Who knows how the instant messaging system works between users on dating sites, for example, in 2005?

Question

Node.js

Hey! Guys, I have such a question, in our time, Node JS, WebSocket, and something similar, modern are recommended to implement a messaging system between users. But Node JS is really a new technology that not all hosts support now. I am interested in the following: How did messaging systems work on dating sites before, approximately, 2005-2009, what technology were they based on? Indeed, to implement the exchange of messages, it was necessary not only to send a message, but also to constantly check whether there are new messages for the user. If, now, use ajax requests with setInterval, for example, 3 seconds, then with the accumulation of a large number of users, the server will be "demolished" (500 users = 500 calls to the server every 3 seconds). Or how to implement server-initiated checking for new messages without Node JS? Thanks in advance.

Answer 1

Not all hosts support

For starters, all these dating sites weren't using shared hosting in 2005 either.
In fact, it is enough to look at Vkontakte. They used long polling in the 200x as they do today. There is also just polling, but this comes out in terms of server loads that are heavy.

Answer 2

long polling.

Answer 3

In addition to Long polling, there was also Flash / rtmp, mamba itself and many other dating sites used it.
Yes, and Long polling was also special, it's an endless iframe. The server simply did not close the connection and, as new data appeared, gave something like

<script>printMessage(userId, messageData)</script>
<script>updateUserList(array)</script>

UPD . In fact, even then, using Flash / rtmp and LocalConnection, they made master / slave on the client, so as not to load the server with connections from each tab. Even now, this is rarely seen.

Answer 4

We have already written about long polling here, I will not repeat it. As for what was used instead of node. For example, for python there is a twisted library which is probably 15 years old. I don’t know about other languages.

Answer 5

You can use a very good SignalR library