location / {

  proxy_pass http://10.110.21.22:9501;  //注意不是ws://。代理ws://用http://；代理wss://用https://

  proxy_http_version 1.1;

  proxy_set_header Upgrade $http_upgrade;

  proxy_set_header Connection "Upgrade";

  proxy_connect_timeout 4s;

  proxy_read_timeout 60s;  //设置保持websocket长连接的时间

  proxy_send_timeout 12s;

}