lvs DR模式 高可用服务器搭建

环境和集群说明

系统：Centos 6.5

# VIP虚拟IP（向外公开的公网IP）
172.20.17.200

# Director 服务器（调度器）
172.20.17.218
172.20.17.219


Real 真实服务器（后端服务器）
172.20.17.210
172.20.17.211

Director 服务器配置

安装依赖包：ipvsadm + keepalived

# 依赖包安装
yum install popt-static kernel-devel make gcc openssl-devel lftp libnl* popt* -y

# 安装lvs
ln -s /usr/src/kernels/2.6.32-642.1.1.el6.x86_64/ /usr/src/linux
wget http://www.linuxvirtualserver.org/software/kernel-2.6/ipvsadm-1.26.tar.gz
tar -zxvf ipvsadm-1.26.tar.gz
cd ipvsadm-1.26
make
make install

# 安装Keepalived
wget http://www.keepalived.org/software/keepalived-1.2.21.tar.gz
wget http://www.keepalived.org/software/keepalived-1.2.4.tar.gz
tar zxvf keepalived-1.2.4.tar.gz
cd keepalived-1.2.4
./configure \
--prefix=/usr/local/keepalived \
--sysconf=/etc/ \
--with-kernet-dir=/usr/src/kernels/2.6.32-642.1.1.el6.x86_64/ \
make
make install

# 将keepalived做成启动服务，方便管理
cp /usr/local/keepalived/sbin/keepalived /usr/sbin/
chkconfig --add keepalived
chkconfig --level 2345 keepalived on
service keepalived start | stop

# 开启路由转发
vim /etc/sysctl.conf 
net.ipv4.ip_forward = 1
sysctl -p

编辑配置文件Keepalived.conf

文件路径：/etc/keepalived/keepalived.conf

# 编辑配置文件
! Configuration File for keepalived

global_defs {
   # 下面都是邮箱配置
   notification_email {
     [e-mail]
     [e-mail]
   }
   notification_email_from [e-mail]
   smtp_server smtp.qq.com
   smtp_connect_timeout 30
   router_id LVS_DEVEL
}

vrrp_instance VI_1 {
    state MASTER                   # 备份服务器上将MASTER改为BACKUP 
    interface eth0                 # HA监测网络接口
    virtual_router_id 51           # 主、备机的virtual_router_id必须相同
    priority 100                   # 主、备机取不同的优先级，主机值较大，备份机值较小
    advert_int 1                   # VRRP Multicast广播周期秒数
    authentication {
        auth_type PASS             # VRRP认证方式
        auth_pass 1111             # VRRP口令字
    }
    virtual_ipaddress {
        172.20.17.200                 # 如果有多个VIP，继续换行填写
    }
}

# VIP设置
virtual_server 172.20.17.200 80 {
    delay_loop 6                   # 每隔2秒查询realserver状态
    
    # 调度算法（一共10种）
    # [静态] rr [Round Robin] 轮询调度，权重无意义
    # [静态] wrr [Weighted Round Robin] 加权轮询，权重有意义
    # [静态] DH [Destination Hashing] 目标地址散列,一个用户一直访问一个服务器，可以缓存一些数据，权重有意义
    # [静态] SH [Source Hashing] 源地址散列
    # [动态] lc [Least Connections] 最少链接
    # [动态] wlc [Weighted Least Connections] 加权最少链接
    # [动态] sed [Shortest Expected Delay Scheduling SED] 最短的期望延迟,不考虑非活动链接，只考虑活动链接数
    # [动态] LBLC [Locality-Based Least Connections] 基于局部性的最少链接 
    # [动态] LBLCR [Locality-Based Least Connections with Replication] 带复制的基于局部性最少链接
    # [动态] NQ [Never Queue Scheduling NQ] 最少队列调度
    
    lb_algo wlc
    
    # 调度模式定义
    # NAT：进出都通过调度器，效率低
    # DR：直接路由模式（进调度器，出真是主机直接回复）
    # TUN：隧道模式（类似CDN模式）
    lb_kind DR
    # persistence_timeout 60       # 同一IP的连接60秒内被分配到同一台realserver
    protocol TCP                   # 用TCP协议检查realserver状态

