LVS+DR模式+keepalived

LVS+DR模式+keepalived

上一篇博客我们说了三种模式，NAT,TUN,DR这次是DR+Keepalived

先了解什么是Keepalived

keepalived采用VRRP热备份协议实现Linux服务器的多机热备功能
VRRP,虚拟路由冗杂协议，是针对路由器的一种备份解决方案

keepalived可以实现多机热备，每个热备组可有多台服务器，最常用的就是双机热备
双击热备的故障切换是由虚拟IP地址的飘逸来实现，适用于各种应用服务器

LVS-DR的ARP问题

在LVS-DR的负载均衡群集中，负载均衡器与节点服务器都要配置相同的VIP地址
在局域网中具有相同的IP地址，势必会造成服务器APR通信的紊乱
当一个ARP广播发送到LVS-DR集群时，因为负载均衡器和节点服务器都是连接到相同的网络上，它们都会接收到ARP广播
此时只有前端的负载均衡器进行响应。其他节点服务器不应该响应ARP广播

LVS-DR的ARP问题解决方案

对节点服务器进行处理，使其不响应针对VIP的ARP请求
使用虚接口lo:0承载VIP地址
设置内核参数arp_ignore=1:系统只响应目的IP为本地IP的ARP请求

下面我们来做实验

实验规划

我们需要五台虚拟机
DR1 主服务器 192.168.100.201
DR4 备份服务器 192.168.100.202
web 5 192.168.100.221
web 7 192.168.100.222
vip 192.168.100.10
clent 192.168.100.50

把需要的LVS模块，keepalived,http分别装好

#1，4
[root@localhost ~]# yum install ipvsadm keepalived -y
#5，7
[root@localhost ~]# yum install httpd -y

第一台主负载均衡调度器选择仅主机模式，配置网卡

[root@localhost ~]# vim /etc/sysconfig/network-scripts/ifcfg-ens33 
BOOTPROTO=static #静态
DEFROUTE=yes
IPV4_FAILURE_FATAL=no
IPV6INIT=yes
IPV6_AUTOCONF=yes

IPV6_DEFROUTE=yes
IPV6_FAILURE_FATAL=no
IPV6_ADDR_GEN_MODE=stable-privacy
NAME=ens33
UUID=849aa04e-1874-490f-8cb0-b2fde4b9a6f8
DEVICE=ens33
ONBOOT=yes
IPADDR=192.168.100.201 #地址
NETMASK=255.255.255.0 #子网 掩码
GATEWAY=192.168.100.1 #网关
[root@localhost ~]# systemctl restart network #ch重启网络服务
[root@localhost ~]# ifconfig #查看固定地址是否生效

第二台4备份负载均衡调度器，绑定仅主机模式，配置网卡

[root@localhost ~]# vim /etc/sysconfig/network-scripts/ifcfg-ens33 

BOOTPROTO=static
DEFROUTE=yes
IPV4_FAILURE_FATAL=no
IPV6INIT=yes
IPV6_AUTOCONF=yes
IPV6_DEFROUTE=yes
IPV6_FAILURE_FATAL=no
IPV6_ADDR_GEN_MODE=stable-privacy
NAME=ens33
UUID=c3f0a196-6819-4702-9b54-7cad18402591
DEVICE=ens33
ONBOOT=yes
IPADDR=192.168.100.202
NETMASK=255.255.255.0
GATEWAY=192.168.100.1
[root@localhost ~]# systemctl restart network
[root@localhost ~]# ifconfig

第三台5web服务器绑定仅主机模式，配置网卡

[root@localhost ~]# vim /etc/sysconfig/network-scripts/ifcfg-ens33 

BOOTPROTO=static
DEFROUTE=yes
IPV4_FAILURE_FATAL=no
IPV6INIT=yes
IPV6_AUTOCONF=yes
IPV6_DEFROUTE=yes
IPV6_FAILURE_FATAL=no
IPV6_ADDR_GEN_MODE=stable-privacy
NAME=ens33
UUID=a6cf69fe-eb42-4a99-9239-0da4cdeae0c7
DEVICE=ens33
ONBOOT=yes
IPADDR=192.168.100.221
NETMASK=255.255.255.0
GATEWAY=192.168.100.1
[root@localhost ~]# systemctl restart network
[root@localhost ~]# ifconfig

