> Is it say possible to run a production quality server that can handle hundreds of thousands of concurrent users on digital ocean lets say?
Absolutely. I used to work as an SRE on Mozilla's WebPush infrastructure. Every running Firefox in the world establishes a connection to it; that means it peaks at tens of millions of concurrent connections every day. We could easily handle hundreds of thousands of connections on a couple CPU cores and gigs of RAM.
Although most connections were usually idle, we also regularly pushed messages to every connected client (e.g. when a collection in our remote settings service was updated).
Absolutely. I used to work as an SRE on Mozilla's WebPush infrastructure. Every running Firefox in the world establishes a connection to it; that means it peaks at tens of millions of concurrent connections every day. We could easily handle hundreds of thousands of connections on a couple CPU cores and gigs of RAM.
Although most connections were usually idle, we also regularly pushed messages to every connected client (e.g. when a collection in our remote settings service was updated).
It's written in Rust using Actix.
https://github.com/mozilla-services/autopush-rs