.

PreferredRolesTheredportionofthePreferredRolechartshowsthenumbersofsegmentsthatnotoperatingintheirpreferredprimaryormirrorroles.Ifthechartisnotsolidgreen,theperformanceoftheGreenplumclusterisnotoptimal.

Primaryandmirrorsegmentsaredistributedevenlyamongthesegmenthoststoensurethateachhostperformsanequivalentshareoftheworkandprimarysegmentsandtheirmirrorsegmentsresideondifferentsegmenthosts.Whenaprimarysegmentgoesdown,itsmirroronanotherhostintheclusterautomaticallyassumestheprimaryrole,increasingthenumberofprimarysegmentsrunningonthathost.Thisunevendistributionoftheworkloadwillaffectqueryperformanceuntilthedownsegmentisrestoredandthesegmentsarereturnedtotheiroriginal,preferred,roles.

SegmentTableThetableatthebottomoftheSegmentStatuspagecontainsadetailedrowforeveryprimaryandmirrorsegmentintheGreenplumCluster.Thetablehasthefollowingcolumnsforeachsegment:

HostnameThenameofthesegmenthostwherethesegmentisrunning.

AddressThenetworkinterfaceonthesegmenthostforthesegment.

PortTheportnumberassignedtothesegment.

DBIDTheuniqueidentifierforthesegmentinstance.

ContentIDThecontentidentifierforthesegment,from0tothenumberofsegmentsminus1.AprimarysegmentanditsmirrorhavethesameContentID.Themasterandstandbymaster,whichhaveContentID−1,areexcludedfromthetable.

Status“UP”ifthesegmentisrunning,“DOWN”ifthesegmenthasfailedorisunreachable.

RoleThesegment’scurrentrole,either“primary”or“mirror”.


PreferredRoleThesegment’sintendedrole,either“primary”or“mirror”.

ReplicationModeThereplicationstatusforthesegment.SeeSegmentHealthforpossiblevalues.

LastEvent|[Total]Thedateandtimeoflastsegmenthealth-relatedactivity.Clicktodisplayalistofrecentevents.


ClusterMetricsTheClusterMetricspageshowsconsolidatedstatisticsforallsegmenthostsintheGreenplumcluster.Masterandstandbymasterhostsareexcludedfromthemetrics.

Thechartsdisplaymetricsforthelasttimeperiodsetbythecontrolinthetoprightcornerofthescreen.

UsetheShow/hideChartscontroltochoosewhichmetricstodisplay.

Hoveroveranyofthechartstoseevaluesforthemetricsatapointintimeinpop-upboxes.Thechartsaresynchronizedsothathoveringoveranychartshowsthesamepointintimeinallcharts.

Thecurrentvalueofametricisshownintheupperrightcornerofitschart.

Onchartswithmultiplemetrics,togglethedisplayforalineonoroffbyclickingtheline’slabelinthelegendatthetoprightofthechart.Atleastonelinemustbedisplayed.Alllinesareredisplayedatthenextquantuminterval.

Thepagehaschartsforthefollowingmetrics:

QueriesThenumberofqueriesrunningandthenumberofqueriesqueuedtorun.

CPUThepercentageCPUusedbysystemprocessesandthepercentageCPUusedbyuserprocesses.

MemoryPercentageofmemoryinuse.

Memoryiscalculatedasfollows:

Total=MemTotalFree=MemFree+Buffers+CachedUsed=MemTotal-Free

DiskI/ODiskreadandwriteratesinmegabytespersecond.

NetworkNetworkI/Oreadandwriteratesinmegabytespersecond.NetworkmetricsincludetrafficoverallNICs(networkinterfacecards),includinginternalinterconnectandadministrativetraffic.

LoadSystemloadaveragefor1-minute,5-minute,and15-minuteperiods.

SwapPercentageofswapspaceused.


HostMetricsTheHostMetricspagedisplaysatableofthehostsintheclusterwithstatisticscollectedatthemostrecentquantuminterval.

Atthetop,LastSyncdisplaysthetimethestatisticswerelastupdated.

Clickacolumnheadertosortthetablebythatcolumn.Clickagaintotogglebetweenascendinganddescendingsort.Masterandstandbyhostsarenotincludedinthesortandarealwaysdisplayedfollowingthesortedlistofsegmenthosts.

Foreachserver,thefollowingcolumnsaredisplayed:

HostnameThehostnamenameoftheserver.

CPUTotal/Sys/User(%)ThetotalpercentageofCPUinuseisdisplayednexttoagraphillustratingtheCPUusedforsystemanduserprocesses.HoveroverthetablecelltoshowthepercentagesusedforsystemanduserprocessesandthepercentageCPUidle.

MemoryInUse(%)Thepercentageofhostmemoryinuseisdisplayednexttoagraphillustratingthememoryinuseandavailable.Hoveroverthetablecelltoseememoryusedandavailableingigabytes.

Memoryiscalculatedasfollows:

Total=MemTotalFree=MemFree+Buffers+CachedUsed=Total-Free

DiskR(MB/s)|SkewDiskreadrateinmegabytespersecondisdisplayednexttoagraphofcalculateddiskreadskew.HoveroverthetablecelltoseeaLow/Medium/Highratingfordiskskew.

DiskW(MB/s)|SkewDiskwriterateinmegabytespersecondisdisplayednexttoagraphofcalculateddiskwriteskew.HoveroverthetablecelltoseeaLow/Medium/Highratingfordiskwriteskew.

NetR(MB/s)|SkewNetworkreadrateinmegabytespersecondisdisplayednexttoagraphofcalculatednetworkreadskew.HoveroverthetablecelltoseeaLow/Medium/Highratingfornetworkreadskew.

NetW(MB/s)|SkewNetworkwriterateinmegabytespersecondisdisplayednexttoagraphofcalculatednetworkwriteskew.HoveroverthetablecelltoseeaLow/Medium/Highratingfornetworkwriteskew.

AboutSkewCalculationsDiskandNetworkskewratingsarecalculatedaseachserver’sstandarddeviationfromthemeancalculatedfromallsegmenthosts.


LowValueiswithin1standarddeviationfromthemean.(Note:ifthevarianceofthesetislessthan3,skewisconsideredlowregardlessofdeviationfrommean.)

ModerateValueisbetween1and2standarddeviationsfromthemean.

VeryHighValueisgreaterthan3standarddeviationsfromthemean.


StorageStatusTheStorageStatuspageshowscurrenthistoricaldiskusageforGreenplummasterandsegmenthosts.

DiskUsageSummaryYoucanseecurrentdiskspaceinuse,spacefree,andtotalspaceintheDiskUsageSummarypanel.Diskspacemetricsforthesegmenthosts(GPSegments)andthemaster(GPMaster)areshowninseparatebarcharts.

TheGPSegmentsbarchartshowscombineddiskspaceforallsegments.

TheGPMastersbarchartshowscombineddiskspaceformasterandstandbymaster.

Hoverovereitherofthechartstoseethespaceused,free,andtotalingigabytesandasapercentageofthetotal.

GPSegmentsUsageHistoryTheGPSegmentsUsageHistorypanelpresentsachartofpercentageofdiskspaceinuseforthetimeperiodsetbythecontrolinthepanelheader.

Hoveroverthecharttoseethepercentagediskinuseonanygivenpoint.

StorageStatusTableTheStorageStatustableprovidescurrentdiskspaceusagemetricsforeachhostandbydatadirectorywithinhosts.


MonitoringandManagingGreenplumDatabaseQueriesQueryMonitor

QueryDetails

QueryHistory


QueryMonitorTheQueryMonitorviewallowsyoutoviewinformationforallGreenplumDatabaseserverqueries,includingdetailsaboutqueriesrunning,queuedtorun,andblockedbyotherqueries.UserswithAdminorOperatorpermissioncanseeandcancelallusers’queries.

IfaCommandCenteradministratorhasenabledQueryMonitorGuestAccess,anyoneabletoaccesstheCommandCenterwebservercanviewthesystemstatusandquerylistonthispagewithoutsigningintoCommandCenter.Anonymoususers,however,cannotcancelqueriesoraccessanyotherCommandCenterfeatures.

Withtheinformationavailableinthisview,GreenplumDatabaseadministratorscaneasily:

Understandhowthesystemisbeingused—bothinreal-timeandtrendingovertime.

Identifyanddiagnoseproblemquerieswhiletheyarerunning,detectskew,findrunawayqueries,andsoon.

Reviewandbalancethequeryloadonthesystembybetteroptimizingandschedulingthequeryload.

Cancelqueriesthatdisruptsystemperformance.

QueryMetricsTheQueryMonitortabledisplaysthefollowingcolumnsforqueries.

QueryIDAnidentificationstringforthequery.Ifthecolumnisblank,noqueryIDhasbeenassignedyet.IntheConsole,thislookslike“1295397846-56415-2”.CommandCentergeneratesthisIDbycombiningthequeryrecord’s tmid , ssid ,and ccnt fields.

tmid isatimeidentifierforthequery.

ssid isthesessionid.

ccnt isthenumberofthecommandwithinthesession.

StatusThestatusofthequery.Thiscanbeoneofthefollowing:


Queued:thequeryhasnotyetstartedtoexecute

Running:executionhasstarted,butisnotyetcomplete

Blocked:thequeryiswaitingforoneormoreotherqueriestoreleaselocks

Done:completedsuccessfully

Cancelling:cancelrequestsent,cancelpending

Cancelled:terminated,nolongerrunning

IdleTransaction:thetransactionisopen,butidle,forexample,waitingwhileauserinaninteractivesessionentersastatement

UserTheGreenplumDatabaserolethatsubmittedthequery.