    # 真实主机1配置
    real_server 172.20.17.210 80 {
        weight 3                     # 权重
        TCP_CHECK {                  # TCP协议检查（HTTP_GET, TCP_CHECK）
            connect_timeout 3        # 连接超时时间
            nb_get_retry 3           # 重试次数
            delay_before_retry 3     # 每次重试前等待延迟时间
            connect_port 80          # 链接端口
        }
    }
    
    # 真实主机2配置
    real_server 172.20.17.211 80 {
        weight 3
        TCP_CHECK {
            connect_timeout 3
            nb_get_retry 3
            delay_before_retry 3
            connect_port 80
        }
    }
}

# 保存退出

启动

# 防火墙设置
vim /etc/sysconfig/iptables

# 增加一条防火墙规则
-A INPUT -m state --state NEW -m tcp -p tcp --dport 80 -j ACCEPT

# 重启防火墙
/etc/init.d/iptables restart

# 重启keepalived
/etc/init.d/keepalived start
ipvsadm -L -n

Real 真实服务器配置

脚本名称：lvs_real_server_dr.sh
脚本路劲：/etc/init.d/lvs_real_server_dr.sh
脚本权限：chmod a+x /etc/init.d/lvs_real_server_dr.sh

#!/bin/bash
# chkconfig: - 55 45
#DR

VIPLIST=("172.20.17.200");
VIPLENG=${#VIPLIST[*]};
VIPI=0;

. /etc/rc.d/init.d/functions

case "$1" in
start)
    while [ $VIPI -lt $VIPLENG ]; do
        ifconfig lo:${VIPI} ${VIPLIST[$VIPI]} broadcast ${VIPLIST[$VIPI]} netmask 255.255.255.255
        /sbin/route add -host ${VIPLIST[$VIPI]} dev lo:${VIPI}
        let VIPI++
    done
    echo "1" >/proc/sys/net/ipv4/conf/lo/arp_ignore
    echo "2" >/proc/sys/net/ipv4/conf/lo/arp_announce
    echo "1" >/proc/sys/net/ipv4/conf/all/arp_ignore
    echo "2" >/proc/sys/net/ipv4/conf/all/arp_announce
    sysctl -p >/dev/null 2>&1
    echo "RealServer Start OK"
    ;;
    
stop)
    while [ $VIPI -lt $VIPLENG ]; do
        ifconfig lo:${VIPI} down
        /sbin/route del ${VIPLIST[$VIPI]} >/dev/null 2>&1
        let VIPI++
    done
    echo "0" >/proc/sys/net/ipv4/conf/lo/arp_ignore
    echo "0" >/proc/sys/net/ipv4/conf/lo/arp_announce
    echo "0" >/proc/sys/net/ipv4/conf/all/arp_ignore
    echo "0" >/proc/sys/net/ipv4/conf/all/arp_announce
    /sbin/sysctl -p >/dev/null 2>&1
    echo "RealServer Stoped"
    ;;

status)
    while [ $VIPI -lt $VIPLENG ]; do
        islothere=`/sbin/ifconfig lo:${VIPI} | grep ${VIPLIST[$VIPI]}`
        isrothere=`netstat -rn | grep "lo:${VIPI}" | grep ${VIPLIST[$VIPI]}`
        if [ ! "$islothere" -o ! "isrothere" ];then
        echo "LVS RealServer Stopped ${VIPLIST[$VIPI]}."
        else
        echo "LVS RealServer Running ${VIPLIST[$VIPI]}."
        fi
        let VIPI++
    done
    ;;

*)
    echo "$0: Usage: $0 {start|status|stop}"
    exit 1
    ;;
esac
exit 0


# 添加开机启动服务器
chkconfig --add lvs_real_server_dr.sh
chkconfig --level 2345 lvs_real_server_dr.sh on

# 启动lvs_real_server_dr.sh脚本
/etc/init.d/lvs_real_server_dr.sh start

lvs集群结果验证

验证前必须保证后端的两台真实服务器可以正常访问，有lnmp环境

# 在master负载均衡器上查看
ipvsadm -L -n