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keepalived高可用

分类: 文章 • 2024-09-30 15:55:22

keepalived实现nginx负载均衡机高可用

环境说明
系统信息 主机名 IP
redhat7 hxdserver 192.168.225.128
redhat7 localhost 192.168.225.129
keepalived安装
//关闭防火墙和selinux
[[email protected] ~]# systemctl stop firewalld 
[[email protected] ~]# systemctl disable firewalld 
Removed symlink /etc/systemd/system/multi-user.target.wants/firewalld.service.
Removed symlink /etc/systemd/system/dbus-org.fedoraproject.FirewallD1.service.
[[email protected] ~]# setenforce 0 
setenforce: SELinux is disabled
[[email protected] ~]# sed -ri 's/^(SELINUX=).*/\1disabled/g' /etc/selinux/config

//安装keepalived
[[email protected] ~]# yum -y install epel-release vim wget gcc gcc-c++
[[email protected] ~]# yum -y install keepalived
在备机上做以上相同操作

//在主备机上分别安装nginx
[[email protected] ~]# yum -y install nginx
[[email protected] ~]# cd /usr/share/nginx/html/
[[email protected] html]# ls
404.html  50x.html  index.html  nginx-logo.png  poweredby.png
[[email protected] html]# mv index.html{,.bak}
[[email protected] html]# echo 'master'>index.html
[[email protected] html]# ls
404.html  50x.html  index.html  index.html.bak  nginx-logo.png  poweredby.png
[[email protected] html]# systemctl start nginx
[[email protected] html]# systemctl enable nginx
Created symlink from /etc/systemd/system/multi-user.target.wants/nginx.service to /usr/lib/systemd/system/nginx.service.
[[email protected] html]# ss -antl
State      Recv-Q Send-Q Local Address:Port               Peer Address:Port              
LISTEN     0      128          *:80                       *:*                  
LISTEN     0      128          *:22                       *:*                  
LISTEN     0      100    127.0.0.1:25                       *:*                  
LISTEN     0      128         :::80                      :::*                  
LISTEN     0      128         :::22                      :::*                  
LISTEN     0      100        ::1:25                      :::*

192.168.225.129

//安装keepalived和nginx
[[email protected] ~]# yum -y install epel-release vim wget gcc gcc-c++
[[email protected] ~]# yum -y install keepalived
[[email protected] ~]# yum -y install nginx
[[email protected] ~]# cd /usr/share/nginx/html/
[[email protected] html]# ls
404.html  50x.html  index.html  nginx-logo.png  poweredby.png
[[email protected] html]# mv index.html{,.bak}
[[email protected] html]# echo 'slave' > index.html
[[email protected] html]# ls
404.html  50x.html  index.html  index.html.bak  nginx-logo.png  poweredby.png
[[email protected] html]# systemctl start nginx
[[email protected] html]# systemctl enable nginx
Created symlink from /etc/systemd/system/multi-user.target.wants/nginx.service to /usr/lib/systemd/system/nginx.service.

分别访问两台服务器的测试页面
keepalived高可用
keepalived高可用

  • 配置主keepalived
    192.168.225.128
//修改配置文件
[[email protected] html]# cd /etc/keepalived/
[[email protected] keepalived]# ls
keepalived.conf
[[email protected] keepalived]# mv keepalived.conf{,.bak}
[[email protected] keepalived]# ls
keepalived.conf.bak
[[email protected] keepalived]# vim keepalived.conf

! Configuration File for keepalived

global_defs { 
    router_id lb01
}

vrrp_instance VI_1 {
    state MASTER
    interface ens33 
    virtual_router_id 51
    priority 100
    advert_int 1
    authentication {
    auth_type PASS 
    auth_pass dubai
 }  
    virtual_ipaddress {
    192.168.225.250
  }
}

virtual_server 192.168.225.250 80 {
    delay_loop 6
    lb_algo rr
    lb_kind DR
    persistence_timeout 50
    protocol TCP
    
    real_server 192.168.225.128 80 {
         weight 1
         TCP_CHECK {
          connect_port 80 
          connect_timeout 3
          nb_get_retry 3
          delay_before_retry 3
          }
     }    
    real_server 192.168.225.129 80 {
        weight 1
        TCP_CHECK {
            connect_port 80
            connect_timeout 3
            nb_get_retry 3
            delay_before_retry 3
            
