【轉】Nginx雙機熱備高可用解決方案

1.用戶通過DNS查詢，得到隨機的VIP1和VIP2。

2.VIP1和VIP2屬於熱備，負載均衡，高可用

當RIP1無法訪問，主機2會檢測到，將VIP1的ip加到的eth0:ha2，即在任何時候都有高可用

3.shell腳本vip和rip要對應，nginx_loadbalance_vip1.sh運行於主機1，運行命令爲

#nohup ./nginx_loadbalance_vip1.sh >/dev/null & 後臺運行

4.對於2臺機器的監控，只需監控RIP即可，同時可以寫一個監控腳本運行的crontab，防止腳本意外終止

結構圖

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主機1的腳本如下

cat nginx_loadbalance_vip1.sh

#!/bin/bash

LANG=C
date=$(date -d "today" +"%Y-%m-%d %H:%M:%S")
BIND_VIP1=192.168.16.238
BIND_VIP2=192.168.16.239
WEB_IP_RIP1=192.168.16.240
WEB_IP_RIP2=192.168.16.241
NETMASK=255.255.255.0
GATEWAY=192.168.16.1
BROADCAST=219.232.254.255
function_bind_vip1()
{
    /sbin/ifconfig eth0:ha1 ${BIND_VIP1} broadcast ${BROADCAST} netmask ${NETMASK} up
    /sbin/route   add -host ${GATEWAY}   dev eth0:ha1
}


function_bind_vip2()
{
    /sbin/ifconfig eth0:ha2 ${BIND_VIP2} broadcast ${BROADCAST} netmask ${NETMASK} up
    /sbin/route  add  -host ${GATEWAY}   dev eth0:ha2
}

function_restart_nginx()
{
    kill -USR1 `cat /var/log/nginx/nginx.pid`
}

function_remove_vip1()
{
   /sbin/ifconfig eth0:ha1 ${BIND_VIP1} broadcast ${BROADCAST} netmask ${NETMASK} down
}

function_remove_vip2()
{
   /sbin/ifconfig eth0:ha2 ${BIND_VIP2} broadcast ${BROADCAST} netmask ${NETMASK} down
}

function_vip_arping1()
{
   /sbin/arping -I eth0 -c 3 -s ${BIND_VIP1} ${GATEWAY} > /dev/null 2>&1
}

function_vip_arping2()
{
   /sbin/arping -I eth0 -c 3 -s ${BIND_VIP2} ${GATEWAY} > /dev/null 2>&1
}

bind_time_vip1="N";
bind_time_vip2="N";




while true
do
      httpcode_rip1=`/usr/bin/curl -o /dev/null -s -w %{http_code} http://${WEB_IP_RIP1}/status.htm`
      httpcode_rip2=`/usr/bin/curl -o /dev/null -s -w %{http_code} http://${WEB_IP_RIP2}/status.htm`
#vip1
if [ x$httpcode_rip1 == "x200" ];
then
   if [ $bind_time_vip1="N" ];
   then
       function_bind_vip1
       function_vip_arping1
       function_restart_nginx
       bind_time_vip1="Y"
   fi
      function_vip_arping1
else
   if [ $bind_time_vip1 == "Y" ];
   then


       function_remove_vip1
       bind_time_vip1="N"
   fi
fi

#vip2
if [ x$httpcode_rip2 == "x200" ];
then
   if [ $bind_time_vip2="Y" ];
   then
       function_remove_vip2
       bind_time_vip2="N"
   fi
else
   if [ $bind_time_vip2 == "N" ];
   then
       function_bind_vip2
       function_vip_arping2
       function_restart_nginx
       bind_time_vip2="Y"
   fi
       function_vip_arping2
fi
sleep 5
done