本文将基于centos7搭建 keepalived 的高可用服务集群。流程如下
1、node1~node4安装centos7， 配置好网络。
/etc/sysconfig/network-scripts/ifcfg-eth0
TYPE=Ethernet PROXY_METHOD=none BROWSER_ONLY=no BOOTPROTO=static DEFROUTE=yes IPV4_FAILURE_FATAL=no IPV6INIT=yes IPV6_AUTOCONF=yes IPV6_DEFROUTE=yes IPV6_FAILURE_FATAL=no IPV6_ADDR_GEN_MODE=stable-privacy NAME=eth0 UUID=233394cb-126d-4101-8dd4-3fdce0d6cf26 DEVICE=eth0 ONBOOT=yes IPADDR=192.168.1.21 NETMASK=255.255.255.0 GATEWAY=192.168.1.1
/etc/resolv.conf
# Generated by NetworkManager nameserver 114.114.114.114 nameserver 115.115.115.115
2、配置好node1 ~ node4 的hostname
在 /etc/hostname 下分别写入各个节点的hostname，完成后可通过hostname命令查看
3、关闭防火墙
#关闭防火墙
systemctl stop firewalld.service
#禁止开机启动
systemctl disable firewalld.service
#查看防火墙状态
firewall-cmd --state
4、服务安装
#ipvsadm及keepalived安装 (node1和node4)
yum install ipvsadm keepalived -y
#httpd安装 (node2和node3)
yum install httpd -y
5、keepalived配置
node1 keepalived配置：/etc/keepalived/keepalived.conf
global_defs{ router_id LVS_DEVEL } vrrp_instance VI_1 { state MASTER interface eth0 virtual_router_id 51 priority 100 advert_int 1 authentication { auth_type PASS auth_pass 1111 } virtual_ipaddress { 192.168.1.100/24 dev eth0 label eth0:3 } } virtual_server 192.168.1.100 80 { delay_loop 6 lb_algo wrr lb_kind DR persistence_timeout 0 protocol TCP real_server 192.168.1.22 80 { weight 1 HTTP_GET { url { path / status_code 200 } connect_timeout 3 nb_get_retry 3 delay_before_retry 3 } } real_server 192.168.1.23 80 { weight 1 HTTP_GET { url { path / status_code 200 } connect_timeout 3 nb_get_retry 3 delay_before_retry 3 } } }
node4 keepalived配置：/etc/keepalived/keepalived.conf
global_defs{ router_id LVS_DEVEL } vrrp_instance VI_1 { state BACKUP interface eth0 virtual_router_id 51 priority 90 advert_int 1 authentication { auth_type PASS auth_pass 1111 } virtual_ipaddress { 192.168.1.100/24 dev eth0 label eth0:3 } } virtual_server 192.168.1.100 80 { delay_loop 6 lb_algo wrr lb_kind DR persistence_timeout 0 protocol TCP real_server 192.168.1.22 80 { weight 1 HTTP_GET { url { path / status_code 200 } connect_timeout 3 nb_get_retry 3 delay_before_retry 3 } } real_server 192.168.1.23 80 { weight 1 HTTP_GET { url { path / status_code 200 } connect_timeout 3 nb_get_retry 3 delay_before_retry 3 } } }
6、real server vip配置（node2、node3）
/etc/sysctl.conf
net.ipv4.conf.all.arp_ignore=1 net.ipv4.conf.lo.arp_ignore=1 net.ipv4.conf.all.arp_announce=2 net.ipv4.conf.lo.arp_announce=2
使用 sysctl -p 刷新到内存
配置VIP
ifconfig lo:6 192.168.1.100 netmask 255.255.255.255
7、写入访问文件至根目录（node2、node3）
vi /var/www/html/index.html
from node2 or node3 service
8、启动httpd服务（node2、node3）
systemctl start httpd
9、启动 keepalived 服务 （node1、node4）
#启动服务
systemctl start keepalived
#查看服务是否正常运行,此时因包含两个real server节点，且node1的VIP正常挂载, node4的VIP没有挂载。
ipvsadm -ln
10、通过VIP访问服务
http://192.168.1.100/
11、停掉node1的keepalived服务，VIP正常飘到node4节点中。服务正常运行。
#在node1中操作
systemctl stop keepalived
若将node1的keepalived服务重新启动，VIP正常飘回到node1中。服务正常运行。
12、停掉node2的服务，所有流量全都注入node3节点中，服务正常运行。
# 在node2中操作
systemctl stop httpd
若将node2的httpd服务重新启动，node2和node3同时提供服务，服务正常运行。