LVS 负载均衡配置

LVS全称Linux Virtual Server，Linux虚拟服务器。现在LVS已经是Linux内核标准的一部分。使用LVS可以达到的技术目标是：通过LVS达到的负载均衡技术和Linux操作系统实现一个高性能高可用的Linux服务器群集，它具有良好的可靠性，可拓展性和可操作性。

注意：此次部署的三个节点采用系统为Centos 8-Stream

更改主机名，三个节点都要做

[root@localhost ~]# hostnamectl set-hostname lb
[root@localhost ~]# bash
[root@lb ~]# 

[root@localhost ~]# hostnamectl set-hostname web1
[root@localhost ~]# bash
[root@web1 ~]#

[root@localhost ~]# hostnamectl set-hostname web2
[root@localhost ~]# bash
[root@web2 ~]#

关闭防火墙和selinux，三个节点都要做

systemctl disable --now firewalld
vi /etc/selinux/config 
SELINUX=disabled

配置yum源，三个节点都要做

下面配置的是centos8的yum源，如果是centos7系统，自行到阿里云镜像站配置7的源

curl -o /etc/yum.repos.d/CentOS-Base.repo https://mirrors.aliyun.com/repo/Centos-vault-8.5.2111.repo

sed -i -e '/mirrors.cloud.aliyuncs.com/d' -e '/mirrors.aliyuncs.com/d' /etc/yum.repos.d/CentOS-Base.repo

安装所需包，三个节点都要做

yum -y install net-tools network-scripts

配置lb节点

[root@lb ~]# ifconfig ens33:0 192.168.88.250/32 broadcast 192.168.88.250 up
[root@lb ~]# ip a
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 scope host lo
       valid_lft forever preferred_lft forever
    inet6 ::1/128 scope host 
       valid_lft forever preferred_lft forever
2: ens33: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc fq_codel state UP group default qlen 1000
    link/ether 00:0c:29:20:b3:9e brd ff:ff:ff:ff:ff:ff
    inet 192.168.88.128/24 brd 192.168.88.255 scope global dynamic noprefixroute ens33
       valid_lft 1149sec preferred_lft 1149sec
    inet 192.168.88.250/0 brd 192.168.88.250 scope global ens33:0
       valid_lft forever preferred_lft forever
    inet6 fe80::20c:29ff:fe20:b39e/64 scope link noprefixroute 
       valid_lft forever preferred_lft forever

配置web1节点

[root@web1 ~]# vi /etc/sysctl.conf 
net.ipv4.conf.all.arp_ignore = 1
net.ipv4.conf.all.arp_announce = 2
[root@web1 ~]# sysctl -p
net.ipv4.conf.all.arp_ignore = 1
net.ipv4.conf.all.arp_announce = 2

[root@web1 ~]# ifconfig lo:0 192.168.88.250/32 broadcast 192.168.88.250 up
[root@web1 ~]# ip a
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 scope host lo
       valid_lft forever preferred_lft forever
    inet 192.168.88.250/0 brd 192.168.88.250 scope global lo:0
       valid_lft forever preferred_lft forever
    inet6 ::1/128 scope host 
       valid_lft forever preferred_lft forever
2: ens33: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc fq_codel state UP group default qlen 1000
    link/ether 00:0c:29:5f:81:55 brd ff:ff:ff:ff:ff:ff
    inet 192.168.88.129/24 brd 192.168.88.255 scope global dynamic noprefixroute ens33
       valid_lft 1670sec preferred_lft 1670sec
    inet6 fe80::20c:29ff:fe5f:8155/64 scope link noprefixroute 
       valid_lft forever preferred_lft forever

配置web2节点

[root@web2 ~]# vi /etc/sysctl.conf 
net.ipv4.conf.all.arp_ignore = 1
net.ipv4.conf.all.arp_announce = 2
[root@web2 ~]# sysctl -p
net.ipv4.conf.all.arp_ignore = 1
net.ipv4.conf.all.arp_announce = 2

