Recovery Manager Architecture.docx

Recovery Manager Architecture.docx

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RecoveryManagerArchitecture

RecoveryManagerArchitecture

ThischapterdescribestheRecoveryManager（RMAN）interfaceandthebasiccomponentsoftheRMANenvironment.

Thischaptercontainsthesetopics:

∙AbouttheRMANEnvironment

∙RMANCommandLineClient

∙RMANRepository

∙MediaManagement

AbouttheRMANEnvironment

RecoveryManager（RMAN）isaclientapplicationthatperformsbackupandrecoveryoperations.TheRecoveryManagerenvironmentconsistsofthevariousapplicationsanddatabasesthatplayaroleinabackupandrecoverystrategy.

Table 1-1listspossiblecomponentsoftheRMANenvironment.

Table1-1ComponentsoftheRMANEnvironment

Component

Description

Required?

Targetdatabase

Thecontrolfiles,datafiles,andoptionalarchivedredologsthatRMANisinchargeofbackinguporrestoring.RMANusesthetargetdatabasecontrolfiletogathermetadataaboutthetargetdatabaseandtostoreinformationaboutitsownoperations.Theworkofbackupandrecoveryisperformedbyserversessionsrunningonthetargetdatabase.

Yes

RMANclient

Theclientapplicationthatmanagesbackupandrecoveryoperationsforatargetdatabase.TheRMANclientcanuseOracleNettoconnecttoatargetdatabase,soitcanbelocatedonanyhostthatisconnectedtothetargethostthroughOracleNet.

Yes

Recoverycatalogdatabase

Adatabasecontainingtherecoverycatalogschema,whichcontainsthemetadatathatRMANusestoperformitsbackupandrecoveryoperations.

No

Recoverycatalogschema

TheuserwithintherecoverycatalogdatabasethatownsthemetadatatablesmaintainedbyRMAN.RMANperiodicallypropagatesmetadatafromthetargetdatabasecontrolfileintotherecoverycatalog.

No

Standbydatabase

Acopyoftheprimarydatabasethatisupdatedusingarchivedlogscreatedbytheprimarydatabase.RMANcancreateorbackupastandbydatabase.Youcanfailovertothestandbydatabaseiftheprimarydatabasegoesdown.

No

Duplicatedatabase

Acopyoftheprimarydatabasethatyoucanusefortestingpurposes.

No

Mediamanagementapplication

Avendor-specificapplicationthatallowsRMANtobackuptoastoragesystemsuchastape.

No

Mediamanagementcatalog

Avendor-specificrepositoryofinformationaboutamediamanagementapplication.

No

EnterpriseManager

Abrowser-basedinterfacetotheOracledatabase,includingbackupandrecoverythroughRMAN.

No

TheonlyrequiredcomponentsinanRMANenvironmentarethetargetdatabaseandtheRMANclient,butmostreal-worldconfigurationsaremorecomplicated.OnemightuseanRMANclientconnectingtomultiplemediamanagersandmultipletarget,recoverycatalog,andauxiliarydatabases,allaccessedthroughEnterpriseManager.

RMANSessionArchitecture

TheRMANclientapplicationdirectsdatabaseserversessionstoperformallbackupandrecoverytasks.Themeaningof"session"inthissensedependsontheoperatingsystem.Forexample,onUNIX,aserversessioncorrespondstoaserverprocess,whileonWindowsitcorrespondstoathreadwithinthedatabaseservice.

TheRMANclientitselfdoesnotperformbackup,restore,orrecoveryoperations.WhenyouconnecttheRMANclienttoatargetdatabase,RMANallocatesserversessionsonthetargetinstanceanddirectsthemtoperformtheoperations.TheRMANclientusesinternal,undocumentedPL/SQLpackagestocommunicatewiththetargetdatabaseandrecoverycatalog.

RMANCommandLineClient

UsetheRMANcommandlineclienttoentercommandsthatyoucanusetomanageallaspectsofbackupandrecoveryoperations.

EvenwhenyouusethebackupandrecoveryfeaturesinEnterpriseManagerthatarebuiltontopofRMAN,anRMANclientexecutesbehindthescenes.

Note:

AllRMANcommandsforOraclerelease8.1andhigheralsoworkinOracleDatabseRelease10g.

HowRMANCompilesandExecutesCommands

RMANprocessesmostcommandsinthetwophasesdiscussedinthissection:

CompilationPhase

Duringthecompilationphase,RMANdetermineswhichobjectsthecommandwillaccess（forexample,resolvingatablespacenameintoitscomponentdatafiles）.Then,RMANconstructsasequenceofremoteprocedurecalls（RPCs）thatinstructtheserversessionsonthetargetdatabasetoperformthedesiredoperation.

ExecutionPhase

Duringtheexecutionphase,RMANsendstheRPCcallstothetargetdatabase,monitorstheirprogress,andcollectstheresults.Ifmorethanonechannelisallocated,thenRMANcanexecutecertaincommandsinparallelsothatallofthechannels'targetdatabasesessionsareconcurrentlyexecutinganRPCcall.

IssuingRMANCommands

RMANusesacommandlanguageinterpreter（CLI）thatcanexecutecommandsininteractiveorbatchmode.

