Today I thought about why the Web traditionally is stateless - opening a connection, then close it as fast as possible.
I realized that this was the HTTP.
And soon we will have fully implemented web-sockets to use for live things.
So I thought, could websockets replace http in the future so that every connection made will be opened til the client disconnects? Why would we want to open -> close, open -> close and so on like we do today?
Simply put, this won't happen, because leaving the connection up takes more resources.
On a "typical" website, much more time is spent reading content vs. requesting content. So why bother keeping a connection around, wasting server resources, when there's no need for further data until the end user performs some sort of user interaction?
Originally HTTP was for simply transferring a single document. The connection was closed, because the request was complete. There was no need for the connection to remain open. These days we have a whole mess of web applications, and we have entire layers of complexity built up to keep a persistent state despite closing and reopening connections. It really is ridiculous. We have entire applications built around a protocol that was designed for something quite different, all because of issues with the end user. (We didn't want to make them download anything, make them click more than they had to, confuse them, etc.)
I don't think it will be too much longer before we clean house a bit and remove all of these layers and get down to business with what our applications are trying to accomplish. I am speaking of not just the protocol used, but the layers of abstraction for execution as well.
At the very least, most HTTP connections are persistent to an extent. There is a keep-alive parameter so that many requests from the same server can be processed all in one TCP connection. Not all servers have it enabled, but many do, and it does keep things moving better than without it.
HTTP was build upon TCP/IP. Though TCP/IP is stateful, HTTP is stateless. The packets sent between the client and the server don't know about each other.
Though you can Mimic stateful by using cookies, sessions etc.
Implementing a StateFul world would mean increases server load, more connections, more hits.
All those connections ON all the time? I don't know if they could build servers fast enough. Google would implode, and even Chuck Norris wouldn't be able to hold FaceBook together if that happened.