keepalived+nginx双机热备

软件下载：
http://www.keepalived.org/software/keepalived-1.1.15.tar.gz
http://www.linuxvirtualserver.org/software/kernel-2.6/ipvsadm-1.24.tar.gz


主从：
                      / 172.16.0.200（master）+nginx\
VIP：172.16.0.199<===>                                 <==>mysql集群
                      \ 172.16.0.201  (slave) +nginx/


主从安装软件：

这里可以省略安装ipvsadm
#ln -s /usr/src/kernels/2.6.18-164.el5-x86_64/ /usr/src/linux
#tar zxvf ipvsadm-1.24.tar.gz
#cd ipvsadm-1.24
#make && make install

#tar zxvf keepalived-1.1.15.tar.gz
#cd keepalived-1.1.15
#./configure && make && make install
#find / -name keepalived # 查看keepalived位置
#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/
#service keepalived start|stop #做成系统启动服务方便管理.

主keepalived配置文件：
! Configuration File for keepalived

global_defs {
   notification_email {
        [e-mail]
   }
   notification_email_from [e-mail]
   smtp_server 127.0.0.1
   smtp_connect_timeout 30
   router_id LVS_DEVEL
}
vrrp_script chk_http_port {
        script "/etc/keepalived/nginx_pid.sh"
        interval 2
         weight 2
}
! VIP1
vrrp_instance VI_1 {
    state MASTER
    interface eth0
    mcast_src_ip 172.16.0.200
    virtual_router_id 51
    lvs_sync_daemon_inteface eth0
    priority 100
    advert_int 1
    authentication {
        auth_type PASS
        auth_pass 1111
    }
    track_script {
        chk_http_port
   }
    virtual_ipaddress {
        172.16.0.199
    }
}
从keepalived配置文件：
! Configuration File for keepalived

global_defs {
   notification_email {
        [e-mail]
   }
   notification_email_from [e-mail]
   smtp_server 127.0.0.1
   smtp_connect_timeout 30
   router_id LVS_DEVEL
}
vrrp_script chk_http_port {
        script "/etc/keepalived/nginx_pid.sh"
        interval 2
         weight 2
}
! VIP1
vrrp_instance VI_1 {
    state BACKUP
    interface eth0
    virtual_router_id 51
    mcast_src_ip 172.16.0.201
    lvs_sync_daemon_inteface eth0
    priority 80
    advert_int 1
    authentication {
        auth_type PASS
        auth_pass 1111
    }
    track_script {
                chk_http_port
    }
    virtual_ipaddress {
        172.16.0.199
    }
}
nginx_pid.sh脚本检查nginx检查：
#/bin/bash
Q=`ps -C nginx --no-header |wc -l`
if [ $Q -eq 0 ];then
        /usr/local/nginx/sbin/nginx
        sleep 3
        if [ `ps -C nginx --no-header |wc -l` -eq 0 ];then
                killall keepalived
        fi
fi