lvs+keepalived-优快云博客

本文链接：https://blog.youkuaiyun.com/wanchaopeng/article/details/80965658

本文详细介绍LVS-DR模式的配置步骤与原理，包括如何在CentOS 7上搭建LVS-DR环境、配置Keepalived实现高可用，以及LVS-DR模式下ARP协议的工作原理等关键技术点。

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lvs

1.arp解析过程
2.lvs-dr模式
1）lvs-把用户的 VIPmac地址转换为后面RS服务器的mac地址。---目标mac地址DMAC
2）RS服务器本地lo要有VIP
3）RS服务器抑制ARP解析

4）lvs-DR模式下面如果RS是web 要有公网地址

centos7 基本软件准备

1.准备环境

yum -y install wget vim bash-completion lrzsz nmap telnet tree net-tools bind-utils

mv /etc/yum.repos.d/CentOS-Base.repo /etc/yum.repos.d/CentOS-Base.repo.backup
wget -O /etc/yum.repos.d/CentOS-Base.repo http://mirrors.aliyun.com/repo/Centos-7.repo
wget -O /etc/yum.repos.d/epel.repo http://mirrors.aliyun.com/repo/epel-7.repo

1.2 关闭防火墙SELinux

sed -i  's#SELINUX=enforcing#SELINUX=disabled#g' /etc/selinux/config
setenforce 0

1.3 机器准备

lb01 10.0.0.5 172.16.1.5
lb02 10.0.0.6 172.16.1.6
web01 10.0.0.8 172.16.1.8

web02 10.0.0.7 172.16.1.7

web01 web02 准备环境安装nginx

yum install pcre-devel openssl-devel -y

mkdir /home/oldboy/tools -p 
cd /home/oldboy/tools/
wget http://nginx.org/download/nginx-1.10.3.tar.gz

useradd -s /sbin/nologin  -M www

tar xf nginx-1.10.3.tar.gz
cd nginx-1.10.3

./configure --user=www --group=www --prefix=/data/nginx-1.10.3 --with-http_sub_module --with-http_ssl_module
 make && make install 
 
ln -s /data/nginx-1.10.3/ /application/nginx

修改配置文件nginx.conf

worker_processes  1;
events {
    worker_connections  1024;
}
http {
    include       mime.types;
    default_type  application/octet-stream;
    sendfile        on;
    keepalive_timeout  65;
    server {
        listen       80;
        server_name  www.etiantian.org;
        location / {
            root   html/www;
            index  index.php index.html index.htm;
        }
    }
    server {
        listen       80;
        server_name  bbs.etiantian.org;
        location / {
            root   html/bbs;
            index  index.php index.html index.htm;
        }
    }
}

创建试用目录和软件

mkdir -p /data/nginx/html/{www,bbs}
for name in www bbs ;do echo $(hostname) $name >/data/nginx/html/$name/na.html ;done

测试

curl -H Host:www.etiantian.org 10.0.0.8/na.html 
curl -H Host:bbs.etiantian.org 10.0.0.8/na.html 
curl -H Host:www.etiantian.org 10.0.0.7/na.html 
curl -H Host:bbs.etiantian.org 10.0.0.7/na.html

添加hosts解析 windows

10.0.0.7 www.etiantian.org bbs.etiantian.org

##手动在lb01上面添加VIP 10.0.0.3
ip addr add 10.0.0.3/24 dev eth0 label eth0:0

cat /proc/sys/net/ipv4/conf/lo/arp_ignore
cat /proc/sys/net/ipv4/conf/lo/arp_announce
cat /proc/sys/net/ipv4/conf/all/arp_ignore
cat /proc/sys/net/ipv4/conf/all/arp_announce

keepalived.conf 配置文件几部分？
GLOBAL CONFIGURATION

VRRPD CONFIGURATION

LVS CONFIGURATION

mv /etc/keepalived/keepalived.conf{,.ori}
mv keepalived.conf.lvs0*-lb0*.oldboy /etc/keepalived/keepalived.conf

