linux nginx负载均衡

upstream xiaogui001 {
　　server 120.78.127.54:7777;
　　server 120.78.127.54:8888;
}

location /tool {
       proxy_pass http://xiaogui001/;
       proxy_redirect off;
       proxy_set_header X-Real-IP $remote_addr;
       proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
       proxy_set_header X-real-ip $proxy_add_x_forwarded_for;
       proxy_set_header Host $host;
       client_max_body_size 10m;
       client_body_buffer_size 128k;
       proxy_connect_timeout 90;
       proxy_send_timeout 90;
       proxy_read_timeout 90;
       proxy_buffer_size 4k;
       proxy_buffers 4 32k;
       proxy_busy_buffers_size 64k;
       proxy_temp_file_write_size 64k;

}