ipvsadm+keepalived 实现高可用负载均衡

一.使用系统Red Hat Enterprise Linux Server release 5.4 二.安装环境   1.说明     realserver:192.168.1.11     realserver:192.168.1.12     lvs控制机 MASTER:192.168.1.100              BACKUP:192.168.1.101     虚拟VIP：192.168.1.200     其中：realserver上只需要简单的安装apache即可          lvs控制机需要安装：ipvsadm，keepalived   2.lvs控制机安装，主备机分别安装ipvsadm     实现LVS/DR最重要的两个东西是ipvs内核模块和ipvsadm工具包，现在的系统已经包含ip_vs模块     1）检查内核模块，看一下ip_vs 是否被加载        # lsmod |grep ip_vs        如果没有显示，则说明没有加载，执行命令 modprobe ip_vs 就可以把ip_vs模块加载到内核        # lsmod |grep ip_vs          ip_vs    35009    0     2）安装ipvsadm       先把目录/usr/src/kernels/2.6.18-164.el5-x86_64链接为/usr/src/linux，命令如下       ln –s /usr/src/kernels/2.6.18-164.el5-x86_64 /usr/src/linux       解压ipvsadm-1.24.tar.gz,执行"make;make install”完成安装。          3）lvs/dr脚本，在主备机上脚本部署        vi lvsdr        #!/bin/bash
       RIP1=192.168.1.11
       RIP2=192.168.1.12
 
       VIP1=192.168.1.200
       . /etc/rc.d/init.d/functions
 
       case "$1" in
 
       start)
           echo " start LVS of DirectorServer"
 
          # set the Virtual IP Address and sysctl parameter
          /sbin/ifconfig eth0:0 $VIP1 broadcast $VIP1 netmask 255.255.255.255 up
          #/sbin/ifconfig eth0:1 $VIP2 broadcast $VIP2 netmask 255.255.255.255 up
          /sbin/route add -host $VIP1 dev eth0:0
          #/sbin/route add -host $VIP2 dev eth0:1
          echo "1" >/proc/sys/net/ipv4/ip_forward
 
          #Clear IPVS table
          /sbin/ipvsadm -C
 
          #set LVS
          #Web Apache
          /sbin/ipvsadm -A -t $VIP1:80 -s rr -p 120
          /sbin/ipvsadm -a -t $VIP1:80 -r $RIP1:80 -g
          /sbin/ipvsadm -a -t $VIP1:80 -r $RIP2:80 -g
 
          #Run LVS
          /sbin/ipvsadm
      ;;
      stop)
          echo "close LVS Directorserver"
          echo "0" >/proc/sys/net/ipv4/ip_forward
          /sbin/ipvsadm -C
          /sbin/ifconfig eth0:0 down
      ;;
      *)
          echo "Usage: $0 {start|stop}"
          exit 1
      esac    4)真实服务器配置 运行脚本如下 #!/bin/bash
#description:start realserver
#chkconfig
VIP1=192.1268.1.200 . /etc/rc.d/init.d/functions
case "$1" in
start)
echo " start LVS of REALServer"
/sbin/ifconfig lo:0 $VIP1 broadcast $VIP1 netmask 255.255.255.255 up
echo "1" >/proc/sys/net/ipv4/conf/lo/arp_ignore
echo "2" >/proc/sys/net/ipv4/conf/lo/arp_announce
echo "1" >/proc/sys/net/ipv4/conf/all/arp_ignore
echo "2" >/proc/sys/net/ipv4/conf/all/arp_announce
;;
stop)
/sbin/ifconfig lo:0 down
echo "close LVS Directorserver"
echo "0" >/proc/sys/net/ipv4/conf/lo/arp_ignore
echo "0" >/proc/sys/net/ipv4/conf/lo/arp_announce
echo "0" >/proc/sys/net/ipv4/conf/all/arp_ignore
echo "0" >/proc/sys/net/ipv4/conf/all/arp_announce
;;
*)
echo "Usage: $0 {start|stop}"
exit 1
esac     5)主备机上分别安装keepalived       tar zxf keepalived-1.1.17.tar.gz       cd keepalived-1.1.17       ./configure --prefix=/usr/local/keepalive       make && make install       mkdir -p /etc/keepalived/       vi keepalived.conf以下配置文件 ! Configuration File for keepalived
global_defs {
   router_id LVS_DEVEL
}
 
vrrp_instance VI_1 {
    state MASTER         #备份服务器上将MASTER改为BACKUP
    interface eth0       #HA监测网络接口
    virtual_router_id 51 #主、备机的virtual_router_id必须相同
    priority 90          #主、备机取不同的优先级，主机值较大，备份机值较小
    advert_int 1         #VRRP Multicast广播周期秒数
    authentication {
        auth_type PASS   #VRRP认证方式
        auth_pass 1111   #VRRP口令字
    }
    virtual_ipaddress { 
        192.168.1.200    #LVS虚拟地址
    }
}
 
virtual_server 192.168.1.200 80 {
    delay_loop 2
    lb_algo rr
    lb_kind DR  
    protocol TCP
 
  real_server 192.168.1.11 80 {
        weight 1
        TCP_CHECK {
            connect_timeout 3
            nb_get_retry 3
            delay_before_retry 3
        }
    }
  real_server 192.168.1.12 80 {
        weight 1
        TCP_CHECK {
            connect_timeout 3
            nb_get_retry 3
            delay_before_retry 3
        }
    }
} 三.分别启动主备机上的lvs脚本和keepalived    sh lvsdr start    /usr/local/keepalived/sbin/keepalived -D 四.测试    停掉主机ipvsadmn和keepalived，从机立即接管服务    启动主机服务，主机负载均衡生效