6.nginx服务之负载均衡服务

谁践踏了优雅 2023-10-09 04:23 7阅读 0赞

#### 1.upstream配置语法 ####

Syntax: upstream name {...}
    Default:-
    Context:http

#### 2.简单示例 ####

upstream balance {
    	server 192.168.127.21:8001;
    	server 192.168.127.21:8002;
    	server 192.168.127.21:8003;
    }
    server {
        listen       80;
        server_name  localhost;
    
        access_log  /var/log/nginx/test_proxy.access.log  main;
        resolver  8.8.8.8;
        
        location / {
            proxy_pass http://balance;
            include proxy_params;
        }
    }

upstream backend {
    	server backend1.example.com weight=5;
    	server backend2.example.com:8080;
    	server unix:/tmp/backend3;
    	
    	server backend1.example.com:8080 backup;
    	server backend2.example.com:8080 backup;
    }

#### 3.后端服务器在负载均衡调度中的状态 ####

<table> 
 <tbody> 
  <tr> 
   <td>down</td> 
   <td>当前的server暂时不参与负载均衡</td> 
  </tr> 
  <tr> 
   <td>backup</td> 
   <td>预留的备份服务器</td> 
  </tr> 
  <tr> 
   <td>max_fails</td> 
   <td>允许请求失败的次数</td> 
  </tr> 
  <tr> 
   <td>fail_timeout</td> 
   <td>经过max_fails失败后，服务暂停的时间</td> 
  </tr> 
  <tr> 
   <td>max_conns</td> 
   <td>限制最大的接收的连接数</td> 
  </tr> 
 </tbody> 
</table>

#### 4.调度算法 ####

<table> 
 <tbody> 
  <tr> 
   <td>轮询</td> 
   <td>按时间顺序逐一分配到不同的后端服务器</td> 
  </tr> 
  <tr> 
   <td>加权轮询</td> 
   <td>weight值越大，分配到的访问几率越高</td> 
  </tr> 
  <tr> 
   <td>ip_hash</td> 
   <td>每个请求按访问IP的hash结果分配，这样来至同一个IP的固定访问一个后端服务器</td> 
  </tr> 
  <tr> 
   <td>url_hash</td> 
   <td>按照访问的URL的hash结果来分配请求，是每个URL定向到同一个后端服务器</td> 
  </tr> 
  <tr> 
   <td>least_conn</td> 
   <td>最少链接数，哪个机器连接数少就分发</td> 
  </tr> 
  <tr> 
   <td>hash关键数值</td> 
   <td>hash自定义的key</td> 
  </tr> 
 </tbody> 
</table>

#### 5.ip\_hash配置 ####

upstream balance {
    	ip_hash;
    	server 192.168.127.21:8001;
    	server 192.168.127.21:8002;
    	server 192.168.127.21:8003;
    }

#### 6.url\_hash ####

Syntax: hash key [consistent];
    Default: -
    Context: upstream
    # since version 1.7.2

upstream balance {
    	hash $remote_uri;
    	server 192.168.127.21:8001;
    	server 192.168.127.21:8002;
    	server 192.168.127.21:8003;
    }