构建⾼可⽤集群Nginx

上一章我们讲解了nginx的集群，那么如果碰到下面的问题，我们改怎么办了？
分发器宕机怎么办
数据服务器宕机怎么办
别怕，我们有Keepalive
Keepalived的作⽤是检测服务器的状态，如果有⼀台web服务器宕机，或⼯作出现故障，Keepalived将检测到，并将有故障的服务器从系统中剔除，同时使⽤其他服务器代
替该服务器的⼯作，当服务器⼯作正常后Keepalived⾃动将服务器加⼊到服务器群中，这些⼯作全部⾃动完成，不需要⼈⼯⼲涉，需要⼈⼯做的只是修复故障的服务器。
⼀个监控+⾃愈的软件
1:根据提供地址进行下载

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

image.png

2：解压到文件夹

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

3:编译和安装

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

软件环境部署
1分发器 nginx+keepalived
2数据服务器 Nginx
3配置Nginx分发器
4配置数据服务器⻚⾯（web01 web02）
5配置keepalived.conf
6测试

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，进行备份后编辑
vim /etc/keepalived/keepalived.conf

! Configuration File for keepalived

global_defs {
   router_id NGINX_DEVEL
}
#定义一个脚本，名字叫做check_nginx 
vrrp_script check_nginx {
    script "/etc/keepalived/nginx_pid.sh"   #脚本路径
    interval 2   #每2s运行一次脚本
    fall 1    #失败次数1
}
vrrp_instance nginx {   #一个实例就是一个集群，名称为nginx
     state MASTER    #定义状态为主播
     interface ens33    #配置网卡名称，指向本机具体的网卡名称
     mcast_src_ip 192.168.10.40  #宣告自己还活着，闲杂人等都给朕退下
     virtual_router_id 51  #指定vrrp实例id，范围0-255
     priority 100  #指定优先级，优先级高的将成为master组播
     advert_int 1  #多久发一次组播
     authentication {
     auth_type PASS
     auth_pass 1111
 }
 track_script {
      check_nginx 
}
 virtual_ipaddress {   #虚拟ip
     192.168.10.213/24
   }
}

关联脚本 nginx_pid.sh（注意是上文中定义的脚本路径）

#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}

启动keepalived

systemctl start keepalived

配置备份Nginx分发器

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~~~~