     }      
   } 
}  
//启动服务
[[email protected] ~]# systemctl start keepalived
[[email protected] ~]# systemctl enable keepalived
Created symlink from /etc/systemd/system/multi-user.target.wants/keepalived.service to /usr/lib/systemd/system/keepalived.service.
  • 配置备keepalived
    192.168.225.129
//修改配置文件
[[email protected] ~]# vim /etc/keepalived/keepalived.conf 
! Configuration File for keepalived

global_defs {
    router_id lb02
}
vrrp_instance VI_1 {
    state BACKUP
    interface ens33
    virtual_router_id 51
    priority 90
    advert_int 1
    authentication {
        auth_type PASS
        auth_pass dubai
 }
    virtual_ipaddress {
    192.168.225.250
  }
}

virtual_server 192.168.225.250 80 {
   delay_loop 6
    lb_algo rr
    lb_kind DR
    persistence_timeout 50
    protocol TCP

    real_server 192.168.225.128 80 {
         weight 1
         TCP_CHECK {
          connect_port 80
          connect_timeout 3
          nb_get_retry 3
          delay_before_retry 3
          }
     }
    real_server 192.168.225.129 80 {
        weight 1
        TCP_CHECK {
            connect_port 80
            connect_timeout 3
            nb_get_retry 3
            delay_before_retry 3

     }
   }
}

//开启服务
[[email protected] ~]# systemctl start keepalived
[[email protected] ~]# systemctl enable keepalived
Created symlink from /etc/systemd/system/multi-user.target.wants/keepalived.service to /usr/lib/systemd/system/keepalived.service.
  • 查看VIP在哪
    192.168.225.128
[[email protected] ~]# ip a
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN qlen 1
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 scope host lo
       valid_lft forever preferred_lft forever
    inet6 ::1/128 scope host 
       valid_lft forever preferred_lft forever
2: ens33: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000
    link/ether 00:0c:29:4b:7c:b8 brd ff:ff:ff:ff:ff:ff
    inet 192.168.225.128/24 brd 192.168.225.255 scope global dynamic ens33
       valid_lft 1517sec preferred_lft 1517sec
    inet 192.168.225.250/32 scope global ens33  //这个就是我所设置的VIP
       valid_lft forever preferred_lft forever
    inet6 fe80::20c:29ff:fe4b:7cb8/64 scope link 
       valid_lft forever preferred_lft forever
  • 在192.168.225.129上查看
[[email protected] ~]# ip a
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN qlen 1
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 scope host lo
       valid_lft forever preferred_lft forever
    inet6 ::1/128 scope host 
       valid_lft forever preferred_lft forever
2: ens33: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000
    link/ether 00:0c:29:b8:f7:10 brd ff:ff:ff:ff:ff:ff
    inet 192.168.225.129/24 brd 192.168.225.255 scope global dynamic ens33
       valid_lft 1325sec preferred_lft 1325sec
    inet6 fe80::20c:29ff:feb8:f710/64 scope link 
       valid_lft forever preferred_lft forever
让keepalived监控nginx负载均衡机

keepalived通过脚本来监控nginx负载均衡机的状态
在master（192.168.225.128）上编写脚本

[[email protected] ~]# mkdir /scripts
[[email protected] ~]# cd /scripts/
[[email protected] scripts]# vim check_n.sh
#!/bin/bash
nginx_status=$(ps -ef|grep -Ev "grep|$0"|grep '\bnginx\b'|wc -l)
if [ $nginx_status -lt 1 ];then
    systemctl stop keepalived
fi
[[email protected] scripts]# chmod +x check_n.sh 

