I have a big enough project still not programmed in my head, where there'll be a few static pages, a lot of managing pages, but also dynamic ones. By dynamic, I mean async, which they'll be updated on a regular basis (let say every second during a specific period of time). I still haven't choose the technology I'll use, but I'm really familiar with .NET technologies. On the other hand, I'm starting to learn NodeJS / Angular. I'm asking because I know I could take a look for tutorials (such as a chat app) but considering I may have 1000 users logged simultaneously, and having a lot of events to handles, I want to be sure of which technologies to use priorly to start coding - also, maybe a "chat-like" app is the best approach too to base my analysis on!

So, what could be the best approach, for this particular scenarios;

1. On the server, routines will raise many events/start multiple process, every second or so (sometime more, sometime less);
2. Related to those events, users (maybe a thousand of 'em) would be on a page and keep it open. Every time an event/process occurs, the page MUST be refresh with new values.

So, my final question is;

• What could be the best / cost efficient way to do this, without (or knowing at least if there's no other way), loading the server with a million of requests and have a lot of server costs?
• What could be the best tools/technologies/languages, or maybe tutorials shall I look for (independently of the technology, I can learn everything).
• Finally, things to pay attention, no-go or known issues of doing things like that.

Addendum If the every seconds is too costly, maybe 10 seconds could be an option. But since, what are my possibilities?