keepalived+lvs集群，实现高可用

环境准备：两台虚拟机，关闭防火墙，selinux,配置阿里云仓库，配置epel

192.168.88.21 dr1 负载均衡器 master

192.168.88.22 dr2 负载均衡器 backup

192.168.88.23        rs1 web1

192.168.88.24        rs2 web2

实验说明：给主机配置一个虚拟IP192.168.88.100 当访问虚拟IP时，可以访问到nginx服务器下的项目。当主机服务器宕机时，备用机可以代替主机工作。当主机nginx服务挂掉后，实现自动启动nginx服务，保持项目可以随时访问。

一、安装Keepalived

1、在master上安装配置Keepalived  ipvsadm

yum install keepalived  ipvsadm -y

2、在master上修改配置文件

vim /etc/keepalived/keepalived.conf

! Configuration File for keepalived
global_defs {						router_id Director1    #两边不一样。}vrrp_instance VI_1 {				state MASTER				#另外一台机器是BACKUP	interface ens33				#心跳网卡	virtual_router_id 51			#虚拟路由编号，主备要一致priority 150				#优先级	advert_int 1				#检查间隔，单位秒	authentication {auth_type PASSauth_pass 1111}virtual_ipaddress {192.168.88.100/24       dev      ens33   	#VIP和工作接口}}virtual_server 192.168.88.100 80 {		#LVS 配置，VIP,就是keepalived配置的对外地址delay_loop 3				#服务论询的时间间隔，#每隔3秒检查一次real_server状态lb_algo rr				#LVS 调度算法lb_kind DR	 			#LVS 集群模式protocol TCPreal_server 192.168.88.23 80 {weight 1                    #权重TCP_CHECK {connect_timeout 3       #健康检查方式,连接超时时间}}real_server 192.168.88.24 80 {weight 1TCP_CHECK {connect_timeout 3    #设定连接超时时间为3秒 超过视为掉线}}
}

3、在backup上安装配置Keepalived  ipvsadm

yum install keepalived   ipvsadm -y

4、在backup上修改配置文件

vim /etc/keepalived/keepalived.conf

! Configuration File for keepalived
global_defs {router_id Director2}vrrp_instance VI_1 {state BACKUP                            #另外一台机器是BACKUPinterface ens33                         #心跳网卡virtual_router_id 51priority 90                            #优先级advert_int 1                            #检查间隔，单位秒authentication {auth_type PASSauth_pass 1111}virtual_ipaddress {192.168.88.100/24 dev ens33       #VIP和工作端口}}virtual_server 192.168.88.100 80 {                #LVS 配置，VIPdelay_loop 3                            #服务论询的时间间隔lb_algo rr                              #LVS 调度算法lb_kind DR                              #LVS 集群模式protocol TCPreal_server 192.168.88.23 80 {weight 1TCP_CHECK {connect_timeout 3}}real_server 192.168.88.24 80 {weight 1TCP_CHECK {connect_timeout 3}}
}

5、master和backup上启动服务

systemctl enable keepalived

 systemctl start keepalived

二、web1和web2配置

1、192.168.88.23(web1)和24(web2)安装nginx,并且设置开机自启

yum install -y nginx

systemctl start nginx

systemctl enable nginx

2、copy网卡配置文件，配置虚拟地址

cp /etc/sysconfig/network-scripts/{ifcfg-lo,ifcfg-lo:0}

vim /etc/sysconfig/network-scripts/ifcfg-lo:0

DEVICE=lo:0
IPADDR=192.168.88.100   #对外提供服务的地址
NETMASK=255.255.255.255
ONBOOT=yes

systemctl restart network

3、、配置路由

route add 192.168.88.100 dev lo

4、配置ARP

 vim /etc/sysctl.conf

net.ipv4.conf.all.arp_ignore = 1
net.ipv4.conf.all.arp_announce = 2
net.ipv4.conf.default.arp_ignore = 1
net.ipv4.conf.default.arp_announce = 2
net.ipv4.conf.lo.arp_ignore = 1
net.ipv4.conf.lo.arp_announce = 2

三、测试： 观察lvs路由条目

1、master上 查询 # ipvsadm -Ln

ipvsadm -Ln

2、观察vip地址在哪台机器上

ip a

3、修改nginx默认项目文件，便于区分访问到那个服务器

web1

echo nginx111 > /usr/share/nginx/html/index.html

web2

echo nginx222 > /usr/share/nginx/html/index.html

4、客户端浏览器访问vip

5、关闭master上的keepalived服务，再次访问vip

systemctl stop keepalived.service 

6、关闭web1站点服务，再次访问VIP

systemctl stop nginx