nginx+keepalived 双机热备

对于中、小型企业，如果没有资金去购买昂贵的四/七层负载均衡交换机，那么Nginx是不错的七层负载均衡选择，并 且可以通过Nginx + Keepalived实现Nginx 负载均衡器双机互备，任意一台机器发生故障，对方都能够将虚拟IP接管过去。以下内容为第三次更新了，下面将其安装步骤详细说明下：

 

 一、安装nginx，上一篇已经有安装步骤，请看上一篇文章

 

 

二、安装keepalived

keepalived 下载地址：http://www.keepalived.org/software/
wget http://www.keepalived.org/software/keepalived-1.2.2.tar.gz
tar zxvf keepalived-1.2.2.tar.gz
cd keepalived-12.2./configure --prefix=/usr/local/keepalived
make
make install
cp /usr/local/keepalived/sbin/keepalived /usr/sbin/
cp /usr/local/keepalived/etc/sysconfig/keepalived /etc/sysconfig/
cp /usr/local/keepalived/etc/rc.d/init.d/keepalived /etc/init.d/
mkdir /etc/keepalived
cd /etc/keepalived/

 

主配置文件

vim keepalived.conf

 

global_defs {        ####全局定义
   notification_email {        #####指定keepalived在发生事件时(比如切换),需要发送的email对象,可以多个,每行一个
    [email protected]
   }
   notification_email_from [email protected]
   smtp_server 127.0.0.1          #####指定发送email的smtp服务器
   smtp_connect_timeout 30
   router_id LVS_DEVEL          #######运行keepalived的机器的一个标识
}
vrrp_sync_group VG1 {
  group {
    VI_1
    VI_2
   }
}
vrrp_script chk_nginx {
        script    "/etc/chk_nginx.sh"     ###监控脚本
        interval 2      ###监控时间
        #weight -2

}
vrrp_instance VI_1 {
    state MASTER
    interface eth0
#    track_interface {
#       eth0
#       eth1
#   }
    virtual_router_id 51      #VRID标记 master和backup必须一致
    mcast_src_ip 192.168.2.113
    #发送多播包的地址,如果不设置默认使用绑定的网卡的primary ip
    priority 150
    advert_int 1
    authentication {
        auth_type PASS
        auth_pass 1111
    }
   track_script {
        chk_nginx         ### 就是上面vrrp_script后面的实例名称   执行监控的服务
    }
    virtual_ipaddress {
       192.168.2.116
        }
}

vrrp_instance VI_2 {
    state BACKUP
    interface eth0
    tual_router_id 52
    mcast_src_ip 192.168.100.113
    priority 149
    advert_int 1
    authentication {
        auth_type PASS
        auth_pass 1111
    }
#    track_interface {
#       eth0
#       eth1
#    }
    virtual_ipaddress {
       192.168.100.117
        }
}

另一主的配置文件

 

 

global_defs { ####全局定义
 notification_email { #####指定keepalived在发生事件时(比如切换),需要发送的email对象,可以多个,每行一个
 123.com
 }
 notification_email_from [email protected]
 smtp_server 127.0.0.1 #####指定发送email的smtp服务器
 smtp_connect_timeout 30
 router_id LVS_DEVEL #######运行keepalived的机器的一个标识
}
vrrp_sync_group VG1 {
 group {
 VI_1
 VI_2
 }
}
vrrp_script chk_nginx {
 script "/etc/chk_nginx.sh" ###监控脚本
 interval 2 ###监控时间
 #weight -2

}
vrrp_instance VI_1 {
 state BACKUP
 interface eth0
# track_interface {
# eth0
# eth1
# }
 virtual_router_id 51 #VRID标记 master和backup必须一致
 mcast_src_ip 192.168.2.112
 #发送多播包的地址,如果不设置默认使用绑定的网卡的primary ip
 priority 149
 advert_int 1
 authentication {
 auth_type PASS
 auth_pass 1111
 }

 virtual_ipaddress {
 192.168.2.116
 }
}

vrrp_instance VI_2 {
 state MASTER
 interface eth0
 tual_router_id 52
 mcast_src_ip 192.168.100.112
 priority 150
 advert_int 1
 authentication {
 auth_type PASS
 auth_pass 1111
 }
 track_script {
 chk_nginx ### 就是上面vrrp_script后面的实例名称 执行监控的服务
 }
# track_interface {
# eth0
# eth1
 }
 virtual_ipaddress {
 192.168.100.117
 }
}

###以上配置在写的时候一定要注意有空格的地方一定要加上（很多小的细节一定要注意）

下面是 自己定义监控nginx的脚本 chk_nginx.sh

 

vim  chk_nginx.sh
#!/bin/bash
url="http://192.168.100.1/index.html"
status=$(/usr/bin/curl -s --head "$url"|awk '/HTTP/ {print $2}')
if[ "$status" != "200" ]; then
/etc/init.d/keepalived stop
fi