EnteringCommandsattheRMANPrompt

TorunRMANcommandsinteractively,startRMANandthentypecommandsintothecommand-lineinterface.Forexample,youcanstartRMANfromtheUNIXcommandshellandthenexecuteinteractivecommandsasfollows:

%rmanTARGETSYS/oracle@trgtCATALOGrman/cat@catdb

AftertheRMANpromptisdisplayed,youcanentercommandssuchasthefollowing:

RMAN>BACKUPDATABASE;

UsingRMANwithCommandFiles

AcommandfileisatextfilewhichcontainsRMANcommandsasyouwouldenterthematthecommandline.Youcanruntheacommandfilebyspecifyingitsnameonthecommandline.Thecontentsofthecommandfilewillbeinterpretedasifenteredatthecommandline.IftheLOGcommandlineargumentisspecified,RMANdirectsoutputtothenamedlogfile.Commandfilesareonewaytoautomatescheduledbackupsthroughanoperatingsystemjobcontrolfacility.

Inthisexample,asampleRMANscriptisplacedintoacommandfilecalledcommandfile.rcv.Youcanrunthisfilefromtheoperatingsystemcommandlineandwritetheoutputintothelogfileoutfile.txtasfollows:

%rmanTARGET/CATALOGrman/cat@catdbCMDFILEcommandfile.rcvLOGoutfile.txt

SeeAlso:

OracleDatabaseRecoveryManagerReferenceformoreinformationaboutRMANcommandlineoptions

StoredScripts

AstoredscriptisablockofRMANjobcommandsthatisstoredintherecoverycatalog.Bystoringscriptsintherecoverycatalog,thescriptisavailabletoanyRMANclientthatconnectstothecatalogandthetargetdatabase.Storedscriptscanbeassociatedwithasingledatabaseinthecatalog,ortheycanbeglobalstoredscripts,whichcanbeexecutedagainstanytargetdatabaseinthecatalog.

SeeAlso:

"WorkingwithRMANStoredScriptsintheRecoveryCatalog"formoreonstoredscripts.Alsorefertothesamplescriptsinthe?

/rdbms/demodirectory.

CommandsValidOnlyinRUNBlocks

ThereareRMANcommandswhichareonlyvalidinRUNblocks.ThesetypicallyinvolvesettinguptheenvironmentwithinwhichthestatementsintheRUNblockwillexecute.TypicalofthisgroupareALLOCATECHANNELandSETNEWNAMEFORDATAFILE.UsingthesecommandsoutsideofaRUNblockwillgenerateanerror.

SeeAlso:

ThesyntaxdiagramsfortheRUNcommandinOracleDatabaseRecoveryManagerReferenceregardingwhichcommandsarevalidinRUNblocks

CommandsNotValidinRUNBlocks

ThereareanumberofRMANcommandswhichcannotbeusedinRUNblocks.TypicallytheseareusedtocontroltheRMANenvironment（connectingtodifferentdatabases,orconfiguringRMANdefaults）,ortomanageorquerytherecoverycatalog（includingcreatingandusingstoredscripts）.Herearesomeexamples:

∙CONNECT

∙CONFIGURE

∙CREATECATALOG,DROPCATALOG,UPGRADECATALOG

∙CREATESCRIPT,DELETESCRIPT,REPLACESCRIPT

∙LIST

∙REPORT

Youcanincludethesecommandsinsidecommandfiles,aslongastheyarenotwrappedinsideaRUNblock.Youcannotusetheminsideastoredscriptfromtherecoverycatalog,becausethecontentsofastoredscriptareexecutedwithinaRUNblock.

SeeAlso:

ThesyntaxdiagramsfortheRUNcommandinOracleDatabaseRecoveryManagerReferenceregardingwhichcommandsarevalidinRUNblocks

ControllingRMANOutput

WhenyourunRMANincommandlinemode,itsendstheoutputtotheterminal.IfyouspecifytheLOGoption,thenRMANwritestheoutputtoaspecifiedlogfileinstead.

OutputforcurrentlyexecutingRMANjobsisalsostoredintheV$RMAN_OUTPUTview,whichreadsonlyfrommemory（thatis,theinformationisnotstoredinthecontrolfile）.TheV$RMAN_STATUSviewstoresmetadataaboutjobsinprogressaswellascompletedjobs.Themetadataforcompletedjobsisstoredinthecontrolfile.

RMANPipeInterface

TheRMANpipeinterfaceisanalternativemethodforissuingcommandstoRMANandreceivingtheoutputfromthosecommands.Withthisinterface,RMANobtainscommandsandsendsoutputbyusingtheDBMS_PIPEPL/SQLpackage.RMANdoesnotreadorwriteanydatausingtheoperatingsystemshell.Byusingthisinterface,itispossibletowriteaportableprogrammaticinterfacetoRMAN.

ThepipeinterfaceisinvokedbyusingthePIPEcommand-lineparameter.RMANusestwoprivatepipes:

oneforreceivingcommandsandtheotherforsendingoutput.ThenamesofthepipesarederivedfromthevalueofthePIPEparameter.Forexample,youcaninvokeRMANwiththefollowingcommand:

%rmanPIPEabcTARGETSYS/oracle@trgt

RMANopensthetwopipesinthetargetdatabase:

ORA$RMAN_ABC_IN,whichRMANusestoreceiveusercommands,andORA$RMAN_ABC_OUT,whichRMANusestosendalloutputbacktoRMAN.

AllmessagesonboththeinputandoutputpipesareoftypeVARCHAR2.

NotethatRMANdoesnotpermitthepipeinterfacetobeusedwithpublicpipes,becausetheyareapotentialsecurityproblem.Withapublicpipe,anyuserwhoknowsthenameofthepipecansendcommandstoRMANandinterceptitsoutput.

SeeAlso:

"ExecutingRMANCommandsThroughaPipe"tolearnhowtoexecuteRMANcommandsthroughapipe

RMANRepository

TheRMANrepositoryis