[root@web2 ~]# ifconfig lo:0 192.168.88.250/32 broadcast 192.168.88.250 up
[root@web2 ~]# ip a
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 scope host lo
       valid_lft forever preferred_lft forever
    inet 192.168.88.250/0 brd 192.168.88.250 scope global lo:0
       valid_lft forever preferred_lft forever
    inet6 ::1/128 scope host 
       valid_lft forever preferred_lft forever
2: ens33: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc fq_codel state UP group default qlen 1000
    link/ether 00:0c:29:94:2f:80 brd ff:ff:ff:ff:ff:ff
    inet 192.168.88.130/24 brd 192.168.88.255 scope global dynamic noprefixroute ens33
       valid_lft 1462sec preferred_lft 1462sec
    inet6 fe80::20c:29ff:fe94:2f80/64 scope link noprefixroute 
       valid_lft forever preferred_lft forever

配置路由信息

[root@lb ~]# route add -host 192.168.88.250 dev ens33:0
[root@lb ~]# route -n
Kernel IP routing table
Destination     Gateway         Genmask         Flags Metric Ref    Use Iface
0.0.0.0         192.168.88.2    0.0.0.0         UG    100    0        0 ens33
192.168.88.0    0.0.0.0         255.255.255.0   U     100    0        0 ens33
192.168.88.250  0.0.0.0         255.255.255.255 UH    0      0        0 ens33

[root@web1 ~]# route add -host 192.168.88.250 dev lo:0
[root@web1 ~]# route -n
Kernel IP routing table
Destination     Gateway         Genmask         Flags Metric Ref    Use Iface
0.0.0.0         192.168.88.2    0.0.0.0         UG    100    0        0 ens33
192.168.88.0    0.0.0.0         255.255.255.0   U     100    0        0 ens33
192.168.88.250  0.0.0.0         255.255.255.255 UH    0      0        0 lo

[root@web2 ~]# route add -host 192.168.88.250 dev lo:0
[root@web2 ~]# route -n
Kernel IP routing table
Destination     Gateway         Genmask         Flags Metric Ref    Use Iface
0.0.0.0         192.168.88.2    0.0.0.0         UG    100    0        0 ens33
192.168.88.0    0.0.0.0         255.255.255.0   U     100    0        0 ens33
192.168.88.250  0.0.0.0         255.255.255.255 UH    0      0        0 lo

配置http

[root@web1 ~]# systemctl enable --now httpd
Created symlink /etc/systemd/system/multi-user.target.wants/httpd.service → /usr/lib/systemd/system/httpd.service.
[root@web1 ~]# echo web1 > /var/www/html/index.html


[root@web2 ~]# yum -y install httpd
[root@web2 ~]# systemctl enable --now httpd
Created symlink /etc/systemd/system/multi-user.target.wants/httpd.service → /usr/lib/systemd/system/httpd.service.
[root@web2 ~]# echo web2 > /var/www/html/index.html

添加规则

[root@lb ~]# yum -y install ipvsadm
[root@lb ~]# ipvsadm -L
IP Virtual Server version 1.2.1 (size=4096)
Prot LocalAddress:Port Scheduler Flags
  -> RemoteAddress:Port           Forward Weight ActiveConn InActConn
[root@lb ~]# ipvsadm -Ln
IP Virtual Server version 1.2.1 (size=4096)
Prot LocalAddress:Port Scheduler Flags
  -> RemoteAddress:Port           Forward Weight ActiveConn InActConn
  
  
[root@lb ~]# ipvsadm -A -t 192.168.88.250:80 -s rr
[root@lb ~]# ipvsadm -Ln
IP Virtual Server version 1.2.1 (size=4096)
Prot LocalAddress:Port Scheduler Flags
  -> RemoteAddress:Port           Forward Weight ActiveConn InActConn
TCP  192.168.88.250:80 rr

[root@lb ~]# ipvsadm -a -t 192.168.88.250:80 -r 192.168.88.129:80 -g
[root@lb ~]# ipvsadm -a -t 192.168.88.250:80 -r 192.168.88.130:80 -g
[root@lb ~]# ipvsadm -Ln
IP Virtual Server version 1.2.1 (size=4096)
Prot LocalAddress:Port Scheduler Flags
  -> RemoteAddress:Port           Forward Weight ActiveConn InActConn
TCP  192.168.88.250:80 rr
  -> 192.168.88.129:80            Route   1      0          0         
  -> 192.168.88.130:80            Route   1      0          0    

查看，打开本机终端使用curl命令

使用watch命令定住屏幕查看进程

[root@lb ~]# watch 'ipvsadm -Ln'