DatabaseThenameofthedatabasethatwasqueried.

WorkloadTheresourcegrouporresourcequeuethatismanagingthequery.

SubmittedThetimethequerywassubmittedtothequeryplanner.

QueuedTimeTheamountoftimethequeryhasbeen(orwas)inqueueawaitingexecution.

RunTimeTheamountoftimesincequeryexecutionbegan.

SpillFilesThetotalsizeofspillfilescreatedforthequery.GreenplumDatabasecreatesspillfileswhenthereisinsufficientmemorytotoexecutethequeryinmemory.SeeManagingSpillFilesGeneratedbyQueries forinformationaboutspillfiles.

BlockedbyShowsthenumberoflocksblockingthequery.Hoveroverthecolumntodisplaydetailsofthelocks.Thetipshowsthetypeofeachlock,theIDofthetransactionorquerythatholdsthelock,theGreenplumDatabaseroleholdingthelock,andtheamountoftimethequeryhasbeenblocked.

UsingtheQueryMonitorControlsClickacolumnheadingtosorttherowsonthatcolumninascendingordescendingorder.

Clickthecheckboxattheleftofarowtochooseaquerytocancelorexport.Clickthecheckboxintheheadingrowtochooseallqueries.

ClickCancelQuerytocancelselectedqueries.

ClickExporttodownloadacomma-separatedvalues(CSV)textfilecontainingrowsfortheselectedqueries.Whennoqueriesareselected,allrowsareexported.Thedefaultfilenameis spreadsheet.csv .

ClickanyqueryIDtoseetheQueryDetails,includingmetrics,thetextofthequery,andthequeryplan.


https://gpdb.docs.pivotal.io/latest/admin_guide/query/topics/spill-files.html

QueryDetailsTheQueryDetailsviewdisplaysquerymetrics,thetextofthequery,andthequeryplanandprogressforasinglequeryselectedfromtheQueryMonitorview.

QueryExecutionMetricsTheQueryID,executionstatus,andruntimeofthequeryaredisplayedatthetop.

Thefollowingmetricsaredisplayedforthequery.

UserTheGreenplumDatabaserolethatsubmittedthequery.


WorkloadThenameoftheresourcegrouporresourcequeuethatismanagingthequery.

SubmittedThetimethequerywassubmittedtothequeryplanner.

QueuedTimeTheamountoftimethequeryhasbeen(orwas)inqueueawaitingexecution.

RunTimeTheamountoftimesincequeryexecutionbegan.

CPUMasterCurrentCPUpercentontheGreenplumDatabasemasterhostforthisquery.


CPUSegments(Activequeriesonly.)CurrentCPUpercentaverageforallsegmentprocessesexecutingthisquery.Thepercentagesforallprocessesrunningoneachsegmentareaveraged,andthentheaverageofallthosevaluesiscalculatedtorenderthismetric.CurrentCPUpercentaverageisalwayszeroinhistoricalandtaildata.Themasterandstandbymasterareexcludedfromthecalculation.

CPUTimeTotalCPUtimeconsumedbyallprocessesonallsegmentsexecutingthisquery.

CPUSkewTheamountofCPUskew.CPUskewoccurswhenqueryexecutorprocessesforonesegmentuseadisproportionateamountofCPUcomparedtoprocessesforothersegmentsexecutingthequery.Thisvalueiscalculatedas

1−(average_segment_CPU/maximum_segment_CPU)

MemoryMemoryconsumedbyallsegmentprocessesexecutingthequery.

SpillFilesThetotalsizeofspillfilescreatedforthequery.GreenplumDatabasecreatesspillfileswhenthereisinsufficientmemorytoexecutethequeryinmemory.SeeManagingSpillFilesGeneratedbyQueries forinformationaboutspillfiles.

DiskRThecurrentaveragediskreadrateforallsegmenthosts.

DiskWThecurrentaveragediskwriterateforallsegmenthosts.

LocksandBlocksContainstwolistsoflockscurrentlyblockingtransactions.Clickalisttoexpandandviewthecontents.

Alistoflocksheldbythisquery,includingthetypeofeachlockandthequeriesblockedbythatlock.

Alistofqueriesthatholdlocksthatblockthisqueryandthelocktype.

QueryTextandExecutionPlanThequerytextandthequery’splanandexecutionprogressareshowninthelowerpanelsoftheQueryDetailsview.Thetextofthequeryisdisplayedintheleftpanel,andtheplanandprogressisdisplayedintherightpanel.

QueryPlanandProgressThePlan&Progresstabinthelowerrightpanelisagraphicalrepresentationofthequeryplanwithanimationandreal-timemetricstoshowexecutionprogress.Eachboxinthetreerepresentsastepinthequeryexecutionplan.TheboxesarelabeledwiththeoperationtheyrepresentandhaveaCPUusagemetric.Queryexecutionbeginsatthebottomofthetreeandendsatthetop.


https://gpdb.docs.pivotal.io/latest/admin_guide/query/topics/spill-files.html

Beforeastepbeginstoexecute,theboxhasasolidwhitefill.Whenthestepbecomesactive,theboxisanimatedwithagreenandwhitefilltoindicatethattheoperatorisworking.Whenthestephascompleted,theboxhasasolidgreenfill.

Queryexecutionplansareexecutedin“slices,”portionsofthequeryplanthatsegmentscanworkonindependentlyinparallel.Theplanisslicedwhereveradatamotionoperatoroccurs.ThetimedisplayedintheupperrightcornerofeachboxistheamountofCPUtimeusedforallstepsintheslicetowhichthestepbelongs.Thevisualqueryplandoesnotillustrateslices,butyoucanfindinformationaboutslicesinthetextualplan.

Ifyouclickastep,theboxexpandstoshowadditionaldetails.

Theexpandedplanboxcontainsthefollowingmetrics.

Thetypeofoperator.Whentheoperatorisatablescan,thenameofthescannedtableisincluded.SeeQueryPlanExecutionfordescriptionsoftheoperators.

Informationrelatedtothecurrentoperation,suchasthehashkey,mergekey,joincondition,orfiltercondition.

RowSkew-theamountofrowskewforthecurrentoperator,avaluefrom0%to100%.Rowskewoccurswhensomesegmentsprocessmorerowsthanothersegments.Thepercentageiscalculatedas (1 − (average_segment_rows / maximum_segment_rows)) * 100 .

EstimatedCompletion-thecurrentpercentageofactualrowstoestimatedrowsforthisplanstep.Thepercentagecanexceed100%iftheoperationproducesmorerowsthantheoptimizer’sestimate.Thepercentagechangesto“Completed”whentheoperationcompletes.

ActualRows-Thecurrentnumberofrowsproducedbythisstep.Notethatfornestedjoinoperators,theActualRowsisestimatedsincetheactualrowcountsarenotavailablewhilethejoinisexecuting.

EstimatedRows-Theestimatednumberofrowstheoperatorwillproduce.

TextualPlanSelecttheTextualPlantabandclickRUNEXPLAINtogeneratethetextrepresentationoftheexplainplan.

TheRUNEXPLAINbuttonisdimmedifCommandCenterisunabletogeneratetheexplainplan.CommandCenterisunabletogeneratetheexplainplanifthesizeofthequerytextisgreaterthan100Korifthequerytextcontainsmultiplestatements.


ThetextualplanistheoutputoftheGreenplumDatabase EXPLAIN commandforthequery.Thequeryplanstepsarelabeledwitharrows( -> )andthestructureofthequeryplantreeisindicatedwithindentation.

The Optimizerstatus: lineatthebottomofthetextualplanreportswhethertheexplainplanwasgeneratedusingtheGPORCAoptimizer(PQO)orthelegacyqueryoptimizer.

Forhelpreadingthetextualexplainplanseethe EXPLAIN commandintheGreenplumDatabaseReferenceGuideandQueryProfiling intheGreenplumDatabaseAdministratorGuide.SeeQueryExecutionfordescriptionsofthequeryoperators.


http://gpdb.docs.pivotal.io/latest/ref_guide/sql_commands/EXPLAIN.html

http://gpdb.docs.pivotal.io/latest/admin_guide/query/topics/query-profiling.html

HistoryTheHistorypageallowsyoutodisplaysystemmetricsandqueriesexecutedduringaspecifiedtimeperiod.Queriesmayalsobefilteredbydatabaseand/oruser.

SetthetimeperiodtodisplaybyenteringdatesandtimesintheFromandTodateandtimefields.Youcanenterdatesbytypingthemintothedatefieldorbychoosingfromthepop-upcalendar.Enter24-hourtimesinHH:MMformat.

Torestrictqueriesthatdisplayinthequerytableatthebottomofthepage,enteraGreenplumdatabasenameintheDatabasefield,ausernameintheUserfield,orboth.Filteringbydatabaseanduseronlyaffectsthequeriesdisplayedinthetable.Themetricsdisplayedinchartsincludeallactivityduringtheselectedtimeperiod.

ClickSearchtodisplayresultsthatmatchyourcriteria.

Note:TheHistorydataisnotderivedfromthereal-timemetricsdisplayedbytheQueryMonitorandQueryDetailview.Historyiscollectedandsavedinthegpperfmondatabasebythe gpmmon and gpsmon agents.Variationsshouldbeexpectedduetothedifferentdatacollectionmethods.