[[email protected] scripts]# vim notify.sh
#!/bin/bash
VIP=$2
sendmail (){
         subject="${VIP}'s server keepalived state is translate"
         content="`date +'%F %T'`: `hostname`'s state change to master"
         echo $content | mail -s "$subject" [email protected]
}
case "$1" in
  master)
        nginx_status=$(ps -ef|grep -Ev "grep|$0"|grep '\bnginx\b'|wc -l)
        if [ $nginx_status -lt 1 ];then
            systemctl start nginx
        fi
        sendmail
;;
  backup)
        nginx_status=$(ps -ef|grep -Ev "grep|$0"|grep '\bnginx\b'|wc -l)
        if [ $nginx_status -gt 0 ];then
            systemctl stop nginx
        fi
;;
*)
        echo "Usage:$0 master|backup VIP"
;;
esac

[[email protected] scripts]# chmod +x notify.sh 

[[email protected] scripts]# ll
总用量 8
-rwxr-xr-x 1 root root 144 11月  1 15:25 check_n.sh
-rwxr-xr-x 1 root root 612 11月  1 15:20 notify.sh
  • 在slave上编写脚本
[[email protected] ~]# mkdir /scripts
[[email protected] ~]# cd /scripts/
[[email protected] scripts]# vim notify.sh
#!/bin/bash
VIP=$2
sendmail (){
         subject="${VIP}'s server keepalived state is translate"
         content="`date +'%F %T'`: `hostname`'s state change to master"
         echo $content | mail -s "$subject" [email protected]
}
case "$1" in
  master)
        nginx_status=$(ps -ef|grep -Ev "grep|$0"|grep '\bnginx\b'|wc -l)
        if [ $nginx_status -lt 1 ];then
            systemctl start nginx
        fi
        sendmail
;;
  backup)
        nginx_status=$(ps -ef|grep -Ev "grep|$0"|grep '\bnginx\b'|wc -l)
        if [ $nginx_status -gt 0 ];then
            systemctl stop nginx
        fi
;;
*)
        echo "Usage:$0 master|backup VIP"
;;
esac
[[email protected] scripts]# vim check_n.sh
#!/bin/bash
nginx_status=$(ps -ef|grep -Ev "grep|$0"|grep '\bnginx\b'|wc -l)
if [ $nginx_status -lt 1 ];then
    systemctl stop keepalived
fi
[[email protected] scripts]# chmod +x check_n.sh 
[[email protected] scripts]# ll
总用量 8
-rwxr-xr-x. 1 root root 142 11月  1 15:39 check_n.sh
-rwxr-xr-x. 1 root root 657 11月  1 15:36 notify.sh

注意：脚本的名字应避免与服务名相同，推荐用服务名的首字母代替。

  • 配置keepalived加入监控脚本的配置
    配置主keepalived
    192.168.225.128
[[email protected] scripts]# vim /etc/keepalived/keepalived.conf
! Configuration File for keepalived

global_defs { 
    router_id lb01
}

vrrp_script nginx_check {
    script "/scripts/check_n.sh"
    interval 1
    weight -20
}

vrrp_instance VI_1 {
    state MASTER
    interface ens33 
    virtual_router_id 51
    priority 100
    advert_int 1
    authentication {
    auth_type PASS 
    auth_pass dubai
     }
    virtual_ipaddress {
          192.168.225.250
     }    
     track_script {
          nginx_check
     }    
     notify_master "/scripts/notify.sh master 192.168.225.250"
     notify_backup "/scripts/notify.sh backup 192.168.225.250"
}    

virtual_server 192.168.225.250 80 {
    delay_loop 6
    lb_algo rr 
    lb_kind DR
    persistence_timeout 50
    protocol TCP
    
    real_server 192.168.225.128 80 {
         weight 1
         TCP_CHECK {
          connect_port 80
          connect_timeout 3
          nb_get_retry 3
          delay_before_retry 3
          }
     }    
    real_server 192.168.225.129 80 {
        weight 1
        TCP_CHECK {
            connect_port 80
            connect_timeout 3
            nb_get_retry 3
            delay_before_retry 3
            
