Oracle Real Application Clusters (RAC) 12c Rel. 2 - Operational Best Practices

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OracleRealApplicationClusters(RAC)12cRel.2–OperationalBestPractices

MarkusMichalewiczSeniorDirectorofProductManagement,OracleRACDevelopmentDecember6,2017

[email protected]@OracleRACpmhttp://www.linkedin.com/in/markusmichalewiczhttp://www.slideshare.net/MarkusMichalewicz


SafeHarborStatementThefollowingisintendedtooutlineourgeneralproductdirection.Itisintendedforinformationpurposesonly,andmaynotbeincorporatedintoanycontract.Itisnotacommitmenttodeliveranymaterial,code,orfunctionality,andshouldnotberelieduponinmakingpurchasingdecisions.Thedevelopment,release,andtimingofanyfeaturesorfunctionalitydescribedforOracle’sproductsremainsatthesolediscretionofOracle.

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Fact

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Way:Automation

Goal:Simplification

BestPracticeRecommendationsGowiththeFlow

IT


Self-Driving -Userdefinesservicelevels,databasemakesthemhappen

Self-Tuning -Continuousadaptiveperformancetuning

Self-Scaling -Instantlyresizecomputeandstoragewithoutdowntime

Self-Securing -Protectionfrombothexternalattacksandinternalusers

Self-Repairing -Automatedprotectionfromalldowntime

LessLabor,LowerCost,FewerErrors,MoreSecure,MoreReliable

RACisNowPartofTheWorld’sFirstAutonomousDatabase

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ProgramAgenda

FundamentalsToBeConsideredFirst

ArchitectureChoices

ApplyingOperationalBestPractices

UsingSmartFeaturesAutomatically

Summary

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ProgramAgenda


ArchitectureChoices



Summary

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Copyright©2017,Oracleand/oritsaffiliates.Allrightsreserved.| 8

SharedStorage Network/Interconnect

Virtualization/Container Cloud



SharedStorage Network/Interconnect

Virtualization/Container Cloud


Moreinformationonthosetopics:https://www.slideshare.net/MarkusMichalewicz/oracle-

real-application-clusters-rac-12c-rel-2-whats-next


SharedStorageFundamentals

•  SharedstorageisthetoprequirementforOracleRAC.•  BlockstoragethatissupportedassharedstorageforRACbythestoragevendorandtheservervendorissupportedforRAC.https://www.slideshare.net/MarkusMichalewicz/how-to-use-oracle-rac-in-a-cloud-a-support-question

•  Exceptionsprovetherule.–  SharedFileSystemrequirecertification.–  Storagesolutionsmaybesubjectto“specialruling”.

•  Currently,No3rdPartyPublicCloudsupportssharedstorageforRAC.•  OracleASMandACFSarebyfarthepreferredstoragemanagementsolutionsforOracleRAC.

•  Caution:noOracleprovidedtoolcanfullyreliablychecktheappropriateconfigurationofsharedstoragebeforehand.

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Network/InterconnectFundamentals

•  TheinterconnectiscrucialtotheoperationofOracleRAC.–  ThinkofitasaRDMAaccesspathratherthananetwork.–  1GigEandredundancyshouldbethebareminimum.–  10GigEandredundancyarestronglyrecommended.

•  Convergednetworksandswitchesaresupported.Routingisnot.–  I.E.combiningpublic/privatenetworkcommunication.•  Inafuturerelease,communicationoninterconnectisplannedtobesecuredbydefault.

–  VLANsarealogicalseparation,notaphysicalone.•  E.g.theydonotprotectfrominterferenceonthesamephysicalnetwork.

– Whennetworkandstoragecommunicationarecombined,storagecommunicationshouldgetprioritized.

•  Caution:noOracleprovidedtoolcanfullyreliablychecktheappropriateconfigurationoftheinterconnectbeforehand.

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ProgramAgenda


ArchitectureChoices



Summary

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OracleRestartNotacluster,

butbackforgood!

SeeupdatesinMOSNote1584742.1

StandaloneClusterDedicatedclusterforOLTP,DWHormixed-WLsystems.

ClusterDomainDomainServicesCluster(DSC)&MemberClustersforlargeclusterestatesandstorageconsolidation.

ExtendedClusterStandaloneClusterorDSC

maintainingtwoindependentstoragearrays(overdistance).

