array本地负载均衡详细技术介绍课件

TMXTechnicalTrainingServerLoadBalancing2023/8/8TMXTechnicalTrainingServerLObjectivesTounderstandServerLoadBalancingconcepts.TounderstandArrayServerLoadBalancingconfigurationsteps.2023/8/82ObjectivesTounderstandServerTopicsUnit1:BasicServerLoadBalancingConceptsandConfigurationUnit2:AdditionalServerLoadBalancingConceptsandConfigurationAppendix:WebConcepts2023/8/83TopicsUnit1:BasicServerLoaUnit1:BasicSLBConceptsWhatisServerLoadBalancing?SLBTerminologyArraySLBBenefitsSLBModesRealServicesSimpleGroupMethodsVirtualServicesSimplePolicyTypes2023/8/84Unit1:BasicSLBConceptsWhatWhatisLoadBalancing?It’sineverywhereactually!!!EmergencyClinicExpertClinicLoadBalancingAFEConnectionReuseSLB:PolicySLB:Method2023/8/85WhatisLoadBalancing?It’siWhatisServerLoadBalancing(SLB)?SLBallowswebsitestobescaledfromasingleservicetoagroupofservices(servicefarm)whiledistributingtheloadbetweentheservicesbasedontheirloadandhealth.SLBBenefitsGreaterscalabilityinthenumberofservicesforasitereducesloadonindividualservicesandimprovesresponsetimetoclientsImprovedresiliencythroughHealthCheckingofservices,services,andwebcontentBettercontrolofserviceresourceusagethroughimplementationofdifferentloadbalancingalgorithmsTrafficmanagementbasedonTCP/UDPportnumber,URL,HTTPHostHeader,Cookiecontent,orSSLSessionID2023/8/86WhatisServerLoadBalancingSLBTerminologyRealService(“Real”)RepresentsaphysicalservicewhichwillhandleclientrequestsRealServiceGroup(“Group”)RepresentsagroupofrealserviceswhichtrafficwillbedistributedtoDefineswhichloadbalancingalgorithmtouseVirtualService(“Virtual”)RepresentsavirtualservicethatclientscanconnecttoPolicyAssociatesrealservicegroupswithvirtualservicesservice1service5service4service3service2Real1Real3Real4Real5Real2Group1Group2Virtual1Virtual2Internet2023/8/87SLBTerminologyRealService(“ServerLoadBalancingExampleBasicServerLoadbalancingInternetServiceGroupRealservicesVirtualIP012345Userentersintheirbrowser.HostnamesenttoDNSforresolution.1DNSresolvestotheVirtualIPaddress(VIP)of0.2ClientsendsrequesttoVIP.3Arrayproxiesrequesttoselectedrealservice.4Furtherrequestsfromtheclientmaybesenttothesameoradifferentrealservice,dependingonpersistencyconfiguration.5DNS2023/8/88ServerLoadBalancingExampleBSLBModesServerLoadBalancingcanbeperformedintwomodes:ReverseProxyModeArrayTMproxiesallclientconnectionstorealservices.TransparentModeArrayTMtransparentlyproxiesallclientconnectionstorealservices.2023/8/89SLBModesServerLoadBalancingReverseProxyModePacketFlowClientconnectstoVIPonArrayTMandsendsrequesttoArrayTM.ArrayTMopensanewconnectiontorealserviceandsendsrequesttoservice.servicerespondstoArrayTM.ArrayTMrespondstoClient.VirtualInternetservice1service2InsideInterfaceOutsideInterface12342023/8/810ReverseProxyModePacketFlowVReverseProxyModeTranslationsVirtualInternetservice1service2InsideInterfaceOutsideInterface1234StepSourceIPSourcePortDestinationIPDestinationPort1Client-IPClient-PortVirtual-IPVirtual-Port2Inside-IPInside-PortReal-IPReal-Port3Real-IPReal-PortInside-IPInside-Port4Virtual-IPVirtual-PortClient-IPClient-Port2023/8/811ReverseProxyModeTranslationsReverseProxyModeBenefitsOne-armedtopologyispossible.ResponsesautomaticallyreturntotheArrayTM.Enablesconnectionpoolingforincreasedperformance.Limitationsservicelogsdonotshowrealclient’sIPaddress(connectionsproxied).Solution:EnablingX-Forwarded-Forheaderinsertionallowsclient’soriginalsourceIPaddresstobeinsertedintoHTTPrequestsbeforesendingtobackendrealservice.2023/8/812ReverseProxyModeBenefits2023ConnectionPoolingProvidesTCPaccelerationforbackendconnectionstorealservices.Arrayopensconnection(s)tobackendserviceasneededandleavesit(them)open.Arraysendsmultiplerequestsfromdifferentclientsthroughthesamebackendserviceconnection(s).Thissignificantlyreducesthenumberofclientconnectionsaservicehastohandle(typicallybyupto90%withcacheoff).Improvesserviceperformance.servicedoesn’tspendasmuchtimeperformingTCPsetups/teardowns.servicedoesn’tneedtokeepsomanyconnectionsopen.OnlypossiblewithReverseProxyMode.2023/8/813ConnectionPoolingProvidesTCPTransparentModePacketFlowClientsendsrequesttoVIPonArrayTM.ArrayTMforwardsrequesttorealservice,maintainingtheclient’sIP.RealservicereturnsresponseviaclientIP(handledbyArrayTM).ArrayTMforwardsresponsetoClient.VirtualIPInternetservice1service22354612023/8/814TransparentModePacketFlowVirTransparentModeTranslationsVirtualIPInternetservice1service2235461StepSourceIPSourcePortDestinationIPDestinationPort1Client-IPClient-PortVirtual-IPVirtual-Port23Client-IPClient-PortReal-IPReal-Port4Real-IPReal-PortClient-IPClient-Port56Virtual-IPVirtual-PortClient-IPClient-Port2023/8/815TransparentModeTranslationsViTransparentModeBenefitsservicelogswillshowactualclientIPaddress.LimitationsRealserviceresponsesmustberoutedthroughtheArrayTMX.EnsuresthattheArrayTMXcanseetheresponses.One-armedtopologyisnotalwayspossible.Cannotuseconnectionpoolingfeature.ArrayTMXcannotreusethesameserviceconnectionformultipleclientssinceeachclient’sIPaddressisdifferent.Reverseproxymodeispreferredforperformancebenefits.2023/8/816TransparentModeBenefits2023/8SLBRealServicesThefollowingparametersareassociatedwitharealservice:Realserviceprotocol(udp,tcp,ftp,http;tcpsandhttpsforSSL)RealservicenameRealserviceIPaddressRealserviceportHealthcheckmethodHealthcheckupHealthcheckdown2023/8/817SLBRealServicesThefollowingSLBGroupMethodsAgroupallowsrequeststobesenttoasetofsimilarservices.Example:3webservicescontainingthesamecontent.Agroupmethoddetermineswhichservicestosendrequeststo.Non-PersistentGroupMethodsEachnewclientconnectionmaybedistributedtoadifferentrealservicewithinagroup.PersistentGroupMethodsAllnewconnectionsfromaparticularclientaresenttothesamerealservicewithinagroup.Note:Realservicesthataredownwillnotbeused.RealbRealcRealaGroup2023/8/818SLBGroupMethodsAgroupallowSLBGroupMethodsNon-PersistentGroupMethodsRoundRobin(rr)LeastConnections(lc)FastestResponsetime(frt)PersistentGroupMethodsIP-BasedPersistentIP(pi)HashIP(hi)ConsistentHashIP(chi)Header/Request-BasedHashHeader(hh)PersistentHostname(ph)PersistentURL(pu)SSLSessionID(sslsid)Cookie-BasedPersistentCookie(pc)Re-writeCookie(rc)InsertCookie(ic)HashCookie(hc)Proximity2023/8/819SLBGroupMethodsNon-PersistenNon-PersistentGroupMethodsRoundRobin(rr)LeastConnections(lc)FastestResponsetime(frt)2023/8/820Non-PersistentGroupMethodsRoRoundRobin(rr)Distributesnewconnectionssequentiallybetweenavailablerealservices.Example:Connectionsaredistributedtotherealservicesinthefollowingorder:1,2,3,4,5,1,2,3The“granularity”optionmaybeconfiguredsothateachrealservicehandlesaspecificnumberofnewconnectionsbeforethenextserviceisselected.Example:Granularityvalueof“3”illustratesthedistribution:1,1,1,2,2,2,3,3,3,etc.Internet2023/8/821RoundRobin(rr)DistributesneRoundRobinClientsRouterTMXServersClientrequestsaredistributedevenly12345678InternetRoundRobin(rr)2023/8/822RoundRobinClientsRouterTMXSerLeastConnections(lc)Distributesnewconnectionstotherealservicethathastheleastnumberofcurrentconnections.Example:realservice5hasthefewestcurrentconnections,sothenextconnectionwillgotorealservice5.The“granularity”optioncanbeusedtotreatrealserviceswithinthesameconnectioncountrangeasthesame;anewrealservicewillnotbechosenuntilthisrangeisexceededforthecurrentone.Internet2023/8/823LeastConnections(lc)DistribuClientsRouterServers12InternetDistributesnewconnectionstotherealservicethathastheleastnumberofcurrentconnections