haproxy VS µWebSockets

I wanted to try it out just now but hit a roadblock immediately - it cannot automatically obtain and maintain TLS certificates. You have to use an external client (e.g. acme.sh), set up a cron to check/renew them, and poke HAProxy to reload them if necessary. I'm way past doing this in 2023.

https://www.haproxy.com/blog/haproxy-and-let-s-encrypt

https://github.com/haproxy/haproxy/issues/1864

For context I think this might be useful: https://github.com/haproxy/haproxy/blob/master/addons/promex/README

I turn on 1 relatively cheap cloud server to process DNS, https and stratum connections and route them via haproxy to one of N miner servers described above.

Full technical writeup here: https://github.com/haproxy/haproxy/commit/a8598a2eb11b6c989e81f0dbf10be361782e8d32

With the recent discussions about memory safe languages, HAProxy is still surprisingly written in C [0].

[0]: https://github.com/haproxy/haproxy

It does not, because HAProxy does not perform any disk access at runtime and thus would be unable to persist the certificates anywhere. Disks accesses can be unpredictably slow and would block the entire thread which is not something you want when handling hundreds of thousands of requests per second.

See this issue and especially the comment from Lukas Tribus: https://github.com/haproxy/haproxy/issues/1864

Disclosure: Community contributor to HAProxy, I help maintain HAProxy's issue tracker.

Code link: https://github.com/haproxy/haproxy

They use (uWebSockets)[https://github.com/uNetworking/uWebSockets], which was written in C++, but has an interface to use in NodeJS. It's been really performant for me in my simple tests compared to other popular websocket libs that slow down fairly quickly.

µWebSockets, pronounced as "microWebSocket”, is a WebSocket library written in C++ and has Node.js bindings. Its design focuses on being efficient and scalable, making it ideal for applications that require high concurrency and low latency.

You can do that with any single threaded library that leaves threading to you. Like for example https://github.com/uNetworking/uWebSockets

Websockets are also pretty valuable for updating the page in real time, there are servers in many languages. I'm a big fan of https://github.com/uNetworking/uWebSockets which is C++ but also has JS bindings to use with Node.js.

Can you include uWebsockets? https://github.com/uNetworking/uWebSockets

μWebSockets Génial, rapide, peut transformer l’eau en vin. Nécessite C++17.

Not exaclty -- it looks like it's pretty overkill for my needs

I'm looking for something more like websocketpp[0], or even just grpc without a requisite proxy. uWebsockets looks really promising, being header only, but in the fine print requires a runtime library. unfortunately, none of that ecosystem seems to use cmake, making integrating it that much more of a pain.

why use cpp for this, I'm sure some HNer will ask. the ray tracer itself is using cuda, that's why. I've also debated

- running it as a grpc server and having some proxy in a more web-accessible language

- creating python bindings and using python to make a websocket/http server for it

neither of those are out of the question, but they're not my first choices, because I'd like to keep the build & execution simple. introducing dependencies, especially other executables, is in conflict with that.

i don't need anything particularly scalable -- a threaded implementation, or one using select() would be fine, if not preferable.

[0] https://docs.websocketpp.org/

[1] https://github.com/uNetworking/uWebSockets

Really cool i also made and CAPI for using WebSocket in C, https://github.com/uNetworking/uWebSockets/tree/master/capi

I will take a deep look on your project thanks for sharing!

We discover a really fast, small, and well maintained C++ Library called uNetworking/uWebSockets, but no C API available, so we create and adapt the full C API from uNetworking/uWebSockets and will integrate libuv powered fetch and file IO, this same C API is used by Bun