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LVS只是做一个负载均衡，通过访问VIP来访问后端的网站程序，一旦LVS宕机，整个网站就访问不了，这就出现了单点。所以要结合keepalive这种高可用软件来保证整个网站的高可用。本文将介绍如何利用keepalive来实现LVS的高可用(以LVS的DR模式为例，生产环境后台的real server 网站内容是一致的，为了看到实验效果，这里是两个不同的页面)。
一、环境介绍
VIP：192.168.1.188
RIP1(Web1): 192.168.1.2
RIP2(Web2): 192.168.1.5
LVS1 :192.168.1.6
LVS2: 192.168.1.7
web1页面
web2页面
二、配置realserver
分别在web1和web2上执行lvs_rserver.sh
| 1 2 3 4 5 6 | [root@web1 ~] # ./lvs_rserver.sh start RealServer Start OK [root@web1 ~] # [root@web2 ~] # ./lvs_rserver.sh start RealServer Start OK [root@web2 ~] # |
lvs_rserver.sh脚本内容如下：
| 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 | [root@web1 ~] # cat lvs_rserver.sh #!/bin/sh #LVS Client Server VIP=192.168.1.188 case $1 in start) ifconfig lo:0 $VIP netmask 255.255.255.255 broadcast $VIP /sbin/route add –host $VIP dev lo:0 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 sysctl -p > /dev/null 2>&1 echo "RealServer Start OK" exit 0 ;; stop) ifconfig lo:0 down route del $VIP > /dev/null 2>&1 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 "RealServer Stoped OK" exit 1 ;; *) echo "Usage: $0 {start|stop}" ;; esac [root@web2 ~] # |
三、安装配置lvs及keepalive
分别在lvs1和lvs2上安装lvs及keepalive
lvs及keppalive的安装见
在lvs1和lvs2上配置VIP并加载相关模块
| 1 2 3 4 5 | [root@lvs1 ~] # ifconfig eth0:0192.168.1.188 netmask 255.255.255.0 [root@lvs1 ~] # modprobe ip_vs [root@lvs1 ~] # modprobe ip_vs_rr [root@lvs1 ~] # modprobe ip_vs_wrr [root@lvs1 ~] # |
| 1 2 3 4 5 | [root@lvs2 ~] # ifconfig eth0:0192.168.1.188 netmask 255.255.255.0 [root@lvs2 ~] # modprobe ip_vs [root@lvs2 ~] # modprobe ip_vs_rr [root@lvs2 ~] # modprobe ip_vs_wrr [root@lvs2 ~] # |
在lvs1上修改keepalive.conf文件，修改后内容如下
| 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 | [root@lvs1 ~] # vim/etc/keepalived/keepalived.conf [root@lvs1 ~] # cat/etc/keepalived/keepalived.conf ! Configuration File for keepalived global_defs { notification_email { 654001593@qq.com } notification_email_from 654001593@qq.com smtp_server 127.0.0.1 smtp_connect_timeout 30 router_id LVS_DEVEL } # VIP1 vrrp_instance VI_1 { state MASTER interface eth0 lvs_sync_daemon_inteface eth0 virtual_router_id 51 priority 100 advert_int 5 nopreempt authentication { auth_type PASS auth_pass 1111 } virtual_ipaddress { 192.168.1.188 } } virtual_server 192.168.1.188 80 { delay_loop 6 lb_algo wrr lb_kind DR # persistence_timeout 60 protocol TCP real_server 192.168.1.2 80 { weight 100 TCP_CHECK { connect_timeout 10 nb_get_retry 3 delay_before_retry 3 connect_port 80 } } real_server 192.168.1.5 80 { weight 100 TCP_CHECK { connect_timeout 10 nb_get_retry 3 delay_before_retry 3 connect_port 80 } } } [root@lvs1 ~] # |
lvs2上的keepalive.conf文件基本和lvs1上的一致，但是state这一项lvs1上是MASTER，而lvs2上的BACKUP；优先级priority在lvs1上为100，在lvs2上为90
在lvs2上修改keepalive.conf文件，修改后内容如下
| 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 | [root@lvs2 ~] # cat/etc/keepalived/keepalived.conf ! Configuration File for keepalived global_defs { notification_email { 654001593@qq.com } notification_email_from 654001593@qq.com smtp_server 127.0.0.1 smtp_connect_timeout 30 router_id LVS_DEVEL } # VIP1 vrrp_instance VI_1 { state BACKUP interface eth0 lvs_sync_daemon_inteface eth0 virtual_router_id 51 priority 90 advert_int 5 nopreempt authentication { auth_type PASS auth_pass 1111 } virtual_ipaddress { 192.168.1.188 } } virtual_server 192.168.1.188 80 { delay_loop 6 lb_algo wrr lb_kind DR # persistence_timeout 60 protocol TCP real_server 192.168.1.2 80 { weight 100 TCP_CHECK { connect_timeout 10 nb_get_retry 3 delay_before_retry 3 connect_port 80 } } real_server 192.168.1.5 80 { weight 100 TCP_CHECK { connect_timeout 10 nb_get_retry 3 delay_before_retry 3 connect_port 80 } } } [root@lvs2 ~] # |
四、测试
停掉lvs1的网卡
去ping VIP一样一直在通信(配置有nopreempt)
通过VIP访问网站
刷新
即使lvs1宕机后又恢复，此时依旧是通过lvs2访问(由是否配置nopreempt决定）。
本文转自Jacken_yang 51CTO博客，原文链接：http://blog.51cto.com/linuxnote/1655103，如需转载请自行联系原作者