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环境

系统：Windows7
Nginx版本：1.26.2

负载均衡模式

1. round-robin轮询模式。

http {
	upstream backend {
		server backend1.com:8081;
		server backend2.com:8082;
		server backend3.com:8000;
	}
    server {
        listen       80;
        server_name  localhost;

        location / {
            proxy_pass http://backend;
        }
    }
}

2. least-connected最少连接模式：适用于请求花费时间较长的场景。

http {
	upstream backend {
	    least_conn;
		server backend1.com:8081;
		server backend2.com:8082;
		server backend3.com:8000;
	}
    server {
        listen       80;
        server_name  localhost;

        location / {
            proxy_pass http://backend;
        }
    }
}

3. ip_hash：适用于需要保持会话的场景，确保每一次请求都发送到同一台服务器。

http {
	upstream backend {
	    ip_hash;
		server backend1.com:8081;
		server backend2.com:8082;
		server backend3.com:8000;
	}
    server {
        listen       80;
        server_name  localhost;

        location / {
            proxy_pass http://backend;
        }
    }
}

配置服务器权重

以round-robin为例

http {
	upstream backend {
		server backend1.com:8081 weight=3;
		server backend2.com:8082;
		server backend3.com:8000;
	}
    server {
        listen       80;
        server_name  localhost;

        location / {
            proxy_pass http://backend;
        }
    }
}

健康检查：Nginx会自动探测服务的存活状态

探测次数：max_fails=3 ，默认0
探测超时时间：fail_timeout=30s

http {
	upstream backend {
		server backend1.com:8081 weight=3;
		server backend2.com:8082 max_fails=3 fail_timeout=30s;
		server backend3.com:8000;
	}
}

参考链接

Using nginx as HTTP load balancer