第四台7web服务器绑定仅主机模式，配置网卡

[root@localhost ~]# vim /etc/sysconfig/network-scripts/ifcfg-ens33 
BOOTPROTO=static
DEFROUTE=yes
IPV4_FAILURE_FATAL=no
IPV6INIT=yes
IPV6_AUTOCONF=yes
IPV6_DEFROUTE=yes
IPV6_FAILURE_FATAL=no
IPV6_ADDR_GEN_MODE=stable-privacy
NAME=ens33
UUID=447e510f-fea3-4b6c-8f47-d0c6319ead28
DEVICE=ens33
ONBOOT=yes
IPADDR=192.168.100.222
NETMASK=255.255.255.0
GATEWAY=192.168.100.1
[root@localhost ~]# systemctl restart network
[root@localhost ~]# ifconfig

配置第一台1主服务器

[root@localhost ~]# vim /etc/sysctl.conf
net.ipv4.ip_forward=1
#proc响应关闭重定向功能
net.ipv4.conf.all.send_redirects = 0
net.ipv4.conf.default.send_redirects = 0
net.ipv4.conf.ens33.send_redirects = 0
[root@localhost ~]# sysctl -p #生效
net.ipv4.ip_forward = 1
net.ipv4.conf.all.send_redirects = 0
net.ipv4.conf.default.send_redirects = 0
net.ipv4.conf.ens33.send_redirects = 0

创建虚拟网卡

[root@localhost ~]# cd /etc/sysconfig/network-scripts/

[root@localhost network-scripts]# cp -p ifcfg-ens33 ifcfg-ens33:0
[root@localhost network-scripts]# vim ifcfg-ens33:0
100dd

DEVICE=ens33:0
ONBOOT=yes
IPADDR=192.168.100.10
NETMASK=255.255.255.0

[root@localhost network-scripts]# ifup ens33:0 #开启网卡，这个网关是用来做虚拟IP的，相当于一给访问入口

[root@localhost network-scripts]# ifconfig
[root@localhost network-scripts]# cd /etc/init.d/
[root@localhost init.d]# vim dr.sh
#!/bin/bash
GW=192.168.100.1
VIP=192.168.100.10
RIP1=192.168.100.221
RIP2=192.168.100.222
case "$1" in
start)
        /sbin/ipvsadm --save > /etc/sysconfig/ipvsadm
        systemctl start ipvsadm
        /sbin/ifconfig ens33:0 $VIP broadcast $VIP netmask 255.255.255.255 broadcast $VIP up
        /sbin/route add -host $VIP dev ens33:0
        /sbin/ipvsadm -A -t $VIP:80 -s rr
        /sbin/ipvsadm -a -t $VIP:80 -r $RIP1:80 -g
        /sbin/ipvsadm -a -t $VIP:80 -r $RIP2:80 -g
        echo "ipvsadm starting --------------------[ok]"
        ;;
        stop)
        /sbin/ipvsadm -C
        systemctl stop ipvsadm
        ifconfig ens33:0 down
        route del $VIP
        echo "ipvsadm stoped---------------------[ok]"
        ;;
        status)
        if [ ! -e /var/lock/subsys/ipvsadm ];then
        echo "ipvsadm stoped---------------"
        exit 1
                else
                echo "ipvsamd Runing ---------[ok]"
        fi
        ;;
        *)
        echo "Usage: $0 {start|stop|status}"
    exit 1
        esac
        exit 0
   [root@localhost init.d]# service dr.sh start
ipvsadm starting --------------------[ok]
[root@localhost init.d]# systemctl status ipvsadm

配置第一台5web服务器

[root@localhost ~]# systemctl start httpd.service 
[root@localhost ~]# systemctl stop firewalld.service 
[root@localhost ~]# setenforce 0
[root@localhost ~]# cd /var/www/html/
[root@localhost html]# echo "this is accp web" > index.html
[root@localhost html]# cd /etc/sysconfig/network-scripts/
[root@localhost network-scripts]# cp ifcfg-lo ifcfg-lo:0
[root@localhost network-scripts]# vim ifcfg-lo:0
DEVICE=lo:0
IPADDR=192.168.100.10
NETMASK=255.255.255.0
ONBOOT=yes

[root@localhost network-scripts]# cd /etc/init.d/
[root@localhost init.d]# vim web.sh
#写一个脚本让它能响应调度服务器的控制，服务的启动和关闭
#!/bin/bash
VIP=192.168.100.10
        case "$1" in
        start)
                ifconfig lo:0 $VIP netmask 255.255.255.255 broadcast $VIP
                /sbin/route add -host $VIP dev lo:0
                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)
                ifconfig lo:0 down
                route del $VIP /dev/null 2>&1
                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
                echo "RealServer Stopd"
                ;;
        *)
                echo "Usage: $0 {start|stop}"
                exit 1
        esac
        exit 0