     }      
   } 
}  
[[email protected] ~]# systemctl restart keepalived
  • 配置备keepalived
    192.168.225.129
[[email protected] ~]# vim /etc/keepalived/keepalived.conf
! Configuration File for keepalived

global_defs {
    router_id lb02
}
vrrp_instance VI_1 {
    state BACKUP
    interface ens33
    virtual_router_id 51
    priority 90
    advert_int 1
    authentication {
        auth_type PASS
        auth_pass dubai
 }
    virtual_ipaddress {
    192.168.225.250
  }
         notify_master "/scripts/notify.sh master 192.168.225.250"
         notify_backup "/scripts/notify.sh backup 192.168.225.250"
}

virtual_server 192.168.225.250 80 {
    delay_loop 6
    lb_algo rr
    lb_kind DR
    persistence_timeout 50
    protocol TCP

    real_server 192.168.225.128 80 {
         weight 1
         TCP_CHECK {
          connect_port 80
          connect_timeout 3
          nb_get_retry 3
          delay_before_retry 3
          }
     }
    real_server 192.168.225.129 80 {
        weight 1
        TCP_CHECK {
            connect_port 80
            connect_timeout 3
            nb_get_retry 3
            delay_before_retry 3

     }
   }
}
[[email protected] ~]# systemctl restart keepalived

访问虚拟ip192.168.225.250

[[email protected] ~]# curl http://192.168.225.250
master

模拟master挂了

[[email protected] ~]# systemctl stop nginx
[[email protected] ~]# curl http://192.168.225.250
slave  //再次访问虚拟ip，备就接管了请求

192.168.225.129

[[email protected] ~]# ip a 
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN qlen 1
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 scope host lo
       valid_lft forever preferred_lft forever
    inet6 ::1/128 scope host 
       valid_lft forever preferred_lft forever
2: ens33: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000
    link/ether 00:0c:29:b8:f7:10 brd ff:ff:ff:ff:ff:ff
    inet 192.168.225.129/24 brd 192.168.225.255 scope global dynamic ens33
       valid_lft 1462sec preferred_lft 1462sec
    inet 192.168.225.250/32 scope global ens33  //虚拟IP会自动跳到backup
       valid_lft forever preferred_lft forever
    inet6 fe80::20c:29ff:feb8:f710/64 scope link 
       valid_lft forever preferred_lft forever

当master的服务修复起来的时候，虚拟IP会被原master抢占回来，若要其不抢占，在配置文件中添加 nopreempt。
手动将原master的nginx和keepalived开启，虚拟IP又会回到原master

[[email protected] ~]# systemctl start nginx.service 
[[email protected] ~]# systemctl start keepalived.service 
[[email protected] ~]# ip a 
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN qlen 1
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 scope host lo
       valid_lft forever preferred_lft forever
    inet6 ::1/128 scope host 
       valid_lft forever preferred_lft forever
2: ens33: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000
    link/ether 00:0c:29:4b:7c:b8 brd ff:ff:ff:ff:ff:ff
    inet 192.168.225.128/24 brd 192.168.225.255 scope global dynamic ens33
       valid_lft 1428sec preferred_lft 1428sec
    inet 192.168.225.250/32 scope global ens33
       valid_lft forever preferred_lft forever
    inet6 fe80::20c:29ff:fe4b:7cb8/64 scope link 
       valid_lft forever preferred_lft forever
[[email protected] ~]# curl http://192.168.225.250
master

在192.168.225.128上安装邮件工具

[[email protected] ~]# yum -y install mailx

将服务都开启，看能否收到邮件通知

[[email protected] ~]# systemctl start nginx.service 
[[email protected] ~]# systemctl start keepalived.service 
[[email protected] ~]# ip a 
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN qlen 1
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 scope host lo
       valid_lft forever preferred_lft forever
    inet6 ::1/128 scope host 
       valid_lft forever preferred_lft forever
2: ens33: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000
    link/ether 00:0c:29:4b:7c:b8 brd ff:ff:ff:ff:ff:ff
    inet 192.168.225.128/24 brd 192.168.225.255 scope global dynamic ens33
       valid_lft 1406sec preferred_lft 1406sec
    inet 192.168.225.250/32 scope global ens33
       valid_lft forever preferred_lft forever
    inet6 fe80::20c:29ff:fe4b:7cb8/64 scope link 
       valid_lft forever preferred_lft forever

keepalived高可用

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