Keepalived 双主(互为主从)安装与配置

t4fewq

安装环境:
     OS:   CentOS release 6.5 (Final)
   WEB1:   192.168.1.100
   WEB2:   192.168.1.101
    VIP:   192.168.1.201/202/203/204/205/206

注:VIP 可以根据需要进行配置,例如只需要配置192.168.1.201/202 做双主.
一. keepalived 安装,WEB1,WEB2服务器都需要安装.
安装依赖程序包:
yum install openssl-devel
yum install popt-devel
keepalived安装
cd /opt
wget http://www.keepalived.org/software/keepalived-1.2.12.tar.gz
tar xzf keepalived-1.2.12.tar.gz;
cd keepalived-1.2.12
./configure --prefix=/usr/local/keepalived-1.2.12;
make && make install
cp /usr/local/keepalived-1.2.12/etc/rc.d/init.d/keepalived /etc/init.d/
cp /usr/local/keepalived-1.2.12/etc/sysconfig/keepalived /etc/sysconfig/
chmod +x /etc/init.d/keepalived;
chkconfig --add keepalived;
chkconfig keepalived on
mkdir -p /etc/keepalived     //程序默认使用此目录下面的应用配置.
ln -s /usr/local/keepalived-1.2.12/sbin/keepalived /usr/sbin/

安装错误处理:
configure: error:
!!! OpenSSL is not properly installed on your system. !!!
!!! Can not include OpenSSL headers files. !!!

安装keepalived出现如上错误。
解决方案：安装OpenSSL。
方法很简单，如果是centos，用yum安装就行。

sudo yum install -y openssl openssl-devel

二.keepalived 应用配置
1> WEB1服务器 keepalived配置:

[iyunv@WEB1:~]# cat /etc/keepalived/keepalived.conf
! Configuration File for keepalived
global_defs {
   notification_email {
   admin@domain.com
        }
   notification_email_from admin@domain.com
   smtp_server 192.168.1.254
   smtp_connect_timeout 30
   router_id LVS_DEVEL
}
vrrp_script chk_http_port {
                script "/etc/keepalived/nginx_pid.sh"
                interval 2
                weight 2
}
vrrp_instance VI_1 {
    state MASTER                //主要IP
    interface eth0
    virtual_router_id 51
    priority 100
    advert_int 1
    authentication {
        auth_type PASS
        auth_pass domain.com
    }
track_script {
        chk_http_port
        }

    virtual_ipaddress {
        192.168.1.201
        192.168.1.203
        192.168.1.205
    }
}
vrrp_instance VI_2 {
    state BACKUP                 //备用IP
    interface eth0
    virtual_router_id 52
    priority 99
    advert_int 1
    authentication {
        auth_type PASS
        auth_pass 1domain.com
    }
    virtual_ipaddress {
        192.168.1.202
        192.168.1.204
        192.168.1.206
    }
}
2> WEB2服务器 keepalived配置:

[iyunv@WEB2:~]# cat /etc/keepalived/keepalived.conf
! Configuration File for keepalived
global_defs {
   notification_email {
   admin@domain.com
        }
   notification_email_from admin@domain.com
   smtp_server 192.168.1.254
   smtp_connect_timeout 30
   router_id LVS_DEVEL
}
vrrp_script chk_http_port {
                script "/etc/keepalived/nginx_pid.sh"
                interval 2
                weight 2
}
vrrp_instance VI_1 {
    state BACKUP                  //备用IP
    interface eth0
    virtual_router_id 51
    priority 99
    advert_int 1
    authentication {
        auth_type PASS
        auth_pass domain.com
    }
track_script {
        chk_http_port
        }

    virtual_ipaddress {
        192.168.1.201
        192.168.1.203
        192.168.1.205
    }
}
vrrp_instance VI_2 {
    state MASTER            //主要IP
    interface eth0
    virtual_router_id 52
    priority 100
    advert_int 1
    authentication {
        auth_type PASS
        auth_pass 1domain.com
    }
    virtual_ipaddress {
        192.168.1.202
        192.168.1.204
        192.168.1.206
}
}   
三. WEB1,WEB2 服务器上面的nginx 监控脚本:
chmod 755 /etc/keepalived/nginx_pid.sh
# cat /etc/keepalived/nginx_pid.sh
#!/bin/bash
A=`ps -C nginx --no-header |wc -l`
if [ $A -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

四.keepalived 的关闭与启动:

/etc/init.d/keepalived stop
/etc/init.d/keepalived start

注: WEB1:/]# /etc/init.d/keepalived
Usage: /etc/init.d/keepalived {start|stop|reload|restart|condrestart|status}

五.功能验证

1> WEB1/WEB2 服务器的keepalived 正常启动后:
WEB1服务器检查:
   [iyunv@WEB1:/]# ip add   
2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000
    link/ether 02:0c:33:4f:da:4t brd ff:ff:ff:ff:ff:ff
    inet 192.168.1.100/24 brd 192.168.1.255 scope global eth0
    inet 192.168.1.201/32 scope global eth0
    inet 192.168.1.203/32 scope global eth0
    inet 192.168.1.205/32 scope global eth0

WEB2服务器检查:
   [iyunv@WEB2:/]# ip add   
2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000
    link/ether 02:0c:33:4f:ya:4t brd ff:ff:ff:ff:ff:ff
    inet 192.168.1.101/24 brd 192.168.1.255 scope global eth0
    inet 192.168.1.202/32 scope global eth0
    inet 192.168.1.204/32 scope global eth0
    inet 192.168.1.206/32 scope global eth0

2>当WEB1 keepalived 启动,而WEB2关闭后;所有的VIP 都跑在WEB1上面,反之者在WEB2上面:

WEB1服务器检查:
   [iyunv@WEB1:/]# ip add   
2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000
    link/ether 02:0c:33:4f:da:4t brd ff:ff:ff:ff:ff:ff
    inet 192.168.1.100/24 brd 192.168.1.255 scope global eth0
    inet 192.168.1.201/32 scope global eth0
    inet 192.168.1.203/32 scope global eth0
    inet 192.168.1.205/32 scope global eth0
    inet 192.168.1.202/32 scope global eth0
    inet 192.168.1.204/32 scope global eth0
    inet 192.168.1.206/32 scope global eth0

WEB2服务器检查:
   [iyunv@WEB2:/]# ip add   
2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000
    link/ether 02:0c:e3:4f:bb:4t brd ff:ff:ff:ff:ff:ff
    inet 192.168.1.101/24 brd 192.168.1.255 scope global eth0
注:如果VIP不能正常漂移请检查防火墙配置,及分析 keepalived 日志,本文暂未进行格式化日志配置.
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