LVS + Keepalived 高可用高性能负载均衡案例实战
前言
Keepalived 作为一个高性能的集群高可用解决方案。提供了集群节点心跳检测、健康检查以及故障切换的功能。原生支持 LVS 负载均衡集群。接下来，我将详细介绍。
一、架构设计
负载均衡方案系统架构拓扑图
两台负载均衡器部署详细拓扑图
二、环境准备
| role | host | ip | software installed | OS |
|---|---|---|---|---|
| LVS Dir、Keepalive MASTER | node01 | 192.168.5.11 | LVS、keepalived-2.0.12 | Centos 7.8 |
| LVS Dir、Keepalive BACKUP | node02 | 192.168.5.12 | LVS、keepalived-2.0.12 | Centos 7.8 |
| nginx web server1、LVS RS | node03 | 192.168.5.13 | Nginx-1.18.0 | Centos 7.8 |
| nginx web server1、LVS RS | node04 | 192.168.5.14 | Nginx-1.18.0 | Centos 7.8 |
| Client | node05 | 192.168.5.15 | ---- | Centos 7.8 |
三、案例部署
配置前端 keeapalived + lvs
---node01
[root@node01 ~]# vim /etc/keepalived/keepalived.conf
! Configuration File for keepalived
global_defs {
notification_email {
acassen@firewall.loc
failover@firewall.loc
sysadmin@firewall.loc
}
notification_email_from Alexandre.Cassen@firewall.loc
smtp_server 192.168.5.10
smtp_connect_timeout 30
router_id LVS_DEVEL1
}
vrrp_instance VI_1 {
state MASTER
interface ens33
virtual_router_id 51
priority 200
advert_int 1
authentication {
auth_type PASS
auth_pass 1111
}
virtual_ipaddress {
192.168.5.20
}
}
virtual_server 192.168.5.20 80 {
delay_loop 6
lb_algo rr
lb_kind DR
#persistence_timeout 50
protocol TCP
real_server 192.168.5.13 80 {
weight 1
TCP_CHECK {
connect_timeout 3
nb_get_retry 3
delay_before_retry 3
connect_port 80
}
}
real_server 192.168.5.14 80 {
weight 1
TCP_CHECK {
connect_timeout 3
nb_get_retry 3
delay_before_retry 3
connect_port 80
}
}
}
[root@node01 ~]# systemctl restart keepalived.service
---node02
! Configuration File for keepalived
global_defs {
notification_email {
acassen@firewall.loc
failover@firewall.loc
sysadmin@firewall.loc
}
notification_email_from Alexandre.Cassen@firewall.loc
smtp_server 192.168.5.10
smtp_connect_timeout 30
router_id LVS_DEVEL2
}
vrrp_instance VI_1 {
state BACKUP
interface ens33
virtual_router_id 51
priority 100
advert_int 1
authentication {
auth_type PASS
auth_pass 1111
}
virtual_ipaddress {
192.168.5.20
}
}
virtual_server 192.168.5.20 80 {
delay_loop 6
lb_algo rr
lb_kind DR
#persistence_timeout 50
protocol TCP
real_server 192.168.5.13 80 {
weight 1
TCP_CHECK {
connect_timeout 3
nb_get_retry 3
delay_before_retry 3
connect_port 80
}
}
real_server 192.168.5.14 80 {
weight 1
TCP_CHECK {
connect_timeout 3
nb_get_retry 3
delay_before_retry 3
connect_port 80
}
}
}
[root@node02 ~]# systemctl restart keepalived.service
配置后端 web 服务
---node03
[root@node03 ~]# yum install nginx-1.18.0-1.el7.ngx.x86_64.rpm -y
[root@node03 ~]# echo "`hostname -I` web test page..." > /usr/share/nginx/html/index.html
[root@node03 ~]# systemctl enable --now nginx
----node04
[root@node04 ~]# yum install nginx-1.18.0-1.el7.ngx.x86_64.rpm -y
[root@node04 ~]# echo "`hostname -I` web test page..." > /usr/share/nginx/html/index.html
[root@node04 ~]# systemctl enable --now nginx
配置后端 lvs
---node03
[root@node03 ~]# vim /etc/init.d/lvs_dr_rs
#!/bin/sh
#
# Startup script handle the initialisation of LVS
# chkconfig: - 28 72
# description: Initialise the Linux Virtual Server for DR
#
### BEGIN INIT INFO
# Provides: ipvsadm
# Required-Start: $local_fs $network $named
# Required-Stop: $local_fs $remote_fs $network
# Short-Description: Initialise the Linux Virtual Server
# Description: The Linux Virtual Server is a highly scalable and highly
# available server built on a cluster of real servers, with the load
# balancer running on Linux.
# description: start LVS of DR-RIP
LOCK=/var/lock/ipvsadm.lock
VIP=192.168.5.20
. /etc/rc.d/init.d/functions
start() {
PID=`ifconfig | grep lo:100 | wc -l`
if [ $PID -ne 0 ];
then
echo "The LVS-DR-RIP Server is already running !"