ArchitectureChoices

SiteA SiteB

DomainServicesCluster


OracleRAC12cRel.2ClusterDomain

•  SimplifiedManagement– FleetManagementforinstallation,update,patchingandmaintenance

• ReducedLocalOverhead– MemberClustersbenefitfromtheconsolidationofcommonservicesontheDomainServicesCluster

•  ImprovedIOPerformance– Utilizingconsolidatedsharedstorage

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CentralizedManagementforClusterEstates“toobigtomanage”otherwise


OracleRAC12cRel.2ClusterDomain

•  SimplifiedManagement– FleetManagementforinstallation,update,patchingandmaintenance

• ReducedLocalOverhead– MemberClustersbenefitfromtheconsolidationofcommonservicesontheDomainServicesCluster

•  ImprovedIOPerformance– Utilizingconsolidatedsharedstorage

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CentralizedManagementforClusterEstates“toobigtomanage”otherwise

Moreinformation:https://www.slideshare.net/MarkusMichalewicz/oracle-rac-12c-rel-2-cluster-architecture-internals-

oow17-by-anil-nair-80543101(PPT)

http://www.oracle.com/technetwork/database/database-technologies/clusterware/overview/oracle-clusterware-12cr2-wp-3659203.pdf(WP)


BestPracticesApplyAcrossArchitectures

•  BParedesignedforStandaloneClusterdeployments

•  ADSCisaStandaloneCluster–  thatoffersadditionalservicestoMemberClusters.– BPforStandaloneClustersapplytoaDSC

• MemberClusterscomewithasimplifieddeployment– BasicBPforStandaloneClustersapplytoMemberClusters

•  ExtendedClustersforRACcomewithadditionalBP:–  https://www.slideshare.net/MarkusMichalewicz/oracle-extended-clusters-for-oracle-rac

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ThesimplifiedBestPractices(BP)equation



ProgramAgenda


ArchitectureChoices



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Read&implementOracleDocumentation

andMyOracleSupport(MOS)Notes

Read&implementBlogs&ForumEntriesNotalwaysvettedbyOracle.

Run&applyClusterVerificationUtility(CVU)&OracleUniversalInstaller(OUI)

Run&followORAchk

HowToObtainandApplyBestPracticesforOracleRAC?


Each“Tool”hasaDifferentPurpose

Establishthebasesystem;e.g.:hardwareandOSminimumrequirements

(fundamentals)

Checkandconfirmbaseline;e.g.checkforandapplyOS

minimumparameterrequirements;supportsdiffcomparison

Checkforrecommendedbestpracticesandimplementmanually

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ForautomatedandsimplerbestpracticesapplicationOracleAutonomousHealthFramework(AHF)

OracleAHFintegratesnextgenerationtoolsrunningas

components-24/7


EstablishesBaselineandMaintainsBestPracticeConfigurationsOracleClusterVerificationUtility(CVU)

•  Useduringinstallandoperation•  ChecksO/S,GIandDBmandatory

complianceandbestpracticeswithhealthcheckoption

•  Runsasdaemonevery6hours•  ASMBestPracticesCheck•  CreatesBaselinecollections•  Adduser-specified/disable

problemchecks•  Newuser-friendlyreportformat


ScheduleORAchk

?

Hour(0–23)

? ? ?

Dayofmonth(1–31)

Month(1–12)

Dayofweek(0–6)(0to6areSundaytoSaturday)

example:orachk-set'AUTORUN_SCHEDULE=8,20**2,5'willschedulerunsonTuesdayandFridayat08:00&20:00

AUTORUN_SCHEDULE=

2222


ViewORAchkReport

•  Healthscore•  SummaryofORAchkrun

•  Tableofcontent•  Controlsforreportfeatures•  Findings•  Recommendations

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ViewORAchkFindings

•  Checkstatus•  TypeofCheck•  CheckMessage

• Wherethecheckwasrun

•  Linktoexpanddetails

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•  Whattodotosolvetheproblem

•  LinkstorelevantKnowledgedocs•  Whererecommendationapplies

•  Whereproblemdoesn’tapply

•  Exampleofdatatherecommendationisbasedon

ActonRecommendations

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ProgramAgenda


ArchitectureChoices



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SmartFencing

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•  Pre-12.2,nodeevictionfollowsarather“ignorant”pattern–  Exampleina2-nodecluster:Thenodewiththelowestnodenumbersurvives.

•  Customersmustnotbasetheirapplicationlogiconwhichnodesurvivesthesplitbrain.–  Asthismay(!)changeinfuturereleases

NodeEvictionBasicshttp://www.slideshare.net/MarkusMichalewicz/oracle-clusterware-node-management-and-voting-disks

✔1 2


•  NodeWeightingisanewfeaturethatconsiderstheworkloadhostedintheclusterduringfencing

•  Theideaistoletthemajorityofworksurvive,ifeverythingelseisequal–  Example:Ina2-nodecluster,thenodehostingthe

majorityofservices(atfencingtime)ismeanttosurvive

NodeWeightinginOracleRAC12cRelease2Idea:Everythingequal,letthemajorityofworksurvive

✔1 2


Athreenodeclusterwillbenefitfrom“NodeWeighting”,ifthreeequallysizedsub-clustersare

builtassresultofthefailure,sincetwodifferentlysizedsub-clustersarenot

equal.

