What technology to choose for real-time updates?

Question

Node.js

Lord!
I write like a social network. I am currently implementing a messaging system. There is a desire to make its architecture similar to the architecture of social giants - VKontakte, Facebook, etc.
And in more detail - update messages in realtime dialogs.
In the last question, I was directed to the true path - to use web sockets. But beyond the many ways I can develop this - I can't figure out which would be faster/better/terrifying.
Offered PHP daemon for websockets, offered NodeJS + websockets, offered socket.io with the same node.
I want to achieve as much speed as possible, less time between sending and receiving a message in my network.
I do not want to use PHP - not really for this, it seems to me that it is intended, but maybe I'm wrong. But there are almost no ready-made solutions for it
. On the other hand, I read in the next question that the node is many times slower to work with mysql.
What technology will be faster and more correct for such a task? Perhaps I did not voice the most correct one?

Answer 1

I did it on NodeJs Mysql Socket.Io I did
n’t check it under load, because I don’t know where to get it)
It works quickly (instantly).
For real-time updates, of course, NodeJs Socket.io
And you can choose the base yourself, there are Mongodb, MySQL, Ppostgresql, and so on.
The only thing I can advise is to look towards relational databases