##Nginx反向代理负载均衡

Posted 2023-03-07

介绍： Ngin x是一个高性能的http和反向代理web服务器，同时也提供了IMAP/POP3/SMTP服务，特点：占有内存少，并发能力强。作为中间件具有如下功能：1、制作静态页面 2、反向代理 3、负载均衡 4、动静分离 5、会话保持

 端口号：80

主配置文件：vim /usr/local/nginx/conf/nginx.conf

​负载均衡的三种方式

负载均衡有三种部署方式：路由模式、桥接模式、服务直接返回模式。路由模式部署灵活，约60%的用户采用这种方式部署；桥接模式不改变现有的网络架构；服务直接返回（DSR）比较适合吞吐量大特别是内容分发的网络应用。约30%的用户采用这种模式。

1、路由模式（推荐）

路由模式的部署方式，服务器的网关必须设置成负载均衡机的LAN口地址，且与WAN口分署不同的逻辑网络。因此所有返回的流量也都经过负载均衡。这种方式对网络的改动小，能均衡任何下行流量。

2、桥接模式

桥接模式配置简单，不改变现有网络。负载均衡的WAN口和LAN口分别连接上行设备和下行服务器。LAN口不需要配置IP（WAN口与LAN口是桥连接），所有的服务器与负载均衡均在同一逻辑网络中。

由于这种安装方式容错性差，网络架构缺乏弹性，对广播风暴及其他生成树协议循环相关联的错误敏感，因此一般不推荐这种安装架构。

3、服务直接返回模式

这种安装方式负载均衡的LAN口不使用，WAN口与服务器在同一个网络中，互联网的客户端访问负载均衡的虚IP（VIP），虚IP对应负载均衡机的WAN口，负载均衡根据策略将流量分发到服务器上，服务器直接响应客户端的请求。因此对于客户端而言，响应他的IP不是负载均衡机的虚IP（VIP），而是服务器自身的IP地址。也就是说返回的流量是不经过负载均衡的。因此这种方式适用大流量高带宽要求的服务。

接下来就用nginx来实操一下反向代理！！！！

1、WEB服务器环境准备

准备5台服务器

2、环境配置

1.克隆HA1/HA2/WEB1/WEB2/WEB3

2.开机启动 - 修改主机名字 - IP地址 - 修改软件源 - yum cache

3.WEB构建完毕-apache

HA1主机配置

[root@localhost ~]# hostnamectl set-hostname HA1 && bash
[root@ha1 ~]# mkdir /etc/yum.repos.d/bak
[root@ha1 ~]# mv /etc/yum.repos.d/*.repo /etc/yum.repos.d/bak/
[root@ha1 ~]# wget -O /etc/yum.repos.d/CentOS-Base.repo https://mirrors.aliyun.com/repo/Centos-7.repo && yum clean all && yum makecache
[root@ha1 html]# systemctl stop firewalld.service && systemctl disable firewalld.service

HA2主机配置

[root@localhost ~]# hostnamectl set-hostname HA2 && bash
[root@ha2 ~]# mkdir /etc/yum.repos.d/bak
[root@ha2 ~]# mv /etc/yum.repos.d/*.repo /etc/yum.repos.d/bak/
[root@ha2 ~]# wget -O /etc/yum.repos.d/CentOS-Base.repo https://mirrors.aliyun.com/repo/Centos-7.repo && yum clean all && yum makecache
[root@ha2 html]# systemctl stop firewalld.service && systemctl disable firewalld.service

web1

[root@localhost ~]# hostnamectl set-hostname web1 && bash
[root@web1 ~]# mkdir /etc/yum.repos.d/bak
[root@web1 ~]# mv /etc/yum.repos.d/*.repo /etc/yum.repos.d/bak/
[root@web1 ~]# wget -O /etc/yum.repos.d/CentOS-Base.repo https://mirrors.aliyun.com/repo/Centos-7.repo && yum clean all && yum makecache
[root@web1 ~]# systemctl stop firewalld.service && systemctl disable firewalld.service
[root@web1 ~]# yum install -y httpd
[root@web1 ~]# echo "web-server1" >> /var/www/html/index.html
[root@web1 ~]# systemctl start httpd.service && systemctl enable httpd.service && systemctl status httpd.service

web2

[root@localhost ~]# hostnamectl set-hostname web2 && bash
[root@web2 ~]# mkdir /etc/yum.repos.d/bak
[root@web2 ~]# mv /etc/yum.repos.d/*.repo /etc/yum.repos.d/bak/
[root@web2 ~]# wget -O /etc/yum.repos.d/CentOS-Base.repo https://mirrors.aliyun.com/repo/Centos-7.repo && yum clean all && yum makecache
[root@web2 ~]# systemctl stop firewalld.service && systemctl disable firewalld.service
[root@web2 ~]# yum install -y httpd
[root@web2 ~]# echo "web-server1" >> /var/www/html/index.html
[root@web2 ~]# systemctl start httpd.service && systemctl enable httpd.service && systemctl status httpd.service

web3

[root@localhost ~]# hostnamectl set-hostname web3 && bash
[root@web3 ~]# mkdir /etc/yum.repos.d/bak
[root@web3 ~]# mv /etc/yum.repos.d/*.repo /etc/yum.repos.d/bak/
[root@web3 ~]# wget -O /etc/yum.repos.d/CentOS-Base.repo https://mirrors.aliyun.com/repo/Centos-7.repo && yum clean all && yum makecache
[root@web3 ~]# systemctl stop firewalld.service && systemctl disable firewalld.service
[root@web3 ~]# yum install -y httpd
[root@web3 ~]# echo "web-server1" >> /var/www/html/index.html
[root@web3 ~]# systemctl start httpd.service && systemctl enable httpd.service && systemctl status httpd.service

