配置
参考Nginx官网，最简单的负载均衡配置如下：
http {
upstream myapp1 {
server srv1.example.com;
server srv2.example.com;
server srv3.example.com;
}
server {
listen 80;
location / {
proxy_pass http://myapp1;
}
}
}
Nginx支持三种类型的负载均衡实现算法：
round-robin — requests to the application servers are distributed in a round-robin fashion,
least-connected — next request is assigned to the server with the least number of active connections,
ip-hash — a hash-function is used to determine what server should be selected for the next request (based on the client’s IP address).
其对应的配置如下：
//Least connected load balancing
upstream myapp1 {
least_conn;
server srv1.example.com;
server srv2.example.com;
server srv3.example.com;
}
//Session persistence
upstream myapp1 {
ip_hash;
server srv1.example.com;
server srv2.example.com;
server srv3.example.com;
}
//Weighted load balancing
upstream myapp1 {
server srv1.example.com weight=3;
server srv2.example.com;
server srv3.example.com;
}
注意事项
1、负载均衡服务器的配置文件，如果是再原来的/etc/nginx/nginx.conf文件上进行修改的话，需要将include /etc/nginx/sites-enabled/*;这句话给注释掉，否则会返回负载均衡服务器的应用响应。
2、修改配置文件后，记得重启nginx
3、还有一点，配置文件的ip地址，可以是内网ip也可以是公网ip，这在使用阿里云的时候要注意一下。
参考网站：
