Oleg Zorin - 2016-10-29 03:38:41
Good day, Dima.
Your topic describes very good idea of chat realization.
I had one project (it have been closed). There were notification and chat systems based on the same idea, but it used long polling implementation.
We used: Browser > JS - PHP - Redis > Redis - NodeJS - JS > Browser.
Redis provides publish / subscribe tools and we used it as cache storage also.
NodeJS used as events server.
It was fine, but under high load NodeJS had memory leaking. And time to time we restarted it (once in couple days).
So, have you tested your chat system under high load?
Or if you have expirience of notification (chat) system's development in high load projects, please, share you knowledge.