AX-Training-2.7v2.0-S_07-High_Availability

1HighAvailability(HA)Section72SectionobjectivesDiscussHighAvailabilityanditsoptionsActive-StandbymodeActive-ActivemodeConfigureActive-StandbyHA3Active-StandbymodeActiveAXprocessesalltheproductiontrafficStandbyAXdoesnotprocessanyproductiontrafficStandbyAXmirrorsallL4sessioninformationfromActiveAXReliabilityisscaledbutnotperformance4Active-StandbyFailoverPeerAXelectedasactiveGratuitousARPsforvirtual,floatingandNATIPsaresentExistingmirroredsessionsarepickedupbynewlyelectedactiveAXNewsessionsareservedbynewlyelectedactiveAX5Active-ActivemodeBothAXunitsprocesstheproductiontrafficSessionandstateinformationismirroredbetweenbothAXunitsPerformanceisscaledinadditiontoreliabilityNote:Donotexceed50%utilizationoneachunitforfullHA6Active-ActiveFailoverPeerAXiselectedactiveforHAgroup2andsendsgratuitousARPsforvirtualIPs,floatingIPs,andNATIPsExistingmirroredsessionsarepickedupbypeerAXPeerAXservesrequestsforbothHAgroups9HAsupportAllAXintegrationmodessupportHARoutedmodeActive-Standby,Active-ActiveOne-ArmmodeActive-Standby,Active-ActiveTransparentmodeL2Active-StandbyDSRmodeActive-Standby,Active-Active10InitialselectionofActiveAXAfterinitialselection,AXremainsActiveunless:StandbyAXstopsreceivingHAheartbeatfromActiveAXHAinterfacestatusoftheActiveAXbecomeslowerthanStandbyAX’sVLAN-basedfailoveristriggeredGateway-basedfailoveristriggeredHApre-emptionisenabled,andtheconfiguredHApriorityischangedtobehigherontheStandbyAX11EventscausingHAFailoverBydefault,afailoveroccursonlyinthefollowingcases:StandbyAXstopsreceivingHAheartbeatformActiveAXHAinterfacestatechangesgivetheStandbyAXdeviceabetterHAstatethantheActiveAXdeviceVLAN-basedfailoverisconfiguredandtheVLANbecomesinactive.Gateway-basedfailoverisconfiguredandthegatewaybecomesunavailable.VIP-basedfailoverisconfiguredandtheunavailabilityofrealserverscausestheStandbyAXtohavethegreaterHApriorityfortheVIP’sHAgroupBydefault,failoverdoesnotoccurduetoHAconfigurationchangestotheHApriority.ToenabletheAXdevicestofailoverinresponsetochangesinpriority,enableHApre-emption.12Active-Standbyconfiguration(p.1of2)ConfigureHAGlobalsettingsIdentifier(AX1=1,AX2=2)HAStatus:Enabled(optional)HAMirroringIPaddress:RemoteAXSyncinterface(optional)Preempt:tofailovertoahigherAXwhenavailableGroup1withpriority200onAX1(priority100onAX2)FloatingVIPforGroup1:IPaddressesdefinedonservers'gateway(VRRP-like)(optional)IPandVLANcheck(Note:IPshavetobedefinedasSLB-Servertoo)ConfigureHAinterfacesAllinterfacesusedwithproductiontraffic(+AXinterlinkifexists)Note:WerecommendadedicateddirectinterlinkbetweentheAXsosynctrafficisofftheproductionnetwork13Active-Standbyconfiguration(p.2of2)ConfigureNATpoolHAsettingsInIPSourceNAT,associatetheHAGroupwithIPv4Pools,IPv6Pools,NATRanges,orStaticNATConfigureVIPHAsettingsInVIPsettings,associateHAGroupwiththeVIP(optional)EnableDynamicServerWeight:ReducetheAXHAGroupprioritywhenaserverisdown(optional)EnableHAConnectionMirroringontheVIPports:TosynchronizeSLBsessiontable(availableforTCP,UDP,RTSP,FTP,MMSandSIPVIPtypes)Note:ForHTTP/HTTPSVIPtypes,theclientsessionisterminatedontheAXdevice.HAConnectionMirroringisnotavailablefortheseVIPtypes.14Active-ActiveconfigurationSameasActive-StandbywithtwogroupsdefinedStep2:Group1withpriority200onAX1(priority100onAX2)Group2withpriority100onAX1(priority200onAX2)Step3:AssociateGroup1withhalfoftheVIPsandGroup2withthesecondhalfStep4:AssociateGroup1withtheNATPoolsusedbyVIPsinGroup1andGroup2withtheNATPoolsusedbyVIPsinGroup215LabConfigureHAActive/Standbymodewithyourneighbor16SectionsummaryWediscussedHighAvailabilitymodesActive-StandbyActive-ActiveWehaveconfiguredActive–StandbyHAmode17TableofContentsSection0:CourseIntroductionSection1:LoadBalancingConceptsSection2:AXManagementSection3:HTTPSection4:HTTPSSection5:AXAccelerationSection6:AXSecuritySection7:HighAvailabilitySection8:AXTroubleshootingSection9:aFleX