else
/sbin/ifconfig lo:100 $VIP netmask 255.255.255.255 broadcast $VIP up
/sbin/route add -host $VIP dev lo:100
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/ens33/arp_ignore
echo "2" >/proc/sys/net/ipv4/conf/ens33/arp_announce
echo "1" >/proc/sys/net/ipv4/conf/all/arp_ignore
echo "2" >/proc/sys/net/ipv4/conf/all/arp_announce
/bin/touch $LOCK
echo "starting LVS-DR-RIP server is ok !"
fi
}
stop() {
/sbin/route del -host $VIP dev lo:100
/sbin/ifconfig lo:100 down >/dev/null
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/ens33/arp_ignore
echo "0" >/proc/sys/net/ipv4/conf/ens33/arp_announce
echo "0" >/proc/sys/net/ipv4/conf/all/arp_ignore
echo "0" >/proc/sys/net/ipv4/conf/all/arp_announce
rm -rf $LOCK
echo "stopping LVS-DR-RIP server is ok !"
}
status() {
if [ -e $LOCK ];
then
echo "The LVS-DR-RIP Server is already running !"
else
echo "The LVS-DR-RIP Server is not running !"
fi
}
case "$1" in
start)
start
;;
stop)
stop
;;
restart)
stop
start
;;
status)
status
;;
*)
echo "Usage: $1 {start|stop|restart|status}"
exit 1
esac
exit 0
[root@node03 ~]# chmod +x /etc/init.d/lvs_dr_rs
[root@node03 ~]# chkconfig --add lvs_dr_rs
[root@node03 ~]# chkconfig lvs_dr_rs on
[root@node03 ~]# systemctl enable --now lvs_dr_rs
---node04
[root@node04 ~]# vim /etc/init.d/lvs_dr_rs
#!/bin/sh
#
# Startup script handle the initialisation of LVS
# chkconfig: - 28 72
# description: Initialise the Linux Virtual Server for DR
#
### BEGIN INIT INFO
# Provides: ipvsadm
# Required-Start: $local_fs $network $named
# Required-Stop: $local_fs $remote_fs $network
# Short-Description: Initialise the Linux Virtual Server
# Description: The Linux Virtual Server is a highly scalable and highly
# available server built on a cluster of real servers, with the load
# balancer running on Linux.
# description: start LVS of DR-RIP
LOCK=/var/lock/ipvsadm.lock
VIP=192.168.5.20
. /etc/rc.d/init.d/functions
start() {
PID=`ifconfig | grep lo:100 | wc -l`
if [ $PID -ne 0 ];
then
echo "The LVS-DR-RIP Server is already running !"
else
/sbin/ifconfig lo:100 $VIP netmask 255.255.255.255 broadcast $VIP up
/sbin/route add -host $VIP dev lo:100
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/ens33/arp_ignore
echo "2" >/proc/sys/net/ipv4/conf/ens33/arp_announce
echo "1" >/proc/sys/net/ipv4/conf/all/arp_ignore
echo "2" >/proc/sys/net/ipv4/conf/all/arp_announce
/bin/touch $LOCK
echo "starting LVS-DR-RIP server is ok !"
fi
}
stop() {
/sbin/route del -host $VIP dev lo:100
/sbin/ifconfig lo:100 down >/dev/null
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/ens33/arp_ignore
echo "0" >/proc/sys/net/ipv4/conf/ens33/arp_announce
echo "0" >/proc/sys/net/ipv4/conf/all/arp_ignore
echo "0" >/proc/sys/net/ipv4/conf/all/arp_announce
rm -rf $LOCK
echo "stopping LVS-DR-RIP server is ok !"
}
status() {
if [ -e $LOCK ];
then
echo "The LVS-DR-RIP Server is already running !"
else
echo "The LVS-DR-RIP Server is not running !"
fi
}
case "$1" in
start)
start
;;
stop)
stop
;;
restart)
stop
start
;;
status)
status
;;
*)
echo "Usage: $1 {start|stop|restart|status}"
exit 1
esac
exit 0
[root@node04 ~]# chmod +x /etc/init.d/lvs_dr_rs
[root@node04 ~]# chkconfig --add lvs_dr_rs
[root@node04 ~]# chkconfig lvs_dr_rs on
[root@node04 ~]# systemctl enable --now lvs_dr_rs
查看lvs集群
查看集群状态
客户端访问 VIP
实现web服务负载均衡！
四、测试
1、Keepalived 健康检查
动态监控 ipvsadm 列表
模拟后端服务故障
[root@node04 ~]# systemctl stop nginx
node05 访问 VIP
后端故障恢复
[root@node04 ~]# systemctl start nginx
node05 访问 VIP
Web集群正常提供相应！
2、Keepalived MASTER/BACKUP 切换
查看keeapalived ip地址状况
node01
node02
模拟 Keepalived MASTER 故障
[root@node01 ~]# systemctl stop keepalived.service
node01
node02
web 服务访问不受影响
模拟 Keepalived MASTER 故障恢复
[root@node01 ~]# systemctl start keepalived.service
node01
node02
keeapalived 实现 VIP 漂移 ！
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