Nginx反向代理负载均衡模块功能详述

Posted 2022-09-10

1、ngx_http_upstream_module
http://nginx.org/en/docs/http/ngx_http_upstream_module.html#upstream

模块常用功能说明：

1）定义后端集群web节点信息，定义一个地址的池子
upstream oldboy 
    server 10.0.0.7:80;
    server 10.0.0.8:80;
    server 10.0.0.9:80;


2）实现权重值负载访问功能
upstream oldboy 
    server 10.0.0.7:80 weight=3;
    server 10.0.0.8:80 weight=1;
    server 10.0.0.9:80 weight=1;


3）定义后端访问的失败次数-max_fails
upstream oldboy 
    server 10.0.0.7:80 weight=3 max_fails=3;
    server 10.0.0.8:80 weight=1 max_fails=3;
    server 10.0.0.9:80 weight=1 max_fails=3;


4）定义后端失败重试的间隔-fail_timeout
upstream oldboy 
    server 10.0.0.7:80 weight=3 max_fails=3 fail_timeout=10s;
    server 10.0.0.8:80 weight=1 max_fails=3;
    server 10.0.0.9:80 weight=1 max_fails=3;

说明：在尝试多次失败后，在超时时间过去之后，会再给相应节点一次机会

5）定义后端服务的热备节点-backup
upstream oldboy 
    server 10.0.0.7:80;
    server 10.0.0.8:80;
    server 10.0.0.9:80 backup;

模块常用调度算法：

1）定义轮询调度算法-rr-默认调度算法
   采取平均分配

2）定义权重调度算法-wrr
   能者多劳

3）定义静态调度算法-ip_hash
说明：配置ip_hash时，一定不能和backup与weight参数同时出现
upstream oldboy 
    ip_hash;
    server 10.0.0.7:80;
    server 10.0.0.8:80;
    server 10.0.0.9:80 backup;


4）定义最小的连接数-least_conn
upstream oldboy 
    least_conn;
    server 10.0.0.7:80;
    server 10.0.0.8:80;
    server 10.0.0.9:80 backup;

2、ngx_http_proxy_module
http://nginx.org/en/docs/http/ngx_http_proxy_module.html#proxy_pass

模块常用功能：

 proxy_set_header   --- 设置反向代理服务器到web服务器的HTTP请求报文中的头部信息
说明：通过该配置，可以实现访问负载均衡看到不同虚拟主机页面信息 
server 
    listen       80;
    server_name  www.etiantian.org;
    root   html;
    index  index.html index.htm;
    location / 
    proxy_pass http://oldboy;
    proxy_set_header host $host;
   

server 
    listen       80;
    server_name  bbs.etiantian.org;
    proxy_set_header host $host;
    root   html;
    index  index.html index.htm;
    location / 
    proxy_pass http://oldboy;
    proxy_set_header host $host;
   


 说明：实现用户访问反向代理服务，让web服务器日志中记录真实用户IP地址信息 
server 
listen       80;
server_name  www.etiantian.org;
root   html;
index  index.html index.htm;
location / 
proxy_pass http://oldboy;
proxy_set_header host $host;
proxy_set_header X-Forwarded-For $remote_addr;
 

server 
   listen       80;
   server_name  bbs.etiantian.org;
   root   html;
   index  index.html index.htm;
   location / 
   proxy_pass http://oldboy;
   proxy_set_header X-Forwarded-For $remote_addr;