LVS+Keepalived高可用部署

一、LVS+Keepalived高可用部署

  一、keepalived节点部署

　　1、安装keepalived

yum install keepalived ipvsadm -y
mkdir -p /opt/ytd_scripts/keepalived
cat>/opt/ytd_scripts/keepalived/UDP_CHECK.sh<<EOF
#!/bin/bash
/usr/bin/nc -uz -w1 $1 $2 | grep succeeded >/dev/null
exit $?
EOF
cp -rp  /etc/keepalived/keepalived.conf{,.bak}

　　2、更改keepalived.conf

　　注意：加权平均时，2个节点不要设置成1

　　　　1、master节点配置

vrrp_instance VI_1 {
    state BACKUP
    interface ens160
    virtual_router_id 51
    priority 90
    advert_int 1
    authentication {
        auth_type PASS
        auth_pass 20180126
    }
    virtual_ipaddress {
        10.100.62.66
    }
}

###zuul-8080####
virtual_server 10.100.62.66 8080 {
    delay_loop 6
    lb_algo wrr
    lb_kind DR
    persistence_timeout 5
    protocol TCP

    real_server 10.100.62.43 8080 {
        weight 20
        TCP_CHECK {
            connect_timeout 10
            nb_get_retry 3
            delay_before_retry 3
            connect_port 8080
        }
    }

    real_server 10.100.62.44 8080 {
        weight 20
        TCP_CHECK {
            connect_timeout 10
            nb_get_retry 3
            delay_before_retry 3
            connect_port 8080
        }
    }
}

###zuul-8080-udp####
virtual_server 10.100.62.66 8080 {
    delay_loop 6
    lb_algo wrr
    lb_kind DR
    persistence_timeout 5
    protocol UDP
    
    real_server 10.100.62.43 8080 {
        weight 20        MISC_CHECK {
        misc_path "/opt/ytd_scripts/keepalived/UDP_CHECK.sh 10.100.62.43 8080"
        misc_timeout 3
        }
    }   
    
    real_server 10.100.62.44 8080 {
        weight 20
        MISC_CHECK {
        misc_path "/opt/ytd_scripts/keepalived/UDP_CHECK.sh 10.100.62.44 8080"
        misc_timeout 3
        }
    }   
}

　　　　2、slave节点配置

state MASTER -> state BACKUP
priority 100 -> priority 90

　　3、节点开启转发功能

echo 1 > /proc/sys/net/ipv4/ip_forward

  二、验证keepalived

　　1、启动keepalived并设置自启

systemctl enable keepalived
systemctl start keepalived
systemctl status keepalived

　　2、关掉master节点，验证VIP是否到slave上

#在master上执行
systemctl stop keepalived
ip a|grep 'VIP'

#在slave上执行
ip a|gep 'VIP'

  三、两台RS上为ens160:0绑定VIP地址、抑制ARP广播

　　若不绑定循环网卡，将lo网卡换成需要绑定网卡（例如：ens160）

　　1、在RS上写相应脚本

#!/bin/bash
#description: Config realserver

VIP=10.100.62.66

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

case "$1" in
start)
       /sbin/ifconfig ens160:0 $VIP netmask 255.255.255.255 broadcast $VIP
       /sbin/route add -host $VIP dev ens160:0
       echo "1" >/proc/sys/net/ipv4/conf/ens160/arp_ignore
       echo "2" >/proc/sys/net/ipv4/conf/ens160/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)
       /sbin/ifconfig ens160:0 down
       /sbin/route del $VIP >/dev/null 2>&1
       echo "0" >/proc/sys/net/ipv4/conf/ens160/arp_ignore
       echo "0" >/proc/sys/net/ipv4/conf/ens160/arp_announce
       echo "0" >/proc/sys/net/ipv4/conf/all/arp_ignore
       echo "0" >/proc/sys/net/ipv4/conf/all/arp_announce
       echo "RealServer Stoped"
       ;;
*)
       echo "Usage: $0 {start|stop}"
       exit 1
esac

