Load Balancing cluster Introduction LVS introduction LVS scheduling algorithm LVS NAT mode construction

Main open source software LVs, keepalived, Haproxy, Nginx, etc.
The LVS belong to 4 layer (network OSI 7 layer model), Nginx belongs to 7 layer, Haproxy can be considered as 4 layer, can also be used as 7 layer
The Keepalived load balancing function is actually the LVS
LVS This 4-tier load balancer can distribute other ports except 80, such as MySQL, while Nginx supports only Http,https,mail,haproxy and MySQL.
In comparison, the 4-layer LVS is more stable, can withstand more requests, and nginx this 7-layer more flexible, to achieve more personalized requirements

Lvs
Three hosts
1 host Add host only native network card
23 host modifies the IP of the gateway to a 1 NIC
Execute on all three machines
Systemctl Stop Firewalld; SYSTEMC Disable FIREWALLD
Systemctl start iptables-services;
No found, systemctl start iptables
Iptables-f; Service Iptables Save

Install Yum Install-y ipvsadm on the Dispatcher
script on Dir, vim/usr/local/sbin/lvs_nat.sh//the following
#!/bin/bash
#director Enable route forwarding on the server
Echo 1 >/proc/sys/net/ipv4/ip_forward
#关闭icmp的重定向
Echo 0 >/proc/sys/net/ipv4/conf/all/ Send_redirects
Echo 0 >/proc/sys/net/ipv4/conf/default/send_redirects
#注意区分网卡名字, the Amin two NICs are ENS33 and ENS37, respectively
Echo 0 >/proc/sys/net/ipv4/conf/eno16777736/send_redirects
Echo 0 >/proc/sys/net/ipv4/conf/ Eno33554984/send_redirects
Director Set NAT firewall
iptables-t nat-f
iptables-t nat-x
#实现同网段ip能够联网
Iptables-t nat-a postrouting-s 192.168.67.0/24-j Masquerade
Director Settings Ipvsadm
ipvsadm= '/usr/sbin/ipvsadm '
$IPVSADM-C
$IPVSADM-A-T 192.168.32.128:80-s wlc-p 3 #新增规则wlc
$IPVSADM-T 192.168.32.128:80-r 192.168.67 .129:80-m-W 1
$IPVSADM-T 192.168.32.128:80-r 192.168.67.130:80-m-W 1

View Firewall rules


Edit Configuration

Two hosts installed Nginx
This is all source package installation, modify Nginx configuration
Host 1:z

Host 2:

Testing: Access to the service IP, experimental success.

Load Balancing cluster Introduction LVS introduction LVS scheduling algorithm LVS NAT mode construction