单主模型的IPVS高可用和nginx+keepalived的双主高可用模型

Posted 2020-11-08 sanqianfanhua01

一、IPVS的单主高可用

（1）配置RS，我们使用两台服务器作为RS服务器配置过程我们可以使用脚本来配置，这样当我们完成试验后便于卸载，脚本如下：

#!/bin/bash
#
vip=192.168.125.198 #你用的虚拟路由的IP地址
case $1 in
start)

echo 1 > /proc/sys/net/ipv4/conf/all/arp_ignore
echo 1 > /proc/sys/net/ipv4/conf/lo/arp_ignore
echo 1 > /proc/sys/net/ipv4/conf/all/arp_announce
echo 1 > /proc/sys/net/ipv4/conf/lo/arp_announce
ifconfig lo:0 $vip broadcast $vip netmask 255.255.255.255 up
route add -host $vip dev lo:0
;;
stop)
ifconfig lo:0 down
echo 0 > /proc/sys/net/ipv4/conf/all/arp_ignore
echo 0 > /proc/sys/net/ipv4/conf/lo/arp_ignore
echo 0 > /proc/sys/net/ipv4/conf/all/arp_announce
echo 0 > /proc/sys/net/ipv4/conf/lo/arp_announce
;;
*)echo "Usage: $(basename $0) start|stop"
exit 1
;;
esac

接下来我们可以配置keepalived服务器两台服务器配置大多是相通的，只需修改少量配置参数即可[email protected] keepalived]# vim /etc/keepalived/keepalived.conf! Configuration File for keepalived

#全局配置段
global_defs {
notification_email {
[email protected]
}
notification_email_from [email protected]
smtp_server 127.0.0.1
smtp_connect_timeout 15
router_id node1
vrrp_mcast_group4 224.0.192.100
}


#配置虚拟IP
vrrp_instance VI_1 {
state MASTER
interface ens33
virtual_router_id 11
priority 100

advert_int 1
authentication {
auth_type PASS
auth_pass 11111111
}
virtual_ipaddress {
192.168.125.198/24 dev ens33 label ens33:0
}
track_interface {  
ens33
}

notify_master "/etc/keepalived/notify.sh master"
notify_backup "/etc/keepalived/notify.sh backup"
notify_fault "/etc/keepalived/notify.sh fault"
}

vrrp_instance VI_2 {
state BACKUP
interface ens33
virtual_router_id 21
priority 98
advert_int 1
authentication {
auth_type PASS
auth_pass 18181818
}
virtual_ipaddress {
192.168.125.199/24 dev ens33
}
track_interface {
ens33
}


notify_master "/etc/keepalived/notify.sh master"
notify_backup "/etc/keepalived/notify.sh backup"
notify_fault "/etc/keepalived/notify.sh fault"

}
#定义虚拟服务器
virtual_server 192.168.125.198 80 {
delay_loop 2
lb_kind DR
lb_algo rr
protocol TCP
sorry_server 127.0.0.1 80

real_server 192.168.125.156 80 {
weight 1
HTTP_GET {
url {
path /
status_code 200
}

nb_get_retry 3
delay_before_retry 1
connect_timeout 3
    }
}
real_server 192.168.125.157 80 {
weight 2
HTTP_GET {
url {
path /
status_code 200
}

nb_get_retry 3
delay_before_retry 1
connect_timeout 3
        }
    }
}

    

最后完成测试即可；

二、keepalived+nginx的高可用集群服务

（1）分析：在做此实验时我们不仅要监控节点我们还需要监控节点上nginx是否可用，这就需要我们调用脚本来监控他们，首先我们做通知脚本示例如下：

#!/bin/bash
#实现通知脚本

contact=‘[email protected]‘

notify() {
local mailsubject="$(hostname) to be $1, vip floating"
notify() {
local mailsubject="$(hostname) to be $1, vip floating"
echo "$mailbody" | mail -s "$mailsubject" $contact
}

case $1 in
master)
notify master
;;
backup)
notify backup
systemctl restart nginx
;;
fault)
notify fault
;;
*)
echo "Usage: $(basename $0) {master|backup|fault}"
exit 1
;;
esac

（2）　脚本调用方法如下：

第一步将脚本放在/etc/keepalived/下并给执行权限
第二步编辑配置文件：vim /etc/keepalived/keepalived.conf
第三步：在vrrp_instance 的上下文编写如下语句：
track_interface {
ens33
}
notify_master "/etc/keepalived/notify.sh master"
notify_backup "/etc/keepalived/notify.sh backup"
notify_fault "/etc/keepalived/notify.sh fault"

（3）接着我们要完成脚本监控nginx服务：

keepalived调用外部辅助脚本进行资源监控，并根据监控的结果状态能实现优先级的动态调整：

　　分两步：　（1）先定义一个脚本
　　　　　　     (2)调用此脚本

vrrp_script <SCRIPT_NAME> {
　　　　　　script “”
　　　　　　interval INT #返回值0或者1
　　　　　　weight -INT
　　　　}
　　　　track_script {
　　　　　　SCRIPT _NAME_1
　　　　　　SCRIPT_NAME_2
　　　　　　.....　

　　　　}　　

　　最后我们在上一个脚本的backup下加一行重启nginx服务的命令就可以起到一定的排错能力，如果是nginx服务听了他可以自动帮我们讲服务重启。

（4）接着我们要配置nginx的反代服务这个是在keepalived的两台服务器上做：

编辑代理服务器nginx的主配置文件：vim /etc/nginx/nginx.conf
在http上下文编辑：
upstream websrvs {
server 192.168.125.156:80 weight=1;
server 192.168.125.157:80 weight=1;
}

记着：nginx -s reload
在server段的location中写下：proxy_pass http://websrvs;

（5）接着编辑反代服务器的keepalived 文件：

! Configuration File for keepalived

global_defs {
notification_email {
[email protected]
}
notification_email_from [email protected]
smtp_server 127.0.0.1
smtp_connect_timeout 15
router_id node1
vrrp_mcast_group4 224.0.192.100
}
vrrp_script chk_nginx {
script "killall -0 nginx"
interval 1
weight -5
}
vrrp_instance VI_1 {
state MASTER
interface ens33
virtual_router_id 11
priority 100
advert_int 1
authentication {
auth_type PASS
auth_pass 11111111
}
virtual_ipaddress {
192.168.125.198/24 dev ens33 label ens33:0
}
track_interface {
ens33
}
track_script {
chk_nginx
}
notify_master "/etc/keepalived/notify.sh master"
notify_backup "/etc/keepalived/notify.sh backup"
notify_fault "/etc/keepalived/notify.sh fault"
}

vrrp_instance VI_2 {
state BACKUP
interface ens33
virtual_router_id 21
priority 98
advert_int 1
authentication {
auth_type PASS
auth_pass 18181818
}
virtual_ipaddress {
192.168.125.199/24 dev ens33
}
track_interface {
ens33
}
track_script {
chk_nginx
}
notify_master "/etc/keepalived/notify.sh master"
notify_backup "/etc/keepalived/notify.sh backup"
notify_fault "/etc/keepalived/notify.sh fault"

}

　　

另一个发代节点也这样编辑就可以完成然后启动keepalived服务即可。