记录一下，一个简单可用的Nginx负载均衡配置文件。
本地测试是可以用的。

本地环境：

开启了三个本地服务:

127.0.0.1:8082;
127.0.0.1:8083;
127.0.0.1:8084;

每个服务器，提供两个测试接口：
以127.0.0.1:8082服务为例：
http://localhost:8082/ # index
http://localhost:8082/user?userId=12345 # userId

HomeController和UserController

@Slf4j
@RestController
public class HomeController {

    @Value("${server.port}")
    private String port;

    @GetMapping("/")
    public String index() {
        log.info("HomeController#index port:{}", port);
        return "index:" + port;
    }
}

UserController

@RestController
@RequestMapping("user")
public class UserController {

    @Value("${server.port}")
    private String port;

    @GetMapping
    public String get(@RequestParam Long userId) {
        return "port:" + port + ",userId:" + String.valueOf(userId);
    }
}

用于测试的URL

http://localhost/
http://localhost/user?userId=12345

nginx配置文件如下：

upstream 是关键

user       www www;  ## Default: nobody
worker_processes  1;  ## Default: 1
error_log  /Users/lucas/logs/error.log;
pid        /Users/lucas/logs/nginx.pid;
worker_rlimit_nofile 8192;

events {
  worker_connections  1024;  ## Default: 1024
}

http {
  include     /Users/lucas/Desktop/local-mime.types;
  #include    /etc/nginx/proxy.conf;
  #include    /etc/nginx/fastcgi.conf;
  index    index.html index.htm index.php;

  default_type application/octet-stream;
  log_format   main '$remote_addr - $remote_user [$time_local]  $status '
    '"$request" $body_bytes_sent "$http_referer" '
    '"$http_user_agent" "$http_x_forwarded_for"';
  access_log   /Users/lucas/logs/access.log  main;
  sendfile     on;
  tcp_nopush   on;
  server_names_hash_bucket_size 128; # this seems to be required for some vhosts

  server { # test
    listen       80;
    server_name  test1.com test2.com;
    access_log   /Users/lucas/logs/test1.access.log  main;
    root         html;

    location ~ \.php$ {
      fastcgi_pass   127.0.0.1:1025;
    }
  }

  upstream spacex-fox-qiong {
    server 127.0.0.1:8082;
    server 127.0.0.1:8083;
    server 127.0.0.1:8084;
  }

  server { # simple reverse-proxy
    listen       80;
    server_name  localhost;
    access_log   /Users/lucas/logs/localhost.access.log  main;

    # serve static files
    location ~ ^/(images|javascript|js|css|flash|media|static)/  {
      root    /var/www/virtual/spacex.server.com/htdocs;
      expires 30d;
    }

    # pass requests for dynamic content to rails/turbogears/zope, et al
    location / {
      proxy_pass      http://spacex-fox-qiong;
    }
  }

  upstream spacex-server.com {
    server 127.0.0.3:8000 weight=5;
    server 127.0.0.3:8001 weight=5;
    server 192.168.0.1:8000;
    server 192.168.0.1:8001;
  }

  server { # simple load balancing
    listen          80;
    server_name     big.server.com;
    access_log      /Users/lucas/logs/spacex.server.access.log main;

    location / {
      proxy_pass      http://spacex-server.com;
    }
  }
}

(完)