Oracle英文版培訓(xùn)課件之Data Guard Administration：L06-DataProt-LogTrans

ConfiguringDataProtectionModes

andRedoTransportServicesObjectivesAftercompletingthislesson,youshouldbeabletodothefollowing:DescribethedataprotectionmodesChangethedataprotectionmodeofyourconfigurationModifyredotransportservicestoserveyourneedsDataProtectionModesand

RedoTransportModesAdataprotectionmoderequiresaspecificredotransportmode.Aredotransportmodealonedoesnotdefineadataprotectionmode.DefiningtheRedoTransportModeUsetheattributesofLOG_ARCHIVE_DEST_n:ARCHandLGWRSpecifythateitherthearchiverprocessorthelogwriterprocessisresponsiblefortransmittingredotothestandbydestinationARCHisthedefault.SYNCandASYNC(LGWRonly)SpecifythatnetworkI/OoperationsaretobeperformedsynchronouslyorasynchronouslywhenusingLGWRSYNCisthedefault.AFFIRMandNOAFFIRMEnsurethatredohasbeensuccessfullywrittentodiskonthestandbydestinationNOAFFIRMisthedefault.SettingtheRedoTransportModeClickEdittoaccesstheEditStandbyDatabasePropertiespage.SettingtheRedoTransportModeSelectthemodefromtheLogTransportModelist.DataProtectionModesThreedataprotectionmodes:MaximumprotectionMaximumavailabilityMaximumperformanceHelptobalancedataavailabilityandsystemperformanceMaximumProtectionEnableszerodatalossRedodatamustbewrittentoboththelocalonlineredologandthestandbyredologonatleastonestandbydatabase.Primarydatabaseshutsdownifafaultpreventsitfromwritingitsredostreamtoatleastoneremotestandbyredolog.Configurationrequirements:StandbyredologfilesonatleastonestandbydatabaseSYNC,LGWR,andAFFIRMattributes foratleastonestandbydatabaseMaximumAvailabilityEnableszerodatalossProvidesthehighestpossiblelevelofdataprotectionwithoutcompromisingtheavailabilityoftheprimarydatabaseRedodatamustbewrittentoboththelocalonlineredologandthestandbyredologonatleastonestandbydatabase.Primarydatabasedoesnotshutdownifafaultpreventsitfromwritingitsredostream.Configurationrequirements:StandbyredologfilesonatleastonestandbydatabaseSYNC,LGWR,andAFFIRMattributes foratleastonestandbydatabaseMaximumPerformanceDefaultlevelofdataprotectionProvidesthehighestpossiblelevelofdataprotectionwithoutaffectingtheperformanceoftheprimarydatabaseTransactionscancommitassoonastheredodataiswrittentothelocalonlineredolog.Redostreamiswrittenasynchronouslywithrespecttothecommitmentofthetransactionsthatcreatetheredodata.SettingtheDataProtectionModeClicktheProtectionModelink.SettingtheDataProtectionModeSettingtheDataProtectionMode

byUsingtheCLIConfigurestandbyredologs.SettheLogXptModeproperty(ifnecessary).Setthedataprotectionmode.DGMGRL>EDITDATABASE'site1_edrsr8p1'SETPROPERTY'LogXptMode'='SYNC';DGMGRL>EDITCONFIGURATIONSETPROTECTIONMODEASMAXAVAILABILITY;SettingtheProtectionMode

byUsingSQLYoumustsetattributestosupportthetypeofprotectiondesired.IssuetheALTER

DATABASEstatementontheprimarydatabase:ALTERDATABASESETSTANDBYTOMAXIMIZEPROTECTION;DelayingtheApplicationofRedoDelayingtheapplicationofredohelpssafeguardagainst:DatacorruptionUsererrorsProductiondatabaseStandbydatabaseOracleNetDelayedapplicationUsingEnterpriseManagertoDelay

theApplicationofRedoSpecifythedelayinminutes.SettingLOG_ARCHIVE_DEST_n

toDelaytheApplicationofRedoUsetheattributesofLOG_ARCHIVE_DEST_ntocontroltheapplicationofredo:DELAY:numberofminutestodelayapplicationofredo(default:30minutes)UsingFlashbackDatabase

InsteadofApplyDelayNodelay4-hourdelayStandby1Standby2Standby38-hourdelayStandbyPrimarydatabasePrimarydatabaseAdditionalAttributesThatAffect

RedoTransportServicesALTERNATEDEPENDENCYMAX_FAILURENET_TIMEOUTREOPENUsingtheALTERNATEAttributeCanspecifyonealternatedestinationfortheLOG_ARCHIVE_DEST_nparameterAllowafaileddestinationtochangedestinationsDiskfull:switchtonewdiskOracleNetlinkfails:switchtonewnetworklinkRequireREOPEN=0orMAX_FAILUREEnabledwithLOG_ARCHIVE_DEST_STATE_nlog_archive_dest_3='SERVICE=stby1_path1REOPEN=0ALTERNATE=LOG_ARCHIVE_DEST_4'log_archive_dest_4='SERVICE=stby1_path2REOPEN=0OPTIONAL'log_archive_dest_state_3=ENABLElog_archive_dest_state_4=ALTERNATEUsingtheMAX_FAILUREAttributeMAX_FAILURE[=count]NumberoftimesredotransportservicesattemptstoreestablishcommunicationRequiresREOPENNodefaultcountlog_archive_dest_3='SERVICE=o10g1LGWRMAX_FAILURE=30REOPEN'UsingtheNET_TIMEOUTAttributeEnablestheLGWRprocesstoavoidanetworktimeoutissueValidwithSYNCorASYNCdestinationsValuesuppliedisthenumberofsecondstowait.RangeofvaluesforNET_TIMEOUT:15to1200Default:180Usecautioninmaximumprotectionmode.log_archive_dest_2='SERVICE=o10g2LGWRSYNCNET_TIMEOUT=30'UsingtheREOPENAttributeREOPEN[=seconds]MinimumnumberofsecondstowaitbeforeretryingafaileddestinationatlogswitchFailurescanbenetworkfailures,quotaexceptions,diskfull,andsoon.Default:300seconds(5minutes)REOPEN=0Faileddestinationsremaindisableduntil:ManuallyreenabledALTERSYSTEMSETLOG_ARCHIVE_DEST_STATE_n=ENABLEissuedInstancerestartRequiredwhenusingALTERNATEdestinationswithMAX_FAILURE=0attributesOptimizedAsynchronousRedoTransmissionLGWRPrimarydatabasetransactionsOnlineredologsARC0FALRFSMRPorLSPArchivedredologs(MRPonly)ArchivedredologsARC1ARC2LNSnOracleNetReportsBackupStandbydatabaseEnablingMultipleConn