lvs keepalived 负载均衡器

shenyg

lvs keepalived 实现负载均衡

环境


主机名
IP地址
os
软件





lvs01
172.16.50.104
CentOS 7.4.1708
ipvsadm keepalived
master


lvs02
172.16.50.111
CentOS 7.4.1708
ipvsadm keepalived
backup


nginx01
172.16.50.124
CentOS 7.4.1708
nginx



nginx02
172.16.50.112
CentOS 7.4.1708
nginx

　　Vip地址 172.16.50.230

部署

Nginx 部署
　　主机nginx01，nginx02

yum install nginx -y
　　启动

systemctl enable nginx && systemctl start nginx
　　主机nginx01

echo "124" > /usr/share/nginx/html/index.html
　　主机nginx02

echo "112" > /usr/share/nginx/html/index.html
　　创建realserver.sh脚本，内容如下：

#!/bin/bash
#description: Config realserver
VIP=172.16.50.230
. /etc/rc.d/init.d/functions
case "$1" in
start)
/sbin/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)
/sbin/ifconfig lo:0 down
/sbin/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
　　添加执行权限及运行脚本

chmod +x realserver.sh && ./realserver.sh start
lvs，keepalived 部署
　　开启路由转发
　　临时生效

echo "1" > /proc/sys/net/ipv4/ip_forward
　　永久生效，编辑配置文件/etc/sysctl.conf添加

net.ipv4.ip_forward= 1
sysctl -p #生效
　　主机 lvs01，lvs02

yum install ipvsadm keepalived -y
　　主机lvs01编辑配置文件/etc/keepalived/keepalived.conf

! Configuration File for keepalived
! 全局配置
global_defs {
! 标识
router_id keep-50.104
}
! VRRPD配置
vrrp_instance VI_1 {
! 指定该keepalived节点的初始状态:MASTER|BACKUP
state MASTER
! vrrp实例绑定的接口，用于发送VRRP包
interface eth0
! 指定VRRP实例ID，范围是0-255,主备的virtual_router_id 必须相同
virtual_router_id 51
! 指定优先级，优先级高的将成为MASTER
priority 100
! 指定发送VRRP通告的间隔,单位秒
advert_int 1
authentication {
! 指定认证方式:PASS|AH
auth_type PASS
! 指定认证所使用的密码,最多8位
auth_pass 1111
}
virtual_ipaddress {
! 指定VIP地址
172.16.50.230
}
}
virtual_server 172.16.50.230 80 {
! 健康检查的时间间隔
delay_loop 6
! LVS调度算法:rr|wrr|lc|wlc|lblc|sh|dh
lb_algo rr
! LVS模式:NAT|DR|TUN
lb_kind DR
! 持久化超时时间,单位秒
persistence_timeout 50
! 协议: TCP|UDP|SCTP
protocol TCP
! 后端服务器
real_server 172.16.50.124 80 {
! 权重
weight 1
! 健康检查方式
TCP_CHECK {
! 超时时间,单位秒
connect_timeout 3
! 尝试次数
nb_get_retry 3
! 在尝试之前延迟多少秒
delay_before_retry 10
! 尝试间隔
delay_before_retry 2
}
}
real_server 172.16.50.112 80 {
! 权重
weight 1
! 健康检查方式
TCP_CHECK {
! 超时时间,单位秒
connect_timeout 3
! 尝试次数
nb_get_retry 3
! 在尝试之前延迟多少秒
delay_before_retry 10
! 尝试间隔
delay_before_retry 2
}
}
}
　　主机lvs02 参考主机lvs01配置文件
　　修改部分

router_id keep-50.111
state BACKUP
priority 90
　　启动

systemctl enable keepalived && systemctl start keepalived
测试

ipvsadm -Ln
IP Virtual Server version 1.2.1 (size=4096)
Prot LocalAddress:Port Scheduler Flags
-> RemoteAddress:Port           Forward Weight ActiveConn InActConn
TCP  172.16.50.230:80 rr persistent 50
-> 172.16.50.112:80             Route   1      0          0         
-> 172.16.50.124:80             Route   1      0          0         
curl 172.16.50.230
112

• 　　停止主机nginx02  Nginx 服务
  　　观察主机lvs01      keepalived日志
  
  lvs01keepalived[10879]: TCP connection to [172.16.50.112]:80 failed.
  Keepalived_healthcheckers[10879]: TCP connection to [172.16.50.112]:80 failed.
  Keepalived_healthcheckers[10879]: Check on service [172.16.50.112]:80 failed after 1 retry.
  Keepalived_healthcheckers[10879]: Removing service [172.16.50.112]:80 from VS [172.16.50.230]:80
  curl 172.16.50.230
  124
  
• 　　停止主机lvs01     Keepalived 服务
  　　观察主机lvs02     Keepalived 日志
  
  Keepalived_vrrp[10774]: VRRP_Instance(VI_1) Transition to MASTER STATE
  Keepalived_vrrp[10774]: VRRP_Instance(VI_1) Entering MASTER STATE
  Keepalived_vrrp[10774]: VRRP_Instance(VI_1) setting protocol VIPs.
  Keepalived_vrrp[10774]: Sending gratuitous ARP on eth0 for 172.16.50.230
  Keepalived_vrrp[10774]: VRRP_Instance(VI_1) Sending/queueing gratuitous ARPs on eth0 for 172.16.50.230
  Keepalived_vrrp[10774]: Sending gratuitous ARP on eth0 for 172.16.50.230
  Keepalived_vrrp[10774]: Sending gratuitous ARP on eth0 for 172.16.50.230
  Keepalived_vrrp[10774]: Sending gratuitous ARP on eth0 for 172.16.50.230
  Keepalived_vrrp[10774]: Sending gratuitous ARP on eth0 for 172.16.50.230
  Keepalived_vrrp[10774]: Sending gratuitous ARP on eth0 for 172.16.50.230
  Keepalived_vrrp[10774]: VRRP_Instance(VI_1) Sending/queueing gratuitous ARPs on eth0 for 172.16.50.230
  Keepalived_vrrp[10774]: Sending gratuitous ARP on eth0 for 172.16.50.230
  Keepalived_vrrp[10774]: Sending gratuitous ARP on eth0 for 172.16.50.230
  Keepalived_vrrp[10774]: Sending gratuitous ARP on eth0 for 172.16.50.230
  Keepalived_vrrp[10774]: Sending gratuitous ARP on eth0 for 172.16.50.230
  　　Vip地址漂移到了主机 lvs02