测试环境
系统 | IP | 软件 |
Centos8 | 192.168.248.80 | lvs+keepalived |
Centos8 | 192.168.248.81 | lvs+keepalived |
Centos8 | 192.168.248.100 | Web server |
Centos8 | 192.168.248.101 | Web server |
vip暂定192.168.248.254
配置keepalived
master配置
[root@master ~]# yum install ipvsadm keepalived -y [root@master ~]# cat /etc/keepalived/keepalived.conf ! Configuration File for keepalived global_defs { router_id LVS_01 } vrrp_instance VI_1 { state MASTER interface eth0 virtual_router_id 90 #虚拟路由 ID(0-255),在一个 VRRP 实例中主备服务器 ID 必须一样 mcast_src_ip 192.168.248.80 priority 100 # 优先级值设定:MASTER 要比 BACKUP 的值大 advert_int 1 authentication { auth_type PASS auth_pass 123456 } virtual_ipaddress { 192.168.248.254 } } virtual_server 192.168.248.254 80 { delay_loop 6 lb_algo rr lb_kind DR persistence_timeout 50 protocol TCP real_server 192.168.248.100 80 { weight 1 TCP_CHECK { connect_port 80 connect_timeout 3 nb_get_retry 3 delay_before_retry 3 } } real_server 192.168.248.101 80 { weight 1 TCP_CHECK { connect_port 80 connect_timeout 3 nb_get_retry 3 delay_before_retry 3 } } } [root@master ~]# systemctl start keepalived
backup配置
[root@backup ~]# yum install ipvsadm keepalived -y [root@backup ~]# cat /etc/keepalived/keepalived.conf ! Configuration File for keepalived global_defs { router_id LVS_02 } vrrp_instance VI_1 { state BACKUP interface eth0 virtual_router_id 90 mcast_src_ip 192.168.248.81 priority 90 advert_int 1 authentication { auth_type PASS auth_pass 123456 } virtual_ipaddress { 192.168.248.254 } } virtual_server 192.168.248.254 80 { delay_loop 6 lb_algo rr lb_kind DR persistence_timeout 50 protocol TCP real_server 192.168.248.100 80 { weight 1 TCP_CHECK { connect_port 80 connect_timeout 3 nb_get_retry 3 delay_before_retry 3 } } real_server 192.168.248.101 80 { weight 1 TCP_CHECK { connect_port 80 connect_timeout 3 nb_get_retry 3 delay_before_retry 3 } } } [root@backup ~]# systemctl start keepalived
配置 RS
在 RS 的lo网卡上配置 VIP
配置脚本,两台RS都需要
[root@RS1 ~]# cat /scripts/lvs_rs.sh #!/bin/bash VIP=192.168.248.254 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" ;; 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" ;; *) echo "Usage: $0 {start|stop}" exit 1 esac exit 0 #安装nginx测试 [root@RS1 ~]# yum -y install nginx [root@RS1 ~]# echo '192.168.248.100' /usr/share/nginx/html/index.html [root@RS1 ~]# systemctl start nginx
检查测试
主节点查看ip,可以看到 VIP 目前已经正确配置在网卡上。
输入ipvsadm -Ln 或watch ipvsadm -Ln --stats可以看到负责均衡状态
[root@master ~]# ipvsadm -ln IP Virtual Server version 1.2.1 (size=4096) Prot LocalAddress:Port Scheduler Flags -> RemoteAddress:Port Forward Weight ActiveConn InActConn TCP 192.168.248.254:80 rr persistent 50 -> 192.168.248.100:80 Route 1 0 0 -> 192.168.248.101:80 Route 1 0 0
测试访问VIP
手动停止一个 RS,再次访问 VIP,LVS 会自动剔除无法访问的服务,重启后,服务会被自动添加
[root@RS1 ~]# systemctl stop nginx
手动停止master上的 keepalived,模拟 master节点挂了,VIP 会自动转移到backup上。
在backup上查看
重启master后,由于master的优先级高于backup,此时vip会转移到master,从而实现 HA。