Youcanclickanddragonacharttozoominonatimerange.ClickSearchtoupdatethequerylistandchartstotheselectedrange.

Scrollchartsleftorrightbyhoveringovertheedgeofthechartandclickinganarrow.Click‹or›tomoveinhalfsteps.Click«or»tomoveinfullsteps.

Inthequerylist,selectorhoveroveraquerytohighlightitsqueuedandruntimeinthecharts.

Chartsofthefollowingmetricsareavailable.Showorhidethematanytimewiththechecklistattheupperrightoftheview.

QueriesThenumberofqueriesrunningandthenumberofqueriesqueuedtorun.

CPUThepercentageofCPUusedbysystemprocessesandthepercentageofCPUusedbyuserprocesses.

MemoryPercentageofmemoryinuse.

DiskI/ODiskreadandwriteratesinmegabytespersecond.

NetworkNetworkI/Oreadandwriteratesinmegabytespersecond.NetworkmetricsincludetrafficoverallNICs(networkinterfacecards),includinginternalinterconnectandadministrativetraffic.

LoadSystemloadaveragefor1-minute,5-minute,and15-minuteperiods.

SwapPercentageofswapspaceused.

QueryMetricsTheQuerytabledisplaysqueriesthatwereactiveduringthespecifiedtimeperiod,includingqueriesthatstartedbeforeorfinishedafterthespecifiedtime.However,queriesthatarestillactivearenotincludedinthetable;thesequeriescanbeviewedontheQueryMonitorpage.

Thequerytablehasthefollowingcolumns:

QueryIDAnidentificationstringforthequery.IntheConsole,thislookslike“1295397846-56415-2”.

StatusThefinalstatusofthequery.Thiscanbeoneofthefollowing:

Done

Cancelled

UserTheGreenplumDatabaseuserwhosubmittedthequery.


SubmitTimeThetimethequerywassubmittedtothequeryplanner.

QueuedTimeTheamountoftimeaqueryspentinthequeuebeforeitwasexecuted.

RunTimeTheamountoftimethequeryrequiredtoproducearesult.

EndTimeThetimethequerycompletedorwascancelled.

CPUSkewTheamountofCPUskew.CPUskewoccurswhenqueryexecutorprocessesforonesegmentuseadisproportionateamountofCPUcomparedtoprocessesforothersegmentsexecutingthequery.ThisvalueisthecoefficientofvariationfortheCPUusedbyprocessesrunningthisqueryoneachsegment,multipliedby100.Forexample,avalueof.95isshownas95.

RowSkew


Ameasureofrowskewinthesystem.Rowskewoccurswhenonesegmentproducesadisproportionatenumberofrowsforaquery.ThisvalueisthecoefficientofvariationfortheRowsOutmetricofalliteratorsacrossallsegmentsforthisquery,multipliedby100.Forexample,avalueof.95isshownas95.

QueueThenameoftheresourcequeueforthequery.

PriorityEachqueryinheritsthepriorityassignedtoitsresourcequeue.

FormoreinformationaboutResourceQueuesandQueryPlans,refertotheGreenplumDatabaseAdministratorGuide.


ManagingGreenplumDatabaseWorkloadsAboutWorkloads

ManagingGreenplumDatabaseResourceGroups

ImportingResourceQueuestoResourceGroups

AccessingtheWorkloadManagementConfigurationProgrammatically

TroubleshootingEnablingResourceGroups


AboutGreenplumCommandCenterWorkloadManagementGreenplumDatabasesegmenthostshaveasetamountofmemory,CPU,I/O,andnetworkresources.Iftheseresourcesstarttorunshortduetoheavydatabaseload,queriescanfailortheentiredatabasesystemcanbecomeunacceptablyslow.Forthisreason,itisimportanttomanagedatabaserequeststopreventresourcedepletion.

SeeUsingResourceGroups intheGreenplumDatabaseAdministratorGuideforafulldescriptionofresourcemanagementfeaturesavailablewithresourcegroupsandinstructionstoenableresourcegroupsinGreenplumDatabase.

OntheCommandCenterAdmin>WorkloadMgmtview,youcanperformthefollowingtasks:

CreatenewresourcegroupsinGreenplumDatabase

Deleteexistingresourcegroups

Changethenumberofconcurrenttransactionseachresourcegroupallows

ChangethepercentagesofavailablesystemCPUandmemoryeachresourcegroupmanages

ChangeGreenplumDatabaseroles’defaultresourcegroups

Writequeryassignmentrulestooverrideauser’sdefaultresourcegroupwhenatransactionexecutes

Writeidlesessiontimeoutrulesforeachresourcegrouptosettheamountoftimeasessioncanbeidlebeforeitiskilled

FormoreinformationaboutLinuxcgroupsandGreenplumDatabaseresourcegroupsseeUsingResourceGroups intheGreenplumDatabaseAdministratorGuide.

QueryassignmentrulesisaGreenplumCommandCenterresourcegroupenhancementthatyoucanusetomoreflexiblyassigntransactionstoresourcegroups.Withidlesessiontimeoutrulesyoucansettheamountoftimeasessionmanagedbyaresourcegroupisidlebeforeitisterminated.ThefollowingsectionsprovidemoreinformationabouttheseCommandCenterfeatures.

AboutQueryAssignmentRulesGreenplumDatabasedeferstotheworkloadmanagementdatabaseextensiontoassigntransactionstoresourcegroups.CommandCenteruserswithAdminpermissionlevelcancreateassignmentrulesinCommandCentertoassigntransactionstoresourcegroups.

Whenatransactionbegins,GreenplumDatabasecallstheworkloadmanagementextensiontodeterminetheresourcegroup.Theextensionevaluatestheassignmentrulesand,ifamatchingruleisfound,returnsthatrule’sresourcegroup.Ifnoassignmentrulematches,GreenplumDatabasefallsbacktothedefaultbehavior,assigningthetransactiontotheresourcegroupspecifiedforthecurrentuserinthe pg_authid systemtable.

AssignmentrulescanredirectatransactiontoaresourcegroupbasedonquerytagsoracombinationofquerytagsandtheGreenplumDatabaseroleexecutingthetransaction.

Aquerytagisauser-definedname=valuepairthatyoucansetinaGreenplumDatabasesessionwhentheworkloadmanagementdatabaseextensionisenabled.Querytagsaredefinedbysettingthe gpcc.query_tags parameterontheconnectstringwhenrequestingadatabaseconnectionorinthesessionwith SETgpcc.query_tagsTO'<query-

tags>'.Multiplequerytagscanbesetbyseparatingthemwithasemicolon.Querytagsaresetbeforeatransactionbegins

andcannotbechangedinsideofatransaction.

SeeWorkloadManagementfordetailsaboutcreatingassignmentrulesandforexamplesthatusequerytags.

AboutTimeoutRules

GreenplumDatabasehastworesourcemanagementsystems:resourcequeuesandresourcegroups.CommandCenterworkloadmanagementisbasedonresourcegroups,theresourcemanagementsystemintroducedinGreenplumDatabaseversion5.ResourcegroupsrequireenablingLinuxcontrolgroups(cgroups),soGreenplumDatabaseinitiallyissettoperformresourcemanagementusingresourcequeues.

WhenCommandCenterstarts,itcheckstheresourcemanagementsystemenabledinyourGreenplumDatabasesystem.IfyouhavenotyetenabledresourcegroupsinyourGreenplumDatabasesystem,theCommandCenterworkloadmanagementviewdisplaysamessageencouragingyoutoenableresourcegroups,includingalinktodocumentationwiththeprocedureforcompletingthetask.WhenyoustartCommandCenterafterenablingresourcegroups,clicktheENABLEWORKLOADSbutton.CommandCenterpresentsaviewtohelpyousettheintialresourcegroupconfigurationbyimportingyourexistingresourcequeuestoresourcegroups.


http://gpdb.docs.pivotal.io/latest/admin_guide/workload_mgmt_resgroups.html


CommandCenteradministratorscancreatesessiontimeoutrulesforresourcegroupsthatspecifythemaximumtimethatasessioncanremainidlebeforeitisterminated.WhenthesessionprocessontheGreenplumDatabasemasterbecomesidleandthespecifiedtimehaselapsed,thesessionterminatesitself.Sessionsthatbecomeidlewhileinsideofatransactionarenotsubjecttotimeoutrules.

Sessiontimeoutrulesareperresourcegroup,allowingyoutodeterminehowlongtowaitfordifferentclassesoftransactions.YoucanincludealistofGreenplumDatabaserolestoexemptfromtheruleandacustommessagetoaddtothesessionterminationerroroutput.

Creatingtimeoutrulesforthe admin_group resourcegroupisnotrecommended.AvoidcreatingrulesthatkillsessionsstartedbyGreenplumDatabaseclientapplicationsthataredesignedtohavealong-lastingorpersistentsession.Forexample,the gpmmon processcreatesasessionasthe gpmon roletoupdatethegpperfmondatabase.Anidlesessiontimeoutrulethatkillsidle gpmon sessionstooquicklycouldcauseGreenplumDatabasetologmanysessionterminationmessagesandunnecessarilycreatenewsessions.SeeWorkloadManagementfordetailsaboutcreatingtimeoutrules.