2、ARP协议工作原理---wireshark抓包
3、工作中ARP带来的实际问题和解决方案
a.局域网ARP欺骗原理及解决方法。
b.切换网关路由器，arp表带来的问题。
c.集群架构中高可用服务器对之间的切换，arp表带来的问题及解决办法。

1.5 LVS技术点小结：
1、真正实现调度的工具是IPVS内核模块，工作在linux内核层面。
2、LVS自带的IPVS命令行管理工具是ipvsadm。
3、keepalived实现管理IPVS（配置文件）及负载均衡器的高可用。

####lvs-dr模式配置过程
###lb01 操作
####1.关闭keepalived iptables selinux

####2.手工添加LVS转发

#####1)配置lvs 添加vip
ip addr add 10.0.0.3/24 dev eth0 label eth0:0
#####2)配置lvs规则
ipvsadm-save -n
###查看下当前都已经保存了什么规则
###可以把当前的lvs规则以可以再次使用的形式导出

ipvsadm -C #clear 情况lvs的规则
ipvsadm --set 30 5 60 #tcp超时时间
ipvsadm -A -t 10.0.0.3:80 -s wrr -p 20 #添加一个虚拟服务 vip -s 轮询算法
#rr wrr lc wlc #-p 会话保持的时间
ipvsadm -a -t 10.0.0.3:80 -r 10.0.0.7:80 -g -w 1
ipvsadm -a -t 10.0.0.3:80 -r 10.0.0.8:80 -g -w 1
#-a 添加RS服务器 -r指定RS服务器IP和端口 -g 表示的是 dr模式 -w(weight) 权重
ipvsadm -ln --stats

[root@lb01 ~]# ipvsadm -ln #查看当前lvs的规则
IP Virtual Server version 1.2.1 (size=4096)
Prot LocalAddress:Port Scheduler Flags
协议本地的地址 :端口号码轮询算法其他的参数
-> RemoteAddress:Port Forward Weight ActiveConn InActConn
-> RS服务器的ip地址:端口号码转发规则（lvs模式）
TCP 10.0.0.3:80 wrr persistent 20
-> 10.0.0.7:80 Route 1 0 0
-> 10.0.0.8:80 Route 1 0 0

#####3)手工在RS端绑定
####每台real server端执行
#####绑定vip
ip addr add 10.0.0.3/32 dev lo label lo:0

#####4)手工在RS端抑制ARP响应
cat >>/etc/sysctl.conf<<EOF
net.ipv4.conf.all.arp_ignore = 1
net.ipv4.conf.all.arp_announce = 2
net.ipv4.conf.lo.arp_ignore = 1
net.ipv4.conf.lo.arp_announce = 2
EOF
sysctl -p

####3.lb01 测试 web01 web02 是否可用
[root@lb01 ~]# curl 10.0.0.7/xiaoyu.html
web02 www
[root@lb01 ~]# curl -H Host:blog.etiantian.org 10.0.0.7/xiaoyu.html
web02 blog
[root@lb01 ~]# curl 10.0.0.8/xiaoyu.html
web01 www
[root@lb01 ~]# curl -H Host:blog.etiantian.org 10.0.0.8/xiaoyu.html
web01 blog

