Nginx高可用配置实战教程之负载均衡 + 健康检查 + 动态扩展

Client → Nginx (负载均衡+健康检查)
          ↓
   ┌───────────────┬───────────────┬───────────────┐
   │ App1          │ App2          │ App3          │
   │ 商品服务节点1 │ 商品服务节点2 │ 商品服务节点3 │
   └───────────────┴───────────────┴───────────────┘

sudo apt update
sudo apt install nginx -y

nginx -v

upstream product_cluster {
    # 轮询策略（默认）
    server 192.168.10.101:8080 max_fails=3 fail_timeout=10s;
    server 192.168.10.102:8080 max_fails=3 fail_timeout=10s;
    server 192.168.10.103:8080 max_fails=3 fail_timeout=10s backup;
}
server {
    listen 80;
    server_name product.demo.local;
    location / {
        proxy_pass http://product_cluster;
        proxy_set_header Host $host;
        proxy_set_header X-Real-IP $remote_addr;
    }
}

nginx -t
systemctl reload nginx

sudo apt install openresty -y

http {
    upstream product_cluster {
        server 192.168.10.101:8080;
        server 192.168.10.102:8080;
        check interval=5000 rise=2 fall=5 timeout=3000 type=http;
        check_http_send "HEAD /health HTTP/1.0\r\n\r\n";
        check_http_expect_alive http_2xx http_3xx;
    }
    server {
        listen 80;
        location / {
            proxy_pass http://product_cluster;
        }
        location /status {
            check_status;
            access_log off;
            allow 192.168.10.0/24;
            deny all;
        }
    }
}

upstream product_cluster {
    include /etc/nginx/upstreams/*.conf;
}

echo "server 192.168.10.104:8080;" > /etc/nginx/upstreams/node4.conf

nginx -s reload

/var/log/nginx/access.log

192.168.10.201 - - [05/Nov/2025:14:32:01 +0800] "GET /api/product/1001 HTTP/1.1" 200 524 "-" "Mozilla" upstream_addr=192.168.10.101:8080
192.168.10.201 - - [05/Nov/2025:14:32:02 +0800] "GET /api/product/1002 HTTP/1.1" 200 530 "-" "Mozilla" upstream_addr=192.168.10.102:8080

awk '{print $NF}' /var/log/nginx/access.log | sort | uniq -c | sort -nr

sudo systemctl stop product-service@192.168.10.102

sudo systemctl start product-service@192.168.10.102

/etc/nginx/
 ├── conf.d/
 │    └── loadbalance.conf
 ├── upstreams/
 │    ├── node1.conf
 │    ├── node2.conf
 │    └── node3.conf
 ├── logs/
 │    └── access.log
 └── nginx.conf