exit 0

　　2、在RS上执行脚本

sh realserver.sh start

二、LVS+Keepalived学习链接

  一、使用LVS实现负载均衡原理及安装配置详解

　　https://www.cnblogs.com/liwei0526vip/p/6370103.html

  二、LVS自动化添加及删除ipvsadm和后端服务器健康状态检测脚本

　　1、LVS director 负载均衡器增加IPVSADM脚本

#!/bin/bash
#chkconfig: - 88 66
#description: this script to add lvs IP

VIP=192.168.0.254
DIP=192.168.0.100
RIP1=192.168.0.101
RIP2=192.168.0.102
PORT=80
SCHELE=wrr
LOCKFILE=/var/lock/subsys/ipvsadm

case $1 in
start)
#增加vip地址
 /sbin/ifconfig eth0:0 $VIP broadcast $VIP netmask 255.255.255.255 up
 /sbin/route add -host $VIP dev eth0:0
#清除防火墙规则
 /sbin/iptables -F
 /sbin/iptables -X
 /sbin/iptables -Z
#开启ip转发功能
 echo 1 > /proc/sys/net/ipv4/ip_forward
#清除ipvsadm 规则
 /sbin/ipvsadm -C
#增加ipvsadm direcotor规则
 /sbin/ipvsadm -A -t $VIP:$PORT -s $SCHELE
#增加realserver 规则
 /sbin/ipvsadm -a -t $VIP:$PORT -r $RIP1 -g
 /sbin/ipvsadm -a -t $VIP:$PORT -r $RIP2 -g
#增加ipvsadm 锁文件
 /bin/touch  $LOCKFILE
;;
stop)
 if [ ! -e $LOCKFILE ];then
  echo "the ipvsadm is stopped..."
 else
 #删除vip地址
  /sbin/ifconfig eth0:0 down
 #关闭ip转发
  echo 0 > /proc/sys/net/ipv4/ip_forward
 #清除ipvsadm 规则
  /sbin/ipvsadm -C
 #删除锁文件
  /bin/touch $LOCKFILE
 fi
;;
status)
 if [ ! -e $LOCKFILE ];then
  echo "the ipvsadm is stopped..."
 else
  echo "the ipvsadm is running..."
 fi
;;
*)
 echo "Usage；$0:{start|stop|status}"
;;
esac

　　2、LVS 增加 real server脚本

#!/bin/bash
#chkconfig: - 77 66
#description: this script to add real server 
#
VIP=192.168.0.254
case $1 in
start)
#arp_ignore: 定义接收到ARP请求时的响应级别；1表示仅在请求的目标地址配置请求到达的接口上的时候，才给予响应
#arp_announce：定义将自己地址向外通告时的通告级别：2表示仅向与本地接口上地址匹配的网络进行通告；
 echo 1 >/proc/sys/net/ipv4/conf/lo/arp_ignore
 echo 1 >/proc/sys/net/ipv4/conf/all/arp_ignore
 echo 2 >/proc/sys/net/ipv4/conf/lo/arp_announce
 echo 2 >/proc/sys/net/ipv4/conf/all/arp_announce
#增加VIP地址到lo:0接口,增加路由条目：目的地址为VIP,由lo:0接口响应（即：源地址为VIP作为响应报文给客户端）
 
 /sbin/ifconfig lo:0 $VIP broadcast $VIP netmask 255.255.255.255 up && /sbin/route add -host $VIP dev lo:0
 
