OracleDaabasec最大化应用程序的可用性

MaximumApplicationAvailabilitywithOracleDatabase12cKuassiMensah

DirectorProductManagementThefollowingisintendedtooutlineourgeneralproductdirection.Itisintendedforinformationpurposesonly,andmaynotbeincorporatedintoanycontract.Itisnotacommitmenttodeliveranymaterial,code,orfunctionality,andshouldnotberelieduponinmakingpurchasingdecisions.Thedevelopment,release,andtimingofanyfeaturesorfunctionalitydescribedforOracle’sproductsremainsatthesolediscretionofOracle.MyNextSessionOracleIn-DatabaseMapReduce:WhenHadoopMeetsExadata7/25/13,12:00–13:00,Room431ProgramAgendaProblemstoSolveNewConceptsTransactionGuardApplicationContinuityApplicationDesignConsiderationsProblemstoSolveUponDatabaseOutageFourProblemsConfrontApplicationsHangErrorsOutcomeofIn-FlightWorkResubmissionofIn-FlightWorkHang->FastApplicationNotification(FAN)

ErrorsHandling?Notformalized

In-FlightWork?Lost!ResubmissionofIn-FlightWork?N/A!CurrentSituationProgramAgendaProblemstoSolveNewConceptsTransactionGuardApplicationContinuityApplicationDesignConsiderationsRecoverableErrorFormalizedOracleException.IsRecoverablepropertyApplicationsNolongerneedtomaintainownlistoferrorcodes

(e.g.,ora-1033,ora-1034,ora-xxx)

JDBCthrows

SQLRecoverableException

DatabaseRequest

UnitofWorkPoolDataSourcepds=GetPoolDataSource();Connectionconn=getConnection(pds);PreparedStatementpstmt=……SQL,PL/SQL,localcalls,RPC …mit();conn.close();RequestBeginsRequestBody

UsuallyendswithCOMMITRequestEndsProgramAgendaProblemstoSolveNewConceptsTransactionGuardApplicationContinuityApplicationDesignConsiderationsTransactionGuardToolthatsupportsknownoutcomeforeverytransactionWithoutTransactionGuard,retrycancauselogicalcorruptionUsedbyApplicationContinuityCanbeusedindependentlyofApplicationContinuity4.EnforceOutcomeWorkRequest2.DBCalls12cORACLEDatabase3.Errors4.ReliableCommitOutcomeTransactionGuard–TypicalUsageUpondatabaseinstancecrashFANabortsdeadsessionApplicationgetsanerrorPoolremovesorphanconnectionfrompoolIf“recoverableerror”thenGetlastLTXIDfromdeadsessionObtainnewdatabasesessionGettransactionstatusTransactionGuardInActiongetConnection()Txn.Commit();getLastLTXID<newsession>Commitoutcome?COMMIT/ROLLBACKstarttransactionassignLTXIDCOMMIT?Return&PreserveCOMMITOUTCOMEClient/Mid-tierDatabaseTimeRecoverableErrorCOMMITGetLogicalTXIDSQL,PL/SQL,RPCResultsTGinActionOnServiceCOMMIT_OUTCOMEValues–TRUEandFALSEDefault–FALSEAppliestonewsessionsRETENTION_TIMEOUTUnits––secondsDefault–24hours(86400)Maximumvalue–30days(2592000)TransactionGuardConfigurationTransactionGuardinOracledatabase12cJDBC-thin,ODP.NET,OCI,OCCICommitModelsLocalTXNAuto-commit,CommitonSuccessCommitembeddedinPL/SQLDDL,DCL,ParallelDDLRemote,DistributedExclusionsXAR/WDBLinksfromActiveDataGuardorReadOnlyProgramAgendaProblemstoSolveNewConceptsTransactionGuardApplicationContinuityDesignConsiderationsApplicationContinuityMaskDatabaseOutageWhenSuccessfulReplaysin-flightworkonrecoverableerrorsMasksmanyhardware,software,network,storageerrorsandoutageswhensuccessfulImprovesenduserexperience5.ResponseWorkRequest2.DBCalls12cORACLEDatabase4.Replay3.ErrorsPhasesinApplicationContinuity1-Capture2-Reconnect3-ReplayDemarcatesdatabaserequestHoldsoriginalcallswithbinds&validationManagesqueuesChecksrequesthasreplayenabledHandlestimeoutsCreatesanewconnectionValidatestargetdatabaseUsesTransactionGuardtoenforcelastcommitReplaysheldcallsContinuesreplay,ifuservisibleresultsmatch,basedonvalidationsContinuesrequestApplicationContinuityInActionCall1Application

Proxy1

Proxy2RACDatabaseInstance1Instance2Instance3Call2

Connection

ReplayContextOracleJDBCDriverDEMOSolutionCoverageApplicationContinuityforJavaClientJDBC-ThindriverUCP,WebLogicServerDatabaseSQL,PL/SQL,RPCSelect,ALTERSESSION,DML,DDL,COMMIT/ROLLBACK/SAVEPOINTTransactionmodels:Local,Parallel,Remote,DistributedMutablefunctionsupportHardwareaccelerationoncurrentIntel&SPARCchipsExclusionsGlobalRequestTargetDatabaseDonotusedefaultdatabaseserviceExcludesXAForJava,deprecatedconcreteclassesRestrictedcallsAlterSystemAlterDatabaseNotsupportedforActiveDataGuardwithread/writedatabaselinksDoesnotsupport:LogicalStandbyGoldenGateRestrictionsWhenDoesReplayNotOccur?NormalRuntimeReconnectReplayAnycallinsamerequestaftersuccessfulcommitindynamicmode

(default)arestrictedcalldisableReplayAPIErrorisnotrecoverableReconnectionfailureReplayinitiationtimeoutMaxconnectionretriesMaxretriesperincidentTargetdatabasenotvalidforreplayLastcallcommitted

indynamicmodeValidationdetectsdifferentresultsProgramAgendaProblemstoSolveNewConceptsTransactionGuardApplicationContinuityApplicationDesignConsiderationsApplicationAssessmentDecideWhattodoRequestBoundariesMarkRequestBoundaries,ifyouarenotusingOraclePoolsJDBCConcreteClassesReplacedeprecatedconcreteclasseswithJavainterfacesSideEffectsUsedisableAPIifadatabaserequesthasanexternalcallthatshouldnotbereplayedCallbacksEnsureacallbackisregisteredifstatechangesoutsideanyrequest(WLS/UCPlabelingincludedbydefault)MutableFunctionsGrantkeepingmutablevaluesifthesearecompatiblewithyourapplicationSideEffectsWhenReplayisenabled,somecallsmayberepeated.AppsmayneedtousedisableReplay()APItopreventthis:AutonomoustransactionsUTL_HTTP,UTL_URLUTL_FILE,UTL_FILE_TRANSFER-filesoperationsUTL_SMPT,UTL_TCP,UTL_MAIL-sendingmessagesDBMS_PIPE,RPCs-toexternalsourcesDBMS_ALERT-emailorothernotificationsConfigureJDBCReplayDriverSetreplaydatasourceinpropertyfileEnableApplicationContinuityonServiceSetFA