TCP套接字连接是否具有“保持活动状态”？

本文介绍了TCP套接字连接是否具有“保持活动状态”？的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！ 问题描述

我听说过HTTP keep-alive但是现在我想打开与远程服务器的套接字连接。 现在这个套接字连接将永远保持打开状态，或者是否存在与之关联的超时限制类似于HTTP keep-alive？

I have heard of HTTP keep-alive but for now I want to open a socket connection with a remote server. Now will this socket connection remain open forever or is there a timeout limit associated with it similar to HTTP keep-alive?

推荐答案

TCP套接字在关闭之前一直保持打开状态。

TCP sockets remain open till they are closed.

也就是说，在没有实际发送数据的情况下，很难检测出连接断开（断路，如路由器死机等，而不是关闭），因此大多数应用程序都会进行某种ping / pong反应。通常只是为了确保连接仍然存在。

That said, it's very difficult to detect a broken connection (broken, as in a router died, etc, as opposed to closed) without actually sending data, so most applications do some sort of ping/pong reaction every so often just to make sure the connection is still actually alive.