Most of the work of accepting and holding concurrent TCP sockets done by the OS, not the language runtime. One can easily tune Linux kernel to 1M of concurrent sockets.
The real issues: memory usage per concurrent socket (idle or active), and ability to do something usefull with all these active connections, e.g. send pings every 30s, or broadcast a message to all of them.
I'm not sure NodeJS/C++ based system from this post will allow sending pings every 30s to 1M websockets, let alone to do something useful with them, beside some low-traffic or infrequent notifications (Of course one always need to perform realistic loadtests in order to answer these kinds of questions).
Erlang/Elixir/BEAM have a relatively large memory usage per active socket, but it to do something useful with them under an easy to use programming model (read no callback hell).
I might by mistake, since I'm not up-to-date with the multithreading/concurrency/isolates in nodejs/V8.
IMO async/await is error-prone and isn't an ideal programming model.
That doesn't mean anything. V8 is single-threaded but Node.js I/O is non-blocking. The reason Node became popular in the first place is that companies started adopting it to fill the gaps in their existing infrastructure (e.g. Java) to offer "realtime" (i.e. web sockets or its experimental equivalents) communication.
> IMO async/await is error-prone and isn't an ideal programming model.
What's the point of unsubstantiated statements like that (btw "x is error-prone" is an empirical claim, so prefixing it with "IMO" just means "I can't back this up and don't care if it's true") other than stirring up pointless language rivalries?
Just acknowledge that your off-hand comment about "callback hell" was anachronistic and don't try to come up with excuses to justify your preferences. I think Elixir is neat and hope it can see sufficient adoption for me to justify getting invested in it but that doesn't justify poopooing other languages, especially ones you admit not to have up-to-date knowledge about.
That's the problem with Software Engineering in general.
> "IMO" just means "I can't back this up and don't care if it's true")
The research study that will either back or refute my claim would be prohibitively expensive and therefore impractical.
E.g. "in my experience async/await can easily result in bugs that can be hard to detect" or "when teaching beginners, I've found that they have a harder time wrapping their head around async/await than when learning about agents" or "async/await still requires writing imperative code, requiring the programmer to pay attention to behavior that agents can abstract away through declarative code". Now, I don't know if any of those statements are true or if they reflect your experience but these are examples for what you could have said, assuming you didn't just want to say "I don't like JavaScript and I prefer Elixir or Erlang".
And yes, people just dumping strong opinions with little more substance than gut feelings is very much a problem in Software Engineering. That doesn't mean we can't work on that and practice a little more hygiene and respect for each other.
EDIT: To be clear, saying "I don't like X an I prefer Y or Z" is perfectly fine too as long as you are honest about this being your own preference rather than some grand truth about the universe. The problem comes from insisting that everyone else is wrong for not feeling the same way.
The Readme says:
> µWebSockets.js is a web server bypass for Node.js that reimplements eventing, networking, encryption, web protocols, routing and pub/sub in highly optimized C++
Maybe someone with more swift experience can chime in! Whats the state of swift on the server these days?
Any developer out there who have been fascinated by and have used socket.io should already be using this.
You do actually see the same kinda thing happening in other ecosystems, especially Python – something runs slower than you want it to (because Python), so you re-write it in Rust/C/C++ and hook into the extension system of the lang for a seamless DX. Off the top of my head things like `asyncpg`, `orson`, `uvloop` and esp relevant in this case `websockets` are all async libs that do this.
Mildly tangential but as someone who has spent a lot of time making the Python backend for my startup run as fast as possible, I would recommend avoiding Python if performance is your primary concern.
The actual library, as already pointed out, is written is C/C++ and bypasses Node for everything, other than providing an usage API layer.
Its the same as claiming that Tensorflow is written in Python ;)