3、Nginx软件部署（只在两个HA节点上部署）

HA1

安装nginx软件

[root@ha1 ~]# wget -O /etc/yum.repos.d/epel.repo http://mirrors.aliyun.com/repo/epel-7.repo
[root@ha1 ~]# yum install -y nginx nginx-mod-stream
[root@ha1 ~]# systemctl daemon-reload && systemctl start nginx && systemctl enable nginx && systemctl status nginx 
[root@ha1 ~]# pstree -ap | grep -v grep | grep -i nginx                                                                                                                                                                            
  |-nginx,10687                                                                                                                                                                                                                    
  |   |-nginx,10688                                                                                                                                                                                                                
  |   `-nginx,10689 
  [root@ha1 ~]# netstat -nltp | grep -i nginx                                                                                                                                                                                        
tcp        0      0 0.0.0.0:80              0.0.0.0:*               LISTEN      10687/nginx: master                                                                                                                                
tcp6       0      0 :::80                   :::*                    LISTEN      10687/nginx: master

Nginx反向代理-负载均衡部署

[root@ha1 ~]# cd /etc/nginx/
[root@ha1 nginx]# mv nginx.conf nginx.conf.bak

修改配置文件

[root@ha1 nginx]# vim nginx.conf
# For more information on configuration, see:
# * Official English Documentation: http://nginx.org/en/docs/
# * Official Russian Documentation: http://nginx.org/ru/docs/

user nginx;
worker_processes auto;
error_log /var/log/nginx/error.log;
# [alert] 18037#0: 1024 worker_connections are not enough
pid /run/nginx.pid;

# Load dynamic modules. See /usr/share/doc/nginx/README.dynamic.
include /usr/share/nginx/modules/*.conf;

events 
worker_connections 1024;  # 最多可以建这么多工作节点


##### add to config start #####
stream 
log_format main $remote_addr $upstream_addr - [$time_local] $status
$upstream_bytes_sent;
access_log /var/log/nginx/web_cluster.log main;

# upstream-load_balance-Cluster 这个是负载均衡，下面就是负载均衡的配置
upstream web_cluster 
server 192.168.40.101:80; # server1 IP:port
server 192.168.40.102:80; # server2 IP:port
server 192.168.40.103:80; # server3 IP:port


server 
listen 80; # nginx proxy port -
proxy_pass web_cluster; # 添加这个就是反向代理



##### add to config end #####

注意：listen port 端⼝号码 - ⽤户访问访问端⼝

server1 IP:port 端⼝号码 - 后端服务的实际端⼝

检查Nginx配置⽂件格式

[root@ha1 nginx]# nginx -t nginx: the configuration file /etc/nginx/nginx.conf syntax is ok nginx: configuration file /etc/nginx/nginx.conf test is successful

重新加载配置⽂件

[root@ha1 nginx]# nginx -s reload

HA2

安装nginx软件

[root@ha2 ~]# wget -O /etc/yum.repos.d/epel.repo http://mirrors.aliyun.com/repo/epel-7.repo
[root@ha2 ~]# yum install -y nginx nginx-mod-stream
[root@ha2 ~]# systemctl daemon-reload && systemctl start nginx && systemctl enable nginx && systemctl status nginx 
[root@ha2 ~]# pstree -ap | grep -v grep | grep -i nginx 
[root@ha2 ~]# pstree -ap | grep -v grep | grep -i nginx                                                                                                                                                                            
  |-nginx,10361                                                                                                                                                                                                                    
  |   |-nginx,10362                                                                                                                                                                                                                
  |   `-nginx,10363                                                                                                                                                                                                                
[root@ha2 ~]# netstat -nltp | grep -i nginx                                                                                                                                                                                        
tcp        0      0 0.0.0.0:80              0.0.0.0:*               LISTEN      10361/nginx: master                                                                                                                                
tcp6       0      0 :::80                   :::*                    LISTEN      10361/nginx: master

Nginx反向代理-负载均衡部署

[root@ha1 ~]# cd /etc/nginx/ [root@ha1 nginx]# mv nginx.conf nginx.conf.bak

修改配置文件

[root@ha1 nginx]# vim nginx.conf
# For more information on configuration, see:
# * Official English Documentation: http://nginx.org/en/docs/
# * Official Russian Documentation: http://nginx.org/ru/docs/

user nginx;
worker_processes auto;
error_log /var/log/nginx/error.log;
# [alert] 18037#0: 1024 worker_connections are not enough
pid /run/nginx.pid;

# Load dynamic modules. See /usr/share/doc/nginx/README.dynamic.
include /usr/share/nginx/modules/*.conf;

events 
worker_connections 1024;  # 最多可以建这么多工作节点


##### add to config start #####
stream 
log_format main $remote_addr $upstream_addr - [$time_local] $status
$upstream_bytes_sent;
access_log /var/log/nginx/web_cluster.log main;

# upstream-load_balance-Cluster 这个是负载均衡，下面就是负载均衡的配置
upstream web_cluster 
server 192.168.40.101:80; # server1 IP:port
server 192.168.40.102:80; # server2 IP:port
server 192.168.40.103:80; # server3 IP:port


server 
listen 80; # nginx proxy port -
proxy_pass web_cluster; # 添加这个就是反向代理

检查Nginx配置⽂件格式

[root@ha2 nginx]# nginx -t                                                                                                                                                                                                         
nginx: the configuration file /etc/nginx/nginx.conf syntax is ok                                                                                                                                                                   
nginx: configuration file /etc/nginx/nginx.conf test is successful

重新加载配置⽂件

[root@ha2 nginx]# nginx -s reload