这意味着每个服务器推脚本使用2个文件描述符。

That means every server-push script uses 2 file descriptors.

youdao

服务器推：如何告诉如果服务器的邮件已经发送到客户端？

Server push: how does server tell if message has already been sent to client?

youdao

无论何时在服务器上接收到通知，它几乎是立刻被发送(或者说“推”)到客户机并被传递给已注册的侦听器。

Whenever a notification is received on the server, it is almost immediately sent (or "pushed") to the client and handed to the registered listeners.

youdao