DNS服务器LVS方式负载均衡部署与测试测试环境：本测试方案采用LVS（DR）+Keepalived部署高可用的DNS服务集群。

主机IP划分：Master-LB：192.168.100.70Backup-LB：192.168.100.30RS1：192.168.100.40RS2：192.168.100.60Clinet：192.168.100.200拓扑图：LB-2:192.168.100.30Backup LB-1:192.168.100.70Master DNS-RS1:192.168.100.40DNS-RS2:192.168.100.601、配置Maste-LB 服务器：1、 安装ipvsadm ；yum install ipvsadm* -y2、 安装keepalivedyum install keepalived -y3、 配置配置keepalived#cat /etc/keepalived/keepalived.conf! Configuration File for keepalivedglobal_defs {notification_email {****************}**************************************************** smtp_server 127.0.0.1smtp_connect_timeout 30router_id LVS_1}vrrp_instance VI_1 {state MASTERinterface eth1virtual_router_id 50priority 100advert_int 1authentication {auth_type PASSauth_pass 1111}virtual_ipaddress {192.168.100.100}}virtual_server 192.168.100.100 53 {delay_loop 1lb_algo rrlb_kind DRnat_mask 255.255.255.255!persistence_timeout 50protocol UDPreal_server 192.168.100.40 53 {weight 1MISC_CHECK {misc_path "/usr/bin/dig -************************************.100.40+time=1+tries=5+fail>/dev/null"misc_timeout 6}}real_server 192.168.100.60 53 {weight 1MISC_CHECK {misc_path "/usr/bin/dig -************************************.100.60+time=1+tries=5+fail>/dev/null"misc_timeout 6}}}vrrp_instance VI_2 {state MASTERinterface eth1virtual_router_id 52priority 100advert_int 1authentication {auth_type PASSauth_pass 1111}virtual_ipaddress {192.168.100.100}}virtual_server 192.168.100.100 53 { delay_loop 1lb_algo rrlb_kind DRnat_mask 255.255.255.255!persistence_timeout 50protocol TCPreal_server 192.168.100.40 53 {weight 1TCP_CHECK {connect_timeout 5nb_get_retry 3connect_port 53}}real_server 192.168.100.60 53 {weight 1TCP_CHECK {connect_timeout 5nb_get_retry 3connect_port 53}}}4、启动keepalived的服务service keepalived restart5、查看配置是否生效# ipvsadm –Ln[root@localhost ~]# ipvsadm -LnIP Virtual Server version 1.2.1 (size=4096)Prot LocalAddress:Port Scheduler Flags-> RemoteAddress:Port Forward Weight ActiveConn InActConn TCP 192.168.100.100:53 rr-> 192.168.100.40:53 Route 1 0 0-> 192.168.100.60:53 Route 1 0 0UDP 192.168.100.100:53 rr-> 192.168.100.40:53 Route 1 0 0 -> 192.168.100.60:53 Route 1 0 02、配置Backup-LB服务器：1、安装ipvsadm；yum install ipvsadm* -y2、安装keepalivedyum install keepalived -y3、配置配置keepalived#cat /etc/keepalived/keepalived.conf! Configuration File for keepalivedglobal_defs {notification_email {****************}****************************************************smtp_server 127.0.0.1smtp_connect_timeout 30router_id LVS_2}vrrp_instance VI_1 {state BACKUPinterface eth1virtual_router_id 50priority 90advert_int 1authentication {auth_type PASSauth_pass 1111}virtual_ipaddress {192.168.100.100}}virtual_server 192.168.100.100 53 {delay_loop 1lb_algo rrlb_kind DRnat_mask 255.255.255.255!persistence_timeout 50protocol UDPreal_server 192.168.100.40 53 {weight 1MISC_CHECK {misc_path "/usr/bin/dig -************************************.100.40+time=1+tries=5+fail>/dev/null"misc_timeout 6}}real_server 192.168.100.60 53 {weight 1MISC_CHECK {misc_path "/usr/bin/dig -************************************.100.60+time=1+tries=5+fail>/dev/null"misc_timeout 6}}}vrrp_instance VI_2 {state BACKUPinterface eth1virtual_router_id 52priority 90advert_int 1authentication {auth_type PASSauth_pass 1111}virtual_ipaddress {192.168.100.100}}virtual_server 192.168.100.100 53 { delay_loop 1lb_algo rrlb_kind DRnat_mask 255.255.255.255!persistence_timeout 50protocol TCPreal_server 192.168.100.40 53 {weight 1TCP_CHECK {connect_timeout 5nb_get_retry 3connect_port 53}}real_server 192.168.100.60 53 {weight 1TCP_CHECK {connect_timeout 5nb_get_retry 3connect_port 53}}}4、启动keepalived的服务service keepalived restart5、查看配置是否生效# ipvsadm –Ln[root@localhost ~]# ipvsadm -LnIP Virtual Server version 1.2.1 (size=4096)Prot LocalAddress:Port Scheduler Flags-> RemoteAddress:Port Forward Weight ActiveConn InActConnTCP 192.168.100.100:53 rr-> 192.168.100.40:53 Route 1 0 0-> 192.168.100.60:53 Route 1 0 0UDP 192.168.100.100:53 rr-> 192.168.100.40:53 Route 1 0 0-> 192.168.100.60:53 Route 1 0 0 3、配置DNS-RS1与DNS-RS2：1、配置安装并配置DNS服务，并确保DNS服务能正常工作；2、在每一台REALSERVER上执行如下脚本#!