單主模型

環境四個虛擬機

upstream server:node1:172.16.100.6 ? ? ? ? CeotOS 6

upstream server:node3:172.16.100.69 ? ? ? ? CeotOS 7

節點1:172.16.100.67 ? ? ? ? ? ? ? ? ? ? ? ?CeotOS 7

節點2:node2:172.16.100.68 ? ? ? ? ? ? ? ? ? ? ??CeotOS 7

節1&2

# yum install nginx -y

# cd /etc/nginx

# vim nginx.conf

? ? ? ? ? ? ? ? ? ? ? include /etc/nginx/conf.d/*.conf;
? ? ? ? ? ? ? ? ? ? ? upstream webservers {
  ? ? ? ? ? ? ? ? ? ?  ? ? ? ? ? ? ? ? ? ? server 172.16.100.6:80 weight=1;
  ? ? ? ? ? ? ? ? ? ?  ? ? ? ? ? ? ? ? ? ? server 172.16.100.69:80 weight=1;
 ? ? ? ? ? ? ? ? ? ? ? }

? ? ? ? ? ? ? ? ? ? ?location ? / ? {

? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?proxy_pass ? http://websrvers/;

? ? ? ? ? ? ? ? ? ? ?}

# nginx ? -t ?

# systemctl start nginx.service
# netstat -tnlp
用瀏覽器訪問172.16.100.67
# scp nginx.conf node2:/etc/nginx/

節2
# systemctl start nginx.service
# netstat -tnlp

用瀏覽器訪問172.16.100.68看能否負載均衡

• 用keepalived監控nginx服務

節1&節2
# vim keepalived.conf 
     vrrp_script chk_nginx {
             script "killall -0 nginx &> /dev/null"
             interval 1 
             weight -10
       }
       vrrp_instance VI_1 {
             track_script {
                   chk_nginx
             }
       }
節1

# systemctl status nginx.service

# systemctl start keepalived.service ssh node2:systemctl start keepalived.service

# systemctl status keepalived.service

# ip addr list

如果沒啟動起來，可能是組播地址和虛擬地址的問題，修改一下即可

宕掉nginx，肯是否會轉到節點2上

#?systemctl stop nginx.service

#?systemctl status nginx

節2

# ip addr list

節1

#?systemctl start nginx.service

瀏覽器訪問172.16.100.88

節1（主節點）只要在線，節2（備節點）就搶不走，除非節1宕掉
# vim notify

 #!/bin/bash

 #


 vip=172.16.100.88

 contact='root@localhost' 


 notify() {

 mailsubject="`hostname` to be $1: $vip floating"??? 

 mailbody="`date '+%F %H:%M:%S'`: vrrp transition, `hostname` changed to be $1"???

echo $mailbody | mail -s "$mailsubject" $contact

 }


 case "$1" in

           master)

?             notify master
              systemctl restart nginx.service

              exit 0

           ;;

           backup)

               notify backup
               systemctl restart nginx.service

               exit 0

           ;;

           fault)

               notify fault

                exit 0

           ;;

           *)

               echo 'Usage: `basename $0` {master|backup|fault}'

               exit 1

            ;;

  esac

# scp notify.sh node2:/etc/keepalived/

# systemctl status keepalived

# ip addr list

主停掉，備也停掉，會自動啟動nginx

# systemctl stop httpd.server

節2

# systemctl stop nginx.service

# systemctl status keepalived

節1

# systemctl status nginx.service

# systemctl status keepalived

雙主模型

節1
# vim keepalived.conf
            vrrp_instance VI_2 {

                        state BACKUP

                        interface ens33

                        virtual_router_id 61

                        priority 99

                        advert_int 1

                        authentication {

                                 auth_type PASS

                                 auth_pass 1111

                       }

                       virtual_ipaddress {

                                172.16.100.180/16 dev ens33 label ens33:2

                       }

                       track_script {

                                      chk_nginx

                       }

                        notify_master “/etc/keepalived/notify.sh master”   (不手動啟動nginx，而讓監控系統確保nginx在線）

                        notify_backup “/etc/keepalived/notify.sh backup”

                        notify_fault “/etc/keepalived/notify.sh fault”

             }
節1&節2
(不手動啟動nginx，而讓監控系統確保nginx在線）
# vim notify.sh
   注釋掉systemctl restart nginx.service
節2
# vim keepalived.conf

        vrrp_instance VI_2 {

                        state MASTER

                        interface ens33

                        virtual_router_id 61

                        priority 100

                        advert_int 1

                        authentication {

                                 auth_type PASS

                                 auth_pass 1111

                       }

                       virtual_ipaddress {

                                172.16.100.180/16 dev ens33 label ens33:2

                       }

                       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”

         }
節1

# sytemctl restart keepalived.service; ssh node2'sytemctl restart keepalived.service'
# systemctl status keepalived
# ifconfig ens33:1 down
# sytemctl restart keepalived.service; ssh node2'sytemctl restart keepalived.service'
# systemctl status keepalived

節2
# systemctl status keepalived.service
# ip addr list
用瀏覽器訪問兩個地址，看調度是否有問題
節1

# sytemctl restart keepalived.service; sytemctl start httpd.service
# systemctl status keepalived


節2
# ifconfig
節1
# sytemctl stop httpd.service; sytemctl restart nginx.service'
# systemctl status nginx.service

# systemctl status keepalived

# ifconfig