nginx+keepalived实现负载均衡nginx的高可用

准备四台服务器

两台做主备,另外两台做访问

192.168.1.120 master

192.168.1.121 backup

192.168.1.122 nginx

192.168.1.123 nginx

安装keepalived

yum -y install gcc pcre-devel zlib-devel openssl-devel
 
yum -y install popt-devel
 
wget http://www.keepalived.org/software/keepalived-1.2.7.tar.gz
 
tar zxvf keepalived-1.2..tar.gz
 
cd keepalived-1.2.
 
./configure
 
make&&make install

漫长的等待后.....

cp /usr/local/etc/rc.d/init.d/keepalived /etc/rc.d/init.d/
cp /usr/local/etc/sysconfig/keepalived /etc/sysconfig/
mkdir /etc/keepalived
cp /usr/local/etc/keepalived/keepalived.conf /etc/keepalived/
cp /usr/local/sbin/keepalived /usr/sbin/

加入启动服务 注册成服务

echo "/etc/init.d/keepalived start" >> /etc/rc.local

chkconfig --add keepalived

配置master nginx 192.168.1.110 和 192.168.1.121

#user  nobody;
worker_processes  ;
 
error_log  logs/error.log;
#error_log  logs/error.log  notice;
#error_log  logs/error.log  info;
 
#pid        logs/nginx.pid;
events {
    worker_connections  ;
}
http {
    include       mime.types;
    default_type  application/octet-stream;
    access_log  logs/access.log;
    sendfile        on;
   upstream 120.com {
      #ip_hash;
      server 192.168.1.122:80;
      server 192.168.1.123:80;
    }
    #tcp_nopush     on;
 
    #keepalive_timeout  ;
    keepalive_timeout  ;
 
    #gzip  on;
 
    server {
        listen       ;
        server_name  localhost;
        error_page        /50x.html;
        location = /50x.html {
            root   html;
        }
        location ~ \.php$ {
            root           html;
            fastcgi_pass   127.0.0.1:;
            fastcgi_index  index.php;
            fastcgi_param  SCRIPT_FILENAME  $document_root$fastcgi_script_name;
            proxy_pass http://120.com;
            include        fastcgi_params;
        }
 
    }
 
    include vhost/*.conf;
 
}

然后访问试试

实现了负载均衡调用另外两台服务器

配置master keepalived

vi /etc/keepalived/keepalived.conf

! Configuration File for keepalived
 
global_defs {
   notification_email {
        @qq.com
   }
   notification_email_from @qq.com
   smtp_server 127.0.0.1
   smtp_connect_timeout
   router_id nginx_master
}
vrrp_script check_nginx_is_run {
    script "/etc/keepalived/check_nginx_is_run.sh"
    interval
    weight
}
# 虚拟IP1, 本机作为Master
vrrp_instance VI_1 {
    state MASTER
    interface ens33 #你的网卡
    virtual_router_id
    priority
    advert_int
    track_interface {
        ens33
    }
    authentication {
        auth_type PASS
        auth_pass
    }
    virtual_ipaddress {
        192.168.1.51
    }
    track_script {
        check_nginx_is_run
    }
}

配置backup keepalived

! Configuration File for keepalived
 
global_defs {
   notification_email {
        @qq.com
   }
   notification_email_from @qq.com
   smtp_server 127.0.0.1
   smtp_connect_timeout
   router_id nginx_backup
}
vrrp_script check_nginx_is_run {
    script "/etc/keepalived/check_nginx_is_run.sh"
    interval
    weight
}
# 虚拟IP1, 本机作为Master
vrrp_instance VI_1 {
    state BACKUP
    interface ens33
    virtual_router_id
    priority
    advert_int
    track_interface {
        ens33
    }
    authentication {
        auth_type PASS
        auth_pass
    }
    virtual_ipaddress {
        192.168.1.51
    }
    track_script {
        check_nginx_is_run
    }
}

安装 killall 命令

yum install psmisc

编写 shell 脚本

#!/bin/bash
A=`ps -C nginx --no-header |wc -l`
if [ $A -eq  ];then
      /usr/local/nginx/sbin/nginx                #重启nginx
      sleep
      if [ `ps -C nginx --no-header |wc -l` -eq  ];then    #nginx重启失败，则停掉keepalived服务，进行VIP转移
              killall keepalived
      fi
fi

设置可执行命令

chmod a+x check_nginx_is_run.sh

如果你是window下放进去的,会有

-bash: ./check_nginx_is_run.sh: /bin/bash^M: 坏的解释器: 没有那个文件或目录

解决办法

sed -i 's/\r$//' check_nginx_is_run.sh

查看master keepalived 日记 vim /var/log/messages

查看 backup

好了不说了 停止nginx ,再不行就关机 192.168.1.120 or 121

如果你service nginx stop 来测试,你会发现关不掉,因为脚本重启了

你会发现OK了~