.462460455465CurrentConnectionsLeastConnections(lc)2023/8/824ClientsRouterServers12InternetRealServiceWeighting(rr,lc)Weightingallowsyoutochangethedistributionbetweenrealservicesinthegroup.Example:Youmaysetoneservicetohandletwiceasmanyconnectionsasanotherservice.Useweightingifyouhaveamixofbackendserviceswithdifferentperformancecapabilities.Example:IfyouaddnewservicesthathavefasterCPUs,youcouldweightthemhighersotheyreceivemoreconnections.Internet2023/8/825RealServiceWeighting(rr,lcClientsRouterServersAdministratorsetsratiofordistributingClientrequests3:1:1:1123478910Internet561112RealServiceWeighting(rr,lc)TMX2023/8/826ClientsRouterServersAdministraClientsRouterServers12Internet10ms5ms20ms17msCurrentResponseTimesFastestResponsetime(frt)Distributesnewconnectionstotherealservicethathastheshortestresponsetime.2023/8/827ClientsRouterServers12InternetProximityThismethodisbasedonGSLBproximityinfoandusedbyredirectpolicyonly.ItselecttherealserverwhichhaslowestproximitydistancewiththerequestIP.slbgroupmethod<group_name>prox[rr|sr|lc][threshold]2023/8/828ProximityThismethodisbasedPersistentConceptthenextrequestfromsameclientshouldbeassignedtothesameserver.1231232023/8/829PersistentConceptthenextreqPersistentGroupMethodsIP-BasedPersistentIP(pi)HashIP(hi)ConsistentHashIP(chi)Header/Request-BasedHashHeader(hh)PersistentHostname(ph)PersistentURL(pu)SSLSessionID(sslsid)Cookie-BasedPersistentCookie(pc)Re-writeCookie(rc)InsertCookie(ic)HashCookie(hc)2023/8/830PersistentGroupMethodsIP-BasPersistentIP(pi)PersistentIPsendsallsuccessiveconnectionsfromaclientIPaddress(destinedtoaparticularvirtualservice)tothesamerealservice.Clientsendsarequesttothevirtualservice.ArrayhashessourceIPaddressofrequesttoselectarealservice.ArrayforwardsallrequestswiththesameIPaddresstothesamerealservice.NoteIfarealservicefails,persistencewillbemaintainedforexistingclientsonhealthyservices.TherealservicetouseforaspecificclientIPischosenwhenthefirstrequestfromthatclientIPisreceived,sothismaynotresultinthesamerealservicebeingchosenacrossdifferentArraysonfailover.2023/8/831PersistentIP(pi)PersistentIPersistentIP(pi)Scenario1ClientopensanHTTPconnectiontogetanHTMLpageClientconnectionissenttofirstrealserviceHTMLpagehaslinkstomultipleimagesinit,soclientopensadditionalHTTPconnectionstogettheimagesPersistentIPwillsendtheadditionalconnectionstothesamerealservice2023/8/832PersistentIP(pi)Scenario120PersistentIP(pi)Scenario2ClientopensHTTP(clear-text)connectiontovirtualserviceClientaddsitemstoelectronicshoppingcartWhenreadytopurchaseitems,clientopensHTTPS(encrypted)connectiontovirtualservicePersistentIPwillsendtheHTTPSconnectiontothesamerealserviceastheHTTPconnection(whereclient’sshoppingcartresides)Note:Notthebestsolutionformaintainingshoppingcartpersistence.SeeCookiePersistence(later).2023/8/833PersistentIP(pi)Scenario220thesameIPrequestshouldbeassignedtothesameserver.123123PersistentIP(pi)2023/8/834thesameIPrequestshouldbeHashIP(hi)DistributesnewconnectionstoarealservicebasedonahashofthesourceIPaddress.Clientsendsarequesttothevirtualservice.ArrayhashessourceIPaddressofrequesttoselectarealservice.Arrayforwardsallrequestswithsamehashvaluetothesamerealservice.NoteIfarealservicefails,persistencewillnotbemaintainedforexistingclientsonhealthyservices.ConsistentmappingsofclientIPtorealserviceacrossmultipleArraysduringfailoverisnotguaranteed.2023/8/835HashIP(hi)DistributesnewcoConsistentHashIP(chi)DistributesnewconnectionstoarealservicebasedonahashofthesourceIPaddress.Clientsendsarequesttothevirtualservice.ArrayhashessourceIPaddressofrequesttoselectarealservice.Arrayforwardsallrequestswithsamehashvaluetothesamerealservice.NoteIfarealservicefails,persistencewill