[root@localhost init.d]# chmod +x web.sh
[root@localhost init.d]# service web.sh start
RealServer Start OK 
[root@localhost init.d]# ifup lo:0 #开启虚拟网卡
[root@localhost network-scripts]# ifconfig
lo:0: flags=73<UP,LOOPBACK,RUNNING>  mtu 65536
        inet 192.168.100.10  netmask 255.255.255.0
        loop  txqueuelen 1  (Local Loopback)

[root@localhost network-scripts]# firefox "http://127.0.0.1/" & #用火狐浏览器去访问回访地址，放在后台运行
[2] 17973

配置第二台7web服务器

[root@localhost ~]# systemctl start httpd

[root@localhost ~]# systemctl stop firewalld.service 
[root@localhost ~]# setenforce 0

[root@localhost ~]# cd /var/www/html/
[root@localhost html]# echo "this is kgv web" > index.html
[root@localhost html]# cd /etc/sysconfig/network-scripts/
[root@localhost network-scripts]# cp ifcfg-lo ifcfg-lo:0
[root@localhost network-scripts]# vim ifcfg-lo:0
DEVICE=lo:0
IPADDR=192.168.100.10
NETMASK=255.255.255.0
ONBOOT=yes
[root@localhost network-scripts]# cd /etc/init.d/
[root@localhost init.d]# vim web.sh

#!/bin/bash
VIP=192.168.100.10
        case "$1" in
        start)
                ifconfig lo:0 $VIP netmask 255.255.255.255 broadcast $VIP
                /sbin/route add -host $VIP dev lo:0
                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)
                ifconfig lo:0 down
                route del $VIP /dev/null 2>&1
                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
                echo "RealServer Stopd"
                ;;
        *)
                echo "Usage: $0 {start|stop}"
                exit 1
        esac
        exit 0
[root@localhost init.d]# chmod +x web.sh 
[root@localhost init.d]# ifup lo:0
[root@localhost init.d]# service web.sh start
RealServer Start OK 
[root@localhost init.d]# firefox "http://127.0.0.1/" &
[1] 17916

去客户端去测试一下，先设置同一网段的地址

去1主服务器测试能不能Ping通两个web服务器

[root@localhost init.d]# ping 192.168.100.221
PING 192.168.100.221 (192.168.100.221) 56(84) bytes of data.
64 bytes from 192.168.100.221: icmp_seq=1 ttl=64 time=0.416 ms
64 bytes from 192.168.100.221: icmp_seq=2 ttl=64 time=0.420 ms
[root@localhost init.d]# ping 192.168.100.222
PING 192.168.100.222 (192.168.100.222) 56(84) bytes of data.
64 bytes from 192.168.100.222: icmp_seq=1 ttl=64 time=0.348 ms
64 bytes from 192.168.100.222: icmp_seq=2 ttl=64 time=0.490 ms

再去客户端测试一下，我们的LVS没问题

（我们刷新一下就跳出第二个网页了）

去主服务器1配置keepalive

[root@localhost keepalived]# vim keepalived.conf

 10    smtp_server 127.0.0.1
 12    router_id LVS_01
22     virtual_router_id 10
 27         auth_pass abc123
30         192.168.100.10  #把原来的删掉我们只需要一个

36 virtual_server 192.168.100.10 80 {
 39     lb_kind DR
45         TCP_CHECK {

43     real_server 192.168.100.221 80 {
 44         weight 1
 45         TCP_CHECK {
 46             connect_port 80
 47             connect_timeout 3
 48             nb_get_retry 3
 49             delay_before_retry 3
 50         }   
 51     }         
 52     real_server 192.168.100.222 80 {
 53         weight 1
 54         TCP_CHECK {
 55             connect_port 80
 56             connect_timeout 3

[root@localhost keepalived]# systemctl start keepalived.service 
[root@localhost keepalived]# systemctl status keepalived.service #查看状态，如果没起来在开启一次
[root@localhost keepalived]# ip addr show dev ens33:0 #查看网卡有没有被启动起来
2: ens33: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000
    link/ether 00:0c:29:c9:dd:05 brd ff:ff:ff:ff:ff:ff
    inet 192.168.100.201/24 brd 192.168.100.255 scope global ens33
       valid_lft forever preferred_lft forever
    inet 192.168.100.10/24 brd 192.168.100.255 scope global secondary ens33:0
       valid_lft forever preferred_lft forever
    inet6 fe80::e3c7:14af:6e4d:7216/64 scope link 
       valid_lft forever preferred_lft forever

