lvs通过keepalived实现负载均衡

dyok

1.安装ipvsadm：（注意支持的系统内核版本号，新的版本只支持2.6.2*以上的系统内核，我选择的是1.24这个版本）
http://www.linuxvirtualserver.org/software/ipvs.html
1.1创建linux内核链接
# rpm -ivh /usr/src/kernels/2.6.18-238.el5-x86_64
# ln -s /usr/src/kernels/2.6.18-238.el5-x86_64 /usr/src/linux
1.2安装 ipvsadm
# cd ipvsadm-1.24
# make
# make install

2.安装keepalived
http://www.keepalived.org/download.html
安装keepalived的1.2以上的版本必须指定内核位置（我的CentOs5.6选择的是1.1.19这个版本）
# ./configure --prefix=/usr/local/keepalived (1.2以上需指定--with-kernel-dir=/usr/src/kernels/2.6.18-238.el5-x86_64)
# make
# make install

3.配置keepalived.conf(需要生成md5加密值)
#/usr/local/keepalived/bin/genhash -s 192.168.152.146 -p 80 -u /lived.jsp

生成后的文档，见keepalived.conf

[Python] 纯文本查看 复制代码

#  
#guration File for keepalived  
#global define  
global_defs {  
   router_id LVS_WEB_1  
}  
  
vrrp_sync_group VGM {  
   group {  
      VI_WEB  
   }  
}  
  
################################################################  
#      vvrp_instance  define                                   #  
################################################################  
vrrp_instance VI_WEB {  
    state MASTER  
    interface eth0  
    lvs_sync_daemon_inteface eth0  
    virtual_router_id 51  
    priority 180  
    advert_int 3  
    authentication {  
        auth_type PASS  
        auth_pass 1111  
    }  
    virtual_ipaddress {  
    192.168.152.222  
    }  
}  
  
##############################################################  
#   virtual machine  setting                                 #  
##############################################################  
  
# setting port 80 forward  
virtual_server 192.168.152.222 80 {  
    delay_loop 6  
    lb_algo wlc  
    lb_kind DR  
    persistence_timeout 60  
    protocol TCP  
  
   real_server 192.168.152.146 80 {  
        weight 100  
#            TCP_CHECK {  
            HTTP_GET {  
            url {  
            path /lived.jsp  
            digest 449089bf261dd8b34c786d0aaa8d80b6  
            }  
            connect_timeout 3  
            nb_get_retry 3  
            delay_before_retry 3  
            connect_port 80  
        }  
    }  
   real_server 192.168.152.153 80 {  
        weight 100  
#            TCP_CHECK {  
            HTTP_GET {  
            url {  
            path /lived.jsp  
            digest 449089bf261dd8b34c786d0aaa8d80b6  
            }  
            connect_timeout 3  
            nb_get_retry 3  
            delay_before_retry 3  
            connect_port 80  
        }  
    }  
}  

4.开启负载服务器路由机制
#vi /etc/sysctl.conf
使 net.ipv4.ip_forward = 1
然后使其生效，执行
# sysctl -p


5. web机器上的客户端启动脚本
vi /sbin/lvs_realserver.sh

[Python] 纯文本查看 复制代码

#!/bin/bash  
VIP1=192.168.152.222  
#VIP2=2.3.4.5  
. /etc/rc.d/init.d/functions  
case "$1" in  
start)  
          echo "start LVS of RealServer DR"  
          /sbin/ifconfig lo: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 lo:0            ###VIP绑定至回环接口上  
#          /sbin/route add -host $VIP2 dev eth0:1    
           echo "1" >/proc/sys/net/ipv4/conf/lo/arp_ignore   ###抑制arp广播  
           echo "2" >/proc/sys/net/ipv4/conf/lo/arp_announce      ###抑制arp广播  
           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  
#           /sbin/ifconfig eth0:1 down  
           echo "close LVS of RealServer DR"  
           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  
exit 0  

保存退出
#chmod 775 /sbin/lvs_realserver.sh


从centos6开始，内核进行了内核源地址验证，所以需要再对内核进行如下配置。
echo "0" > /proc/sys/net/ipv4/conf/lo/rp_filter
echo "1" > /proc/sys/net/ipv4/conf/em1/rp_filter
echo "1" > /proc/sys/net/ipv4/conf/em2/rp_filter
echo "0" > /proc/sys/net/ipv4/conf/all/rp_filter

6. 执行测试
# /sbin/lvs_server.sh start
  查看ifconfig是否有ifcfg-eth0:0(有就对了）
  查看route -n 路由表是否多了eth0:0路由（有就对了）
# /sbin/lvs_server.sh stop
  查看ifconfig是否有ifcfg-eth0:0 (无就对了）
  查看route -n 路由表是否多了eth0:0路由（无就对了）
# /sbin/lvs_server.sh adsa
  是否提示参数错误，只能使用{start|stop}

7.启动keepalived
# cp /usr/local/keepalived/etc/rc.d/init.d/keepalived /etc/init.d/keepalived
# chmod +x /etc/init.d/keepalived
# vi /etc/init.d/keepalived
. /etc/sysconfig/keepalived修改为：
.  /usr/local/keepalived/etc/sysconfig/keepalived 即指向正确的文件位置
并添加：如下内容
PATH="$PATH:/usr/local/keepalived/sbin"
export PATH

#vi /usr/local/keepalived/etc/sysconfig/keepalived
KEEPALIVED_OPTIONS="-D -f /usr/local/keepalived/etc/keepalived/keepalived.conf"

service keepalived restart

chkconfig keepalived on

第二种启动方式：启动命令加上指定配置文件的位置
/usr/local/keepalived/sbin/keepalived -D -f /usr/local/keepalived/etc/keepalived/keepalived.conf


8.负载均衡器集群的设置
拷贝keepalived.conf到其他BACKUP集群上，然后修改如下三个参数
   router_id LVS_WEB_2
   state BACKUP
   priority 150

=======================================================================================
lvs服务器查看keepalived进程： ps aux|grep keepalived
lvs服务器查看ipvsadm转发情况： ipvsadm
lvs服务器查看整体信息： cat /var/log/messages

关于监控可以使用nagios全面监控代替全局变量中的设置email报警邮箱
=======================================================================================

falldog

谢谢楼主，共同发展

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