WorkloadManagement

DefiningResourceGroupsandResourceAttributesCommandCenterallowsyoutoviewresourcegroupsthathavebeencreatedinGreenplumDatabase,toaddordeleteresourcegroups,andtoedittheresourcegroupattributesConcurrency,CPU%,andMemory%.

1. ClickEDITtoopentheResourceGroupeditor.

2. Todeletearesourcegroup,selecttheresourcegroup,andclicktheminussignthatappearsattheright.Youcannotdeletethe default_group or admin_group resourcegroups.YoucannotdeletearesourcegroupthatisassignedtoanyGreenplumDatabaserole.

3. Toaddaresourcegroup,clickADDRESOURCEGROUPandenteranamefortheresourcegroupintheNamecolumn.Resourcegroupnamesmustbeuniqueandarecase-sensitive.

4. AdjustthevaluesoftheConcurrency,CPU%,andMemory%resourcegroupattributes.Concurrency

Themaximumnumberofconcurrenttransactions,includingactiveandidletransactions,thatarepermittedintheresourcegroup.Concurrencysetsthe CONCURRENCY attributeoftheresourcegroup.ThetotaloftheConcurrencycolumnscannotexceedthevalueoftheGreenplumDatabase max_connections masterserverconfigurationparameter.

CPU%ThepercentageofCPUresourcesavailabletothisresourcegroup.ThepercentageistheportionofthetotalCPUpercentageallocatedforallresourcegroups(reservedCPUsexcluded),whichissetwiththe gp_resource_group_cpu_limit serverconfigurationparameter.CPU%setsthe CPU_RATE_LIMIT attributeoftheresourcegroup.

Memory%Thepercentageofmemoryresourcesavailabletothisresourcegroup.Thepercentageistheportionofthetotalmemoryallocatedforallresourcegroups,whichissetwiththe gp_resource_group_memory_limit GreenplumDatabaseconfigurationparameter.ChangingtheMemory%valuesetsthe MEMORY_LIMIT attributeoftheresourcegroup.

MinmemoryperqueryTheminimumamountofmemoryallocatedtoaquery.ThiscolumnisrecalculatedasyouadjustConcurrencyandMemory%settings.Thevalueistheresourcegroup’stotalshareofsystemmemory,lesstheresourcegroup’ssharedmemorypool(20%bydefault),dividedbythevalueintheConcurrencycolumn.ThepercentageofmemoryallocatedtothesharedmemorypoolcanbechangedbysettingtheMEMORY_SHARED_QUOTA attributeoftheresourcegroupusingtheALTERRESOURCEGROUP SQLcommand.Eachquerymanagedbytheresourcequeueisallocatedthisamountofmemory.Ifaqueryneedsmorememory,itisallocatedfromtheresourcegroupsharedmemorypoolandtheglobalsharedmemorypool,ifavailable.

ThetotalsoftheCPU%andMemory%columnsmustnotexceed100%.YoushouldnotallowthetotaloftheCPU%columntoexceed90%,becausethiscouldcauseresource-intensivequeriestoconsumenearlyallCPU,starvingotherGreenplumDatabaseprocesses.IfthetotaloftheMemory%columnislessthan100%,theunreservedmemoryispartoftheresourcegroupsharedglobalmemorypool.See“GlobalSharedMemory”inUsingResourceGroups intheGreenplumDatabaseAdministratorGuideforinformationabouttheglobalresourcegroupsharedmemorypool.

5. ClickApplytosaveyourchangesorclickCanceltoabandonyourchanges.

Tochangevaluesofthe MEMORY_AUDITOR , CPUSET , MEMORY_SHARED_QUOTA ,or MEMORY_SPILL_RATIO resourcegroupattributes,usethe ALTERRESOURCEGROUP SQLcommand.


http://gpdb.docs.pvotal.io/latest/ref_guide/sql_commands/ALTER_RESOURCE_GROUP.html

http://gpdb.docs.pivotal.io/latest/ref_guide/config_params/guc-list.html#gp_resource_group_cpu_limit

http://gpdb.docs.pivotal.io/latest/ref_guide/config_params/guc-list.html#gp_resource_group_memory_limit

https://gpdb.docs.pivotal.io/latest/ref_guide/sql_commands/ALTER_RESOURCE_GROUP.html

https://gpdb.docs.pivotal.io/latest/admin_guide/workload_mgmt_resgroups.html

AssigningRolestoResourceGroupsEveryGreenplumDatabaseroleisassignedtoasingleresourcegroupinthe pg_roles systemtable.Transactionsexecutedbyarolearemanagedbyitsassignedresourcegroup,unlessyoucreateanassignmentruletooverridethedefault.

Youcanviewthecurrentresourcegroupassignmentsforallrolesandchangearole’sresourcegroupbyaddingittoadifferentresourcegroup.

Tomovearoletoadifferentresourcegroup:

1. Enterallorpartoftherolenameintheaddrolefieldbeneaththenewresourcegroup.

2. ChoosetherolefromthelistthatisdisplayedandpressEnter.

ThechangeisimmediatelyappliedtotheGreenplumDatabase pg_roles systemtable.

DefiningWorkloadManagementRulesWorkloadmanagementrulesincludequeryassignmentrulesandtimeoutrules.

Queryassignmentrulesallowyouassigntransactionstoaresourcegroupbasedonuser-definedquerytagsand,optionally,thecurrentroleinthedatabasesession.Whennorulematches,thetransactionisassignedtotherole’sdefaultresourcegroup.SeeAboutAssignmentRulesformoreinformationaboutassignmentrules.

Timeoutrulessettheamountoftimeasessioncanbeidlebeforeitisterminated.Youcreateatimeoutruleforeachresourcegroup.SeeAboutTimeoutRulesformoreinformationabouttimeoutrules.

SeeAccessingtheWorkloadConfigurationProgrammaticallyforinformationaboutretrievingandsettingrulesprogrammaticallywithdatabasefunctions.

1. ClickEDITtoopentheWorkloadManagementRuleseditor.

2. Todeletearule,selecttheruleandclicktheminussignthatappearsattheright.

3. Toaddanassignmentrule,clickADDASSIGNMENTRULEandfillinthefields.QueryTags


Thefirstfieldisalistofquerytagstomatchagainstthe gpcc.query_tags parameterintheGreenplumDatabasesession.Aquerytagisauser-defined<name>=<value>pair.Separatemultiplequerytagswithsemicolons.SeeDefiningandSettingQueryTagsformoreinformationaboutquerytags.

Role(Optional)Ifyouenterarolenameinthisfield,therulematchesonlyifboththequerytagsandrolematchthetagsandcurrentroleinthedatabasesession.

ResourceGroupChoosearesourcegroupfromthelist.

Changetheorderoftheassignmentrulesbydraggingarule’shandle(attheleft)upordown.Assignmentrulesareevaluatedfromtoptobottom.GreenplumDatabaseappliesthefirstrulethatmatches.UsetheActive/Inactivetoggletomakearuleactiveorinactive.

4. Toaddatimeoutrule,clickADDTIMEOUTRULEandfillinthefields.ResourceGroup

Choosearesourcegroupfromthelist.Timebeforeidleconnectionskilled

Theamountoftimebeforeanidlesessionisterminated.Enteranintegervalueforthenumberofsecondsorminutesandchooseminutesorsecondsfromthelist.Avalueof600seconds,forexample,terminatesthesessionafterithasbeenidlefor10minutes.SeeAboutTimeoutRulesforwarningsaboutsettingtimeoutsforthe admin_group resourcegroupandresourcegroupswithrolesthatrequirepersistentsessions.

ExemptedrolesTheruleisnotappliedtorolesaddedtothisfield.Openthelisttochooserolestoexemptfromtherule.Onlyrolesfortheselectedresourcegroupareincludedinthelist.Toremovearolefromthefield,clickthexnexttotherolename.

MessageEnterthemessagetologwhenasessioniskilledbythisrule.

5. ClickAPPLYtosaveyourchanges.

DefiningandSettingQueryTagsAquerytagisauser-defined<name>=<value>pair,setintheGreenplumDatabase gpcc.query_tags parameterintheGreenplumDatabasesession.Thegpcc.query_tags parameterisdefinedwhenthe gp_wlm databaseextensionisenabledinthepostgresdatabase.Ifyoutrytosetquerytagswhenthegp_wlm extensionisnotenabled,yougetanunrecognizedconfigurationparametererror.Toseeiftheextensionisenabled,runthefollowingcommand.

$psqlpostgres-c"\dx"ListofinstalledextensionsName|Version|Schema|Description--------+---------+--------+--------------------------------------gp_wlm|0.1|gpcc|GreenplumWorkloadManagerExtension(1row)

Whenyousubmitatransactionandthe gp_wlm extensionisenabled,GreenplumDatabasecallsthe gp_wlm extensiontodeterminetheresourcegroupforthetransaction.TheextensionevaluatesthecurrentroleandquerytagssetinthesessionagainsttherulesyouhavedefinedinCommandCenter.Ifthereisamatch,theextensionreturnstherule’sresourcegroup.Ifthereisnomatch,GreenplumDatabaseassignsthetransactiontotherole’sdefaultresourcegroup.

Thefollowingcommand,executedintheGreenplumDatabasesession,setsthe appName and appUser querytagsto“tableau”and“bi_sales”,respectively.