/bin/bash#description : Start Real ServerVIP=192.168.100.100. /etc/rc.d/init.d/functionscase "$1" instart)echo " Start LVS of Real Server"/sbin/ifconfig lo:0 $VIP broadcast $VIP netmask 255.255.255.255 upecho "1" >/proc/sys/net/ipv4/conf/lo/arp_ignoreecho "2" >/proc/sys/net/ipv4/conf/lo/arp_announceecho "1" >/proc/sys/net/ipv4/conf/all/arp_ignoreecho "2" >/proc/sys/net/ipv4/conf/all/arp_announce;;stop)/sbin/ifconfig lo:0 downecho "close LVS Director server"echo "0" >/proc/sys/net/ipv4/conf/lo/arp_ignoreecho "0" >/proc/sys/net/ipv4/conf/lo/arp_announceecho "0" >/proc/sys/net/ipv4/conf/all/arp_ignoreecho "0" >/proc/sys/net/ipv4/conf/all/arp_announce;;*)echo "Usage: $0 {start|stop}"exit 1esac4、测试结果：[root@localhost ~]# ipvsadm -LnIP Virtual Server version 1.2.1 (size=4096)Prot LocalAddress:Port Scheduler Flags-> RemoteAddress:Port Forward Weight ActiveConn InActConnTCP 192.168.100.100:53 rr-> 192.168.100.40:53 Route 1 0 34-> 192.168.100.60:53 Route 1 0 35UDP 192.168.100.100:53 rr-> 192.168.100.40:53 Route 1 0 6-> 192.168.100.60:53 Route 1 0 6故障转移：Aug 13 22:55:52 centos6 Keepalived_vrrp[52501]: VRRP_Instance(VI_2) Transition to MASTER STATEAug 13 22:55:52 centos6 Keepalived_vrrp[52501]: VRRP_Instance(VI_1) Transition to MASTER STATEAug 13 22:55:53 centos6 Keepalived_vrrp[52501]: VRRP_Instance(VI_2) Entering MASTER STATEAug 13 22:55:53 centos6 Keepalived_vrrp[52501]: VRRP_Instance(VI_2) setting protocol VIPs.Aug 13 22:55:53 centos6 Keepalived_healthcheckers[52500]: Netlink reflector reports IP 192.168.100.100 addedAug 13 22:55:53 centos6 Keepalived_vrrp[52501]: VRRP_Instance(VI_2) Sending gratuitous ARPs on eth1 for 192.168.100.100 Aug 13 22:55:53 centos6 Keepalived_vrrp[52501]: VRRP_Instance(VI_1) Entering MASTER STATEAug 13 22:55:53 centos6 Keepalived_vrrp[52501]: VRRP_Instance(VI_1) setting protocol VIPs.Aug 13 22:55:53 centos6 Keepalived_vrrp[52501]: VRRP_Instance(VI_1) Sending gratuitous ARPs on eth1 for 192.168.100.100 Aug 13 22:55:56 centos6 Keepalived_vrrp[52501]: VRRP_Instance(VI_2) Received higher prio advertAug 13 22:55:56 centos6 Keepalived_vrrp[52501]: VRRP_Instance(VI_2) Entering BACKUP STATEAug 13 22:55:56 centos6 Keepalived_vrrp[52501]: VRRP_Instance(VI_2) removing protocol VIPs.Aug 13 22:55:56 centos6 Keepalived_healthcheckers[52500]: Netlink reflector reports IP 192.168.100.100 removedAug 13 22:55:56 centos6 Keepalived_vrrp[52501]: VRRP_Instance(VI_1) Received higher prio advertAug 13 22:55:56 centos6 Keepalived_vrrp[52501]: VRRP_Instance(VI_1) Entering BACKUP STATEAug 13 22:55:56 centos6 Keepalived_vrrp[52501]: VRRP_Instance(VI_1) removing protocol VIPs.Aug 13 22:55:56 centos6 Keepalived_vrrp[52501]: Netlink: error: Cannot assign requested address, type=(21), seq=1407932349, pid=0 Aug 13 22:56:00 centos6 Keepalived_vrrp[52501]: VRRP_Instance(VI_2) Transition to MASTER STATEAug 13 22:56:00 centos6 Keepalived_vrrp[52501]: VRRP_Instance(VI_1) Transition to MASTER STATEAug 13 22:56:01 centos6 Keepalived_vrrp[52501]: VRRP_Instance(VI_2) Entering MASTER STATEAug 13 22:56:01 centos6 Keepalived_vrrp[52501]: VRRP_Instance(VI_2) setting protocol VIPs.Aug 13 22:56:01 centos6 Keepalived_vrrp[52501]: VRRP_Instance(VI_2) Sending gratuitous ARPs on eth1 for 192.168.100.100Aug 13 22:56:01 centos6 Keepalived_healthcheckers[52500]: Netlink reflector reports IP 192.168.100.100 addedAug 13 22:56:01 centos6 Keepalived_vrrp[52501]: VRRP_Instance(VI_1) Entering MASTER STATEAug 13 22:56:01 centos6 Keepalived_vrrp[52501]: VRRP_Instance(VI_1) setting protocol VIPs.Aug 13 22:56:01 centos6 Keepalived_vrrp[52501]: VRRP_Instance(VI_1) Sending gratuitous ARPs on eth1 for 192.168.100.100Aug 13 22:56:06 centos6 Keepalived_vrrp[52501]: VRRP_Instance(VI_2) Sending gratuitous ARPs on eth1 for 192.168.100.100Aug 13 22:56:06 centos6 Keepalived_vrrp[52501]: VRRP_Instance(VI_1) Sending gratuitous ARPs on eth1 for 192.168.10。