上一章我們講解了nginx的集群，那么如果碰到下面的問(wèn)題，我們改怎么辦了？
分發(fā)器宕機(jī)怎么辦
數(shù)據(jù)服務(wù)器宕機(jī)怎么辦
別怕，我們有Keepalive
Keepalived的作?是檢測(cè)服務(wù)器的狀態(tài)，如果有?臺(tái)web服務(wù)器宕機(jī)，或?作出現(xiàn)故障，Keepalived將檢測(cè)到，并將有故障的服務(wù)器從系統(tǒng)中剔除，同時(shí)使?其他服務(wù)器代
替該服務(wù)器的?作，當(dāng)服務(wù)器?作正常后Keepalived?動(dòng)將服務(wù)器加?到服務(wù)器群中，這些?作全部?動(dòng)完成，不需要???涉，需要??做的只是修復(fù)故障的服務(wù)器。
?個(gè)監(jiān)控+?愈的軟件
1:根據(jù)提供地址進(jìn)行下載

http://www.keepalived.org/download.html
wget http://www.keepalived.org/software/keepalived-2.0.8.tar.gz

image.png

2：解壓到文件夾

[root@localhost src]# tar  -zxvf  keepalived-2.2.4.tar.gz
[root@localhost src]# ./configure --prefix=/usr/local/keepalived

3:編譯和安裝

[root@localhost src]#make
[root@localhost src]#make  install

軟件環(huán)境部署
1分發(fā)器 nginx+keepalived
2數(shù)據(jù)服務(wù)器 Nginx
3配置Nginx分發(fā)器
4配置數(shù)據(jù)服務(wù)器??（web01 web02）
5配置keepalived.conf
6測(cè)試

配置Nginx集群

upstream web {
    server 192.168.10.42 max_fails=2 fail_timeout=3;
    server 192.168.10.43 max_fails=2 fail_timeout=3；
}
server {
   listen 80;
   server_name localhost;
   ocation / {
       proxy_pass http://web;
    }
 }

配置keepalived

#找到配置文件，進(jìn)行備份后編輯
vim /etc/keepalived/keepalived.conf

! Configuration File for keepalived

global_defs {
   router_id NGINX_DEVEL
}
#定義一個(gè)腳本，名字叫做check_nginx 
vrrp_script check_nginx {
    script "/etc/keepalived/nginx_pid.sh"   #腳本路徑
    interval 2   #每2s運(yùn)行一次腳本
    fall 1    #失敗次數(shù)1
}
vrrp_instance nginx {   #一個(gè)實(shí)例就是一個(gè)集群，名稱為nginx
     state MASTER    #定義狀態(tài)為主播
     interface ens33    #配置網(wǎng)卡名稱，指向本機(jī)具體的網(wǎng)卡名稱
     mcast_src_ip 192.168.10.40  #宣告自己還活著，閑雜人等都給朕退下
     virtual_router_id 51  #指定vrrp實(shí)例id，范圍0-255
     priority 100  #指定優(yōu)先級(jí)，優(yōu)先級(jí)高的將成為master組播
     advert_int 1  #多久發(fā)一次組播
     authentication {
     auth_type PASS
     auth_pass 1111
 }
 track_script {
      check_nginx 
}
 virtual_ipaddress {   #虛擬ip
     192.168.10.213/24
   }
}

關(guān)聯(lián)腳本 nginx_pid.sh（注意是上文中定義的腳本路徑）

#chmod 755 /etc/keepalived/nginx_pid.sh

#vim /etc/keepalived/nginx_pid.sh
#!/bin/bash
nginx_kp_check () {
nginxpid=`ps -C nginx --no-header |wc -l`
if [ $nginxpid -eq 0 ];then
  /usr/local/nginx/sbin/nginx
 sleep 1
   nginxpid=`ps -C nginx --no-header |wc -l`
    if [ $nginxpid -eq 0 ];then
      systemctl stop keepalived
   fi
fi}

啟動(dòng)keepalived

systemctl start keepalived

配置備份Nginx分發(fā)器

backuo.ayitula.com
#cat /etc/keepalived/keepalived.conf

! Configuration File for keepalived

global_defs {
   router_id NGINX_DEVEL
}
vrrp_script check_nginx {
    script "/etc/keepalived/nginx_pid.sh"
    interval 2
    fall 1
}
vrrp_instance nginx {
     state BACKUP
     interface ens33
     mcast_src_ip 192.168.10.41
     virtual_router_id 51
     priority 90
     advert_int 1
     authentication {
         auth_type PASS
         auth_pass 1111
     }
   track_script {
      check_nginx
  }
   virtual_ipaddress {
       192.168.10.213/24
   }
}

大功告成，加油~~~~