#新建一个锁文件,前面执行成功则建立锁文件
 if [  $? -eq 0 ];then
  /bin/touch /var/lock/subsys/ipvsreal
 else
  echo "fail to add vip address and route."
 fi
;;
stop)
#恢复arp响应级别
 echo 0 >/proc/sys/net/ipv4/conf/lo/arp_ignore
 echo 0 >/proc/sys/net/ipv4/conf/all/arp_ignore
 echo 0 >/proc/sys/net/ipv4/conf/lo/arp_announce
 echo 0 >/proc/sys/net/ipv4/conf/all/arp_announce
#剔除VIP地址（路由地址自动删掉）
  loip=`/sbin/ifconfig lo:0 |grep $VIP`
  if [ ‘$loip‘  == ‘‘ ];then
   echo "VIP address not found."
  else
   /sbin/ifconfig lo:0 down && rm -rf /var/lock/subsys/ipvsreal
   if [ $? -eq 0 ] ;then
    echo "VIP address had been deled."
   else
    echo "VIP address del failly."
    exit 1
   fi
  fi
;;
status)
 if [ ! -e /var/lock/subsys/ipvsreal ];then
  echo "LVS-DR real server stoped."
 else
  echo "LVS-DR real server is running."
 fi
;;
*)
 echo "Usage: $0 {start | stop |status}"
 exit 1
;;
esac

　　3、RS健康状态检查脚本

#!/bin/bash
#chkconfig: - 88 77
#description: check health real server or not
#设置变量：VIP, director端口, 本地地址, real sever IP数组,状态数组（1表示正常，0表示异常）,权重数组，real server 服务地址，LVS 类型，状态检测次数，日志
VIP=192.168.0.254
CPORT=80
FAIL_BACK=127.0.0.1
RS=("192.168.0.101" "192.168.0.102")
declare -a RSSTATUS
RW=("2" "1")
PPORT=80
TYPE=g
CHKLOOP=3
LOG=/var/log/ipvsmonitor.log
#当real server 恢复时，增加 real server 到 director 中
addrs(){
        ipvsadm -a -t $VIP:$CPORT -r $1:$PPORT -$TYPE -w $2
        [ $? -eq 0 ] && return 0 || return 1
}
#当real server 不可用时，删除director中ipvsadm 条目
delrs(){
                ipvsadm -d -t $VIP:$CPORT -r $1:$PPORT
                [ $? -eq 0 ] && return 0 || return 1
}
#real server 状态检测 
checkrs(){
                local I=1
                while [ $I -le $CHKLOOP ];do
                        if curl --connect-timeout 1 http://$1 &>/dev/null;then
                                return 0
                        fi
                let I++
                done
                return 1
}
#初始化状态数组，当ipvsadm 中条目有real server IP规则时 状态为1；当realserver 在ipvsadm 条目中缺失时 状态为0
initstatus(){
        local I
        local COUNT=0
         for I in ${RS[*]};do
                if ipvsadm -L -n |grep "$I:$PPORT" &>/dev/null;then
                        RSSTATUS[$COUNT]=1
                else
                        RSSTATUS[$COUNT]=0
                fi
        let COUNT++
        done
}
#调用初始化函数
initstatus
#定义死循环
while :;do
        let COUNT=0
        #逐个遍历 real server
        for I in ${RS[*]};do
         #检测real server 正常与否
                if checkrs $I ;then
                #当检测到real 正常但ipvsadm中没有real server 条目时增加 real server 条目
                        if [ ${RSSTATUS[$COUNT]} -eq 0 ];then
                                addrs $I ${RW[$COUNT]}
                                [ $? -eq 0 ]&& RSSTATUS[$COUNT]=1 && echo "`date +%F%H:%M:%S`, $I is back." >>$LOG
                        fi
                else
                 #当检测到real server 异常时，删除在 ipvsadm 中异常的realserver 条目
                        if [ ${RSSTATUS[$COUNT]} -eq 1 ];then
                                delrs $I
                                [ $? -eq 0 ]&& RSSTATUS[$COUNT]=0 && echo "`date +%F%H:%M:%S`, $I is gone." >>$LOG
                        fi
                fi       
        let COUNT++
        done
        
#每个五秒钟遍历一次        
sleep 5
done

  三、LVS + Keepalived 实现高可用、负载均衡 Web 集群

　　https://www.cnblogs.com/wangxiaoqiangs/p/5736210.html