bemaintainedforexistingclientsonhealthyservices.MappingsofclientIPtorealserviceareconsistentacrossallArrayssothatclientswillcontinuetogotothesamerealserviceonfailover.2023/8/836ConsistentHashIP(chi)DistriHashHeader(hh)Distributesnewconnectionstoarealservicebasedonahashofanon-standardHTTPHeaderNon-standardheader=headersnotdefinedinRFC2616(HTTP/1.1)Example:X-MSISDNheadergeneratedbyWAPgatewaysAllwirelessclients(mobilephones)proxiedthroughaWAPgatewayhavethesamesourceIPaddress.Problemforclient-IPpersistencemethods!Optionsincludecookie-persistenceandHashHeadermethods.WAPgatewaycanreceiveMSISDN(phonenumber)ofuserfromRadiusandinsertitintoproxiedHTTPrequestasX-MSISDNheader.HashHeaderonthisheaderprovidesgoodloaddistributionacrosstherealserviceswhilemaintainingclientpersistence.2023/8/837HashHeader(hh)DistributesnePersistentHostname(ph)DistributesnewconnectionstoarealservicebasedonahashofthehostnamefoundintheHTTPrequest’sHostheadersentfromtheclient.ClientsendsarequesttothevirtualservicewithaHost:header.ArrayexaminesHost:headervaluetoselectarealservice.ArrayforwardsallrequestswithsameHost:headervaluetothesamerealservice.2023/8/838PersistentHostname(ph)DistriPersistentURL(pu)DistributesnewconnectionstoarealservicebasedonastaticmatchofaURLTagandValue.ClientsendsarequesttothevirtualservicewithaTagandValueincludedintheURL.ArrayhashesValuetoselectarealservice.ArrayforwardsallrequestswithsameTagandValuetothesamerealservice.2023/8/839PersistentURL(pu)DistributesSSLSessionID(sslsid)SSLSessionID(negotiatedduringSSLconnectionsetup)isusedtomaintainaclient-to-servicebinding.ClientopensanHTTPSconnectiontothevirtualservice.Arrayselectsarealserviceandforwardsrequesttoit.ResponsefromrealservicecontainsanSSLSessionID.ArraytracksSSLSIDandrealservicecombination.NextrequestfromclientcontainsSSLSID.ArrayexaminesSSLSIDandsendsrequesttothesamerealservicethatwaschosenearlier.MayonlybeusedwhenloadbalancingSSLconnections.2023/8/840SSLSessionID(sslsid)SSLSesInsertCookie(ic)ArrayautomaticallyinsertsaCookieintheserviceresponseClientsendsarequesttothevirtualservice.Arrayselectsarealserviceandforwardsrequesttoit.Responsefromrealservicedoesnotcontainacookie,butcookiepersistenceisneeded.Arraycreatesacookiebasedontherealserviceandinsertsitintheresponse.Clientreceivescookieinresponse.Nextrequestfromclientincludescookie.Arrayexaminescookie,stripsoutcookie,andsendsrequesttosamerealserviceasfirstrequest.Usedincaseswherethewebsitedoesnothavebuilt-incookiesupport.2023/8/841InsertCookie(ic)ArrayautomaClientServerHTTPrequest(nocookie)TCPhandshakeTCPhandshakeHTTPrequest(nocookie)HTTPreply(nocookie)HTTPreply(withinsertedcookie)pick