=#SETgpcc.query_tagsTO'appName=tableau;appUser=bi_sales';

Tomatcharule,alltagsintherule’squerytagfieldmustbepresentinthe gpcc.query_tags parameterinthedatabasesession.Theorderofthetagsisnotsignificant,andthe gpcc.query_tags parametercanhaveasupersetofthetagsdefinedinthe queryTags value.

Ifyousetthe gpcc.query_tags parameterinsideofatransaction,youmustcommitthetransactionbeforethenewquerytagsareusedtoevaluateassignmentrules.

Youcansetthevalueofthe gpcc.query_tags parameterusingthe SET command,asintheexampleabove,orasaconnectionparameterwithdatabaseclientsthatsupportit,suchas psql .Followingaretwoexamplesthatshowhowtospecifyquerytagsonthe psql commandline.


$PGOPTIONS="-cgpcc.query_tags='appName=tableau;appUser=bi_sales'"psql

$psqlpostgresql://mdw:5432/postgres?options="-cgpcc.query_tags%3D'appName%3Dtableau;appUser%3Dbi_sales'"

Inthesecondexample,itisnecessarytocodetheequalssignsas %3D toprevent psql frominterpretingthequerytagsascommand-linearguments.


ImportingResourceQueuestoResourceGroupsGreenplumCommandCenterworkloadmanagementworkswithresourcegroups,thenewGreenplumDatabaseresourcemanagementsystem.ThedefaultresourcemanagementsystemforGreenplumDatabaseisresourcequeues.TousetheCommandCenterworkloadmanagementfeatures,youmustfirstenableresourcegroupsinGreenplumDatabase.

CommandCentercanassistyouinenablingresourcegroupsandinimportingexistingresourcequeuestoresourcegroups.

StepOne:EnableResourceGroupsinGreenplumDatabaseIfyourGreenplumDatabasesystemisstillconfiguredtouseresourcequeues,theCommandCenterAdmin>WorkloadMgmtviewdescribesthebenefitsofresourcegroupsandworkloadmanagementwithCommandCenterandprovidesalinktotheGreenplumDatabasedocumentationtohelpyouenableresourcegroups.

ClickVIEWRESOURCEGROUPSETUPGUIDEforinstructionstoenableresourcegroupsinyourGreenplumDatabasesystem.

StepTwo:PreviewandConfigureResourceGroupImportsAfteryouhaveenabledresourcegroupsandrestartedGreenplumDatabase,restartCommandCenter( gpcc

start),login,andchooseAdmin>Workload

Mgmt.

Theworkloadmanagementviewnowdisplaysapreviewofresourcegroupsconvertedfromyourexistingresourcequeues.Youcanusethisone-timeviewtoconvertyourGreenplumDatabaseresourcequeuestoresourcegroups.


Theresourcegrouplistincludestherequired admin_group and default_group resourcegroups,andarowforeachofyourexistingresourcequeues.

Rolesareassignedtotheresourcegroupmatchingtheresourcequeuetowhichtheyareassigned.ClickthePreviewroleslinktoseetheroleassignments.

Ifyouwanttosetupresourcegroupslater,youcanclickSKIPIMPORT.Onlythe default_group and admin_group resourcegroupsarecreated.Roleswiththesuperuserattributeareassignedtothe admin_group resourcegroup;roleswithoutsuperuserprivilegeareassignedtothe default_group resourcegroup.

IfyouwantCommandCentertoimportresourcequeuestoresourcegroups,youmustcompletetheresourceallocationfieldsforallresourcegroups.

SettheConcurrency,CPU%,andMemory%resourcegroupattributestoallocateGreenplumDatabaseresourcestotheresourcequeues.TheConcurrencyfieldsmusteachcontainapositiveinteger.TheCPU%andMemory%fieldsmusteachcontainpositiveintegersbetween1and99andthetotalsfortheCPU%andMemory%columnsmustnotexceed100%.SeeDefiningResourceGroupsandResourceAttributesforhelpdeterminingthevaluestoenter.

TheIMPORTRESOURCEGROUPSbuttonisdisableduntilyouhaveenteredvalidvaluesintheallocationfieldsforeveryresourcegroup.

Whenyouarereadytoimporttheresourcegroups,clickIMPORTRESOURCEGROUPStocreatetheresourcegroups.

StepThree:EnableCommandCenterWorkloadManagementAfteryouimport(orskipimporting)resourcequeuestoresourcegroups,youcanenableCommandCenterworkloadmanagement.


ClickENABLEWORKLOADMANAGEMENTtoenableworkloadmanagementinGreenplumCommandCenter.GreenplumCommandCentercreatesthegp_wlm extension,the gpcc.workload_config table,andtheassociateduser-definedfunctionsinGreenplumDatabase.

YouarenowabletousetheCommandCenterWorkloadManagementinterfacetoadd,remove,andconfigureresourcegroups;changeroleassignments;anddefineworkloadmanagementrules.

SeeWorkloadManagementforhelpusingtheCommandCenterWorkloadManagementview.


AccessingtheWorkloadConfigurationProgrammaticallyTheGreenplumDatabaseworkloadmanagementextension gp_wlm createsatableinthepostgresdatabasetostoretheworkloadmanagementrules,anduser-definedfunctionstogetorsettheworkloadmanagementrules.

The gpcc.workload_config tablestorestheworkloadmanagementrulesasaJSONvalue.Youcanusethe gpcc.get_workload_config() andgpcc.set_workload_config() functionstoreadandwritethisJSONvalue.

ThistopicisareferencefortheworkloadmanagementconfigurationJSONdocumentandthegetandsetfunctions.

WorkloadManagementRulesJSONFormatThissectiondescribestheJSONobjectthatstorestheresourcegroupassignmentandidlesessiontimeoutrules.Theobjecthasthreemembers:

a version key/valuepair

an assignmentRules arraycontainingoneelementforeachassignmentrule

an idleSessionKillRules listcontainingonekey/valuepairforeachresourcegroup

versionpair

versionThe version valueisaninteger.Itisreservedforfutureuse.Itcanbesetto 1 .

assignmentRulesarray

assignmentRulesThe assignmentRules arrayhasoneelementforeachassignmentrule.EachelementmapstheruletoaresourcegroupinGreenplumDatabaseanddefinestheconditionsthatassignatransactiontothatresourcegroup.

GreenplumCommandCenterevaluateseachruleinthe assignmentRules arrayfromtoptobottomandstopsatthefirstmatch,sotheorderisimportant.

Theelementsinthe assignmentRules arraycanhavethefollowingkey/valuepairs.

resourceGroupNameThenameoftheGreenplumDatabaseresourcegroup.TheresourcegroupmustalreadyexistorhavebeencreatedinGreenplumDatabasewiththeCREATE RESOURCE GROUP SQLstatement.

roleNameThenameofaGreenplumDatabaseroletomatchagainstthecurrentroleidentifierintheGreenplumDatabasesession.ThecurrentroleisinitiallythedatabaserolethatauthenticatedwiththeGreenplumDatabasesystemtobeginthesession.Auserwithsufficientprivilegescanchangethecurrentroleinthedatabasesessionusingthe SET ROLE SQLcommand.

Ifnoroleisspecifiedintheassignmentruleandthequerytagsmatch,thetransactionisassignedtothespecifiedresourcegroup.Ifthe roleNamevalueispresent,however,thecurrentdatabaseusermustmatchthespecifiedrole.

queryTagsAlistofquerytagstomatchagainstthe gpcc.query_tags parameterintheGreenplumDatabasesession.Aquerytagisauser-defined<name>=<value>pair.Separatemultiplequerytagswithsemicolons.Forexample,thefollowingstatement,executedintheGreenplumDatabasesession,setsthe appName and appUser querytagsto“tableau”and“bi_sales”,respectively.

Warning!The gpcc.workload_config tableshouldonlybeaccessedbyusingthe gpcc.get_workload_config() and gpcc.set_workload_config() functionsortheCommandCenteruserinterface.Donotdropthetablewhiletheworkloadmanagementextensionisenabled.

The gpcc.set_workload_config() functionrequiresvalidJSONsyntax,butdoesnotvalidatetheworkloadmanagementrules.YoumustensurethattheJSONvaluecontainsa version variable,andcorrectlyspecifiedassignmentandidlesessiontimeoutrules.


=#SETgpcc.query_tagsTO'appName=tableau;appUser=bi_sales';

Tomatch,alltagsintheassignmentrule’s queryTags valuemustbepresentinthe gpcc.query_tags parameterinthedatabasesession.Theorderofthetagsisnotsignificant,andthe gpcc.query_tags parametercanbeasupersetofthetagsdefinedinthe queryTags value.

Ifthe queryTags valueisempty,ortheparameteromitted,therulewillmatcheverysessionforthe roleName databaserole.

Ifyousetthe gpcc.query_tags parameterinsideofatransaction,youmustcommitthetransactionbeforethenewquerytagsareusedtoevaluateassignmentrules.

The gpcc.query_tags parametercanbespecifiedusingthe SET command,asabove,orasaconnectionparameterwithdatabaseclientsthatsupportit,suchas psql .Herearetwoexamplesthatshowhowtospecifyquerytagsonthe psql commandline:

$PGOPTIONS="-cgpcc.query_tags='appName=tableau;appUser=bi_sales'"psql

$psqlpostgresql://mdw:5432/postgres?options="-cgpcc.query_tags%3D'appName%3Dtableau;appUser%3Dbi_sales'"

Inthesecondexample,itisnecessarytocodetheequalssignsas %3D toprevent psql frominterpretingthequerytagsascommand-linearguments.

disabledIfsetto true ,theassignmentruleisignoredwhenCommandCenterevaluatesrulestoassigntransactionstoworkloads.Thisparameterisoptionalanditsdefaultvalueis "false" .

gpcc.get_workload_config()RetrievesthecurrentworkloadassignmentrulesasaJSONvalue.