同样的配置第二台备份的4服务器

[root@localhost ~]# systemctl stop firewalld.service 
[root@localhost ~]# setenforce 0
[root@localhost ~]# vim /etc/sysctl.conf
net.ipv4.ip_forward=1
#proc响应关闭重定向功能
net.ipv4.conf.all.send_redirects = 0
net.ipv4.conf.default.send_redirects = 0
net.ipv4.conf.ens33.send_redirects = 0
[root@localhost ~]# sysctl -p #生效
net.ipv4.ip_forward = 1
net.ipv4.conf.all.send_redirects = 0
net.ipv4.conf.default.send_redirects = 0
net.ipv4.conf.ens33.send_redirects = 0

创建虚拟网卡

[root@localhost ~]# cd /etc/sysconfig/network-scripts/

[root@localhost network-scripts]# cp -p ifcfg-ens33 ifcfg-ens33:0
[root@localhost network-scripts]# vim ifcfg-ens33:0
100dd

DEVICE=ens33:0
ONBOOT=yes
IPADDR=192.168.100.10
NETMASK=255.255.255.0
[root@localhost network-scripts]# service network restart
Restarting network (via systemctl):                        [  确定  ]

[root@localhost network-scripts]# ifup ens33:0 #开启网卡，这个网关是用来做虚拟IP的，相当于一给访问入口

[root@localhost network-scripts]# ifconfig
[root@localhost network-scripts]# cd /etc/init.d/
[root@localhost init.d]# vim dr.sh
#!/bin/bash
GW=192.168.100.1
VIP=192.168.100.10
RIP1=192.168.100.221
RIP2=192.168.100.222
case "$1" in
start)
        /sbin/ipvsadm --save > /etc/sysconfig/ipvsadm
        systemctl start ipvsadm
        /sbin/ifconfig ens33:0 $VIP broadcast $VIP netmask 255.255.255.255 broadcast $VIP up
        /sbin/route add -host $VIP dev ens33:0
        /sbin/ipvsadm -A -t $VIP:80 -s rr
        /sbin/ipvsadm -a -t $VIP:80 -r $RIP1:80 -g
        /sbin/ipvsadm -a -t $VIP:80 -r $RIP2:80 -g
        echo "ipvsadm starting --------------------[ok]"
        ;;
        stop)
        /sbin/ipvsadm -C
        systemctl stop ipvsadm
        ifconfig ens33:0 down
        route del $VIP
        echo "ipvsadm stoped---------------------[ok]"
        ;;
        status)
        if [ ! -e /var/lock/subsys/ipvsadm ];then
        echo "ipvsadm stoped---------------"
        exit 1
                else
                echo "ipvsamd Runing ---------[ok]"
        fi
        ;;
        *)
        echo "Usage: $0 {start|stop|status}"
    exit 1
        esac
        exit 0

[root@localhost init.d]# chmod +x dr.sh
[root@localhost init.d]# service dr.sh start
ipvsadm starting --------------------[ok]
[root@localhost init.d]# cd /etc/keepalived/
[root@localhost keepalived]# vim keepalived.conf 
 10    smtp_server 127.0.0.1
 12    router_id LVS_02
 20     state BACKUP
 22     virtual_router_id 10
 23     priority 99
27         auth_pass abc123
30         192.168.100.10

[root@localhost keepalived]# systemctl start keepalived.service 
[root@localhost keepalived]# systemctl status keepalived.service #查看状态，如果没起来在开启一次

我们把主服务器1关掉，去客户端去测试一下是不是还能Ping通

[root@localhost keepalived]# ifdown ens33:0

C:\Users\CHEN>ping 192.168.100.10

正在 Ping 192.168.100.10 具有 32 字节的数据:
来自 192.168.100.10 的回复: 字节=32 时间<1ms TTL=64
来自 192.168.100.10 的回复: 字节=32 时间<1ms TTL=64
来自 192.168.100.10 的回复: 字节=32 时间<1ms TTL=64
来自 192.168.100.10 的回复: 字节=32 时间<1ms TTL=6

来源：51CTO

作者：wx5d3a7feeb53cc

链接：https://blog.51cto.com/14469918/2465762