serverHTTPrequest(withsamecookie)TCPhandshakeTCPhandshakeHTTPrequest(nocookie)HTTPreply(nocookie)HTTPreply(updatedcookie)cookie

specifies

serverFirstHitSecondHitTMXInsertCookie(ic)2023/8/842ClientServerHTTPrequest(nocRewriteCookie(rc)Arrayrewrites(modifies)anamedcookie’svalueintheserviceresponse.Clientsendsarequesttothevirtualservice.Arrayselectsarealserviceandforwardsrequesttoit.Responsefromrealservicecontainsaspecificcookiewithagenericvalue.Arrayrewritescookievaluebasedontherealservice.Clientreceivescookieinresponse.Nextrequestfromclientincludescookie.Arrayexaminescookieandsendsrequesttoindicatedrealservice.Usedtosimplifycookiebasedpersistenceconfiguration.Allbackendserviceswithinagroupmustsetthesamename=valuepair.2023/8/843RewriteCookie(rc)ArrayrewriClientServerHTTPrequest(nocookie)TCPhandshakeTCPhandshakeHTTPrequest(nocookie)HTTPreply(withblankcookie)HTTPreply(withrewrittencookie)pick

serverHTTPrequest(withsamecookie)TCPhandshakeTCPhandshakeHTTPrequest(withsamecookie)HTTPreply(withblankcookie)HTTPreply(withupdatedcookie)cookie

specifies

serverFirstHitSecondHitTMXRewriteCookie(rc)2023/8/844ClientServerHTTPrequest(nocPersistentCookie(pc)Realserviceisselectedbasedonastaticmatchofthecookiename/valuepair.Clientsendsarequesttothevirtualservice.Arrayselectsarealserviceandforwardsrequesttoit.Responsefromrealservicecontainsaspecificcookiewithavaluedenotingthatservice.Clientreceivescookieinresponse.Nextrequestfromclientincludescookie.Arrayexaminescookieandsendsrequesttoproperrealservice.Eachrealservicewithinagroupmustbeconfiguredwithauniquecookievalue.2023/8/845PersistentCookie(pc)RealserClientServerHTTPrequest(nocookie)TCPhandshakeTCPhandshakeHTTPrequest(nocookie)HTTPreply(withspecialcookie)HTTPreply(withspecialcookie)pick

serverHTTPrequest(withsamecookie)TCPhandshakeTCPhandshakeHTTPrequest(withsamecookie)HTTPreply(withspecialcookie)HTTPreply(withspecialcookie)cookie

specifies

serverFirstHitSecondHitTMXPersistentCookie(pc)2023/8/846ClientServerHTTPrequest(nocHashCookie(hc)Realserviceselectionisbasedonahashofthespecifiedcookie’svalue.Usedwheneachclientbrowsersessiontothewebsiteresultsinauniquecookievalueforthatbrowsersession.2023/8/847HashCookie(hc)RealservicesClientServerHTTPrequest(nocookie)TCPhandshakeTCPhandshakeHTTPrequest(nocookie)HTTPreply(withcookie)HTTPreply(withcookie)pick

serverHTTPrequest(withsamecookie)TCPhandshakeTCPhandshakeHTTPrequest(withsamecookie)HTTPreply(withcookie)HTTPreply(withcookie)cookie

hashspecifies

serverFirstHitSecondHitThirdHitServerTCPhandshakeHTTPrequest(withsamecookie)HTTPreply(withcookie)cookie