Example

postgres=#SELECTgpcc.get_workload_config();get_workload_config--------------------------------------------------------{"version":1,"assignmentRules":[{"resourceGroupName":"default_group","roleName":"gpadmin","queryTags":"appName=tableau;appUser=bi_sales"},{"resourceGroupName":"admin_group","roleName":"gpadmin","queryTags":"appName=tableau;appUser=bi_acct","disabled":true}],"idleSessionKillRules":{"admin_group":{"timeoutSeconds":600},"default_group":{"timeoutSeconds":3600}}}

(1row)

gpcc.set_workload_config()Setstheworkloadassignmentrules.TheargumentisavalidJSONvaluecontainingtheassignmentrulesan.SeeJSONParametersfordescriptionsoftheparameters.


Ifyoucall gpcc.set_workload_config() withinatransaction,youmustcommitthetransactionbeforetheworkloadmanagmentextensionappliesthenewrules.

Example

postgres=#SELECTgpcc.set_workload_config('{"version":1,"assignmentRules":[{"resourceGroupName":"default_group","roleName":"gpadmin","queryTags":"appName=tableau;appUser=bi_sales"},{"resourceGroupName":"admin_group","roleName":"gpadmin","queryTags":"appName=tableau;appUser=bi_acct","disabled":true}],"idleSessionKillRules":{"admin_group":{"timeoutSeconds":600},"default_group":{"timeoutSeconds":3600}}}');set_workload_config---------------------t(1row)

The gpcc.set_workload_config() functionacceptsanyvalidJSONvalue.Youmustensurethatthevaluecontainsa version elementandproperlyspecifiedassignmentandidlesessiontimeoutrules.


TroubleshootingEnablingResourceGroupsIfyouexperienceproblemsenablingresourcegroupsinGreenplumCommandCenter,reviewthefollowinglisttoensureprerequisitesaremetandallofthedependenciesareproperlyconfigured.

RedHat6.xand7.xandCentOS6.xand7.xarecurrentlysupported.

YoumustberunningGreenplumDatabaseversion5.7.0orlater.

ConfiguretheLinuxcgroupskernelfeatureonyourhostsbyfollowingtheinstructionsat“Prerequisite”inUsingResourceGroups .

Makesurethe /etc/cgconfig.d/gpdb.conf filecontainstheobjectsperm,cpu,andcpuacct.Ifthedocumentisincorrectandthe gp_resource_manager

configurationparameterissetto "group" ,GreenplumDatabasecanhangatstartup.

groupgpdb{perm{task{uid=gpadmin;gid=gpadmin;}admin{uid=gpadmin;gid=gpadmin;}}cpu{}cpuacct{}}

OnRedHat7,makesureyourun cgconfigparser-L/etc/cgconfig.d toparsechangestothe /etc/cgconfig.d/gpdb.conf file.Thiscommandmustalsobesetuptorunatboottime.

SettheGreenplumDatabase gp_resource_manager serverconfigurationparameterto "group" .

$gpconfig-cgp_resource_manager-v"group"

Verifybyshowingthevalueoftheparameter:

$gpconfig-sgp_resource_managerValuesonallsegmentsareconsistentGUC:gp_resource_managerMastervalue:groupSegmentvalue:group

AfterinstallingaPivotalGreenplumDatabasedistribution,the shared_preload_libraries configurationparametercontainsthemetricscollectorandworkloadmanagerextensionsharedlibraries.Makesuretheselibrariesarestillpresent:

$gpconfig-sshared_preload_librariesValuesonallsegmentsareconsistentGUC:shared_preload_librariesMastervalue:$libdir/metrics_collector,$libdir/gp_wlmSegmentvalue:$libdir/metrics_collector,$libdir/gp_wlm

Checkthatthesharedlibrariesexistat $GPHOME/lib/postgresql/metrics_collector.so and $GPHOME/lib/postgresql/gp_wlm.so .Ifthelibrariesdonotexist,makesureyouhaveinstalledthePivotalGreenplumDatabasedistribution.TheseextensionsarenotavailableintheGreenplumDatabaseOpenSourceversion.Ifthesharedlibraryfilesexistinthe $GPHOME/lib/postgresql directory,butnotinthe shared_preload_libraries parameter,addthemwiththe gpconfig

command:

$gpconfig-cshared_preload_libraries-v'\$libdir/metrics_collector,\$libdir/gp_wlm'

Notethataddingthelibrariestothe shared_preload_libraries parameterdoesnotenablethemetrics_collectororgp_wlmextensions,butisaprerequisiteforenablingthem.

ThegpmonusermustbeabletoconnecttodatabasesfromtheCommandCenterhost.Makesuretoadda host entrylikethefollowinginthe$MASTER_DATA_DIRECTORY/pg_hba.conf file.

hostallgpmon<IP_of_host>/32md5

Checkwhetherthe gp_wlm extensionisinstalled.TheextensionisaddedwhenyouclickEnableWorkloadsintheGreenplumCommandCenter


http://gpdb.docs.pivotal.io/latest/admin_guide/workload_mgmt_resgroups.html#topic71717999

Admin>WorkloadMgmtview.

$psqlpostgres\dxpostgres=#\dxListofinstalledextensionsName|Version|Schema|Description--------+---------+--------+--------------------------------------gp_wlm|0.1|gpcc|GreenplumWorkloadManagerExtension

Makesurethe gpcc.workload_config tableandfunctionsarepresentinthepostgresdatabase:

$psqlpostgrespostgres=#\dgpcc.*Table"gpcc.workload_config"Column|Type|Modifiers----------+---------+-----------dist_col|integer|config|json|Distributedby:(dist_col)postgres=#\dfgpcc.*ListoffunctionsSchema|Name|Resultdatatype|Argumentdatatypes|Type--------+---------------------+------------------+----------------------+-------gpcc|get_workload_config|json||normalgpcc|set_workload_config|boolean|wlm_json_configjson|normal(2rows)

Ifthe gpcc.workload_config tableorthefunctionsarenotpresent,droppingandrecreatingthegp_wlmextensionwillcreatethem.Notethatanyassignmentrulessavedinthe gpcc.workload_config tablewillhavetoberecreatedinCommandCenter.

$psqlpostgrespostgres=#DROPEXTENSIONgp_wlm;DROPEXTENSIONpostgres=#CREATEEXTENSIONgp_wlm;CREATEEXTENSION


PivotalCommandCenterOnlineHelpTopics

QueryMonitorHelpTopicsCPU

CPUSkew

Locks

QueryOptimization

Memory

SpillFiles


http://gpcc.docs.pivotal.io/440/help/spill-files.html

CPUTheCPUpercentmetricistheaveragecurrentCPUpercentageforallbackendprocessesexecutingthisquery.Thepercentagesforallprocessesrunningaqueryoneachsegmentareaveraged,andthentheaverageofallthosevaluesiscalculatedtorenderthismetric.

YoucanmanagethepercentageofCPUthatqueriescanconsumebycreatingworkloadsandspecifyingthemaximumpercentofCPUeachworkloadcanconsume.Thatpercentageisfurtherdividedamongthesegmentsrunningoneachhostandthenamongtheconcurrentqueriestheworkloadcanexecute.

CPUallocatedtoidleworkloadsisreallocatedtoactivequeriesandreclaimedwhentheidleworkloadbecomesactiveagain.ThismeansthattheCPUpercentvalueforaquerycanexceedlimitsdefinedforworkloadsandcanincreaseanddecreaseasotherqueriesstartorfinish.

MemoryanddiskI/OresourcesaremorelikelycausesfordegradedqueryperformancethanlackofCPUcycles.ThewaystoreduceCPUcontentionmirrorthesolutionsforinsufficientmemory:

ReduceconcurrencyofworkloadstomakemoreCPUavailabletoeachquery.

ReducethenumberofworkloadsandreallocateCPUtotheremainingworkloads.

IfCPUisnotconstrainedandthesizeofspillfilesforsomequeriesisverylarge,makesurethatthe gp_workfile_compress_algorithm serverconfigurationparameterissetto zlib andnot none .CompressingspillfilesreducesdiskI/O,butusesCPUcylestocompressanddecompressthedata.

SeeUsingResourceGroups formoreaboutmanagingperformancewithresourcegroups.

IfyourGreenplumDatabasesystemisconfiguredtomanageresourceswithresourcequeues,seeUsingResourceQueues .


https://gpdb.docs.pivotal.io/latest/admin_guide/workload_mgmt_resgroups.html

https://gpdb.docs.pivotal.io/latest/admin_guide/workload_mgmt.html

CPUSkew

WhatisCPUSkew?CPUskewoccurswhentheworktoexecuteaqueryisnotdistributedevenlyamongthesegments.

TheCPUmetricistheaverageoftheCPUpercentagesusedbyeachprocessexecutingthequery.TheCPUskewmetricisavariancestatisticbasedonthedifferencebetweentheaverageandeachsegment’scurrentCPUmetric.ThesmallertheCPUskew,themoreequallytheworkisdistributed.TheCPUskewmetricvariesbetween0.0(noskew)and1.0.Thelowertheskewmetricthemorefullythedatabasecluster’sresourcesareutilized.