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Secondaryfailureconsiderationcaninfluencewhichnodesurvives.

Secondaryfailureconsiderationwillbeenhancedsuccessively.

Afallbackschemeisappliedifconsiderationsdonotleadtoanactionableoutcome.

Let’sDefine“Equal”

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Publicnetworkcardfailure. “Conflict”.


CSS_CRITICALcanbesetonvariouslevels/componentstomarkthemas

“critical”sothattheclusterwilltrytopreservethemincaseofafailure.

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CSS_CRITICALwillbehonoredifnoothertechnicalreasonprohibitssurvivalofthenodewhichhasatleastonecriticalcomponentatthe

timeoffailure.

AfallbackschemeisappliedifCSS_CRITICALsettingsdonotleadto

anactionableoutcome.

CSS_CRITICAL–FencingwithManualOverride

crsctlsetservercss_critical{YES|NO}

+serverrestart

srvctlmodifydatabase-help|grepcritical

…-css_critical{YES|NO}

DefinewhetherthedatabaseorserviceisCSScritical

✔NodeevictiondespiteWL;WLwillfailover.

“Conflict”.


RecoveryBuddies

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•  RecoveryBuddies•  Trackblockchangesonbuddyinstance

•  Quicklyidentifyblocksrequiringrecoveryduringreconfiguration

•  Allowrapidprocessingoftransactionsafterfailures

NearZeroReconfigurationTimewithRecoveryBuddiesA.k.a.BuddyInstances


•  BuddyInstancemappingissimple(random)–  e.g.I1àI2,I2àI3,I3àI4,I4àI1

•  Recoverybuddiesareassignedduringstartup•  RMS0oneachrecoverybuddyinstancemaintainsanin-memoryareaforredologchange

•  Anin-memoryareaisusedduringrecovery–  Eliminatestheneedtophysicallyreadtheredo

NearZeroReconfigurationTimewithRecoveryBuddiesHowitworksunderthehood

InstanceI1

InstanceI2

InstanceI3

InstanceI4

RecoveryBuddyI3

RecoveryBuddyI4

RecoveryBuddyI1

MyCluster

RecoveryBuddyI2


HowRecoveryBuddiesHelpReducingRecoveryTime

WithoutRecoveryBuddies WithRecoveryBuddies

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Detect

Evict

ElectRecovery

ReadRedo

ApplyRecovery

Detect

Evict

ElectRecovery

ReadRedo

ApplyRecovery

Upto4x

faster


DatabaseHangManager

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•  Alwayson,asenabledbydefault•  Reliablydetectsdatabasehangs•  Automaticallyresolveshangs

•  ConsidersQoSpoliciesforhangresolution•  Logsalldetectedhangs&theirresolutions

IntroductiontoHangManagerHowitworks Session

DIAG0

EVALUATE

DETECT

ANALYZE

Hung?

VERIFY

Victim

QoSPolicy


•  HangManagerauto-tunesitselfbyperiodicallycollectinginstance-andcluster-widehangstatistics

•  Metricslikeclusterhealth/instancehealthistrackedoveramovingaverage

•  Thismovingaverageisconsideredduringresolution

•  HolderswaitingonSQL*Netbreak/resetarefasttracked

HangManagerOptimizationswithOracleRAC12c(Rel.2)Tuningunderthehood


•  Earlywarningexposedvia(V$view)

•  Sensitivitycanbesethigher–  Ifthedefaultlevelistooconservative

•  HangManagerconsidersQoSpoliciesanddataduringthevalidationprocess

DBMS_HANG_MANAGER.SensitivityAnewSQLinterfacetosetHangManagersensitivity

HangSensitivityLevel

Description Note

NORMAL HangManagerusesitsdefaultinternaloperatingparameterstotrytomeettypicalrequirementsforanyenvironments.

Default

HIGH HangManagerismorealerttosessionswaitinginachainthanwhensensitivityisinNORMALlevel.


ProgramAgenda


ArchitectureChoices



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StandaloneCluster ClusterDomain

Virtualizedenvironments Cloud

Summary


Oracle Real Application Clusters (RAC) 12c Rel. 2 - Operational Best Practices

Software

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