hashspecifies

serverTCPhandshakeHTTPrequest(withsamecookie)HTTPreply(withcookie)TMXHashCookie(hc)2023/8/848ClientServerHTTPrequest(nocSLBVirtualServicesThefollowingparametersareassociatedwithavirtualservice:Virtualserviceprotocol(udp,tcp,ftp,http;tcpsandhttpsforSSL)VirtualservicenameVirtualserviceIPaddressVirtualserviceport2023/8/849SLBVirtualServicesThefollowSLBPolicySLBPolicyPolicyMatchingPolicyPrecedencePolicyTypes2023/8/850SLBPolicySLBPolicy2023/8/150SLBPolicyApolicydefinestherulesformatchingclientrequestsonavirtualservicetoaspecificgrouporrealservice.VirtualservicesmayhavemultiplepoliciesassignedtothemallowinghierarchicalL7loadbalancing.Policieshaveprecedencelevelstoresolveconflictsifaclientrequestmatchesmorethanonepolicyofthesametype.PolicyRealbRealcRealaGroupVirtualService2023/8/851SLBPolicyApolicydefinesthevirtualserver

:80Group1Groupmember(server=:80)Intelligent

TrafficControl

(lookatURL,clientIP.Cookie,HostnameHeader、regex、etc.)IncomingrequestLoadBalancingpolicyGroup2Groupmember(server=:80)Groupmember(server=:80)Groupmember(server=:80)Groupmember(server=:80)Groupmember(server=:80)SLBPolicyVirtualservicesmayhavemultiplepoliciesassignedtothemallowinghierarchicalL7loadbalancing.2023/8/852virtualserver

:80GPolicyTypesBasicPolicyTypesStaticDefaultBackupRedirectPersistentPolicyTypesPersistentURLPersistentCookieRewriteCookieInsertCookieHeaderQoSPolicyTypesQoSCookieQoSHostnameQoSURLQoSNetworkRegularExpressionHeader2023/8/853PolicyTypesBasicPolicyTypesBasicPolicyTypesBasicpolicieshandlesimpleornon-persistentclientconnections.Policytypesinclude:StaticDefaultBackup2023/8/854BasicPolicyTypesBasicpoliciStaticSendsallconnectionstoasinglerealservice.One-to-onemappingbetweenavirtualserviceandarealservice.Doesnotrequireagroupbindingordefaultpolicy.Multiplevirtualservicescanbeboundtothesamerealserviceusingstaticpolicies.virtualserver

:80Realserver:80IncomingrequestOne-to-onemappingStaticPolicyExample:2023/8/855StaticSendsallconnectionstoDefaultDefaultpolicyappliesifthereisnomatchingL7policy.Shouldalwayshaveatleastadefaultpolicy.RespondwitherrorifallrealservicesingrouparedownError503ServiceUnavailable.Canbeusedwiththefollowinggrouptypes:Roundrobin,Leastconnections,PersistentIP,Persistenthostname,Hashheader,Insertcookie,Rewritecookie,Hashcookievirtualserver

:80GroupGroupmember(server=:80)Groupmember(server=:80)Groupmember(server=:80)IncomingrequestDefaultPolicyLoadBalancingExample:2023/8/856DefaultDefaultpolicyappliesBackupBackuppolicymatchesonlyiftherewasatleastonesuccessfulmatchinapriorpolicy,butallrealservicesinallmatchedgroupsweredownorunavailable.Iftherewerenomatches,oriftherewasamatchbutthemethodfailedtoresolvedespitetherebeingrealservicesavailable,thenthebackuppolicywillnotbeused.Canbeusedwiththefollowinggrouptypes:Roundrobin,Leastconnections,PersistentIP,Persistenthostname,Hashheader,Insertcookie,Rewritecookie,Hashcookievirtualserver