CPUskewisusuallyrelatedtothevolumeofdataprocessedbythesegmentswhileexecutingthequeryexecutionplan.Therearetwotypesofskewyoushouldinvestigate:dataskewandcomputationalskew.

DataSkewAhighCPUskewmaybeanindicationofdataskew,wheretablesusedbythequeryaredistributedunevenly,sothatsomesegmentshavemoredatatoprocessthantheirpeers.Youcancheckfordataskewinatablebyrunningaquerylikethisone:

=#SELECTgp_segment_id,COUNT(*)FROM<table-name>GROUPBYgp_segment_id;

Therowcountshouldbeapproximatelyequalforeachsegment.Iftherowsaredistributedunevenly,checkthedistributionkeyforthetable.Agooddistributionkeyisacolumnorlistofcolumnswithuniqueornearlyuniquevalues,suchasthetable’sprimarykey.SettingthedistributionpolicytoDISTRIBUTEDRANDOMLY alsoensuresawell-distributedtable,butprecludestakingadvantageofperformance-enhancingstrategiessuchasco-locationfortableswithequivalentprimarykeys.

ComputationalSkewHighCPUskewcanbetheresultofcomputationalskew,whichoccursduringqueryexecution.Someoftheoperationsinthequeryplancancausesomesegmentstodomoreworkthanothers.Forexample,joins,sorts,oraggregationsoncolumnswithlowcardinalityorunevenlydistributedvaluescancontributetoCPUskewbycausingsomesegmentstoprocessmanymoretuplesthanothers.

SeeDistributionandSkew intheGreenplumDatabaseAdministratorGuideandTuningSQLQueries intheGreenplumDatabaseBestPracticesguideformorehelpfindingthecausesofskew.


https://gpdb.docs.pivotal.io/latest/admin_guide/distribution.html

https://gpdb.docs.pivotal.io/latest/best_practices/tuning_queries.html

LocksGreenplumCommandCenterdisplaysthelockscurrentlyheldbyqueriesandqueriesblockedbylocks.

Ablockoccurswhenonequeryneedstoacquirealockthatconflictswithalockheldbyanotherquery.Ifaqueryisblockedforalongperiodoftime,youcaninvestigatetheblockingqueryand,ifnecessary,canceloneofthequeries.

Lockscanbeacquiredusingthe LOCKTABLE SQLstatement.SomeSQLcommandsacquirelocksautomatically.Followingaredescriptionsofthelockmodes,theGreenplumDatabasecommandsthatacquirethem,andwhichlockmodesconflictwiththem.

ACCESSSHAREAcquiredby SELECT and ANALYZE commands.

ConflictswithACCESSEXCLUSIVElocks.

Ingeneral,anyquerythatonlyreadsatableanddoesnotmodifyitacquiresthislockmode.

ROWSHAREAcquiredby SELECT FOR SHARE command.

ConflictswithEXCLUSIVEandACCESSEXCLUSIVElocks.

AROWSHARElockisplacedonthespecifiedtableandanACCESSSHARElockonanyothertablesreferencedinthequery.

ROWEXCLUSIVEAcquiredby INSERT and COPY commands.

ConflictswithSHARE,SHAREROWEXCLUSIVE,EXCLUSIVE,andACCESSEXCLUSIVElocks.

AROWEXCLUSIVElockisplacedonthespecifiedtableandACCESSSHARElocksareplacedonanyotherreferencedtables.

SHAREUPDATEEXCLUSIVEAcquiredby VACUUM and VACUUM FULL .

ConflictswiththeSHAREUPDATEEXCLUSIVE,SHARE,SHAREROWEXCLUSIVE,EXCLUSIVE,andACCESSEXCLUSIVElocks.

SHAREUPDATEEXCLUSIVEprotectsatableagainstconcurrentschemachangesand VACUUM runs.

SHAREAcquiredby CREATE INDEX .

ConflictswithROWEXCLUSIVE,SHAREUPDATEEXCLUSIVE,SHAREROWEXCLUSIVE,EXCLUSIVE,andACCESSEXCLUSIVElocks.

Protectsatableagainstconcurrentdatachanges.

SHAREROWEXCLUSIVEThislockmodeisnotautomaticallyacquiredbyanyGreenplumDatabasecommand.

ConflictswithROWEXCLUSIVE,SHAREUPDATEEXCLUSIVE,SHARE,SHAREROWEXCLUSIVE,EXCLUSIVE,andACCESSEXCLUSIVElocks.

EXCLUSIVEAcquiredby UPDATE , SELECT FOR UPDATE ,and DELETE commandsinGreenplumDatabase.

ConflictswithROWSHARE,ROWEXCLUSIVE,SHAREUPDATEEXCLUSIVE,SHARE,SHAREROWEXCLUSIVE,EXCLUSIVE,andACCESSEXCLUSIVElocks.ThislockmodeallowsonlyconcurrentACCESSSHARElocks-atablecanbereadbyanothertransactionwhilethislockisheld.ThisismorerestrictivelockingthaninregularPostgreSQL.

ACCESSEXCLUSIVEAcquiredbythe ALTER TABLE , DROP TABLE , TRUNCATE , REINDEX , CLUSTER ,and VACUUM FULL commands.DefaultlockmodeforLOCK TABLE statementsthatdonotspecifyalockmode.Alsobrieflyacquiredby VACUUM (without FULL )onappend-optimizedtablesduringprocessing.

Conflictswithalllocks.

Thislockmodeguaranteesthattheholderistheonlytransactionaccessingthetableinanyway.

FormoreonlocksinGreenplumDatabasequeries,seetheLOCK commandReference.SeealsoTuningSQLQueries .


https://gpdb.docs.pivotal.io/latest/ref_guide/sql_commands/LOCK.html

http://gpdb.docs.pivotal.io/latest/best_practices/tuning_queries.html


MemoryTheGreenplumCommandCenterQueryMonitorreportsthecurrenttotalmemoryconsumedbyallprocessesexecutingaquery.Whenthereisinsufficientmemoryavailableforaquerytocomplete,thequeryhasanerrorstatusinthequerymonitorandanoutofmemoryerrorislogged.

IfyouhaveenabledresourcegroupsinGreenplumDatabase,youcanmanagetheamountofmemoryavailabletoqueriesbytuningresourcegroupparameters,andbysettingGreenplumDatabaseconfigurationparametersthataffectresourcegroupmemory.

Foradetaileddescriptionofresourcegroupmemorymanagement,seeUsingResourceGroups intheGreenplumDatabaseAdministratorGuide.

Ifyouareusingresourcequeues,seeMemoryandResourceManagementwithResourceQueues andUsingResourceQueues forwaystotroubleshootmemoryproblemswithresourcequeues.

SeeTuningSQLQueries forhelpwithqueryoptimization.

ThefollowingsummarydescribestheresourcegroupparametersandrelatedGreenplumDatabaseserverconfigurationparametersthatdeterminetheamountofmemoryavailabletodatabasequeriesandhowconfigurationchoicesaffectconcurrency,spillfileusage,andqueryperformance.

ResourceGroupMemoryConfigurationParametersAresourcegrouphasparameters CONCURRENCY , MEMORY_LIMIT , MEMORY_SHARED_QUOTA ,and MEMORY_SPILL_RATIO ,whichdeterminehowmuchmemoryisallocatedtoexecuteaquery.The CPU_LIMIT parameterhasnoeffectonmemoryallocation.Seethe CREATERESOURCEGROUP

SQLreferenceforcommandsyntaxandinformationabouttheseparameters.

MEMORY_LIMIT

Thisparametersetstheamountofmemorytheresourcegroupmanagesasapercentageofthememoryavailabletoresourcegroups.Thesumofallresourcegroups’ MEMORY_LIMIT smustnotexceed100.Ifthesumofallresourcegroups’ MEMORY_LIMIT sislessthan100,theremaining,unallocatedmemoryisglobalresourcegroupsharedmemory,availabletoqueriesfromallresourcegroupsonafirst-come,first-servedbasis.

MEMORY_SHARED_QUOTA

Aresourcegroupdividesthememoryitmanagesintoafixedportionandasharedportion,calledresourcegroupsharedmemory.Thisparameterspecifiesthepercentageofaresourcegroup’smemorythatisshared.Thedefaultis20andthevaluecanrangefrom0to100.

CONCURRENCY

Thisparameterlimitsthenumberofconcurrenttransactionsaresourcegroupallows.Thefixedportionofthememorytheresourcegroupmanagesisdividedequallyamong CONCURRENCY transactionslots.Everytransactionstartswiththisfixedportionofmemoryand,ifneeded,GreenplumDatabaseusesadditionalmemoryfromtheresourcegroupsharedmemoryandglobalresourcegroupsharedmemory.

MEMORY_SPILL_RATIO

Thisparametersetsalimitfortheamountofmemoryaquerycanusebeforeitspillstodisk.Theparametervalueisexpressedasapercentageofthefixedmemoryallocation.Thedefaultis20andthevaluecanrangefrom0to100.Ahighervalueusesmorememory,butcanimprovequeryperformance.Atransactioncanoverridethisvaluebysettingthe memory_spill_ratio configurationparameterinthesession.