#####4.windows hosts 解析
10.0.0.3 www.etiantian.org blog.etiantian.org

####ipvsadm 规则的备份和恢复。
[root@lb01 ~]# ipvsadm-save -n
-A -t 10.0.0.3:80 -s wrr -p 20
-a -t 10.0.0.3:80 -r 10.0.0.7:80 -g -w 1
-a -t 10.0.0.3:80 -r 10.0.0.8:80 -g -w 1
[root@lb01 ~]# ipvsadm-save -n >/tmp/ipvsadm-dr.save
[root@lb01 ~]# cat /tmp/ipvsadm-dr.save
-A -t 10.0.0.3:80 -s wrr -p 20
-a -t 10.0.0.3:80 -r 10.0.0.7:80 -g -w 1
-a -t 10.0.0.3:80 -r 10.0.0.8:80 -g -w 1
[root@lb01 ~]# ipvsadm -ln
IP Virtual Server version 1.2.1 (size=4096)
Prot LocalAddress:Port Scheduler Flags
-> RemoteAddress:Port Forward Weight ActiveConn InActConn
TCP 10.0.0.3:80 wrr persistent 20
-> 10.0.0.7:80 Route 1 0 0
-> 10.0.0.8:80 Route 1 0 0
[root@lb01 ~]# ipvsadm -C
[root@lb01 ~]# ipvsadm -ln
IP Virtual Server version 1.2.1 (size=4096)
Prot LocalAddress:Port Scheduler Flags
-> RemoteAddress:Port Forward Weight ActiveConn InActConn
[root@lb01 ~]# ipvsadm-restore </tmp/ipvsadm-dr.save
[root@lb01 ~]# ipvsadm -ln
IP Virtual Server version 1.2.1 (size=4096)
Prot LocalAddress:Port Scheduler Flags
-> RemoteAddress:Port Forward Weight ActiveConn InActConn
TCP 10.0.0.3:80 wrr persistent 20
-> 10.0.0.7:80 Route 1 0 0

-> 10.0.0.8:80 Route 1 0 0

#####lvs高可用---keepalived
keepalived.conf
#1.global_defs 全局定义
#2.vrrp 实例配置 VIP
#3.lvs的配置

#配置keepalived管理 lvs
#1. 删除之前配置的VIP

#2.配置lb01 lb02 上面的keepalived
[root@lb01 ~]# cat /etc/keepalived/keepalived.conf
global_defs {
router_id LVS_01
}

vrrp_instance VI_1 {
state MASTER
interface eth0
virtual_router_id 51
priority 150
advert_int 1
authentication {
auth_type PASS
auth_pass 1111
}
virtual_ipaddress {
10.0.0.3/24 dev eth0 label eth0:1
}
}

virtual_server 10.0.0.3 80 {
delay_loop 6
lb_algo wrr
lb_kind DR
nat_mask 255.255.255.0
persistence_timeout 50
protocol TCP

real_server 10.0.0.7 80 {
weight 1
TCP_CHECK {
connect_timeout 8
nb_get_retry 3
delay_before_retry 3
connect_port 80
}
}

real_server 10.0.0.8 80 {
weight 1
TCP_CHECK {
connect_timeout 8
nb_get_retry 3
delay_before_retry 3
connect_port 80
}
}
}

[root@lb02 ~]# cat /etc/keepalived/keepalived.conf
global_defs {
router_id LVS_02
}

vrrp_instance VI_1 {
state BACKUP
interface eth0
virtual_router_id 51
priority 100
advert_int 1
authentication {
auth_type PASS
auth_pass 1111
}
virtual_ipaddress {
10.0.0.3/24 dev eth0 label eth0:1
}
}
virtual_server 10.0.0.3 80 {
delay_loop 6
lb_algo wrr
lb_kind DR
nat_mask 255.255.255.0
persistence_timeout 50
protocol TCP

real_server 10.0.0.7 80 {
weight 1
TCP_CHECK {
connect_timeout 8
nb_get_retry 3
delay_before_retry 3
connect_port 80
}
}

real_server 10.0.0.8 80 {
weight 1
TCP_CHECK {
connect_timeout 8
nb_get_retry 3
delay_before_retry 3
connect_port 80
}
}
}

##3.测试是否能管理lvs
ipvsadm-save -n >/tmp/ipvsadm.save

ipvsadm -C

ipvsadm -ln

/etc/init.d/keepalived restart

ipvsadm -ln

1、arp协议的介绍及实现原理。<==加强理解lvs dr模式的原理。
2、lvs几种工作模式: DR,NAT,TUN,FULLNAT
DR
3、lvs高可用 keepalived
4、通过配置keepalived 管理lvs