:80Group1Groupmember:80IncomingrequestDefaultPolicyLoadBalancingGroup2BackupPolicyGroupmember:80Groupmember:80Groupmember:80Groupmember:80Groupmember:80IfGroup1serviceweredownorunavailable,Group2servicewillupExample:2023/8/857BackupBackuppolicymatchesonPersistentPolicyTypesAllconnectionsfromaparticularclientaresenttothesamerealservice.PersistentPolicytypesinclude:PersistentURLPersistentCookieRewriteCookieInsertCookie2023/8/858PersistentPolicyTypesAllconPersistentURLSendsclientrequestswhichmatchaspecificstringintheURLoftheformTag=Valuetoaspecificservice.VirtualservicemustbeboundtoaPersistentURL(pu)group.Defaultpolicyisrecommended.NeededincasethereisnoURLmatch.2023/8/859PersistentURLSendsclientreqPersistentCookieSendsclientrequestswhichcontainaspecificcookienametoaservicebasedonthecookievalue(issuedbyservice).OnClient’sfirstrequest,serviceissuesacookiewithavaluespecifictothatservice.Example:Realweb1:SID=service1Realweb2:SID=service2Realweb3:SID=service3ClientsendscookieandvaluewithnextrequesttoVirtual.Arraysendsrequesttoservicewithmatchingcookievalue.VirtualservicemustbeboundtoaPersistentCookie(pc)group.Defaultpolicyisrequired.Neededincasethereisnocookiematch,soitcansetone.2023/8/860PersistentCookieSendsclientRewriteCookie(rcookie)Sendsclientrequestswhichcontainaspecificcookienametoaservicebasedonthecookievalue(modifiedbyArray).Allservicesinagroupissuesamecookienameandvalue.ArrayTMrewritescookievaluetoincludeanIDfortherealservicethattheresponsecamefrom.Futureclientrequestscontainingcookiearesentbacktosameservice.VirtualservicemustbeboundtoaRewriteCookie(rc)group.Defaultpolicyisrequired.Neededincasethereisnocookiematch,soitcansetone.2023/8/861RewriteCookie(rcookie)SendsInsertCookie(icookie)Sendsclientrequestswhichcontainaspecificcookienametoaservicebasedonthecookievalue(issuedbyArray).servicesdonotusecookies.ArrayTMinsertscookienameandvaluetodenotethatrealservicethattheresponsecamefrom.Futureclientrequestscontainingcookiearesentbacktosameservice.VirtualservicemustbeboundtoanInsertCookie(ic)group.Defaultpolicypointingtothesamegroupisrequired.Neededincasethereisnocookiematch.2023/8/862InsertCookie(icookie)SendscQoSPolicyTypesAllconnectionsfromaparticularclientaresenttothesamegroupofrealservices.QoSPolicytypesinclude:QoSCookieQoSHostnameQoSURLQoSNetworkRegularExpression(Regex)Header2023/8/863QoSPolicyTypesAllconnectionQoSCookieProvidespersistencetoagroupofservicesbasedonacookienameandvaluepair.Allowsservicegroupdifferentiationbasedoncookievalue.Example:Sendclientswith“Gold”cookiestogroupwithfasterservices(payingcustomers)Sendclientswith“Silver”cookiestogroupwithslowerservices(non-payingcustomers)Itisnotrecommendedtoassociategroupsofmethodpcorhcusingthispolicybecausethiswillresultintheselectionofthesamerealserviceeachtime.virtualserver

:80Group1Groupmember:80IncomingrequestQoSCookiePolicyLoadBalancingGroup2QoSCookiePolicyGroupmember:80Groupmember:80Groupmember:80Groupmember:80Groupmember:80Cookie=GoldCookie=SilverExample:2023/8/864QoSCookieProvidespersistenceQoSHostnamePersistencetoagroupbasedonthehostnamefoundintheclientHTTPrequestHostheader.Ifyourrealservicesaresetuptoacceptrequestsformultipledomains(virtualhosting),youcansetupthismetrictomakehostnamebasedbalancingdecisions.Example:DNSresolvestheseFQDN’stosamevirtualsiteSendclientsrequesting“”and“”togroupASendclientsrequesting“”and“”togroupBvirtualserver

:80GroupAGroupmember:80IncomingrequestQoShostnamePolicyLoadBalancingGroupBQoShostnamePolicyGroupmember:80Groupmember:80Groupmember:80Groupmember:80Groupmember:80hostname=hostname=Example:2023/8/865QoSHostnamePersistencetoagQoSURLPersistencetoagroupbasedonaURLsub-st