Whenaqueryexecutes,GreenplumDatabaseallocatesmemorytoitfromthefixedportionoftheresourcegroup’smemory.Ifthequeryneedsmorememoryandtheresourcegrouphasavailablesharedmemory,GreenplumDatabaseallocatesadditionalmemory.Ifinsufficientsharedmemoryisavailable,GreenplumDatabaseallocatesadditionalmemoryfromglobalsharedmemory,ifavailable.Iftherequiredmemoryisnotavailablethetransactionfails.

GreenplumDatabaseMemoryConfigurationParametersThefollowingGreenplumDatabaseconfigurationparametersaffectresourcegroupmemoryallocationandconcurrency.

gp_resource_group_memory_limit

ThisGreenplumDatabaseserverconfigurationparametersetsthepercentageofeachhost’ssystemmemorytobemanagedbyresourcegroups.Thedefaultis 0.7 (70%).Thismemoryisdividedequallyamongtheprimarysegmentsoneachhost,andfurtherdividedamongresourcegroupswiththe MEMORY_LIMIT resourcegroupparameter.Anymemorynotallocatedtoresourcegroupsbecomesglobalsharedmemoryavailabletoqueriesfromallresourcegroups.See gp_resource_group_memory_limit foracompletereferenceforthisparameter.

gp_resgroup_memory_policy

ThisparameterdetermineshowGreenplumDatabaseallocatesmemorytoqueryoperators.Thedefaultvalue, eager_free ,re-allocatesmemoryfromcompletedoperatorstooperatorslaterinthequeryplan.Thealternativevalueforthisparameter, auto ,allocatesafixedamountofmemorytooperatorsthatarenotmemory-intensiveandtheresttothememory-intensiveoperators.Thedefaultvalueisusuallytheoptimalsetting.Seegp_resgroup_memory_policy foracompletereferenceforthisparameter.



http://gpdb.docs.pivotal.io/latest/best_practices/workloads.html

https://gpdb.docs.pivotal.io/latest/admin_guide/workload_mgmt.html

https://gpdb.docs.pivotal.io/latest/best_practices/tuning_queries.html

http://gpdb.docs.pivotal.io/latest/ref_guide/sql_commands/CREATE_RESOURCE_GROUP.html

http://gpdb.docs.pivotal.io/latest/ref_guide/config_params/guc-list.html#gp_resource_group_memory_limit

http://gpdb.docs.pivotal.io/latest/ref_guide/config_params/guc-list.html#gp_resource_group_memory_policy

memory_spill_ratio

Atransactioncanoverridetheresourcegroup’s MEMORY_SPILL_RATIO valuebysettingthe memory_spill_ratio configurationparameterinthesession.Thevalueisapercentageofthefixedmemoryallocationfortransactionsintheresourcegroup,expressedasanintegerfrom0to100.Theperformanceofquerieswithlowmemoryrequirementscanbeimprovedbysettingthe memory_spill_ratio parameterinthesessiontoalowsetting,forexample0to2.See memory_spill_ratio formoreinformationaboutthisparameter.


http://gpdb.docs.pivotal.io/latest/ref_guide/config_params/guc-list.html#memory_spill_ratio

QueryPlanExecutionTheGreenplumDatabaselegacyandGPORCAqueryoptimizersgenerateexecutionplansthatproducetheresultsrequestedbythequery.Aplanisasequenceofoperators,suchastablescans,joins,sorts,aggregates,anddatamotions.

WhenyouselectaqueryontheCommandCenterQueryMonitorview,aQueryDetailsviewpresentsagraphicalrepresentationoftheexecutionplan.

YoucanswitchbetweenthegraphicalandtexualrepresentationsofthequeryexecutionplanbyselectingthePlan&ProgresstabortheTexualPlantab.Inthetextualformat,eachplannodeisflaggedwithanarrow( -> ).Inthegraphicalview,thenodesarerepresentedbyboxesthatfillastheplanexecutes.

Aqueryexecutionplanexecutesfromthebottomup.Eachnodeintheplanperformsanoperationandpassesresultsuptothenextnodeintheplan.

The Optimizerstatus: lineontheTextualPlantabreportswhethertheexplainplanwasgeneratedusingtheGPORCAoptimizerorthelegacyqueryoptimizer.

SlicesandGangsSegmentscanworkonportionsofaqueryinparallel,eachsegmentexecutingoperatorsindependentlyontheirlocaldata.Whentheplanrequiresexchangingdatabetweensegments,adatamotionoperatorcoordinatesthedatatransferbetweensegments.Theplanisdividedinto“slices”wherethesedatamotionsoccur.

Adatamotionnodeinatextualqueryplanidentifiesthesliceandthenumberofsegmentsparticipatinginthemotion.

Example:

->BroadcastMotion4:4(slice2;segments:4)(cost=0.00..867.15rows=10000width=30)

Inabroadcastmotion,eachsegmentbroadcastsallofitsrowsforatableoverthenetworksothateverysegmenthasacompletecopyofthetable.Inthisexample,thebroadcastmotionmarksthecompletionof slice2 withfoursegmentssendingandfoursegmentsreceiving.

Eachsegmenthasoneormorebackendprocessesworkingonaslice.Backendprocessesworkingonthesameslicearecalleda“gang”.

OperatorsOperatorsareprocessesthattakeasinputdatabasetablesortheoutputfromotheroperators,andperformsomeactiontoproduceatransformedoutput.

ScanOperators

InitplanAquerythatrunsbeforethemainqueryisoptimizedtofindthepartitionstoscan.

SequentialscanTheoptimizermaychooseasequentialtablescanifthereisnoindexontheconditioncolumnorifmostrowsareexpectedtosatisifythecondition.Becauseeachsegmentscansanequalportionofthedatainparallelwithothersegments,atablescaninGreenplumDatabaseisveryefficient.Aqueryonapartitionedtablemaybeabletoeliminatepartitionstomakethescanevenfaster.

Append-onlyscanScansrowsinarow-oriented,append-optimizedtable.

Append-onlycolumnarscanScansrowsinacolumn-oriented,append-optimizedtable.

DynamictablescanScansselectedpartitionsinapartitionedtable.

FunctionscanAFunctionScannodeselectsthepartitionstoscan.Thefunctioncanbeoneofthefollowing:


gp_partition_expansion -choosesallnodes

gp_partition_selection -choosesapartitionwithanequalityexpression

gp_partition_inversion -choosespartitionswitharangeexpression

IndexscanScansaB-treeindexonatabletofindrows.Therowsarethenretrievedfromdisk.

BitmapindexscanABitmapIndexScanisanindexscanoptimizedbystoringrowsinabitmapinsteadofretrievingthemfromthetableimmediately.Whenthescaniscomplete,rowsinthebitmapareretrievedwithaBitmapHeapScanoperation.

BitmapAndandBitmapOrGeneratesanewbitmapbyrunninglogicalANDorORonmultiplebitmaps.

BitmapheapscanRetrievesrowsfromheapstorageusingabitmapgeneratedbyaBitmapindexscanorBitmapAndorBitmapOroperation.

NestedloopwithinnersequentialscanjoinForeachrowinthefirsttable,theoperatortestseveryrowinthesecondtablewithasequentialscan.

Onetablemustbebroadcastsothateverysegmentcancompareallrowsofonetablewiththerowsithasfromtheothertable.Thisisexpensiveandisbestusedonlyforsmalltables.

NestedloopwithinnerindexscanForeachrowinthefirsttable,theoperatorsearchesanindexonthesecondtable.

Onetablemustbebroadcastsothateverysegmentcancompareallrowsofonetablewiththerowsithasfromtheothertable.

AppendConcatenatesdatasets.Forexample,combinesrowsscannedfrommultiplepartitions.

FilterSelectsrowsusinga WHERE clause.

LimitLimitsthenumberofrowsreturned.

MaterializeSavesresultsfromasubselectsothatitisnotnecessarytoprocesstheinnertableforeveryrowintheoutertable.

JoinOperators

HashjoinCreatesahashtableonthejoinkeyofthesmallertable.Scansthelargertableandlooksupmatchingrowsinthehashtable.Hashjoinisveryfast.Thehashtableisheldinmemory,soahashjoincanusealotofmemory,dependingonthesizeofthesmallertable.

SortmergejoinThetablestobejoinedaresortedonthejoinattributeandthenscannedinparalleltofindthematchingvalues.Thisisagoodjoinmethodfortablesthataretoolargetouseahashjoin.

ProductjoinJoinseveryqualifyingrowinthefirsttablewitheveryqualifyingrowinthesecondtable.Thistypeofjoincanbeveryexpensiveifspillfilesmustbeused.

SortandAggregateOperators

SortSortsrowstoprepareforoperationssuchasanaggregationormergejoin.

GroupbyGroupsrowsbyoneormorecolumns.

Group/hashaggregate


Aggregatesrowsusingahash.

MotionOperatorsBroadcastmotion

Everysegmentsendsitsownlocaldatatoallothersegmentinstancessothateverysegmentinstancehasacompletelocalcopyofthetable.

RedistributionmotionSendsdatafromonetabletoanothersegmentsothatmatchingrowsarelocatedtogether,enablingalocaljoin.

GathermotionAllsegmentssendrowstothemasterwheretheyaregatheredintoasingleresultset.

DMLOperatorsAssert

Performsconstraintschecking.

SplitUsedforupdateoperations.


Documents

Pivotal Greenplum Command CenterGreenplum Command Center 4.4.0 is a minor release that adds features and resolves some issues. See Enhancements and Changes in Greenplum Command Center